Dicer prevents activation of the type I interferon pathway in lipid-loaded macrophages

Background

The expression of the endonuclease Dicer in macrophages decreases atherosclerosis and necrotic core formation by producing microRNAs such as miR-10a. This effect of Dicer is associated with enhanced mitochondrial respiration in lipid-loaded macrophages. However, the mechanism by which Dicer-dependent production of miRNAs in lipid-loaded macrophages regulates mitochondrial function is unclear.

Purpose

We aimed to determine the effect of Dicer on lipid-loaded macrophages in the context of atherosclerosis.

Methods

Mice with a myeloid cell-specific knockout of Dicer (Lys-Cre/Dicerflox/flox/Apoe−/− mice [M-Dicer−/−]) and control mice (Lys-Cre/DicerWT/WT/Apoe−/− mice [M-Dicer+/+]) were fed a high-fat diet (HFD) for 24 weeks. The oxygen consumption rate (OCR) in aortic arch plaques was studied ex vivo by Seahorse Flux XF 24 Analyzer. Bone marrow-derived macrophages (BMDMs) were stimulated with oxLDL (100 μg/mL) for 72 h. Lipid-loaded macrophages were used for proteomic analysis by mass spectrometry. RIP-prime- seq was performed in tAgo2 immunoprecipitates (IP) from Dicer+/+ and Dicer−/− BMDMs. The miRNA expression profile was determined in lipid-loaded BMDMs by NanoString technology. Stat1 phosphorylation was determined in lipid-loaded macrophages by Jess automated western blot system (ProteinSimple).

Result

The OCR in aortic arch tissue with plaques was higher than in those without plaques in M-Dicer+/+ mice after 24 weeks of HFD feeding. Dicer knockout in macrophages decreased the OCR in aortic arch tissues with plaques but not in aortic arch tissues without plaques (n=3–4, p<0.05). The proteomic analysis of oxLDL-treated BMDMs indicated that Dicer knockout activated the type I interferon signaling pathway by up-regulating the expression of STAT1/2 and interferon-stimulated genes, such as ISG15. Proteins related to mitochondrial DNA were upregulated (e.g., Dnmt3a) or downregulated (e.g., Tfam) by Dicer knockout (n=5, adj.p<0.05). RIP-prime-seq from BMDMs showed that 1376 transcripts were significantly enriched in the tAgo IP from Dicer+/+ compared with that from Dicer−/− BMDMs (n=3–5, adj.p<0.05) including Dnmt3a and Stat2. STAT1 phosphorylation was increased in Dicer−/− compared with Dicer+/+ BMDMs. Among the 299 miRNAs downregulated by Dicer knockout in lipid-loaded macrophages (n=6, adj.p<0.05), miR-29 and miR-30 have highly conserved binding sites (predicted by TargetScan) for Dnmt3a.

Conclusion

Our results indicate that Dicer expression in lipid-loaded macrophages limits Stat1/2-driven type I interferon response due to mitochondrial damage. This effect may be mediated by the suppression of Dnmt3a by miRNAs such as miR-29 and miR-30. This suggests that targeting Dnmt3a-mediated mitochondrial damage in lipid-loaded macrophages by miRNAs may be therapeutic strategy to limit atherosclerosis.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): DFG

Outcomes of patients with ST-segment myocardial infarction admitted during the COVID-19 pandemic : A prospective, observational study from a tertiary care center in Germany

Background

Since the beginning of the SARS-CoV‑2 outbreak, healthcare professionals reported that patients admitted with ST-segment myocardial infarction (STEMI) were in worse condition compared to STEMI patients admitted before the outbreak. However, data on their outcomes are sparse.

Methods

We conducted a prospective, observational, cohort study of STEMI patients admitted during the COVID-19 pandemic from March 21, 2020 to July 31, 2020 (COVID-19 group). Clinical outcomes, 30-day mortality, and reasons potentially related to a delay in patient presentation were assessed and compared with STEMI patients admitted between November 1, 2019 and March 20, 2020 (pre-COVID-19 group).

Results

A total of 124 patients were enrolled, comprising 57 patients in the pre-COVID-19 group and 67 patients in the COVID-19 group. Significantly more patients in the COVID-19 group had a time to first medical contact of greater than 24 h. Additionally, those admitted during the pandemic had a significantly lower left ventricular ejection fraction (LVEF), worse thrombolysis in myocardial infarction (TIMI) flow, received circulatory support significantly more often, and had a significantly higher 30-day mortality. Furthermore, significantly more patients stated that “information by the media” made them hesitate to contact the emergency medical services as soon as possible.

Conclusion

Here, we show that STEMI patients admitted during the COVID-19 pandemic had significantly prolonged times to first medical contact, were in worse condition at admission, and had an increased 30-day mortality. Additionally, we found that “information by the media” made patients during COVID-19 hesitate to contact the emergency medical services. Consequently, public health strategies have to be developed to avoid potential excess mortality of STEMI patients during the pandemic.

Supplementary Information

The online version of this article (10.1007/s00059-021-05058-7) contains supplementary material, which is available to authorized users.

Modification of histone 3 lysine 27 (H3K27) trimethylation in EZH2 and JMJD3 deficient T cells attenuates atherosclerosis through polarization towards anti-inflammatory phenotypes

Background

The trimethylation status of Histone 3 Lysine 27 (H3K27), which is regulated by the methylating enzyme Enchancer of zeste homolog 2 (EZH2) and the demethylating enzyme Jumonji domain containing 3 (JMJD3), is a critical epigenetic signature for the differentiation and polarization of T cells. During atherogenesis, T cells initiate and propagate lesion formation through imbalanced polarization of T helper (Th) cells leading to the accumulation of pro-atherogenic T cell subsets, including Th1, that exacerbate inflammation.

Purpose

We hypothesize that T-cell EZH2 and JMJD3 may contribute to inflammation and atherosclerotic plaque formation through opposing polarization of T helper cells.

Methods

We generated transgenic mice with either Ezh2 or Jmjd3 flanked by loxP-sites that were sensitive to Cre-mediated inactivation. Mice were backcrossed to apolipoprotein E (ApoE−/−) mice expressing Cre in T cells (Cd4Cretg) to generate hypercholesterolemic Ezh2fl/fl-Cd4Cre-ApoE−/− (Ezh2fl/fl) and Jmjd3fl/fl-Cd4Cre-ApoE−/− (Jmjd3fl/fl) mice. Following a 6 week high fat diet, the immune status and atherosclerotic progression of the mice were assessed by histology, flow cytometry, and RNA sequencing.

Results

Mass spectrometry of histones isolated from CD4+ T cells confirmed a decrease in H3K27 trimethylation in Ezh2fl/fl mice and an increase in Jmjd3fl/fl mice (p=0.0002 and p=0.01, respectively). In the aortic root, both Ezh2fl/fl and Jmjd3fl/fl mice developed significantly less atherosclerosis (p=0.001 and p=0.0006, respectively). A shift from naive T cells to effectors was observed in the lymph nodes and spleens in both models (p<0.0001 for all). Flow cytometric analysis revealed a systemic accumulation of Th2 in Ezh2fl/flmice (p<0.0001), which was corroborated by a 2.75 log2 fold change of IL-4 expression (padj<0.0001) (RNA-sequencing) in CD4+ T cells as well as elevated IL-4 plasma concentrations (p=0.04). Ingenuity pathway analysis revealed the canonical Th1 pathway was inhibited in Ezh2fl/fl mice. In Jmjd3fl/fl mice, flow cytometric analysis revealed a 2 fold increase of Foxp3-expressing T regulatory (Treg) cells in the blood (p=0.005), lymph nodes (p<0.0001), and spleen (p<0.0001).

Conclusions

Our data demonstrate deficiency of either EZH2 or JMJD3 strongly reduce lesion progression in atherosclerosis through polarization of T cells towards anti-atherogenic Th2 or Treg populations, respectively. Targeting T-cell H3K27 trimethylation may be a promising candidate for further investigation to treat atherosclerosis.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): German Research Foundation (DFG)

Characterization of the Scattering and Absorption of Colored Zein Colloids in Optically Dense Dispersions

In this research, we model the color of optically dense colloidal dispersions of dyed and undyed zein particles using results from multiple light scattering theory. These particles, as well as monodisperse silica colloids, were synthesized and characterized to obtain particle properties such as particle size, particle size distribution, refractive index, and absorption spectrum of the dye. This information was used to model the diffuse transmission of concentrated particle dispersions, which was measured using a specially designed variable path length quartz glass cuvette. For the nonabsorbing silica dispersions, a transport mean-free path throughout the visible range was obtained. Results showed a difference of less than 5% from the values calculated with a multiple scattering model using the single-particle properties as an input. For undyed zein particles, which are off-white, the deviation between the model and the experiment was about 30% because of slight absorption at wavelengths below 550 nm but <7% at higher wavelengths. From these results, it was concluded that the model correctly describes diffuse transmission and that the measurements are sensitive to absorption. Finally, this method was applied to dispersions of dyed zein particles. Here, the transport mean-free path was first determined for wavelengths at which there is no absorption, which agreed with the theory better than 4%. The modeled transport mean-free path was then used to extract the reciprocal absorption mean-free path in the remaining parts of the visible spectrum, and a reasonable agreement with the absorption spectrum of the dye solution was obtained.

Fast-track versus long-term hospitalizations for patients with non-disabling acute ischaemic stroke

BACKGROUND AND PURPOSE

The aim was to assess the feasibility and safety of fast-track hospitalizations in a selected cohort of patients with stroke.

METHODS

Patients hospitalized at the Stroke Center of the University Hospital Basel, Switzerland, with an acute ischaemic stroke confirmed on magnetic resonance diffusion-weighted imaging were included. Neurological deficits of the included patients were non-disabling, i.e. not interfering with activities of daily living and compatible with a direct discharge home. Patients with premorbid disability were excluded. All patients were admitted to the Stroke Center for ≥24 h. Two study groups were compared - fast-track hospitalizations (≤72 h) and long-term hospitalizations (>72 h). The primary end-point was a composite of any unplanned rehospitalization for any reason within 3 months since hospital discharge and a modified Rankin Scale 3-6 at 3 months. Adjustment for confounders was done using the inverse probability of treatment weights (IPTW).

RESULTS

Amongst the 521 patients who met the inclusion criteria, fast-track hospitalizations were performed in 79 patients (15%). In the fast-track group, seven patients (8.9%) met the primary end-point, compared to 37 (8.4%) in the long-term group [odds ratio (OR) 1.06, 95% confidence interval (CI) 0.42-2.34, P = 0.88]. After weighting for IPTW, the odds of the primary end-point remained similar between the two arms (OR_IPTW 1.27, 95% CI 0.51-3.16, P = 0.61). The costs of fast-track hospitalizations were lower, on average, by $4994.

CONCLUSIONS

Fast-track hospitalizations including a full workup proved to be feasible, showed no increased risk and were less expensive than long-term hospitalizations.

White zein colloidal particles: synthesis and characterization of their optical properties on the single particle level and in concentrated suspensions

Growing interest in using natural, biodegradable ingredients for food products leads to an increase in research for alternative sources of functional ingredients. One alternative is zein, a water-insoluble protein from corn. Here, a method to investigate the optical properties of white zein colloidal particles is presented in both diluted and concentrated suspensions. The particles are synthesized, after purification of zein, by anti-solvent precipitation. Mean particle diameters ranged from 35 to 135 nm based on dynamic light scattering. The value of these particles as white colorant is examined by measuring their optical properties. Dilute suspensions are prepared to measure the extinction cross section of individual particles and this was combined with Mie theory to determine a refractive index (RI) of 1.49 ± 0.01 for zein particles dispersed in water. This value is used to further model the optical properties of concentrated suspensions. To obtain full opacity of the suspension, comparable to 0.1-0.2 wt% suspensions of TiO2, concentrations of 2 to 3.3 wt% of zein particles are sufficient. The optimal size for maximal scattering efficiency is explored by modeling dilute and concentrated samples with RI's matching those of zein and TiO2 particles in water. The transport mean free path of light was determined experimentally and theoretically and the agreement between the transport mean free path calculated from the model and the measured value is better than 30%. Such particles have the potential to be an all-natural edible alternative for TiO2 as white colorant in wet food products.

Determination of the positions and orientations of concentrated rod-like colloids from 3D microscopy data

Confocal microscopy in combination with real-space particle tracking has proven to be a powerful tool in scientific fields such as soft matter physics, materials science and cell biology. However, 3D tracking of anisotropic particles in concentrated phases remains not as optimized compared to algorithms for spherical particles. To address this problem, we developed a new particle-fitting algorithm that can extract the positions and orientations of fluorescent rod-like particles from three dimensional confocal microscopy data stacks. The algorithm is tailored to work even when the fluorescent signals of the particles overlap considerably and a threshold method and subsequent clusters analysis alone do not suffice. We demonstrate that our algorithm correctly identifies all five coordinates of uniaxial particles in both a concentrated disordered phase and a liquid-crystalline smectic-B phase. Apart from confocal microscopy images, we also demonstrate that the algorithm can be used to identify nanorods in 3D electron tomography reconstructions. Lastly, we determined the accuracy of the algorithm using both simulated and experimental confocal microscopy data-stacks of diffusing silica rods in a dilute suspension. This novel particle-fitting algorithm allows for the study of structure and dynamics in both dilute and dense liquid-crystalline phases (such as nematic, smectic and crystalline phases) as well as the study of the glass transition of rod-like particles in three dimensions on the single particle level.

LSD1 controls metastasis of androgen-independent prostate cancer cells through PXN and LPAR6

Lysine-specific demethylase 1 (LSD1) was shown to control gene expression and cell proliferation of androgen-dependent prostate cancer (PCa) cells, whereas the role of LSD1 in androgen-independent metastatic prostate cancer remains elusive. Here, we show that depletion of LSD1 leads to increased migration and invasion of androgen-independent PCa cells. Transcriptome and cistrome analyses reveal that LSD1 regulates expression of lysophosphatidic acid receptor 6 (LPAR6) and cytoskeletal genes including the focal adhesion adaptor protein paxillin (PXN). Enhanced LPAR6 signalling upon LSD1 depletion promotes migration with concomitant phosphorylation of PXN. In mice LPAR6 overexpression enhances, whereas knockdown of LPAR6 abolishes metastasis of androgen-independent PCa cells. Taken together, we uncover a novel mechanism of how LSD1 controls metastasis and identify LPAR6 as a promising therapeutic target to treat metastatic prostate cancer.

Associations of fatty liver disease and other factors affecting serum SHBG concentrations: a population based study on 1657 subjects

Sex hormone binding globulin (SHBG) is a glycoprotein expressed predominantly in the hepatocytes. It regulates the transport of sex steroid hormones in the blood stream to their target tissues. The expression of the SHBG gene is subject to multifactorial regulation including hormonal, metabolic, and nutritional aspects. Against this background, we investigated the effect of fatty liver and metabolic syndrome, together with other parameters, on serum SHBG concentrations in a population-based cohort in Germany. This cross-sectional study included 870 women and 787 men (average age 42.3±12.8 years), who underwent ultrasound screening for fatty liver in addition to providing a complete medical history and undergoing physical and laboratory examination. Fatty liver was diagnosed on ultrasound criteria in 159 women (18.3%) and 287 men (36.5%). Fatty liver was shown to exert a significant influence on serum SHBG concentrations in men and in premenopausal women. Men with grade 1 fatty liver had a 1.96-fold increased risk (95%-confidence interval=1.28-3.02; p=0.0022) and postmenopausal women with grade 1 fatty liver a 2.4-fold risk (95%-confidence interval=1.11-5.27; p=0.0267) for low SHBG concentrations. Among metabolic parameters, HDL-C represented as affecting factor in men (p=0.0058) and premenopausal women (p=0.0002), while cholesterol only showed an association in premenopausal women (p=0.0439) and triglyceride in postmenopausal women (p=0.0436). No association of concentrations of SHBG and metabolic syndrome was observed. Age, BMI and waist-to-hip ratio also influence the SHBG concentration. Based on these findings, we conclude that fat accumulation in the liver influences SHBG concentrations in men and premenopausal women.

Survey of aspergillosis in non-neutropenic patients in Swiss teaching hospitals

Invasive aspergillosis (IA) is a live-threatening opportunistic infection that is best described in haematological patients with prolonged neutropenia or graft-versus-host disease. Data on IA in non-neutropenic patients are limited. The aim of this study was to establish the incidence, disease manifestations and outcome of IA in non-neutropenic patients diagnosed in five Swiss university hospitals during a 2-year period. Case identification was based on a comprehensive screening of hospital records. All cases of proven and probable IA were retrospectively analysed. Sixty-seven patients were analysed (median age 60 years; 76% male). Sixty-three per cent of cases were invasive pulmonary aspergillosis (IPA), and 17% of these were disseminated aspergillosis. The incidence of IPA was 1.2/10 000 admissions. Six of ten cases of extrapulmonary IA affected the brain. There were six cases of invasive rhinosinusitis, six cases of chronic pulmonary aspergillosis, and cases three of subacute pulmonary aspergillosis. The most frequent underlying condition of IA was corticosteroid treatment (57%), followed by chronic lung disease (48%), and intensive-care unit stays (43%). In 38% of patients with IPA, the diagnosis was established at autopsy. Old age was the only risk factor for post-mortem diagnosis, whereas previous solid organ transplantation and chronic lung disease were associated with lower odds of post-mortem diagnosis. The mortality rate was 57%.

Air suctioning during colon biopsy forceps removal reduces bacterial air contamination in the endoscopy suite

BACKGROUND AND STUDY AIMS

Bacterial contamination of endoscopy suites is of concern; however studies evaluating bacterial aerosols are lacking. We aimed to determine the effectiveness of air suctioning during removal of biopsy forceps in reducing bacterial air contamination.

PATIENTS AND METHODS

This was a prospective single-blinded trial involving 50 patients who were undergoing elective nontherapeutic colonoscopy. During colonoscopy, endoscopists removed the biopsy forceps first without and then with suctioning following contact with the sigmoid mucosa. A total of 50 L of air was collected continuously for 30 seconds at 30-cm distance from the biopsy channel valve of the colonoscope, with time starting at forceps removal. Airborne bacteria were collected by an impactor air sampler (MAS-100). Standard Petri dishes with CNA blood agar were used to culture Gram-positive bacteria. Main outcome measure was the bacterial load in endoscopy room air.

RESULTS

At the beginning and end of the daily colonoscopy program, the median (and interquartile [IQR] range) bioaerosol burden was 4 colony forming units (CFU)/m (3) (IQR 3 - 6) and 16 CFU/m (3) (IQR 13 - 18), respectively. Air suctioning during removal of the biopsy forceps reduced the bioaerosol burden from a median of 14 CFU/m (3) (IQR 11 - 29) to a median of 7 CFU/m (3) (IQR 4 - 16) ( P = 0.0001). Predominantly enterococci were identified on the agar plates.

CONCLUSION

The bacterial aerosol burden during handling of biopsy forceps can be reduced by applying air suction while removing the forceps. This simple method may reduce transmission of infectious agents during gastrointestinal endoscopies.

High-resolution soft X-ray beamline ADRESS at the Swiss Light Source for resonant inelastic X-ray scattering and angle-resolved photoelectron spectroscopies

The concepts and technical realisation of the high-resolution soft X-ray beamline ADRESS operating in the energy range from 300 to 1600 eV and intended for resonant inelastic X-ray scattering (RIXS) and angle-resolved photoelectron spectroscopy (ARPES) are described. The photon source is an undulator of novel fixed-gap design where longitudinal movement of permanent magnetic arrays controls not only the light polarization (including circular and 0-180 degrees rotatable linear polarizations) but also the energy without changing the gap. The beamline optics is based on the well established scheme of plane-grating monochromator operating in collimated light. The ultimate resolving power E/DeltaE is above 33000 at 1 keV photon energy. The choice of blazed versus lamellar gratings and optimization of their profile parameters is described. Owing to glancing angles on the mirrors as well as optimized groove densities and profiles of the gratings, the beamline is capable of delivering high photon flux up to 1 x 10(13) photons s(-1) (0.01% BW)(-1) at 1 keV. Ellipsoidal refocusing optics used for the RIXS endstation demagnifies the vertical spot size down to 4 microm, which allows slitless operation and thus maximal transmission of the high-resolution RIXS spectrometer delivering E/DeltaE > 11000 at 1 keV photon energy. Apart from the beamline optics, an overview of the control system is given, the diagnostics and software tools are described, and strategies used for the optical alignment are discussed. An introduction to the concepts and instrumental realisation of the ARPES and RIXS endstations is given.

Brain aging in the oldest-old

Nonagenarians and centenarians represent a quickly growing age group worldwide. In parallel, the prevalence of dementia increases substantially, but how to define dementia in this oldest-old age segment remains unclear. Although the idea that the risk of Alzheimer's disease (AD) decreases after age 90 has now been questioned, the oldest-old still represent a population relatively resistant to degenerative brain processes. Brain aging is characterised by the formation of neurofibrillary tangles (NFTs) and senile plaques (SPs) as well as neuronal and synaptic loss in both cognitively intact individuals and patients with AD. In nondemented cases NFTs are usually restricted to the hippocampal formation, whereas the progressive involvement of the association areas in the temporal neocortex parallels the development of overt clinical signs of dementia. In contrast, there is little correlation between the quantitative distribution of SP and AD severity. The pattern of lesion distribution and neuronal loss changes in extreme aging relative to the younger-old. In contrast to younger cases where dementia is mainly related to severe NFT formation within adjacent components of the medial and inferior aspects of the temporal cortex, oldest-old individuals display a preferential involvement of the anterior part of the CA1 field of the hippocampus whereas the inferior temporal and frontal association areas are relatively spared. This pattern suggests that both the extent of NFT development in the hippocampus as well as a displacement of subregional NFT distribution within the Cornu ammonis (CA) fields may be key determinants of dementia in the very old. Cortical association areas are relatively preserved. The progression of NFT formation across increasing cognitive impairment was significantly slower in nonagenarians and centenarians compared to younger cases in the CA1 field and entorhinal cortex. The total amount of amyloid and the neuronal loss in these regions were also significantly lower than those reported in younger AD cases. Overall, there is evidence that pathological substrates of cognitive deterioration in the oldest-old are different from those observed in the younger-old. Microvascular parameters such as mean capillary diameters may be key factors to consider for the prediction of cognitive decline in the oldest-old. Neuropathological particularities of the oldest-old may be related to "longevity-enabling" genes although little or nothing is known in this promising field of future research.

Gallstone prevalence and risk factors for gallstone disease in an urban population of children and adolescents

BACKGROUND

At present only a few sonography-based studies have assessed gallstone prevalence and associated risk factors in children and adolescents in randomly selected urban population samples. The aim of the present study was to analyze the prevalence of cholecystolithiasis and associated risk factors in children and adolescents.

METHODS

From a randomly selected urban population sample a total of 307 children and adolescents (157 girls, 150 boys; age 12 - 18 years, mean age 15.1 +/- 2.0 years) were studied using ultrasonography, standardized questionnaires and blood samples.

RESULTS

Three adolescents (one girl, two boys), corresponding to a prevalence of 1.0 %, showed gallstones. One 14-year-old girl and one 17-year-old boy were overweight using Cole's classification. A positive family history and female gender could not be confirmed as risk factors.

CONCLUSION

Obesity appears to be a risk factor in the development of gallstones in childhood and adolescence.

Prevalence and risk factors of focal sparing in hepatic steatosis

PURPOSE

The prevalence, localization and potential risk factors for focal sparing were prospectively assessed in subjects with sonographically detectable hepatic steatosis as part of a population-based cross-sectional study.

MATERIALS AND METHODS

A total of 1,624 persons (n = 906 women; n = 718 men) were evaluated using ultrasonography, laboratory testing and a standardized questionnaire. The following were excluded from the analysis: subjects with reported alcohol consumption > 40 g/day (males) or > 20 g/day (females), those with known chronic hepatitis B or C infection, elevated serum transaminases (AST: m > 44 U/l, f > 33 U/l; ALT: m > 45 U/l, f > 35 U/l) and prior right nephrectomy.

RESULTS

The prevalence of focal sparing in patients with hepatic steatosis (grade I) was 25.6 % for men and 13.0 % for women. In patients with grade II/III disease, the prevalence was 70.9 % for men and 77.6 % for women. The most common site of focal sparing was in segment IV. The average diameter was 22.3 mm (range 7 - 84 mm). No correlation was found for postulated risk "age" (p = 0.09) or "status post cholecystectomy" (p = 0.09). Male sex (p = 0.02) and metabolic syndrome (odds ratio, 2.1; 95 % confidence interval, 1.1 - 4.1; p = 0.02) were confirmed as risk factors.

CONCLUSION

Sonographic evidence of focal sparing in subjects with hepatic steatosis is associated with an increased risk for metabolic syndrome and may be an easily obtained diagnostic criterion in routine clinical settings.

Endoscopic scoring of mucus quantity and quality: observer and horse variance and relationship to inflammation, mucus viscoelasticity and volume

REASONS FOR PERFORMING STUDY

Endoscopic scoring of airway mucus quantity and quality has not been critically assessed.

OBJECTIVES

To evaluate mucus scores for 1) observer- and horse-related variance and 2) association with inflammation, mucus viscoelasticity and measured volume.

METHODS

Variance of scoring within and between observers and over time within horses were determined for airway mucus accumulation, apparent viscosity, localisation and colour, and correlations of mucus accumulation scores with neutrophil ratios in secretions. The relationship of accumulation score to measured volumes of 'artificial mucus' was investigated. Correlations of mucus accumulation, apparent viscosity and colour scores with measured viscoelasticity were tested. Viscoelasticity was compared between tracheal secretion samples collected ventrally and dorsally.

RESULTS

Mucus accumulation scoring showed excellent interobserver agreement and moderate horse-related variance, was related to measured volumes of 'artificial mucus', and correlated well with neutrophilic airway inflammation. Scores of mucus viscosity, colour and localisation showed high observer-related variance. Mucus accumulation, apparent viscosity and colour scores did not correlate with measured tracheal mucus viscoelasticity, but dorsally-localised mucus showed 2-fold higher measured viscoelasticity than ventrally-localised samples.

CONCLUSIONS

Mucus accumulation scores are a reproducible measure of mucus volumes in the trachea.

POTENTIAL RELEVANCE

Endoscopic scoring of mucus accumulation is a reliable clinical and research tool. In contrast, apparent viscosity, localisation and colour scores should be interpreted with caution.

Chromium (Cr) accumulation in the freshwater crab, Zilchiopsis collastinensis

The freshwater crab, Zilchiopsis collastinensis was exposed in vivo to determine Cr accumulation in visceral content. After an acclimation period we added Cr(K2Cr2O7) at nominal concentrations of 2 mg l(-1) Cr(VI) and 5 mg l(-1) Cr(VI) and a control (T0) under the same conditions, without Cr. At days 1, 7 and 14, Cr was measured in water sediments and crabs and the bioconcentration factor (BCF) in relation to water and to sediment were obtained. Considering all samples and all the study period, crabs registered 3 times more Cr than sediments and 18 times more Cr than water. Cr levels in Z. collastinensis tissues were always lower in the control than in T1 and T2; no significant differences among days 1, 7 and 14 were found in the control. In the treatments, no significant increase in Cr levels in tissues were found between days 1 and 7, neither between days 7 and 14 in both concentrations tested. Significant differences were found between the control and T1 and T2 (p<0.001), but not between T1 and T2. The highest BCF obtained for Z. collastinensis were 51.82 and 51.42 in T1 and T2 in water at 14 days of exposure. This study shows the efficiency of freshwater crabs to accumulate Cr from water.

[Sepsis and rhabdomyolysis after holidays in Thailand]

We report a case of severe hypophosphatemia with neurologic, hematologic and musculoskeletal symptoms. Acute hypophosphatemia becomes clinically significant if there is underlying phosphate depletion and can induce a variety of symptoms that can be deleterious. The diagnosis is made by clinical presentation and serum phosphate level. Treatment is promptly warranted, once diagnosis is confirmed.

Salermide, a Sirtuin inhibitor with a strong cancer-specific proapoptotic effect

Sirtuin 1 (Sirt1) and Sirtuin 2 (Sirt2) belong to the family of NAD+ (nicotinamide adenine dinucleotide-positive)-dependent class III histone deacetylases and are involved in regulating lifespan. As cancer is a disease of ageing, targeting Sirtuins is emerging as a promising antitumour strategy. Here we present Salermide (N-{3-[(2-hydroxy-naphthalen-1-ylmethylene)-amino]-phenyl}-2-phenyl-propionamide), a reverse amide with a strong in vitro inhibitory effect on Sirt1 and Sirt2. Salermide was well tolerated by mice at concentrations up to 100 muM and prompted tumour-specific cell death in a wide range of human cancer cell lines. The antitumour activity of Salermide was primarily because of a massive induction of apoptosis. This was independent of global tubulin and K16H4 acetylation, which ruled out a putative Sirt2-mediated apoptotic pathway and suggested an in vivo mechanism of action through Sirt1. Consistently with this, RNA interference-mediated knockdown of Sirt1, but not Sirt2, induced apoptosis in cancer cells. Although p53 has been reported to be a target of Sirt1, genetic p53 knockdowns showed that the Sirt1-dependent proapoptotic effect of Salermide is p53-independent. We were finally able to ascribe the apoptotic effect of Salermide to the reactivation of proapoptotic genes epigenetically repressed exclusively in cancer cells by Sirt1. Taken together, our results underline Salermide's promise as an anticancer drug and provide evidence for the molecular mechanism through which Sirt1 is involved in human tumorigenesis.

Elastic properties of hollow colloidal particles

The elastic properties of micrometer-sized hollow colloidal particles obtained by emulsion templating are probed by nanoindentation measurements in which point forces are applied to solvent-filled particles supported on a flat substrate. We show that the shells respond linearly up to forces of 7-21 nN, where the indentation becomes of the order of the shell thickness (20-40 nm). In the linear region, the particle deformation is reversible. The measured Young's modulus (approximately 200 MPa) is comparable to values for stiff rubbers or soft polymers. At larger applied force, we observe a crossover into a nonlinear regime, where the shells assume a buckled shape. Here, the force increases approximately as the square root of the indentation, in agreement with the theory of elasticity of thin shells. We also observe permanent deformation of the shells after probing them repetitively beyond the linear regime. Finally, the measured elastic properties of the shells nicely explain their spontaneous buckling in solution and due to drying.

Anisotropic colloids through non-trivial buckling

We present a study on buckling of colloidal particles, including experimental, theoretical and numerical developments. Oil-filled thin shells prepared by emulsion templating show buckling in mixtures of water and ethanol, due to dissolution of the core in the external medium. This leads to conformations with a single depression, either axisymmetric or polygonal depending on the geometrical features of the shells. These conformations could be theoretically and/or numerically reproduced in a model of homogeneous spherical thin shells with bending and stretching elasticity, submitted to an isotropic external pressure.

Clusterin expression during fetal and postnatal CNS development in mouse

Clusterin (or apolipoprotein J) is a widely distributed multifunctional glycoprotein involved in CNS plasticity and post-traumatic remodeling. Using biochemical and morphological approaches, we investigated the clusterin ontogeny in the CNS of wild-type (WT) mice and explored developmental consequences of clusterin gene knock-out in clusterin null (Clu-/-) mice. A punctiform expression of clusterin mRNA was detected through the hypothalamic region, neocortex and hippocampus at embryonic stages E14/E15. From embryonic stage E16 to the first week of the postnatal life, the vast majority of CNS neurons expressed low levels of clusterin mRNA. In contrast, a very strong hybridizing signal mainly localized in pontobulbar and spinal cord motor nuclei was observed from the end of the first postnatal week to adulthood. Astrocytes expressing clusterin mRNA were often detected through the hippocampus and neocortex in neonatal mice. Real-time polymerase chain amplification and clusterin-immunoreactivity dot-blot analyses indicated that clusterin levels paralleled mRNA expression. Comparative analyses between WT and Clu-/- mice during postnatal development showed no significant differences in brain weight, neuronal, synaptic and astrocyte markers as well myelin basic protein expression. However, quantitative estimation of large motor neuron populations in the facial nucleus revealed a significant deficit in motor cells (-16%) in Clu-/- compared with WT mice. Our data suggest that clusterin expression is already present in fetal life mainly in subcortical structures. Although the lack of this protein does not significantly alter basic aspects of the CNS development, it may have a negative impact on neuronal development in certain motor nuclei.

Disseminated Invasive Aspergillosis with Cerebral Involvement Successfully Treated with Caspofungin and Voriconazole

We describe a case of cerebral aspergillosis which was successfully treated with a combination of caspofungin and voriconazole. The patient remains in remission 18 months after stopping antifungal treatment. We discuss primary and salvage therapy of invasive aspergillosis with focus on cerebral involvement. Since historical data showed a fatal outcome in most cases, amphotericin B does not cross the blood brain barrier while voriconazole does, we chose a combination of voriconazole plus caspofungin as primary therapy.

Encapsulation of emulsion droplets by organo–silica shells

Surfactant-stabilized emulsion droplets were used as templates for the synthesis of hollow colloidal particles. Monodisperse silicone oil droplets were prepared by hydrolysis and polymerization of dimethyldiethoxysiloxane monomer, in the presence of surfactant: sodium dodecyl sulphate (SDS, anionic) or Triton X-100 (non-ionic). A sharp decrease in the average droplet radius with increasing surfactant concentration was found, with a linear dependence of the droplet radius on the logarithm of the surfactant concentration. The surfactant-stabilized oil droplets were then encapsulated with a solid shell using tetraethoxysilane, and hollow particles were obtained by exchange of the liquid core. The size and polydispersity of the oil droplets and the thickness of the shell were determined using static light scattering, and hollow particles were characterized by electron microscopy. Details on the composition of the shell material were obtained from energy-dispersive X-ray analysis. In the case of sodium dodecyl sulphate, the resulting shells were relatively thin and rough, while when Triton X-100 was used, smooth shells were obtained which could be varied in thickness from very thick ( approximately 150 nm) to very thin shells ( approximately 17 nm). Finally, hexane droplets were encapsulated using the same procedure, showing that our method can in principle be extended to a wide range of emulsions.

Mass spectrometric analysis of protein histidine phosphorylation

Protein histidine phosphorylation is now recognized as an important form of post-translational modification. The acid-lability of phosphohistidine has meant that this phosphorylation has not been as well studied as serine/threonine or tyrosine phosphorylation. We show that phosphohistidine and phosphohistidine-containing phosphopeptides derived from proteolytic digestion of phosphohistone H4 are detectable by ESI-MS. We also demonstrate reverse-phase HPLC separation of these phosphopeptides and their detection by MALDI-TOF-MS.

Detection of villous conidia of Conidiobolus coronatus in a blood sample by scanning electron microscopy investigation

Conidiobolus coronatus is a major insect pathogen belonging to the fungal order Entomophthorales, causing a rare subcutaneous infection of the nasofacial region, resulting in swelling of predominantly the nose, mouth, and perinasal tissue. Later in the course of the infection firm, painless, subcutaneous nodules develop that are attached to the underlying tissues but not to the skin. No morphological studies are available in the literature on the morphology of C. coronatus in vivo and all morphological studies have been conducted on in vitro cultures. Here the authors report on the ultrastructural pathology as seen with a scanning electron microscope (SEM) of villous conidia of C. coronatus, detected in a 37-year-old woman who presented to the casualty department at Pretoria Academic Hospital, South Africa with left-sided facial pain and headache. The diagnosis of C. coronatus was confirmed by LightCycler real-time flourescence PCR technique. Research shows that typically diagnosis of the pathogen is established only on histological examination, and in over 85% of cases cultures for the causative organism is negative. This pathogen has not previously been found in a blood sample and the authors present for the first time the morphology of C. coronatus in blood using the SEM.

Microradian X-ray diffraction in colloidal photonic crystals

Ultra-high-resolution small-angle X-ray scattering in various colloidal photonic crystals is reported. It is demonstrated that an angular resolution of about two microradians is readily achievable at a third-generation synchrotron source using compound refractive optics. The scheme allows fast acquisition of two-dimensional X-ray diffraction data and can be realised at sample–detector separations of only a few metres. As a result, diffraction measurements in colloidal crystals with interplanar spacings larger than a micrometre, as well as determination of the range of various order parameters from the width of the Bragg peaks, are made possible.

Transregional Spread of a Single Clone of Methicillin–Resistant Staphylococcus aureus between Groups of Drug Users in Switzerland

BACKGROUND

An epidemic spread of methicillin-resistant Staphylococcus aureus (MRSA) among intravenous drug users (IDUs) has been observed in Zurich. In the present study we investigated the situation in the Grisons, Switzerland.

PATIENTS AND METHODS

We screened IDUs and their caregivers in medical and socio-therapeutical institutions in the Grisons for MRSA. Nose swabs were used for bacterial culture and pulsed-field gel electrophoresis for MRSA genotyping.

RESULTS

A total of 191 nose swabs from 111 IDUs and 80 caregivers was analyzed. None of the caregivers was MRSA positive. Six IDUs were asymptomatic MRSA carriers (5.4%). They participated in the official heroin program (MRSA prevalence in this group 16%). The MRSA genotype was identical with the single clone found in IDUs in Zurich, strongly suggesting an epidemic spread. Decolonization was successful in two persons only. Persistence of MRSA in IDUs must therefore be assumed.

CONCLUSION

We conclude that a single clone of MRSA, found in IDUs in Zurich, has spread to a distant region of Switzerland. A rigorous infection control program in all institutions with IDUs is necessary to prevent a further spread of MRSA.

Overall alcohol intake, beer, wine, and systemic markers of inflammation in western Europe: results from three MONICA samples (Augsburg, Glasgow, Lille)

AIM

Anti-inflammatory effects of moderate alcohol consumption have been proposed to explain why moderate alcohol intake lowers coronary heart disease risk. We investigated the relationship between overall alcohol, beer or wine consumption and markers of systemic inflammation in three different geographical areas in Europe.

METHODS AND RESULTS

Cross-sectional samples, each representative of the general population from Germany, Scotland, and France (MONICA Augsburg 1994/95, 2275 men and 2186 women, 25-74 years; Glasgow MONICA 1994/95, 561/616, 25-74 years, and MONICA Lille 1994/95, 581/574, 35-64 years) were studied. Alcohol intake was assessed by standardized interview. Adjusted means of C-reactive protein (CRP), fibrinogen, white blood cell (WBC) count, plasma viscosity (PV), and albumin were calculated among categories of alcohol intake, and separately for beer or wine consumption, by multiple linear regression. Self-reported moderate daily alcohol intake up to 40 g was associated with lower concentrations of CRP, fibrinogen, PV and WBC count, compared to non-drinking and heavy drinking, even after adjustment for various potential confounders.

CONCLUSIONS

Moderate consumption of either wine or beer is associated with lower levels of systemic inflammatory markers in three different European areas, suggesting that ethanol itself might be largely responsible for the potential anti-inflammatory effects of these beverages.

[The Comprehensive Cohort Design as alternative to the randomized controlled trial in rehabilitation research: advantages, disadvantages, and implementation in the SARAH study]

In rehabilitation research new therapies have to be evaluated within randomized trials as the best choice for proving the efficacy. Randomized controlled trials are widely accepted as the definitive method for evaluating the efficacy of new therapies. The random assignment of patients to their treatment ensures the internal validity of the comparison of new treatments with controls. Often patients in a randomized trial only represent a small proportion of the patients who satisfy the inclusion criteria of the trial. This will especially be true in rehabilitation medicine because of strong preferences of the patients for one or the other therapy. An assessment of the external validity of trial results can best be achieved by comparing the study population to the population of patients who met the eligibility criteria but did not consent to randomization. The Comprehensive Cohort Design (CCD) is designed to have the opportunity of recruiting all patients fulfilling these eligibility criteria regardless of their consent to randomisation. Advantages and disadvantages of this study design will be discussed in detail and on the example of the SARAH-study.

Moderater Alkoholkonsum und Plasmakonzentration sensitiver Entzündungsmarker

BACKGROUND AND OBJECTIVE

Changes in lipoproteins and hemostasis only incompletely explain the reduced cardiovascular mortality associated with light to moderate alcohol consumption. Since increasing evidence suggests that atherosclerosis can be considered to be a chronic inflammatory process, we sought to assess the association between daily alcohol consumption and levels of sensitive markers of inflammation.

STUDY PARTICIPANTS AND METHODS

478 voluntary blood donors (358 men, 120 women) aged 40 to 68 years were categorized into four groups according to their self-reported amount of daily alcohol consumption: 0 g/day, >0 - 20 g/day, >20 - 40 g/day, and > 40 g/day. Means of various sensitive markers of inflammation (C-reactive protein (CRP), serum amyloid A (SAA), interleukin-6 (IL-6), intercellular adhesion molecule-1, plasma viscosity und albumin) were calculated and compared by bivariate and multivariate analyses.

RESULTS

More than 80 % of the study participants reported to consume alcohol, mainly beer. We found statistically significantly decreased levels of SAA, CRP, and plasma viscosity in subjects with light-to-moderate alcohol intake (>0 - 20 g/day and > 20 - 40 g/day, respectively), and a trend for increased levels of albumin in these subjects compared to non-drinkers. After multivariable adjustment for potential confounders (age, gender, body mass index, cigarette smoking, years of school education, and physical activity) a significant U-shaped association (p = 0.02) between levels of SAA and the amount of daily alcohol intake remained: there were 0.75 mg/l and 0.70 mg/l lower mean levels, respectively, of SAA in subjects with light-to-moderate alcohol intake compared to those of non-drinkers. Subjects with an alcohol intake of > 40 grams per day showed a statistically significant increase in levels of interleukin-6 (0.50 pg/ml) compared to non-drinkers.

CONCLUSION

Potential anti-inflammatory properties of moderate alcohol consumption might represent an additional mechanism to explain its atheroprotective effect.

Rapid detection of pathogenic fungi from clinical specimens using LightCycler real-time fluorescence PCR

In the study presented here a LightCycler real-time PCR system was used for the diagnosis of fungal infections from clinical tissue samples. Nine specimens were investigated from six patients with suspected or proven invasive fungal infections. Seven of nine samples were positive in a broad-range fungal PCR assay. In four samples, Aspergillus fumigatus was detected both by a species-specific hybridization assay as well as by sequencing of amplification products. In addition, the broad-range fungal PCR assay and PCR sequencing detected and identified, respectively, the following organisms in the specimens noted: Candida albicans in a culture-negative liver biopsy, Histoplasma capsulatum in a bone marrow sample, and Conidiobolus coronatus in a facial soft tissue specimen. Real-time PCR is a promising tool for the diagnosis of invasive fungal infections in human tissue samples and offers some advantages over culture methods, such as rapid analysis and increased sensitivity.

Measurement of tidal breathing flow-volume loop indices in horses used for different sporting purposes with and without recurrent airway obstruction

Tidal breathing flow-volume loop (TBFVL) indices in healthy horses and in horses suffering from mild and moderate to severe recurrent airway obstruction (RAO) were measured. In addition, the ability of these indices to differentiate healthy controls from horses with mild RAO by separating the horses according to their usage was investigated. The horses were assigned to three sporting categories: 1 Leisure horses; 2 Horses competing at events with a duration of more than five minutes (eventing, coaching and endurance); and 3 Horses competing at events with a duration of less than five minutes (dressage and show jumping). Flow-volume curves were recorded with an ultrasonic spirometer and TBFVL indices were calculated with specially dedicated software. The sporting usage of the horses had a significant effect on the differentiating ability of TBFVL indices in diagnosing different degrees of RAO. The index TIF50 differentiated control horses from horses with minor RAO in all sporting categories.