High Variability of Insulin Sensitivity in Closely Related Obese Mouse Inbred Strains

Obesity is one of several risk factors for insulin resistance and type 2 diabetes. Here we examined males of 6 obese mouse inbred lines derived from the Berlin Fat Mouse (BFM) outbred population with respect to insulin sensitivity and factors of the metabolic syndrome with focus on the skeletal muscle as a major target of insulin dependent glucose uptake.Males were kept on a rodent standard diet and several approaches were carried out to address insulin sensitivity, adiposity and lipids in the serum. Transcript and protein levels of several genes in the insulin signalling pathway were measured. 2 of the lines, BFMI860-12 and in particular BFMI861-S1, showed a markedly reduced insulin sensitivity already at the age of 20 weeks. BFMI861-S1 mice also displayed elevated liver triglyceride levels as a sign of lipid overload and ectopic fat storage. The analysis of the insulin signalling pathway in skeletal muscle provided evidence for low insulin receptor (INSR) and normal glucose 4 transporter (GLUT4) protein amounts in BFMI861-S1 mice, while BFMI860-12 mice showed increased INSR and very low GLUT4 protein amounts. Interestingly, the sublines BFMI860-S2 and BFMI861-S2, which are highly related to the former 2 lines, respectively, were inconspicuously insulin sensitive. The expected few genetic differences among the BFMI lines facilitate the identification of causal genetic variation. This study identified 2 mouse lines with different impairments of insulin signalling. These lines resemble useful models for studying mechanisms leading to the pathophysiology of the metabolic syndrome, in particular insulin resistance.

Relationship between strength qualities and short track speed skating performance in young athletes

This study analyzed the relationships between isometric as well as concentric maximum voluntary contraction (MVC) strength of the leg muscles and the times as well as speeds over different distances in 17 young short track speed skaters. Isometric as well as concentric single-joint MVC strength and multi-joint MVC strength in a stable (without skates) and unstable (with skates) condition were tested. Furthermore, time during maximum skating performances on ice was measured. Results indicate that maximum torques during eversion and dorsal flexion have a significant influence on skating speed. Concentric MVC strength of the knee extensors was higher correlated with times as well as speeds over the different distances than isometric MVC strength. Multi-joint MVC testing revealed that the force loss between measurements without and with skates amounts to 25%, while biceps femoris and soleus showed decreased muscle activity and peroneus longus, tibialis anterior, as well as rectus femoris exhibited increased muscle activity. The results of this study depict evidence that the skating times and speeds are primarily influenced by concentric MVC strength of the leg extensors. To be able to transfer the strength onto ice in an optimal way, it is necessary to stabilize the knee and ankle joints.

[The discussion about the application and impact of music on depressive diseases throughout history and at present]

Music therapy is the customised application of music for therapeutic use. For the treatment of depression it is mostly applied within a multimodal therapeutic approach. Since music was already used in prehistoric societies to cure diseases, it can be considered as a traditional therapy. As early as the antiquity physicians discussed the kind of music, the duration and frequency of its application. In the 19th century the pioneers of modern scientific psychiatry began to follow these questions with empirical experimental research. Since the 20th century, research has been investigating the influence of music on biological and psychological parameters. Current studies show that music therapy appears to improve symptoms of depression, especially in combination with antidepressants. Due to the limited number of randomised studies, the validity of its efficiency is limited. Further research is necessary to provide evidence-based recommendations regarding music therapy for the treatment of depression.

An effective framework for reconstructing gene regulatory networks from genetical genomics data

MOTIVATION

Systems Genetics approaches, in particular those relying on genetical genomics data, put forward a new paradigm of large-scale genome and network analysis. These methods use naturally occurring multi-factorial perturbations (e.g. polymorphisms) in properly controlled and screened genetic crosses to elucidate causal relationships in biological networks. However, although genetical genomics data contain rich information, a clear dissection of causes and effects as required for reconstructing gene regulatory networks is not easily possible.

RESULTS

We present a framework for reconstructing gene regulatory networks from genetical genomics data where genotype and phenotype correlation measures are used to derive an initial graph which is subsequently reduced by pruning strategies to minimize false positive predictions. Applied to realistic simulated genetic data from a recent DREAM challenge, we demonstrate that our approach is simple yet effective and outperforms more complex methods (including the best performer) with respect to (i) reconstruction quality (especially for small sample sizes) and (ii) applicability to large data sets due to relatively low computational costs. We also present reconstruction results from real genetical genomics data of yeast.

AVAILABILITY

A MATLAB implementation (script) of the reconstruction framework is available at www.mpi-magdeburg.mpg.de/projects/cna/etcdownloads.html

CONTACT

klamt@mpi-magdeburg.mpg.de.

Comparative studies on the retardation and reduction of glyphosate during subsurface passage

The herbicide Glyphosate was detected in River Havel (Berlin, Germany) in concentrations between 0.1 and 2 μg/L (single maximum outlier: 5 μg/L). As the river indirectly acts as drinking water source for the city's 3.4 Mio inhabitants potential risks for drinking water production needed to be assessed. For this reason laboratory (sorption and degradation studies) and technical scale investigations (bank filtration and slow sand filter experiments) were carried out. Batch adsorption experiments with Glyphosate yielded a low K(F) of 1.89 (1/n = 0.48) for concentrations between 0.1 and 100 mg/L. Degradation experiments at 8 °C with oxygen limitation resulted in a decrease of Glyphosate concentrations in the liquid phase probably due to slow adsorption (half life: 30 days). During technical scale slow sand filter (SSF) experiments Glyphosate attenuation was 70-80% for constant inlet concentrations of 0.7, 3.5 and 11.6 μg/L, respectively. Relevant retardation of Glyphosate breakthrough was observed despite the low adsorption potential of the sandy filter substrate and the relatively high flow velocity. The VisualCXTFit model was applied with data from typical Berlin bank filtration sites to extrapolate the results to a realistic field setting and yielded sufficient attenuation within a few days of travel time. Experiments on an SSF planted with Phragmites australis and an unplanted SSF with mainly vertical flow conditions to which Glyphosate was continuously dosed showed that in the planted SSF Glyphosate retardation exceeds 54% compared to 14% retardation in the unplanted SSF. The results show that saturated subsurface passage has the potential to efficiently attenuate glyphosate, favorably with aerobic conditions, long travel times and the presence of planted riparian boundary buffer strips.

Comparative studies on effects of three chitin synthesis inhibitors on common malaria mosquito (Diptera: Culicidae)

Toxicities of three chitin synthesis inhibitors (diflubenzuron, nikkomycin Z and polyoxin D) were evaluated using second instars of the common malaria mosquito, Anopheles quadrimaculatus Say (Diptera: Culicidae). Neither nikkomycin Z nor polyoxin D at 50 microg/liter caused significant larval mortality, although they reduced the body weight of the survivors by 20.5 and 33.8%, respectively, in 48 h. In contrast, exposures of the larvae to diflubenzuron at 12.5 microg/liter for 48 h resulted in 86.7% larval mortality and reduced the body weight of the survivors by 29.1%. Exposure of the pupae (<12 h old) to diflubenzuron at 100 microg/liter for 48 h caused 18.9% pupal mortality and consequently reduced the adult emergence by 24.7% from the surviving pupae. Furthermore, exposure of third instars to diflubenzuron at 4, 20, 100, and 500 microg/liter for 24 h resulted in the reduction of larval chitin contents by 4.25, 33.2, 35.2, and 57.7%, respectively. Such an effect seemed to be associated with only cuticular chitin synthesis because the same exposures did not significantly affect chitin contents in the guts. Our results indicated that diflubenzuron was highly toxic to second instars by not only causing high larval mortality but also by affecting their growth. Diflubenzuron was also fairly toxic to pupae by not only causing pupal mortality but also affecting the adult emergence. Our results suggest that diflubenzuron might affect only chitin synthesis in the cuticle but not in the peritrophic matrix, which is probably due to diflubenzuron's direct contact to mosquito larvae in water, slow distribution in insect body, rapid degradation in the insect gut, or a combination.

Seasonal variation of sediment toxicity in the Rivers Dommel and Elbe

Contaminated sediment in the river basin has become a source of pollution with increasing importance to the aquatic ecosystem downstream. To monitor the temporal changes of the sediment bound contaminants in the River Elbe and the River Dommel monthly toxicity tests were applied to layered sediment and river water samples over the course of 10 months. There is an indication that contaminated sediments upstream adversely affected sediments downstream, but this process did not cause a continuous increase of sediment toxicity. A clear decrease of toxic effects in water and upper layer sediment was observed at the River Elbe station in spring related to high water discharge and algal blooms. The less obvious variation of sediment toxicity in the River Dommel could be explained by stable hydrological conditions. Future monitoring programmes should promote a more frequent and intensive sampling regime during these particular events for ecotoxicological evaluation.

Comparison of different activity parameters in atopic dermatitis: correlation with clinical scores

BACKGROUND

Several laboratory markers have been described to correlate positively with disease activity of atopic dermatitis (AD). These include soluble adhesion molecules and eosinophil granular proteins. Although the correlation of these parameters with the severity and extent of skin involvement has been repeatedly studied in the past, no systematic investigation has been performed over a lengthy period of time. In addition, no subjective disease parameters recorded by the patient have been included in studies dealing with disease activity.

OBJECTIVES

To assess the validity of different objective and subjective parameters [soluble E-selectin (sE-selectin), soluble vascular cell adhesion molecule-1 (sVCAM-1), eosinophil cationic protein (ECP), urinary nitrate excretion (reflecting endogenous nitric oxide formation) and the patients' impressions of pruritus, sleeplessness and skin status] as markers of AD disease activity.

METHODS

Twenty patients were examined for 1 year and their skin status was evaluated by an established score (SCORAD). sE-selectin, sVCAM-1 and ECP were analysed by commercial test kits. Urinary nitrate concentration was measured by gas chromatography-mass spectrometry. The subjective parameters, pruritus, sleeplessness and impression of skin status, were recorded by the patients on a visual analogue scale.

RESULTS

In this long-term trial, only sE-selectin and the subjective parameters showed a statistically significant correlation with the SCORAD score.

CONCLUSIONS

Our data indicate that basic clinical scoring remains a most effective and relevant method of recording skin disease activity in AD.

Asthma hospitalization trends in Charleston, South Carolina, 1956 to 1997: twenty-fold increase among black children during a 30-year period

OBJECTIVE

The increase in asthma prevalence has been documented worldwide, affecting many races living in many different climates. Multiple studies have demonstrated that the most striking prevalence and morbidity of asthma in the United States has been in black children, but little research has determined the scale of the increase, or specifically when the disease became severe in this group. This study sought to determine exactly when the rise in asthma hospitalizations among black patients began and what the pattern of asthma hospitalizations has been in different races and age groups over a 40-year period in 1 urban area.

METHODS

A retrospective chart review of discharges from the Medical University of South Carolina was conducted from 1956 to 1997. Charts with the primary discharge diagnosis of asthma were examined for discharge date, race, and age group (0- to 4-year-olds, 5- to 18-year-olds, 19- to 50-year-olds, > or =51-year-olds). The diagnostic codes used were based on the International Classification of Diseases (ICD)-6, 1956-1957; ICD-7, 1958-1967; ICD-8, 1968-1978; and ICD-9, 1979-1997. Over the period studied, this hospital was the primary inpatient provider for children in this area, and the only provider for uninsured children. Between 1960 and 1990, the racial makeup of the area remained stable, as did the percentage of blacks living at the poverty level. The raw number of asthma discharges, rate per 10 000 discharges of the same race, and rate per 100 000 population in Charleston County were tabulated for each age group and racial category.

RESULTS

Over the time period examined, there has been a progressive increase in asthma hospitalizations in black individuals of all age groups and in whites under 18 years. The most striking increase has been in black children 0 to 18 years old (figure). The increase either as raw values or as a rate per 100 000 began around 1970, and was linear. This increase in black children discharged with asthma as a rate per 100 000 population was 20-fold: the rate increased from 18 in 1970 to 370 in 1997. Asthma discharges as a rate per 10 000 black children discharged increased by 24-fold from 1960 to 1997. Total discharges from the hospital increased from 49 000 to 128 000 per year over this period. Blacks made up only 28% of discharges in 1957, but that proportion increased to 56% in 1960 and remained relatively stable over the following 35 years. The increase seen in white children 0 to 18 years of age as a rate per 100 000 population was 5-fold and began around 1980. Both increases seem to be consistent over the time period studied, and continued to 1997. [figure: see text].

CONCLUSIONS

Among a predominantly poor black population living in a southern US city, there has been a steady increase in childhood asthma hospitalizations over the past 30 years. A significant although less dramatic rise has occurred in white children. Over this time period, although there have been many changes in lifestyle that could have contributed to this rise, there have been no major changes in housing conditions for poor patients. In addition, Medicaid coverage for children in South Carolina did not change significantly until 1999. The time course of these increases parallels increases reported in other Western populations, suggesting that there must be 1 or more common factors contributing to the rise. Many explanations have been offered for the changes in incidence and severity of asthma. The scale of the change, time course, and linearity of the increase in this study represent a challenge to many of the hypotheses proposed to explain this epidemic.

Double-blind placebo-controlled house dust mite control measures in adult patients with atopic dermatitis

BACKGROUND

Avoidance of allergens has been shown to be of benefit in patients with atopic asthma sensitized to indoor allergens. In atopic dermatitis, there is so far little information about the effect of house dust mite elimination strategies.

OBJECTIVES

We therefore performed a randomized controlled study of house dust mite control in patients with this disease.

METHODS

Twenty adult patients with moderate to severe atopic dermatitis were included. Inclusion criteria were a positive RAST to house dust mite antigen (CAP class > 3) and a concentration of > 2 microg g(-1) of the house dust mite antigen Der p1 in the patient's mattress dust. Patients were randomized to either the active treatment group (allergen-impermeable mattress encasing, acaricide spray containing tannic acid and benzylbenzoate) or a control group (allergen-permeable encasing, spray containing water and traces of ethanol). Severity of disease was estimated every 2 months by an established score (SCORAD), and eosinophil cationic protein (ECP) in the serum was determined by enzyme-linked immunosorbent assay. Furthermore, the use of topical steroids was quantified. Patients assessed daytime pruritus and pruritus-induced sleeplessness weekly on a visual analogue scale. The study lasted 1 year.

RESULTS

At the end of the study, the active treatment group showed a statistically significant reduction in Der p1 exposure as compared with the control group. However, when comparing the change from the start to the end of the study, there was no statistically significant difference between active treatment and control groups as measured by the SCORAD score and by ECP levels in the serum. Some patients in the active treatment group reported less pruritus-induced sleeplessness, but there was no statistically significant difference between the two treatment groups.

CONCLUSIONS

For adult patients with atopic dermatitis it was shown that 1 year of house dust mite avoidance reduced the allergen exposure, but an improvement of overall disease activity was not demonstrated.

Reasons for the decomposition of the fungicide thiram during preparation of fruit and vegetable samples and consequences for residue analysis

The concentration of thiram in aqueous solution decreases by 50-75% within 20 min in the presence of cut pieces of apple, cucumber or celeriac with a section surface area of 160 cm2 each. The decomposition rate is predominantly influenced by the section surface area of the cut fruit and vegetable samples. Denaturing reaction conditions (exchange of the solvent water by methanol; boiling of sample material) will significantly slow down the decomposition rate. It was concluded that the thiram decomposition had been caused by enzymes on the section surface of the fruit and vegetable samples. For a specific determination of thiram, a simple rinsing of the intact fruit and vegetable material was appropriate as extraction method. For the screening of thiram residues, the often used Keppel method, which determines CS2 from thiram or dithiocarbamates seems to be applicable even if samples had been coarsely cut, since decomposition of the CS2-forming intermediates is slower than the breakdown of thiram itself. Therefore, specific determination of thiram is necessary only, if maximum residue limits for dithiocarbamates are not adhered to.

[The infected arterial stent]

Vascular infections after percutaneous endovascular procedures are rare. We report a case of bacterial arteritis following PTA and stent implantation into an iliac artery. It was complicated by septic embolization, ipsilateral empyema of the knee joint and formation of an infected false aneurysm. Contamination of the stent with Staphylococcus aureus is likely to be the cause. The treatment included resection of the infected arterial segment, removal of the stent, and autologous reconstruction.

[Pelvic and leg vein thrombosis in azygous and hemi-azygous vein continuity syndrome and complete agenesis of the inferior vena cava]

A patient with a complete agenesis of the inferior vena cava is presented. In this rare anomaly the blood of the pelvic veins is drained through the dilated venae lumbales, vena azygos and vena hemiazygos into the superior vena cava. The malformation was detected within the scope diagnostics of deep vein thrombosis. The diagnosis was made by sonography, computed tomography and magnetic resonance angiography.

Treatment of uterine fibroids with a slow-release formulation of the gonadotrophin releasing hormone antagonist Cetrorelix

A depot preparation of the third-generation gonadotrophin-releasing hormone (GnRH) antagonist Cetrorelix (SB-75) was used for preoperative treatment in twenty premenopausal patients with symptomatic uterine fibroids who were to undergo surgery. In a prospective, open, randomized setting 60 mg of Cetrorelix pamoate salt was administered i.m. on cycle day 2. Patients were randomized for a second dose of 30 or 60 mg of Cetrorelix depot, which was administered according to the degree of oestradiol suppression (<50 pg/ml) on treatment day 21 or 28. Surgery was done after 6 or 8 weeks of treatment, depending on second dosage administration. Weekly transvaginal sonography (TVS) and magnetic resonance imaging (MRI) before and after treatment was performed, for fibroid volume assessment. Sixteen patients showed satisfactory suppression of gonadotrophins and sex steroid secretion, avoiding any initial flare-up effect. In these patients a mean shrinkage rate of largest fibroid volume of 33.5% at the end of treatment could be observed according to TVS, while the mean shrinkage rate obtained after 14 days of treatment was 31.3%. In good responders (shrinkage >20%) largest fibroid volume at day 14 was approximately 56.7% of basic assessment. Although MRI showed minor mean shrinkage rates of only 25.4% of the initial volume, these differences in comparison to TVS assessment were not statistically significant. The avoidance of any initial flare-up in gonadotrophin secretion may explain this extremely fast reduction in fibroid size. The advantages of GnRH antagonist treatment in this indication consist in the short treatment time with a fast restoration of the ovarian function. The rate of poor responders may be reduced by using an improved slow release preparation.