Effectiveness of a bedaquiline, linezolid, clofazimine "core" for multidrug-resistant tuberculosis

Rationale

Treatment outcomes may be compromised among patients with multidrug- or rifampicin-resistant tuberculosis with additional fluoroquinolone resistance. Evidence is needed to inform optimal treatment for these patients.

Objectives

We compared the effectiveness of longer individualized regimens comprised of bedaquiline for 5 to 8 months, linezolid, and clofazimine to those reinforced with at least 1 third-tier drug and/or longer duration of bedaquiline.

Methods

We emulated a target trial to compare the effectiveness of initiating and remaining on the core regimen to one of five regimens reinforced with (1) bedaquiline for ≥9 months, (2) bedaquiline for ≥9 months and delamanid, (3) imipenem, (4) a second-line injectable, or (5) delamanid and imipenem. We included patients in whom a fluoroquinolone was unlikely to be effective based on drug susceptibility testing and/or prior exposure. Our analysis consisted of cloning, censoring, and inverse-probability weighting to estimate the probability of successful treatment.

Measurements and Main Results

Adjusted probabilities of successful treatment were high across regimens, ranging from 0.75 (95%CI:0.61, 0.89) to 0.84 (95%CI:0.76, 0.91). We found no substantial evidence that any of the reinforced regimens improved effectiveness of the core regimen, with ratios of treatment success ranging from 1.01 for regimens reinforced with bedaquiline ≥9 months (95%CI:0.79, 1.28) and bedaquiline ≥9 months plus delamanid (95%CI:0.81, 1.31) to 1.11 for regimens reinforced by a second-line injectable (95%CI:0.92, 1.39) and delamanid and imipenem (95%CI:0.90, 1.41).

Conclusions

High treatment success underscores the effectiveness of regimens comprised of bedaquiline, linezolid, and clofazimine, highlighting the need for expanded access to these drugs.

Practical strategies for operationalizing optimal allocation in stratified cluster-based outcome-dependent sampling designs

Cluster-based outcome-dependent sampling (ODS) has the potential to yield efficiency gains when the outcome of interest is relatively rare, and resource constraints allow only a certain number of clusters to be visited for data collection. Previous research has shown that when the intended analysis is inverse-probability weighted generalized estimating equations, and the number of clusters that can be sampled is fixed, optimal allocation of the (cluster-level) sample size across strata defined by auxiliary variables readily available at the design stage has the potential to increase efficiency in the estimation of the parameter(s) of interest. In such a setting, the optimal allocation formulae depend on quantities that are unknown in practice, currently making such designs difficult to implement. In this paper, we consider a two-wave adaptive sampling approach, in which data is collected from a first wave sample, and subsequently used to compute the optimal second wave stratum-specific sample sizes. We consider two strategies for estimating the necessary components using the first wave data: an inverse-probability weighting (IPW) approach and a multiple imputation (MI) approach. In a comprehensive simulation study, we show that the adaptive sampling approach performs well, and that the MI approach yields designs that are very near-optimal, regardless of the covariate type. The IPW approach, on the other hand, has mixed results. Finally, we illustrate the proposed adaptive sampling procedures with data on maternal characteristics and birth outcomes among women enrolled in the Safer Deliveries program in Zanzibar, Tanzania.

Optimal sampling allocation for outcome-dependent designs in cluster-correlated data settings

In clinical and public health studies, it is often the case that some variables relevant to the analysis are too difficult or costly to measure for all individuals in the population of interest. Rather, a subsample of these individuals must be identified for additional data collection. A sampling scheme that incorporates readily-available information for the entire target population at the design stage can increase the statistical efficiency of the intended analysis. While there is no universally optimal sampling design, under certain principles and restrictions, a well-designed and efficient sampling strategy can be implemented. In two-phase designs, efficiency can be gained by stratifying on the outcome and/or auxiliary information that is known at phase I. Additional gains in efficiency can be obtained by determining the optimal allocation of the sample sizes across the strata, which depends on the quantity that is being estimated. In this paper, the inference is concerned with one or multiple regression parameter(s) where the study units are naturally clustered and, thus, exhibit correlation in outcomes. We propose several allocation strategies within the framework of two-phase designs for the estimation of the regression parameter(s) obtained from weighted generalized estimating equations. The proposed methods extend existing theory to address the objective of the estimating regression parameters in cluster-correlated data settings by minimizing the asymptotic variance of the estimator subject to a fixed sample size. Through a comprehensive simulation study, we show that the proposed allocation schemes have the potential to yield substantial efficiency gains over alternative strategies.

Gender equity in health research publishing in Africa

Introduction

Women researchers find it more difficult to publish in academic journals than men, an inequity that affects women’s careers and was exacerbated during the pandemic, particularly for women in low-income and middle-income countries. We measured publishing by sub-Saharan African (SSA) women in prestigious authorship positions (first or last author, or single author) during the time frame 2014–2016. We also examined policies and practices at journals publishing high rates of women scientists from sub-Saharan Africa, to identify potential structural enablers affecting these women in publishing.

Methods

The study used Namsor V.2, an application programming interface, to conduct a secondary analysis of a bibliometric database. We also analysed policies and practices of ten journals with the highest number of SSA women publishing in first authorship positions.

Results

Based on regional analyses, the greatest magnitude of authorship inequity is in papers from sub-Saharan Africa, where men comprised 61% of first authors, 65% of last authors and 66% of single authors. Women from South Africa and Nigeria had greater success in publishing than those from other SSA countries, though women represented at least 20% of last authors in 25 SSA countries. The journals that published the most SSA women as prominent authors are journals based in SSA. Journals with overwhelmingly male leadership are also among those publishing the highest number of SSA women.

Conclusion

Women scholars in SSA face substantial gender inequities in publishing in prestigious authorship positions in academic journals, though there is a cadre of women research leaders across the region. Journals in SSA are important for local women scholars and the inequities SSA women researchers face are not necessarily attributable to gender discrepancy in journals’ editorial leadership.

Optimal allocation in stratified cluster-based outcome-dependent sampling designs

In public health research, finite resources often require that decisions be made at the study design stage regarding which individuals to sample for detailed data collection. At the same time, when study units are naturally clustered, as patients are in clinics, it may be preferable to sample clusters rather than the study units, especially when the costs associated with travel between clusters are high. In this setting, aggregated data on the outcome and select covariates are sometimes routinely available through, for example, a country's Health Management Information System. If used wisely, this information can be used to guide decisions regarding which clusters to sample, and potentially obtain gains in efficiency over simple random sampling. In this article, we derive a series of formulas for optimal allocation of resources when a single-stage stratified cluster-based outcome-dependent sampling design is to be used and a marginal mean model is specified to answer the question of interest. Specifically, we consider two settings: (i) when a particular parameter in the mean model is of primary interest; and, (ii) when multiple parameters are of interest. We investigate the finite population performance of the optimal allocation framework through a comprehensive simulation study. Our results show that there are trade-offs that must be considered at the design stage: optimizing for one parameter yields efficiency gains over balanced and simple random sampling, while resulting in losses for the other parameters in the model. Optimizing for all parameters simultaneously yields smaller gains in efficiency, but mitigates the losses for the other parameters in the model.

Quantitative and qualitative assessment of plasma cell dyscrasias in dual-layer spectral CT

Objectives

Virtual non-calcium (VNCa) images could improve assessment of plasma cell dyscrasias by enhancing visibility of bone marrow. Thus, VNCa images from dual-layer spectral CT (DLCT) were evaluated at different calcium suppression (CaSupp) indices, correlating results with apparent diffusion coefficient (ADC) values from MRI.

Methods

Thirty-two patients with initial clinical diagnosis of a plasma cell dyscrasia before any chemotherapeutic treatment, who had undergone whole-body low-dose DLCT and MRI within 2 months, were retrospectively enrolled. VNCa images with CaSupp indices ranging from 25 to 95 in steps of 10, conventional CT images, and ADC maps were quantitatively analyzed using region-of-interests in the vertebral bodies C7, T12, L1-L5, and the iliac bone. Independent two-sample t-test, Wilcoxon-signed-rank test, Pearson’s correlation, and ROC analysis were performed.

Results

Eighteen patients had a non-diffuse, 14 a diffuse infiltration in conventional MRI. A significant difference between diffuse and non-diffuse infiltration was shown for VNCa-CT with CaSupp indices from 55 to 95, for conventional CT, and for ADC (each p < 0.0001). Significant quantitative correlation between VNCa-CT and MRI could be found with strongest correlation at CaSupp index 65 for L3 (r = 0.68, p < 0.0001) and averaged L1-L5 (r = 0.66, p < 0.0001). The optimum CT number cut-off point for differentiation between diffuse and non-diffuse infiltration at CaSupp index 65 for averaged L1-L5 was −1.6 HU (sensitivity 78.6%, specificity 75.0%).

Conclusion

Measurements in VNCa-CT showed the highest correlation with ADC at CaSupp index 65. VNCa technique may prove useful for evaluation of bone marrow infiltration if MRI is not feasible.

Key Points

• VNCa-CT images can support the evaluation of bone marrow infiltration in plasma cell dyscrasias.

• VNCa measurements of vertebral bodies show significant correlation with ADC in MRI.

• Averaging L1-L5 at CaSupp index 65 allowed quantitative detection of infiltration comparable to MRI ADC.

Small-sample inference for cluster-based outcome-dependent sampling schemes in resource-limited settings: Investigating low birthweight in Rwanda

The neonatal mortality rate in Rwanda remains above the United Nations Sustainable Development Goal 3 target of 12 deaths per 1000 live births. As part of a larger effort to reduce preventable neonatal deaths in the country, we conducted a study to examine risk factors for low birthweight. The data were collected via a cost-efficient cluster-based outcome-dependent sampling (ODS) scheme wherein clusters of individuals (health centers) were selected on the basis of, in part, the outcome rate of the individuals. For a given data set collected via a cluster-based ODS scheme, estimation for a marginal model may proceed via inverse-probability-weighted generalized estimating equations, where the cluster-specific weights are the inverse probability of the health center's inclusion in the sample. In this paper, we provide a detailed treatment of the asymptotic properties of this estimator, together with an explicit expression for the asymptotic variance and a corresponding estimator. Furthermore, motivated by the study we conducted in Rwanda, we propose a number of small-sample bias corrections to both the point estimates and the standard error estimates. Through simulation, we show that applying these corrections when the number of clusters is small generally reduces the bias in the point estimates, and results in closer to nominal coverage. The proposed methods are applied to data from 18 health centers and 1 district hospital in Rwanda.

Stuck in the middle: a systematic review of authorship in collaborative health research in Africa, 2014-2016

Background

Collaborations are often a cornerstone of global health research. Power dynamics can shape if and how local researchers are included in manuscripts. This article investigates how international collaborations affect the representation of local authors, overall and in first and last author positions, in African health research.

Methods

We extracted papers on 'health' in sub-Saharan Africa indexed in PubMed and published between 2014 and 2016. The author's affiliation was used to classify the individual as from the country of the paper's focus, from another African country, from Europe, from the USA/Canada or from another locale. Authors classified as from the USA/Canada were further subclassified if the author was from a top US university. In primary analyses, individuals with multiple affiliations were presumed to be from a high-income country if they contained any affiliation from a high-income country. In sensitivity analyses, these individuals were presumed to be from an African country if they contained any affiliation an African country. Differences in paper characteristics and representation of local coauthors are compared by collaborative type using χ² tests.

Results

Of the 7100 articles identified, 68.3% included collaborators from the USA, Canada, Europe and/or another African country. 54.0% of all 43 429 authors and 52.9% of 7100 first authors were from the country of the paper's focus. Representation dropped if any collaborators were from USA, Canada or Europe with the lowest representation for collaborators from top US universities-for these papers, 41.3% of all authors and 23.0% of first authors were from country of paper's focus. Local representation was highest with collaborators from another African country. 13.5% of all papers had no local coauthors.

Discussion

Individuals, institutions and funders from high-income countries should challenge persistent power differentials in global health research. South-South collaborations can help African researchers expand technical expertise while maintaining presence on the resulting research.

Pedestrian hit by a car impacted metal pole: reconstructing the head load

Fatal head injuries are frequently seen in pedestrians hit by motorized vehicles. In our case, the pedestrian sustained a devastating head injury with skull splitting in the mediosagittal plane. A car collided with a traffic sign causing a bending of the pole. The metal pole hit a man standing close beside it; the man had a head injury severity that is more commonly due to falling objects than due to traffic accidents. Assuming a head mass of 5 kg, simplified calculations yield maximum contact forces of ca. 36 kN exceeding mean parietal fracture forces which are in the order of magnitude of 12.5 kN. The influences of the effective body mass and the horizontal distance between the pole and the pedestrian on maximum contact forces are investigated. High contact forces in our case can be mainly explained by the comparably high impact velocity and by a partial mass transfer of the total car mass to the pole.

Reliability and main findings of the flexible endoscopic evaluation of swallowing-Tensilon test in patients with myasthenia gravis and dysphagia

BACKGROUND AND PURPOSE

Diagnosis of pharyngeal dysphagia caused by myasthenia gravis (MG) based on clinical examination alone is often challenging. Flexible endoscopic evaluation of swallowing (FEES) combined with Tensilon (edrophonium) application, referred to as the FEES-Tensilon test, was developed to improve diagnostic accuracy and to detect the main symptoms of pharyngeal dysphagia in MG. Here we investigated inter- and intra-rater reliability of the FEES-Tensilon test and analyzed the main endoscopic findings.

METHODS

Four experienced raters reviewed a total of 20 FEES-Tensilon test videos in randomized order. Residue severity was graded at four different pharyngeal spaces before and after Tensilon administration. All interpretations were performed twice per rater, 4 weeks apart (a total of 160 scorings). Intra-rater test-retest reliability and inter-rater reliability levels were calculated.

RESULTS

The most frequent FEES findings in patients with MG before Tensilon application were prominent residues of semi-solids spread all over the hypopharynx in varying locations. The reliability level of the interpretation of the FEES-Tensilon test was excellent regardless of the rater's profession or years of experience with FEES. All four raters showed high inter- and intra-reliability levels in interpreting the FEES-Tensilon test based on residue clearance (kappa = 0.922, 0.981). The degree of residue normalization in the vallecular space after Tensilon application showed the highest inter- and intra-rater reliability level (kappa = 0.863, 0.957) followed by the epiglottis (kappa = 0.813, 0.946) and pyriform sinuses (kappa = 0.836, 0.929).

CONCLUSION

Interpretation of the FEES-Tensilon test based on residue severity and degree of Tensilon clearance, especially in the vallecular space, is consistent and reliable.

The bioequivalence of a single intravenous administration of the anesthetic alfaxalone in cyclodextrin versus alfaxalone in cyclodextrin plus preservatives in cats

To demonstrate the bioequivalence of alfaxalone in cyclodextrin (Reference Product) to a formulation of alfaxalone in cyclodextrin also containing the preservatives ethanol, chlorocresol, and benzethonium chloride (Test Product) when administered for the purpose of inducing anesthesia in the cat. Blinded, single-dose, randomized, two-period, two-sequence, cross-over bioequivalence study with a 7-day washout period between treatments. Twenty-four (12 neutered males and 12 intact females), healthy, adult cats weighing 4.1±0.9 kg. Cats were administered 5 mg/kg IV of alfaxalone in the Reference or Test Product using a randomized cross-over design. One-milliliter venous blood samples were collected at predetermined time points to 12 hr after drug administration to determine alfaxalone plasma concentration over time. Alfaxalone concentrations were determined by a validated analytical testing method using HPLC-MS/MS. Plasma profiles of alfaxalone concentration against time were analyzed by noncompartmental analysis. The pivotal variables for bioequivalence were AUC_last and C_max . Equivalence was achieved if the 90% confidence interval for AUC_last and C_max fell into the asymmetric ±20% interval (0.80-1.25). Physiological variables, quality of anesthesia visual analog scale (VAS) scoring and anesthetic event times were recorded. ANOVA or ANCOVA (single time point), RMANOVA or RMANCOVA (multiple time point) was used for normally distributed data. GLIMMIX was used for nonnormally distributed data. VAS scores were analyzed as for blood bioequivalence data. Variables were evaluated for safety and assessed at alpha = 0.10. C_max and AUC_last for Reference and Test Products were statistically bioequivalent. No physiological variables except for a drug by time interaction for respiratory rate differed between treatment groups, and this difference was not clinically relevant. No anesthetic event times or VAS scores for quality of anesthesia were different between treatment groups. Neither formulation caused pain upon injection. The Reference and Test Products are pharmaceutically bioequivalent formulations when administered as a single intravenous administration for the purpose of induction of anesthesia in cats.

Towards a Mg Lattice Clock: Observation of the ^{1}S_{0}-^{3}P_{0} Transition and Determination of the Magic Wavelength

We optically excite the electronic state 3s3p ^{3}P_{0} in ^{24}Mg   atoms, laser cooled and trapped in a magic-wavelength lattice. An applied magnetic field enhances the coupling of the light to the otherwise strictly forbidden transition. We determine the magic wavelength, the quadratic magnetic Zeeman shift, and the transition frequency to be 468.46(21) nm, -206.6(2.0)  MHz/T^{2}, and 655 058 646 691(101) kHz, respectively. These are compared with theoretical predictions and results from complementary experiments. We also develop a high-precision relativistic structure model for magnesium, give an improved theoretical value for the blackbody radiation shift, and discuss a clock based on bosonic magnesium.

Melissa officinalis extract induces apoptosis and inhibits proliferation in colon cancer cells through formation of reactive oxygen species

PURPOSE

Efficient strategies for the prevention of colon cancer are extensively being explored, including dietary intervention and the development of novel phytopharmaceuticals. Safe extracts of edible plants contain structurally diverse molecules that can effectively interfere with multi-factorial diseases such as colon cancer. In this study, we describe the antiproliferative and proapoptotic effects of ethanolic lemon balm (Melissa officinalis) leaves extract in human colon carcinoma cells. We further investigated the role of extra- and intracellular reactive oxygen species (ROS).

METHODS

Antitumor effects of lemon balm extract (LBE) were investigated in HT-29 and T84 human colon carcinoma cells. Inhibition of proliferation was analyzed by DNA quantification. The causal cell cycle arrest was determined by flow cytometry of propidium iodide-stained cells and by immunoblotting of cell cycle regulator proteins. To investigate apoptosis, cleavage of caspases 3 and 7 was detected by immunoblotting and fluorescence microscopy. Phosphatidylserine externalization was measured by Annexin V assays. Mechanistic insights were gained by measurement of ROS using the indicator dyes CM-H2DCFDA and Cell ROX Green.

RESULTS

After 3 and 4 days of treatment, LBE inhibited the proliferation of HT-29 and T84 colon carcinoma cells with an inhibitory concentration (IC50) of 346 and 120 µg/ml, respectively. Antiproliferative effects were associated with a G2/M cell cycle arrest and reduced protein expression of cyclin dependent kinases (CDK) 2, 4, 6, cyclin D3, and induced expression of cyclin-dependent kinase inhibitor 2C (p18) and 1A (p21). LBE (600 µg/ml) induced cleavage of caspases 3 and 7 and phosphatidylserine externalization. LBE-induced apoptosis was further associated with formation of ROS, whereas quenching of ROS by antioxidants completely rescued the colon carcinoma cells from LBE-induced apoptosis.

CONCLUSIONS

Lemon balm (Melissa officinalis) extract inhibits the proliferation of colon carcinoma cells and induces apoptosis through formation of ROS. Taken together, LBE or subfractions thereof could be used for the prevention of colon cancer.

Therapeutic safety of high myocardial expression levels of the molecular inotrope S100A1 in a preclinical heart failure model

Low levels of the molecular inotrope S100A1 are sufficient to rescue post-ischemic heart failure (HF). As a prerequisite to clinical application and to determine the safety of myocardial S100A1 DNA-based therapy, we investigated the effects of high myocardial S100A1 expression levels on the cardiac contractile function and occurrence of arrhythmia in a preclinical large animal HF model. At 2 weeks after myocardial infarction domestic pigs presented significant left ventricular (LV) contractile dysfunction. Retrograde application of AAV6-S100A1 (1.5 × 10(13) tvp) via the anterior cardiac vein (ACV) resulted in high-level myocardial S100A1 protein peak expression of up to 95-fold above control. At 14 weeks, pigs with high-level myocardial S100A1 protein overexpression did not show abnormalities in the electrocardiogram. Electrophysiological right ventricular stimulation ruled out an increased susceptibility to monomorphic ventricular arrhythmia. High-level S100A1 protein overexpression in the LV myocardium resulted in a significant increase in LV ejection fraction (LVEF), albeit to a lesser extent than previously reported with low S100A1 protein overexpression. Cardiac remodeling was, however, equally reversed. High myocardial S100A1 protein overexpression neither increases the occurrence of cardiac arrhythmia nor causes detrimental effects on myocardial contractile function in vivo. In contrast, this study demonstrates a broad therapeutic range of S100A1 gene therapy in post-ischemic HF using a preclinical large animal model.

Amorfrutin B is an efficient natural peroxisome proliferator-activated receptor gamma (PPARγ) agonist with potent glucose-lowering properties

AIMS/HYPOTHESIS

The nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ) is an important gene regulator in glucose and lipid metabolism. Unfortunately, PPARγ-activating drugs of the thiazolidinedione class provoke adverse side effects. As recently shown, amorfrutin A1 is a natural glucose-lowering compound that selectively modulates PPARγ. In this study we aimed to characterise, in vitro, a large spectrum of the amorfrutins and similar molecules, which we isolated from various plants. We further studied in vivo the glucose-lowering effects of the so far undescribed amorfrutin B, which featured the most striking PPARγ-binding and pharmacological properties of this family of plant metabolites.

METHODS

Amorfrutins were investigated in vitro by binding and cofactor recruitment assays and by transcriptional activation assays in primary human adipocytes and murine preosteoblasts, as well as in vivo using insulin-resistant high-fat-diet-fed C57BL/6 mice treated for 27 days with 100 mg kg(-1) day(-1) amorfrutin B.

RESULTS

Amorfrutin B showed low nanomolar binding affinity to PPARγ, and micromolar binding to the isotypes PPARα and PPARβ/δ. Amorfrutin B selectively modulated PPARγ activity at low nanomolar concentrations. In insulin-resistant mice, amorfrutin B considerably improved insulin sensitivity, glucose tolerance and blood lipid variables after several days of treatment. Amorfrutin B treatment did not induce weight gain and furthermore showed liver-protecting properties. Additionally, amorfrutins had no adverse effects on osteoblastogenesis and fluid retention.

CONCLUSIONS/INTERPRETATION

The application of plant-derived amorfrutins or synthetic analogues thereof constitutes a promising approach to prevent or treat complex metabolic diseases such as insulin resistance or type 2 diabetes.

Lattice fluctuations at a double phonon frequency with and without squeezing: an exactly solvable model of an optically excited quantum dot

Time-dependent lattice fluctuations of an optically excited strongly confined quantum dot are investigated with the aim to analyze the characteristics commonly used for identifying the presence of squeezed phonon states. It is demonstrated that the appearance of fluctuations oscillating with twice the phonon frequency, commonly regarded as a clear indication of squeezed states, cannot be considered as such. The source of the discrepancy with earlier investigations is discussed. Conditions for generating a squeezed state by using a two-pulse excitation are analyzed.

Total and cardiovascular disease mortality predicted by metabolic syndrome is inferior relative to its components

OBJECTIVES

This study examined the predictive role of metabolic syndrome (MetS) and its single components for total and cardiovascular disease (CVD) mortality.

METHODS

We analyzed data from 3,927 participants aged 20-79 years without history of CVD, recruited for the prospective population-based Study of Health in Pomerania (SHIP). During the mean 7.2 years (25 (th), 6.6; 75 (th): 8.0) of follow-up, 240 deaths (79 CVD deaths) occurred. MetS was defined by National Cholesterol Education Program Adult Treatment Panel III guidelines. The association of MetS with total and CVD mortality was analyzed by Cox proportional hazards regression models. The impact of single MetS components on survival time was compared using standardized beta coefficients from multivariable linear regression models.

RESULTS

Baseline MetS prevalence was 28.8%. Age- and gender-adjusted Cox models revealed that participants with MetS had an increased risk of total mortality (hazard ratio (HR) 1.41; 95% confidence interval (95% CI) 1.09-1.82) and CVD mortality (HR 1.82; 95% CI 1.22-3.13) compared to participants without MetS. Of the single MetS components, participants with increased waist circumference (WC) and glucose levels exposed highest risk of total (HR 1.49; 95% CI 1.10-2.01; HR 2.13; 95% CI 1.58-2.90, respectively) and CVD mortality (HR 2.02; 95% CI 1.13-3.61; HR 3.15; 95% CI 1.94-5.11, respectively). Increasing WC or glucose by 1 standard deviation (SD) significantly decreased age- and gender-adjusted beta coefficients for survival time by 0.09, and 0.08 SD, respectively.

CONCLUSION

There was no added predictive value of MetS beyond its individual components with respect to mortality risk. Attention should be redirected to the individual components, particularly visceral obesity and high glucose, to treat each abnormality appropriately.

Exploring the genetic link between RLS and ADHD

Attention deficit/hyperactivity disorder (ADHD) is a highly heritable neurodevelopmental disorder of childhood onset. Clinical and biological evidence points to shared common central nervous system (CNS) pathology of ADHD and restless legs syndrome (RLS). It was hypothesized that variants previously found to be associated with RLS in two large genome-wide association studies (GWA), will also be associated with ADHD. SNPs located in MEIS1 (rs2300478), BTBD9 (rs9296249, rs3923809, rs6923737), and MAP2K5 (rs12593813, rs4489954) as well as three SNPs tagging the identified haplotype in MEIS1 (rs6710341, rs12469063, rs4544423) were genotyped in a well characterized German sample of 224 families comprising one or more affected sibs (386 children) and both parents. We found no evidence for preferential transmission of the hypothesized variants to ADHD. Subsequent analyses elicited nominal significant association with haplotypes consisting of the three SNPs in BTBD9 (chi2 = 14.8, df = 7, nominal p = 0.039). According to exploratory post hoc analyses, the major contribution to this finding came from the A-A-A-haplotype with a haplotype-wise nominal p-value of 0.009. However, this result did not withstand correction for multiple testing. In view of our results, RLS risk alleles may have a lower effect on ADHD than on RLS or may not be involved in ADHD. The negative findings may additionally result from genetic heterogeneity of ADHD, i.e. risk alleles for RLS may only be relevant for certain subtypes of ADHD. Genes relevant to RLS remain interesting candidates for ADHD; particularly BTBD9 needs further study, as it has been related to iron storage, a potential pathophysiological link between RLS and certain subtypes of ADHD.

Extratumoral spiral fixed wire marking of small pulmonary nodules for thoracoscopic resection

BACKGROUND

Video-assisted thoracoscopic surgery (VATS) for pulmonary nodules close to the visceral pleura is an established procedure. Different methods have been developed to mark these nodules when resecting small nodules distant to the pleural surface. The possibility of tumor cell spread due to nodule penetration is a major drawback. Furthermore, guide wire-based marking systems have revealed the problem of accidental wire dislocation prior to resection.

METHODS

In this study, a new marker system for computed tomography-guided extranodular spiral fixed wire marking (ESFWM) was evaluated in an attempt to maintain tumor integrity while reducing the risk of wire dislocation.

RESULTS

Our study included 42 patients with 44 marked nodules. 40 nodules were resected by VATS in 38 of these patients. The remaining 4 patients required conversion to thoracotomy due to adhesions and a non-deflated lung. Wire dislocation and nodule penetration occurred only once.

CONCLUSION

The new lung marker system revealed a very low risk of wire dislocation. Peritumoral marking allows the safe resection of subpleural nodules without a risk of tumor cell spread.

Association and linkage of allelic variants of the dopamine transporter gene in ADHD

Previously, we had reported a genome-wide scan for attention-deficit/hyperactivity disorder (ADHD) in 102 families with affected sibs of German ancestry; the highest multipoint LOD score of 4.75 was obtained on chromosome 5p13 (parametric HLOD analysis under a dominant model) near the dopamine transporter gene (DAT1). We genotyped 30 single nucleotide polymorphisms (SNPs) in this candidate gene and its 5' region in 329 families (including the 102 initial families) with 523 affected offspring. We found that (1) SNP rs463379 was significantly associated with ADHD upon correction for multiple testing (P=0.0046); (2) the global P-value for association of haplotypes was significant for block two upon correction for all (n=3) tested blocks (P=0.0048); (3) within block two we detected a nominal P=0.000034 for one specific marker combination. This CGC haplotype showed relative risks of 1.95 and 2.43 for heterozygous and homozygous carriers, respectively; and (4) finally, our linkage data and the genotype-IBD sharing test (GIST) suggest that genetic variation at the DAT1 locus explains our linkage peak and that rs463379 (P<0.05) is the only SNP of the above haplotype that contributed to the linkage signal. In sum, we have accumulated evidence that genetic variation at the DAT1 locus underlies our ADHD linkage peak on chromosome 5; additionally solid association for a single SNP and a haplotype were shown. Future studies are required to assess if variation at this locus also explains other positive linkage results obtained for chromosome 5p.

[Characteristics of risk groups with an insufficient demand for dental services - results of the study of health in Pomerania (SHIP)]

AIM

The purpose of this study was to identify risk groups for low dental care utilisation and to highlight adequate determinants for necessary action.

METHODS

The database was the "Study of Health in Pomerania" (SHIP), a cross-sectional sample drawn from the adult population (20 - 79 years) in a northeast region of Germany. 4310 of 7008 randomly selected inhabitants participated in the examinations (response rate 68.8 %). The use of dental care in the last year was analysed using logistic regression according to the conceptual model by Andersen and Newman.

RESULTS

Multivariate analysis revealed that participation in the bonus scheme system of the statutory sickness funds (OR = 8.2) and participation in the bonus system of the private health insurance companies (OR = 2.6) as "enabling resources" predicted dental care use in the last year. "Objektive need" (OR = 1.02) is weaker associated with dental care utilisation than "subjective need", for instance the attitude towards need of regular dental checkups. Presence of own teeth is a significant predictor for dental care utilization (OR = 3.3), whereas edentulous persons, those with complete denture prosthesis, don't think about possible oral problems and don't visit the dentist at least once a year. Among "predisposing factors" only gender and education were significant determinats for dental care utilization.

CONCLUSIONS

The conclusions concerning the significant influence of subjective need and promotional impact of the bonus scheme are important for health care. Financial incentives and motivation for regular prevention should be continued and upgraded. Measures to improve preventive dental care utilization should focus on persons with low educational levels and on men with inadequate dental care utilisation. The mental anchorage of the term "oral health" rather than the conventional term "dental health" is important, so that edentulous persons become conscious of regular prevention pointers to maintain a high quality of life.

Zubereitungen zur Anwendung am Auge unter Berücksichtigung der Therapie des Sicca-Syndroms

Da das Auge ein empfindliches Körperorgan ist, stellt die Behandlung von Augenerkrankungen hohe Ansprüche an die applizierten Zubereitungen. So darf die Zubereitung weder chemisch noch physikalisch reizen und muss zu jeder Zeit steril sein. Zudem sollte sie den physiologischen Gegebenheiten des Auges wenn möglich angepasst werden, um Reizungen zu vermeiden. Mit der Wahl der Applikationsform können z.B. Wirkintensität und Wirkdauer bestimmt werden. Vom so genannten Sicca-Syndrom ist ein Großteil der Bevölkerung betroffen. Die Therapie umfasst sowohl nichtmedikamentöse als auch medikamentöse Maßnahmen. Dabei kommen unter anderem künstliche Tränen zum Einsatz. Die Auswahl eines geeigneten Präparates richtet sich nach dem Schweregrad der Erkrankung und auch nach der Viskosität der Zubereitung. In schwerwiegenderen Fällen werden Substanzen wie Hyaluronsäure oder Formulierungen, die Lipide enthalten, hinzugezogen.

Non-associative defensive responses of rats to ferret odor

Predators and their odors offer an ethologically valid model to study learning processes. The present series of experiments assessed the ability of ferret odor to serve as an unconditioned stimulus and examined behavioral and endocrine changes in male Sprague-Dawley rats with single or repeated exposures in a defensive withdrawal paradigm or in their home cages. Rats exposed to ferret odor avoided the ferret odor stimulus more, exhibited greater risk assessment and displayed higher adrenocorticotropin hormone (ACTH) and corticosterone release compared with control odor exposed rats and these measures did not significantly habituate over repeated exposures. Ferret odor exposure did not show associative conditioning effects during extinction trials. However, rats that were pre-exposed to ferret odor only once, as compared to control and repeatedly exposed rats, displayed a sensitized ACTH and corticosterone response to an additional ferret odor exposure in small cages. These experiments suggest that ferret odor is a highly potent unconditioned stimulus that has long lasting effects on behavior and endocrine responses, and further suggests the independence of habituation and sensitization processes.

Late-onset neurologic disease in glutaryl-CoA dehydrogenase deficiency

Neurologic disease in glutaryl-CoA dehydrogenase (GCDH) deficiency usually presents with acute encephalopathic crises before 2 years of age. The authors report two previously asymptomatic patients with macrocephaly presenting with progressive neurologic deterioration and a severe leukoencephalopathy during adolescence or adulthood.

Ferret odor as a processive stress model in rats: neurochemical, behavioral, and endocrine evidence

Predator odors have been shown to elicit stress responses in rats. The present studies assessed the use of domestic ferret odor as a processive stress model. Plasma corticosterone and adrenocorticotropin hormone levels were higher after 30 min of exposure to ferret odor (fur/skin) but not control odors, ferret feces, urine, or anal gland secretions. Behavioral differences were also found between ferret and the control odors as tested in a defensive withdrawal paradigm. In addition, c-fos messenger RNA expression in several brain areas previously associated with processive stress was significantly higher in ferret odor-exposed rat brains than in control odor-exposed brains. These results suggest that ferret odor produces a reliable unconditioned stress response and may be useful as a processive stress model.

[The problem of response in epidemiologic studies in Germany (Part II)]

The first part of this paper introduced various definitions of response and discussed their significance in the context of different study types. This second part addresses incentives as a method to increase response and evaluates the impact of non response or delayed response on the validity of the study results. Recruitment aims at minimising the proportion of refusal. To achieve this, incentives can be used and potential participants can be contacted in a sequence of increasing intensity. The effectiveness of different incentives was investigated within the pretest of the German survey on children and adolescents by the Robert Koch Institute. A low response is often interpreted in terms of non-response bias. This assumption, however, is as incorrect as would be opposite conclusion, that a high response guarantees valid results. Any study of the influence of nonresponse requires information on non-responders. The comparison between early and late responders as an indirect method to evaluate systematic differences between participants and non-participants by wave analysis is demonstrated within the Northern Germany Leukaemia and Lymphoma study (NLL). The German guidelines for Good Epidemiologic Practice recommend to solicit a minimum of information on the principal hypotheses of a study from non-participants. The example of a population-based health survey (Cooperative Health Research in the Region of Augsburg, KORA) illustrates how information on non-responders within a quantitative non-responder analysis can be achieved and used for the estimation of prevalences. Recommendations how to deal with the response in epidemiological studies in Germany are suggested.

The fixed combination of valerian and hops (Ze91019) acts via a central adenosine mechanism

The aim of the study was to demonstrate competition between caffeine and a fixed valerian/hop extract combination (Ze91019) by the central adenosine mechanism. EEG was used to describe the action of caffeine on the central nervous system after oral administration (200 mg) in healthy volunteers. In addition to caffeine, the volunteers (16 in each group) received either placebo or verum (2 and 6 tablets containing the valerian/hop extract). The EEG responses were recorded every 30 min thereafter. The verum medication was capable of reducing (2 tablets) or inhibiting (6 tablets) the arousal induced by caffeine. This pharmacodynamic action was observed 60 minutes after oral administration, indicating not only competition between the antagonist caffeine and the partial agonist, i. e., the valerian/hop extract but also bio-availability of the compound(s) responsible for the agonistic action. In conclusion, the valerian/hop extract acts via a central adenosine mechanism which is possibly the reason for its sleep-inducing and -maintaining activity.

Comparative regression analysis of concurrent elimination-phase blood and breath alcohol concentration measurements to determine hourly degradation rates

Following the introduction of limit values for blood alcohol and breath alcohol concentrations of 0.5 g/kg and 0.25 mg/L, respectively, as provided under s. 24 a of the German Road Traffic Act the question is whether also breath alcohol concentrations can be back calculated to the time of the traffic offence in cases where it is definite that the person to be examined is in the period of alcohol elimination. To this end, a study was performed in which 56 healthy volunteers consumed 0.5, 0.8 and 1.0 g of ethanol mixed with fruit juice per kilogram of body weight over a period of 10-20 min. Calculations included all 391 pairs of concurrent blood alcohol and breath alcohol concentration values obtained after 2 h following the end of drinking. All volunteers exceeded the peak value of the alcohol curve. The measured values included were above 0.1 g/kg and 0.05 mg/L. For an average intake of alcohol of 0.88 g/kg the following regression lines were calculated for the period starting 2 h after the end of drinking: blood alcohol concentration [g/kg] = 1.318 - 0.172 h and breath alcohol concentration [mg/L] = 0.589 - 0.079 h. Subtracting the simple standard deviation from the mean value yielded hourly degradation rates above 0.1 g/kg and above 0.05 mg/L, respectively. Subtracting two standard deviations, the values fell below this level in both cases. In fact, back calculation of breath alcohol concentrations based on 0.05 mg/h seems to be possible for traffic offences if certain conditions are complied with, such as the use of Evidential 7110, a calibrated breath alcohol analyser approved by the Federal Physical-Technical Laboratory for measuring the breath alcohol concentration.

Zum Problem der Response in epidemiologischen Studien in Deutschland (Teil I)

To achieve high response rates in German epidemiological studies is growing more difficult. Low response in epidemiological studies may decrease the acceptance of the results. Response, however, is not identical with the quality of a study. In the first part of this paper various definitions of response (contact, cooperation, response, recruitment proportions) are introduced and discussed in the context of different study designs with reference to practical examples. A population-based survey such as the Study of Health in Pomerania (SHIP) investigates the distribution of risk factors and health-related endpoints. Surveys should yield representative results which can be generalised to apply to the entire population (external validity). This study design usually requires large participitation proportions. In a prospective cohort study such as the European Investigation into Cancer and Nutrition (EPIC) the emphasis is on internal validity. A stable study population willing to participate in regular follow-ups is a primary recruitment goal. If the response in a case-control study such as the Northern Germany Leukaemia and Lymphoma Study (NLL) is low, the priority is to achieve approximately equal response proportions for cases and controls. Simultaneous public relation and media activities can improve participitation in a study. Multidimensional strategies combining public communications, cooperation with local and regional officials and frequent press and media coverage are emphasised. The second part of this paper will discuss methods to quantify the effects of the response proportions on the validity of the study results.

Animal models for glutaryl-CoA dehydrogenase deficiency

In vitro studies suggest that excitotoxic cell damage is an underlying mechanism for the acute striatal damage in glutaryl-CoA dehydrogenase (GCDH) deficiency. It is believed to result from an imbalance of glutamatergic and GABAergic neurotransmission induced by the accumulating organic acids 3-hydroxyglutaric acid (3-OH-GA) and to a lesser extent glutaric acid (GA). Stereotaxic administration of 3-OH-GA and GA into the rat striatum have confirmed these results, but may not truly represent the effect of chronic exposure to these compounds. In an attempt to better understand the pathophysiology of GCDH deficiency in vivo , two animal models have been utilized. A mouse that lacks GCDH activity in all tissues was generated by gene targeting in embryonic stem cells. These animals develop the characteristic biochemical phenotype of the human disease. Pathologically, these mice have a diffuse spongiform myelinopathy similar to that in human patients; however, there is no evidence for acute striatal damage or sensitivity to acute encephalopathy induced by catabolism or inflammatory cytokines. A naturally occurring animal model, the fruit-eating bat Rousettus aegypticus, lacks hepatic and renal GCDH activity, but retains cerebral enzyme activity. Like the mouse, these bats develop the characteristic biochemical phenotype of glutaryl-CoA dehydrogenase deficiency, but lack overt neurological symptoms such as dystonia. It is not known whether they also develop the spongiform myelinopathy seen in the Gcdh-deficient mice. Otherwise, these constellations would suggest that cerebral GCDH deficiency is responsible for the development of neuronal damage. The lack of striatal damage in these two rodent models may also be related to species differences. However, they also highlight our lack of a comprehensive understanding of additional factors that might modulate the susceptibiliy of neurons to accumulating 3-OH-GA and GA in GCDH deficiency. Unravelling these mechanisms may be the key to understanding the pathophysiology of this unique disease and to the development of neuroprotective strategies.

S-Acetylglutathione normalizes intracellular glutathione content in cultured fibroblasts from patients with glutathione synthetase deficiency

Glutathione synthetase deficiency is an autosomal recessive inherited metabolic defect in the gamma-glutamyl cycle. Decreased intracellular glutathione levels are one of the characteristic biochemical features. In this study we show that addition of S-acetylglutathione to the medium raised intracellular glutathione content in cultured fibroblasts from patients with glutathione synthetase deficiency. This has implications for the treatment of patients with this inborn error of metabolism.

Excitotoxicity and bioenergetics in glutaryl-CoA dehydrogenase deficiency

Glutaryl-CoA dehydrogenase deficiency is an inherited organic acid disorder with predominantly neurological presentation. The biochemical hallmark of this disease is an accumulation and enhanced urinary excretion of two key organic acids, glutaric acid and 3-hydroxyglutaric acid. If untreated, acute striatal damage is often precipitated by febrile illnesses during a vulnerable period of brain development in infancy or early childhood, resulting in a dystonic dyskinetic movement disorder. 3-hydroxyglutaric and glutaric acids are structurally similar to glutamate, the main excitatory amino acid of the human brain, and are considered to play an important role in the pathophysiology of this disease. 3-hydroxyglutaric acid induces excitotoxic cell damage specifically via activation of N-methyl-D-aspartate receptors. It has also been suggested that secondary amplification loops potentiate the neurotoxic properties of these organic acids. Probable mechanisms for this effect include cytokine-stimulated NO production, a decrease in energy metabolism, and reduction of cellular creatine phosphate levels. Finally, maturation-dependent changes in the expression of neuronal glutamate receptors may affect the vulnerability of the immature brain to excitotoxic cell damage in this disease.

The dynamics of sleep-like behaviour in honey bees

At night, honey bees pass through a physiological state that is similar to mammalian sleep. Like sleep in mammals, sleep-like behaviour in honey bees is an active process. This is expressed most clearly in these insects by spontaneous antennal movements which appear at irregular intervals throughout the night and interrupt episodes of antennal immobility. Here we present a newly developed video technique for the continuous recording of the position and movements of the bee's antennae. The same technique was used to record head inclination and ventilatory movements. Despite the constancy of the ambient temperature, the magnitudes of antennae-related parameters, as well as head inclination and ventilatory cycle duration, displayed dynamic unimodal time-courses which exhibited a high degree of temporal covariance. The similarity between these time-courses and the nightly time-course of the reaction threshold for a sensory stimulus, investigated previously, indicates that, in honey bees, deepest "sleep" and least ventilatory activity occur at the same time (in the 7th hour of the rest phase).

Study of Health In Pomerania (SHIP): a health examination survey in an east German region: objectives and design

OBJECTIVES

The reason for the Study of Health in Pomerania (SHIP) is the lack of epidemiological studies with a broad range of health indicators. Furthermore, in Germany there is a need for studies that take into account the particular situation of life after the reunification. One objective of SHIP is to provide prevalence estimates on a broad range of diseases, risk and health factors for a defined region in the former GDR.

METHODS

A sample of 7008 women and men aged 20 to 79 years in a north-east region of Germany, 4900 expected participants. The sample was drawn in two steps: First, 32 communities in the region were selected. Second, within the communities a simple random sample was drawn from residence registries, stratified by gender and age. The data collection and instruments include four parts: oral health examination, medical examination, health-related interview, and a health- and risk-factor-related questionnaire. The oral health examination includes the teeth, periodontium, oral mucosa, craniomandibular system, and prosthodontics. The medical examination includes blood pressure measurements, electrocardiography, echocardiography, carotid, thyroid and liver ultrasounds, neurological screening, blood and urine sampling. The computer-aided health-related interview includes cardiovascular symptoms, utilisation of medical services, health-related behaviours, and socioeconomic variables. The self-administered questionnaire comprises housing conditions, social network, work conditions, subjective well-being and individual consequences from the German reunification.