Long-term exposure to traffic-related air pollution and insulin resistance in children: results from the GINIplus and LISAplus birth cohorts

AIMS/HYPOTHESIS

Epidemiological studies that have examined associations between long-term exposure to traffic-related air pollution and type 2 diabetes mellitus in adults are inconsistent, and studies on insulin resistance are scarce. We aimed to assess the association between traffic-related air pollution and insulin resistance in children.

METHODS

Fasting blood samples were collected from 397 10-year-old children in two prospective German birth cohort studies. Individual-level exposures to traffic-related air pollutants at the birth address were estimated by land use regression models. The association between air pollution and HOMA of insulin resistance (HOMA-IR) was analysed using a linear model adjusted for several covariates including birthweight, pubertal status and BMI. Models were also further adjusted for second-hand smoke exposure at home. Sensitivity analyses that assessed the impact of relocating, study design and sex were performed.

RESULTS

In all crude and adjusted models, levels of insulin resistance were greater in children with higher exposure to air pollution. Insulin resistance increased by 17.0% (95% CI 5.0, 30.3) and 18.7% (95% CI 2.9, 36.9) for every 2SDs increase in ambient NO2 and particulate matter ≤10 μm in diameter, respectively. Proximity to the nearest major road increased insulin resistance by 7.2% (95% CI 0.8, 14.0) per 500 m.

CONCLUSIONS/INTERPRETATION

Traffic-related air pollution may increase the risk of insulin resistance. Given the ubiquitous nature of air pollution and the high incidence of insulin resistance in the general population, the associations examined here may have potentially important public health effects despite the small/moderate effect sizes observed.

Improving cytocompatibility of Co28Cr6Mo by TiO2 coating: gene expression study in human endothelial cells

Cobalt-based materials are widely used for coronary stents, as well as bone and joint implants. However, their use is associated with high corrosion incidence. Titanium alloys, by contrast, are more biocompatible owing to the formation of a relatively inactive titanium oxide (TiO2) layer on their surface. This study was aimed at improving Co28Cr6Mo alloy cytocompatibility via sol-gel TiO2 coating to reduce metal corrosion and metal ion release. Owing to their role in inflammation and tissue remodelling around an implant, endothelial cells present a suitable in vitro model for testing the biological response to metallic materials. Primary human endothelial cells seeded on Co28Cr6Mo showed a stress phenotype with numerous F-actin fibres absent on TiO2-coated material. To investigate this effect at the gene expression level, cDNA microarray analysis of in total 1301 genes was performed. Compared with control cells, 247 genes were expressed differentially in the cells grown on Co28Cr6Mo, among them genes involved in proliferation, oxidative stress response and inflammation. TiO2 coating reduced the effects of Co28Cr6Mo on gene expression in endothelial cells, with only 34 genes being differentially expressed. Quantitative real-time polymerase chain reaction and protein analysis confirmed microarray data for selected genes. The effect of TiO2 coating can be, in part, attributed to the reduced release of Co(2+), because addition of CoCl2 resulted in similar cellular responses. TiO2 coating of cobalt-based materials, therefore, could be used in the production of cobalt-based devices for cardiovascular and skeletal applications to reduce the adverse effects of metal corrosion products and to improve the response of endothelial and other cell types.

Anti-tumour activity of two novel compounds in cisplatin-resistant testicular germ cell cancer

BACKGROUND

Resistance to cisplatin-based chemotherapy is associated with poor prognosis in testicular germ cell cancer, emphasising the need for new therapeutic approaches. In this respect, the therapeutic concept of anti-angiogenesis is of particular interest. In a previous study, we presented two novel anti-angiogenic compounds, HP-2 and HP-14, blocking the tyrosine kinase activity of angiogenic growth factor receptors, such as vascular endothelial growth factor receptor-2 (VEGFR-2), and related signalling pathways in testicular cancer. In this study, we investigated the efficacy of these new compounds in platinum-resistant testicular germ cell tumours (TGCTs), in vitro and in vivo.

METHODS AND RESULTS

Drug-induced changes in cell proliferation of the cisplatin-sensitive TGCT cell line 2102EP and its cisplatin-resistant counterpart 2102EP-R, both expressing the VEGFR-2, were evaluated by crystal violet staining. Both compounds inhibited the growth of cisplatin-resistant TGCT cells in a dose-dependent manner. In combination experiments with cisplatin, HP-14 revealed additive growth-inhibitory effects in TGCT cells, irrespective of the level of cisplatin resistance. Anti-angiogenic effects of HP compounds were confirmed by tube formation assays with freshly isolated human umbilical vein endothelial cells. Using TGCT cells inoculated onto the chorioallantoic membrane of fertilised chicken eggs (chicken chorioallantoic membrane assay), the anti-angiogenic and anti-proliferative potency of the novel compounds was also demonstrated in vivo. Gene expression profiling revealed changes in the expression pattern of genes related to DNA damage detection and repair, as well as in chaperone function after treatment with both cisplatin and HP-14, alone or in combination. This suggests that HP-14 can revert the lost effectiveness of cisplatin in the resistant cells by altering the expression of critical genes.

CONCLUSION

The novel compound HP-14 effectively inhibits the growth of cisplatin-resistant TGCT cells and suppresses tumour angiogenesis. Thus, HP-14 may be an interesting new agent that should be further explored for TGCT treatment, especially in TGCTs that are resistant to cisplatin.

[Distribution of carotid intima media thickness in men and women with and without coronary heart disease. Cross-sectional data of the Heinz Nixdorf Recall Study]

PURPOSE

The aim of this study was to introduce population-based sex and age-stratified distributions of carotid intima media thickness (CIMT), to compare fixed cut-off and percentile values for subjects with and without known coronary heart disease (CHD) and to describe CIMT percentiles.

METHODS

Between 2000 and 2003, a total of 4,814 subjects aged 45-75 years were recruited into the Heinz Nixdorf recall study (HNR). Ultrasound examination of extracranial arteries was performed and the CIMT was measured manually over a distance of 1 cm proximal to the bulb in the common carotid artery (CCA). Both sides were measured and the average of the right and left artery were calculated (mean CIMT).

RESULTS

The CIMT was measured for 1,749 men and 1,802 women without prevalent CHD and 177 men and 50 women with prevalent CHD. Mean CIMT values were higher in men compared to women (men 0.71 ± 0.14 mm vs. women 0.65 ± 0.11 mm, p ≤ 0.0001) and in subjects with CHD compared to those without (men with and without CHD: 0.76 ± 0.14 mm and 0.70 ± 0.14 mm, p ≤ 0.0001, respectively; women with and without CHD: 0.73 ± 0.15 mm and 0.64 ± 0.11 mm, p ≤ 0.0001, respectively). In men the mean CIMT increased from 0.62 ± 0.10 mm in the youngest (45-49 years old) up to 0.79 ± 0.13 mm in the highest age group (≥ 70 years) (0.57 ± 0.08 mm up to 0.71 ± 0.12 mm in women, p ≤ 0.0001 for both).

CONCLUSIONS

Compared to international studies similar CIMT distributions were found in this study using both continuous and percentile distributions. However, lower CIMT values were observed in older participants, which can be explained by exclusion of carotid plaque formation in CIMT measurements.

[Pediatric fracture diagnosis--ultra-low-dose CT with an effective dose equal to that of radiographs]

PURPOSE

Computed tomography (CT) plays an important role in trauma diagnosis in children, especially for complex fractures. The aim of this study was to examine the diagnostic value of ultra-low-dose-CT (ULD-CT) with an effective dose equal to that of radiographs in an experimental study and to compare its results with those of radiographs.

MATERIALS AND METHODS

Limb bones of dead young pigs served as a model for pediatric bones. A total of 51 fractured and non-fractured bones were examined with a 64 multislice-CT with a standard dose protocol as gold standard, with two ultra-low-dose-protocols, and with standard radiographs with different exposures.

RESULTS

In spite of high background noise the examinations of ULD-CT were not adequate only in 2 of 204 cases. ULD-CT was slightly superior to radiographs in detection of fractures. ULD-CT could significantly better characterize the fractures than radiographs. The overall result of ULD-CT was significantly better than that of radiographs with standard exposure.

CONCLUSION

ULD-CT with the effective dose of radiographs is successfully applicable in pediatric fracture diagnosis, and its overall result is significantly better than that of radiographs.

Epidemiological Follow-up 15 Years after the Breast Cancer Scandal in Essen

Purpose: In the years 1993-1996 a number of presumably false-positive breast cancer diagnoses were made by a pathologist in Essen. A follow-up, undertaken 15 years later, investigated how many women had tumour recurrence and/or metastasis or had died from breast cancer. Material and Methods: A total of 151 (68 %) out of 222 women could be traced. One hundred and forty-seven (66.2 %) of the 222 women were alive. The observed survival rate, number of recurrences and/or metastases, and number of deaths from breast cancer were compared with data from the Munich Tumour Registry. The number of breast cancer cases among daughters of the affected women was ascertained. Results: The total observed survival rate at follow-up after 15 years was 93 %, a much higher figure than the survival rate of 45 % given by the Munich Tumour Registry. Recurrence and/or metastasis or death from breast cancer occurred in 9/222 cases (4.1 %). The incidence for these events calculated according to data from the Munich Tumour Registry is 13 %. Two daughters (2.2 %) out of a total of 90 were diagnosed with breast cancer whereas, according to the German Cancer Research Centre, the expected rate would have been between 5 and 10 %. Conclusions: The results of our follow-up after 15 years show that more women survived than expected and that the number of recurrences and/or metastases and deaths due to breast cancer was lower than expected. Fewer daughters of affected women were diagnosed with breast cancer than expected. These results support our suspicion that not all women diagnosed with breast cancer by a pathologist in Essen actually had breast cancer.

Organ distribution of Schmallenberg virus RNA in malformed newborns

A novel orthobunyavirus was first detected in German dairy cows in autumn 2011 and was subsequently found in the brains of malformed lambs, kids and calves in the Netherlands, Germany, Belgium, France, Italy, Great Britain, Luxembourg and Spain. For rapid detection of this novel virus, named Schmallenberg virus, a real time quantitative reverse transcription PCR (RT-qPCR) was developed at the Friedrich-Loeffler-Institut and provided to the federal veterinary state laboratories in Germany. For diagnostic purposes, the organ distribution of this new virus was analyzed in several organs and body fluids of 15 lambs and two calves showing typical malformations. Spleen, cerebrum, meconium, spinal cord, rib cartilage, umbilical cord, placental fluid out of the stomach as well as external placental fluid scraped from the coat of the foetuses were collected during necropsy. All animals were tested RT-qPCR positive in the external placental fluid, and all but one were also RT-qPCR positive in the cerebrum, the umbilical and the spinal cord. Our results suggest that both the external placental fluid and the umbilical cord could be suitable sample materials for the confirmation of an infection with Schmallenberg virus in malformed newborns, at least in lambs. This is of special interest since those samples can be collected very easily on the farm without the need of a necropsy.

Clinical course and pathology in rats (Rattus norvegicus) after experimental cowpox virus infection by percutaneous and intranasal application

Recently, several cases of human cowpox virus (CPXV) infections were reported in France and Germany, which had been acquired through close contact with infected pet rats. The animals exhibited respiratory signs or skin lesions and died shortly after purchase. After natural infection of white rats with CPXV in the USSR in 1978, a peracute pulmonary form, a milder dermal form, and a mixed form exhibiting features of both have been described. To the best of the authors' knowledge, 3 experimental cowpox virus infection studies using rats have been performed to date; however, neither results of histomorphological examinations nor immunohistochemical analyses have yet been reported in rats after experimental infections. To investigate the impact of the infection route on the clinical course, the development of lesions, and tropism, rats were infected intradermally, intranasally, or by a combination of both routes. The authors found a correlation between clinical manifestation, pathology, and infection routes. Intradermal and contact exposure yielded a mild dermal form, characterized by the development of vesiculopustular dermatitis. In contrast, intranasally infected animals died peracutely, showing severe dyspnea. Occasionally, a combination of the dermal and the respiratory form occurred after intranasal infection. Immunohistochemically, CPXV antigen was detected in the epithelial and mesenchymal cells of the upper respiratory tract and affected skin lesions and rarely in mesenchymal cells of lymph nodes. This is the first histomorphological and immunohistochemical analysis of CPXV in rats after experimental infection.

Fatalities in wild goats in Kurdistan associated with Peste des Petits Ruminants virus

Between August 2010 and February 2011, over 750 deaths were recorded among wild goats (Capra aegagrus, the endangered progenitor of the domestic goat) in Kurdistan. Based on the clinical signs and post-mortem findings, the involvement of peste des petits ruminants virus (PPRV) was suspected. This was confirmed by laboratory analysis, and the virus was found to be closely related to a Turkish strain isolated in 2000. During the outbreak in wild goats, no disease in domestic animals was reported. Domestic ruminants in the region are routinely vaccinated with an attenuated vaccine based on the 'Nigeria/75/1' strain of PPRV. This is the first report of active PPRV infection in Kurdistan and most likely the immunity afforded by vaccination prevented spillover infections. It is therefore recommended to continue with the campaign. Conversely, there is no justification for the use of force to keep the endangered wild goats away from domestic flocks.

Development of semen quality following reversible downregulation of testicular function in male dogs with a GnRH agonist implant

Slow-release GnRH agonist implants have shown to be an effective and reversible alternative to surgical castration. Testicular function is downregulated with an arrest of spermatogenesis on the level of spermatogonia/primary spermatocytes but is fully restored after abolition of downregulation. Aim of this study was to assess the quality of ejaculates after active abolishment of downregulation by implant removal and to follow recrudescence of spermatogenesis. Five dogs - which served as their own controls - were treated with a slow-release implant containing the GnRH agonist azagly-nafarelin. Implants were removed during full downregulation (testosterone <0.1 ng/ml), and attempts to collect ejaculates started from week 4 onwards to week 29. First ejaculates could be obtained between weeks 8 and 12 with the first fully elongated spermatozoa observed in week 10. Volume, %motility and total sperm count increased and %pathomorphology decreased during the course of the study with all ejaculates being in the normal range by week 29. Our data indicate that onset of recrudescence of spermatogenesis coincides with the first testosterone increase after active abolishment of downregulation. Semen quality was fully regained with a significant improvement of %pathomorphology (p < 0.05) and a tendency of improved %motility. However, these observations on an improved semen quality need further validation and no final conclusions can be drawn yet.

Dynamics of shiga-toxin producing Escherichia coli (STEC) and their virulence factors in cattle

Starting at birth, twenty Holstein calves were housed individually, in groups of five and finally in one large freestall while fecal samples were collected weekly for 25 weeks. From each sample, twenty isolates of Escherichia coli were screened for 6 virulence markers including shiga-toxin 1, 2, intimin, enterohemolysin, the fimbrial antigen efa1 and the adhesin saa. Dynamic models of transmission of E. coli were used to model the transmission of different virulotypes between calves and the loss of the same virulotypes from the calves. It was found that, once E. coli encoding shiga-toxins in combination with enterohemolysin were transmitted and established in a calf, they tended to be eliminated less efficiently compared to E. coli without this combination of virulence markers. It was concluded that the presence of certain combinations of virulence markers coincided with persistence of E. coli in the bovine gastrointestinal tract. In addition, the combinations of stx with either eae or ehxA in E. coli have a greater impact on the loss rates than on the transmission rates.