Preservation of the soft protein corona in distinct flow allows identification of weakly bound proteins

Nanocarriers that are used for targeted drug delivery come in contact with biological liquids and subsequently proteins will adsorb to the nanocarriers' surface to form the so called 'protein corona'. The protein corona defines the biological identity and determines the biological response towards the nanocarriers in the body. To make nanomedicine safe and reliable it is required to get a better insight into this protein corona and, therefore, the adsorbed proteins have to be characterized. Currently, centrifugation is the common method to isolate the protein corona for further investigations. However, with this method it is only possible to investigate the strongly bound proteins, also referred to as 'hard protein corona'. Therefore, we want to introduce a new separation technique to separate nanoparticles including the soft protein corona containing also loosely bound proteins for further characterization. The used separation technique is the asymmetric flow field-flow fractionation (AF4). We were able to separate the nanoparticles with proteins forming the soft protein corona and were able to show that in our system only the hard protein corona directly influenced the cell uptake behavior.

STATEMENT OF SIGNIFICANCE

Currently, there is an ongoing debate whether only strongly bound proteins (hard corona) or also loosely bound proteins (soft corona) contribute to the biological identity of nanocarriers, because up to now isolation of the soft corona was not possible. Here, asymmetric flow field-flow fractionation was used to isolate nanoparticles with a preserved soft corona from the biological medium. This enabled the characterization of the soft corona composition and to evaluate its influence on cellular uptake. For our system we found that only the strongly bound proteins (hard corona) determined cell internalization. This method can now be used to evaluate the impact of the soft corona further and to characterize nanomaterials that cannot be separated from blood plasma by other means.

Insulin immuno-neutralization decreases food intake in chickens without altering hypothalamic transcripts involved in food intake and metabolism

In mammals, insulin regulates blood glucose levels and plays a key regulatory role in appetite via the hypothalamus. In contrast, chickens are characterized by atypical glucose homeostasis, with relatively high blood glucose levels, reduced glucose sensitivity of pancreatic beta cells, and large resistance to exogenous insulin. The aim of the present study was to investigate in chickens the effects of 5 h fasting and 5 h insulin immuno-neutralization on hypothalamic mRNA levels of 23 genes associated with food intake, energy balance, and glucose metabolism. We observed that insulin immune-neutralization by administration of anti-porcine insulin guinea pig serum (AI) significantly decreased food intake and increased plasma glucose levels in chickens, while 5 h fasting produced a limited and non-significant reduction in plasma glucose. In addition, 5 h fasting increased levels of NPY, TAS1R1, DIO2, LEPR, GLUT1, GLUT3, GLUT8, and GCK mRNA. In contrast, AI had no impact on the levels of any selected mRNA. Therefore, our results demonstrate that in chickens, food intake inhibition or satiety mechanisms induced by insulin immuno-neutralization do not rely on hypothalamic abundance of the 23 transcripts analyzed. The hypothalamic transcripts that were increased in the fasted group are likely components of a mechanism of adaptation to fasting in chickens.

Erratum: Addendum: Comparative Genomic Analysis of the Class Epsilonproteobacteria and Proposed Reclassification to Epsilonbacteraeota (phyl. nov.)

[This corrects the article on p. 682 in vol. 8, PMID: 28484436.].

Gender Specific Differences in Disease-Free, Cancer Specific and Overall Survival after Radical Cystectomy for Bladder Cancer: A Systematic Review and Meta-Analysis

PURPOSE

We summarize the evidence on gender specific differences in disease-free, cancer specific and overall survival after radical cystectomy for bladder cancer.

MATERIALS AND METHODS

We performed a systematic literature search of MEDLINE®, Embase® and the Cochrane Library in July 2017. Studies evaluating gender specific differences in disease-free, cancer specific or overall survival after radical cystectomy for bladder cancer were included in study. Analyses included random effect meta-analysis, subgroup analyses, meta-influence and cumulative meta-analyses. Funnel plots and the Egger test were used to assess publication bias.

RESULTS

Of the 3,868 studies identified during the literature search 59 published between 1998 and 2017 were included in analysis. Of the studies 30 in a total of 38,321 patients evaluated disease-free survival, 44 in a total of 69,666 evaluated cancer specific survival and 26 in a total of 30,039 evaluated overall survival. Random effect meta-analyses revealed decreased disease-free, cancer specific survival and overall survival in female patients than in their male counterparts. Pooled estimates showed a HR of 1.16 (95% CI 1.06-1.27, p = 0.0018) for disease-free survival, 1.23 (95% CI 1.15-1.31, p <0.001) for cancer specific survival and 1.08 (95% CI 1.03-1.12, p = 0.0004) for overall survival. Subgroup analyses confirmed impaired disease-free, cancer specific and overall survival in female patients in all strata. Publication bias was evident only for studies of cancer specific survival (Egger test p = 0.0029). After adjusting for publication bias by the trim and fill method the corrected pooled estimated HR of cancer specific survival was 1.13 (95% CI 1.05-1.21, p = 0.0012).

CONCLUSIONS

Female patients who underwent radical cystectomy for bladder cancer demonstrated worse disease-free, cancer specific and overall survival than their male counterparts. The multifactorial etiology might include epidemiological differences, gender specific health care discrepancies and hormonal influences.

Incidence and costs of herpes zoster and postherpetic neuralgia in German adults aged ≥50 years: A prospective study

OBJECTIVES

Herpes zoster (HZ) mainly affects elderly people and immunocompromised individuals. HZ is usually characterized by a unilateral painful skin rash. Its most common complication, postherpetic neuralgia (PHN), may cause chronic debilitating pain. This study aimed to estimate the HZ incidence in individuals aged ≥50 years in Germany, the proportion of PHN and the economic burden.

METHODS

From 2010 to 2014, HZ patients were recruited when consulting physicians in physician networks covering about 157,000 persons aged ≥50 years. PHN was defined as "worst pain" rated ≥3 on the zoster brief pain inventory persisting or appearing over 90 days after rash onset. Costs were calculated based on medical resource utilization and lost working time.

RESULTS

HZ incidence was estimated as 6.7/1000 person-years, increasing with age to 9.4/1000 in ≥80 year-olds. Among 513 HZ patients enrolled, the proportion of PHN was 11.9%, rising with age to 14.3% in HZ patients ≥80 years. Estimated total cost per HZ patient was €156 from the healthcare system perspective and €311 from the societal perspective.

CONCLUSIONS

The study confirmed previous findings that HZ causes a substantial clinical and economic burden in older German adults. It also confirmed the age-related increasing risk of HZ and PHN.

The Digital Pen and Paper

Objectives: To evaluate the efficiency and acceptance of digital pen and paper technology for real-time clinical data acquisition.

Methods: A prospective interventional unblinded study involving consecutive patients in two clinical settings during a defined time-frame was proposed. The first trial was designed as a stress test to evaluate acceptance in a workload-intensive environment. Acceptance was assessed using observations and a satisfaction questionnaire. The second trial was intended to determine the reliability of data acquisition in a controlled environment. Reliability was assessed by comparing the performance of the digital pen against scanner analysis and a double human blinded acquisition.

Results: Overall, users were satisfied with the use of the digital pen (median 3 on a Likert-scale (–5, 5)). Without any specific user training, successful data acquisition was greater than 80%. Use of this technology required less adaptation than standard computer devices, and was easy to learn and use. Ergonomic problems shaded the perception of the technology by inducing an increased cognitive load. Digitalized data was missing either because of a bug or due to lack of data validation. The reliability obtained with the digital pen was significantly lower to that obtained with the scanner.

Conclusions: Natural technology such as the digital pen proved to be a good tool in stressful clinical environments without interfering with the normal workload or increasing the time for data acquisition. However, in order to improve quality of data acquisition, designing acquisition forms specifically for the use of digital pens is of paramount importance.

Immunoscintigraphy with Anti-225.28S for Ocular Melanoma - a Comparison with Histology and Immunohistochemistry,

Aim: The purpose of this prospective study was to evaluate the value of Immunoscintigraphy (ISG) with anti-225.28S in clinically suspected ocular melanoma. Methods: For this purpose standardized ISG was performed in 36 patients using both planar acquisition and emission computed tomography (ECT). Ocular melanoma was present in 31 patients. In 21 patients therapy was enucleation of the eye. These specimens were evaluated by histology and immunohistochemistry in 11 of 21 patients. Results: Regarding the clinical diagnosis, ISG was positive only in 15 of 31 patients with ocular melanoma, regarding histology in 11 of 21 and regarding immunohistochemistry in 5 of 6 patients with a positive Immunoreaction. 5 patients showed no immunoreactivity, their ISG was negative. Conclusion: Thus a good correlation between ISG and immunohistochemistry was observed. However ISG using the cutaneous melanoma antibody 225.28S cannot be recommanded for the diagnostic work-up of an ocular melanoma considering the poor immunoreactivity.

TsdC, a unique lipoprotein from Wolinella succinogenes that enhances tetrathionate reductase activity of TsdA

The diheme cytochromes c of the widespread TsdA family are bifunctional thiosulfate dehydrogenase/tetrathionate reductases. Here, biochemical information was collected about TsdA from the Epsilonproteobacterium Wolinella succinogenes (WsTsdA). The situation in W. succinogenes is unique since TsdA is closely associated with the unprecedented lipoprotein TsdC encoded immediately downstream of tsdA in the same direction of transcription. WsTsdA purified from Escherichia coli catalyzed both thiosulfate oxidation and tetrathionate reduction. After co-production of TsdC and WsTsdA in E. coli, TsdC was found to mediate membrane attachment of TsdA and to ensure its full catalytic activity. This effect was much stronger in the tetrathionate-reducing than in the thiosulfate-oxidizing direction. It is concluded that the TsdAC complex predominantly acts as a tetrathionate reductase in vivo.

Clade II nitrous oxide respiration of Wolinella succinogenes depends on the NosG, -C1, -C2, -H electron transport module, NosB and a Rieske/cytochrome bc complex

Microbial reduction of nitrous oxide (N₂ O) is an environmentally significant process in the biogeochemical nitrogen cycle. However, it has been recognized only recently that the gene encoding N₂ O reductase (nosZ) is organized in varying genetic contexts, thereby defining clade I (or 'typical') and clade II (or 'atypical') N₂ O reductases and nos gene clusters. This study addresses the enzymology of the clade II Nos system from Wolinella succinogenes, a nitrate-ammonifying and N₂ O-respiring Epsilonproteobacterium that contains a cytochrome c N₂ O reductase (cNosZ). The characterization of single non-polar nos gene deletion mutants demonstrated that the NosG, -C1, -C2, -H and -B proteins were essential for N₂ O respiration. Moreover, cells of a W. succinogenes mutant lacking a putative menaquinol-oxidizing Rieske/cytochrome bc complex (QcrABC) were found to be incapable of N₂ O (and also nitrate) respiration. Proton motive menaquinol oxidation by N₂ O is suggested, supported by the finding that the molar yield for W. succinogenes cells grown by N₂ O respiration using formate as electron donor exceeded that of fumarate respiration by about 30%. The results demand revision of the electron transport chain model of clade II N₂ O respiration and challenge the assumption that NosGH(NapGH)-type iron-sulfur proteins are menaquinol-reactive.

Transcriptional analysis of abdominal fat in chickens divergently selected on bodyweight at two ages reveals novel mechanisms controlling adiposity: validating visceral adipose tissue as a dynamic endocrine and metabolic organ

Background

Decades of intensive genetic selection in the domestic chicken (Gallus gallus domesticus) have enabled the remarkable rapid growth of today’s broiler (meat-type) chickens. However, this enhanced growth rate was accompanied by several unfavorable traits (i.e., increased visceral fatness, leg weakness, and disorders of metabolism and reproduction). The present descriptive analysis of the abdominal fat transcriptome aimed to identify functional genes and biological pathways that likely contribute to an extreme difference in visceral fatness of divergently selected broiler chickens.

Methods

We used the Del-Mar 14 K Chicken Integrated Systems microarray to take time-course snapshots of global gene transcription in abdominal fat of juvenile [1-11 weeks of age (wk)] chickens divergently selected on bodyweight at two ages (8 and 36 wk). Further, a RNA sequencing analysis was completed on the same abdominal fat samples taken from high-growth (HG) and low-growth (LG) cockerels at 7 wk, the age with the greatest divergence in body weight (3.2-fold) and visceral fatness (19.6-fold).

Results

Time-course microarray analysis revealed 312 differentially expressed genes (FDR ≤ 0.05) as the main effect of genotype (HG versus LG), 718 genes in the interaction of age and genotype, and 2918 genes as the main effect of age. The RNA sequencing analysis identified 2410 differentially expressed genes in abdominal fat of HG versus LG chickens at 7 wk. The HG chickens are fatter and over-express numerous genes that support higher rates of visceral adipogenesis and lipogenesis. In abdominal fat of LG chickens, we found higher expression of many genes involved in hemostasis, energy catabolism and endocrine signaling, which likely contribute to their leaner phenotype and slower growth. Many transcription factors and their direct target genes identified in HG and LG chickens could be involved in their divergence in adiposity and growth rate.

Conclusions

The present analyses of the visceral fat transcriptome in chickens divergently selected for a large difference in growth rate and abdominal fatness clearly demonstrate that abdominal fat is a very dynamic metabolic and endocrine organ in the chicken. The HG chickens overexpress many transcription factors and their direct target genes, which should enhance in situ lipogenesis and ultimately adiposity. Our observation of enhanced expression of hemostasis and endocrine-signaling genes in diminished abdominal fat of LG cockerels provides insight into genetic mechanisms involved in divergence of abdominal fatness and somatic growth in avian and perhaps mammalian species, including humans.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-017-4035-5) contains supplementary material, which is available to authorized users.

Remote mood monitoring for adults with bipolar disorder: An explorative study of compliance and impact on mental health service use and costs

BACKGROUND

Remote monitoring of mood disorders may be an effective and low resource option for patient follow-up, but relevant evidence remains very limited. This study explores real-life compliance and health services impacts of mood monitoring among patients with bipolar disorder in the UK.

METHODS

Patients with a diagnosis of bipolar disorder who were registered users of the True Colours monitoring system for at least 12months at study assessment were included in this retrospective cohort study (n=79). Compliance was measured as the proportion of valid depression and mania scale messages received in comparison to their expected numbers over the first 12months of monitoring. Mental health service use data were extracted from case notes, costed using national unit costs, and compared 12months before (pre-TC period) and 12months after (TC period) patients' engagement with monitoring. Associations with relevant patient factors were investigated in a multiple regression model.

RESULTS

Average compliance with monitoring was 82%. Significant increases in the annual use and costs of psychiatrist contacts and total mental health services were shown for patients newly referred to the clinic during the pre-TC period but not for long-term patients of the clinic. Psychiatric medication costs increased significantly between the pre-TC and TC periods (£235, P=0.005) unrelated to patients' referral status.

CONCLUSIONS

Remote mood monitoring has good compliance among consenting patients with bipolar disorder. We found no associations between observed changes in mental health service costs and the introduction of monitoring except for the increase in psychiatric medication costs.

Comparative Genomic Analysis of the Class Epsilonproteobacteria and Proposed Reclassification to Epsilonbacteraeota (phyl. nov.)

The Epsilonproteobacteria is the fifth validly described class of the phylum Proteobacteria, known primarily for clinical relevance and for chemolithotrophy in various terrestrial and marine environments, including deep-sea hydrothermal vents. As 16S rRNA gene repositories have expanded and protein marker analysis become more common, the phylogenetic placement of this class has become less certain. A number of recent analyses of the bacterial tree of life using both 16S rRNA and concatenated marker gene analyses have failed to recover the Epsilonproteobacteria as monophyletic with all other classes of Proteobacteria. In order to address this issue, we investigated the phylogenetic placement of this class in the bacterial domain using 16S and 23S rRNA genes, as well as 120 single-copy marker proteins. Single- and concatenated-marker trees were created using a data set of 4,170 bacterial representatives, including 98 Epsilonproteobacteria. Phylogenies were inferred under a variety of tree building methods, with sequential jackknifing of outgroup phyla to ensure robustness of phylogenetic affiliations under differing combinations of bacterial genomes. Based on the assessment of nearly 300 phylogenetic tree topologies, we conclude that the continued inclusion of Epsilonproteobacteria within the Proteobacteria is not warranted, and that this group should be reassigned to a novel phylum for which we propose the name Epsilonbacteraeota (phyl. nov.). We further recommend the reclassification of the order Desulfurellales (Deltaproteobacteria) to a novel class within this phylum and a number of subordinate changes to ensure consistency with the genome-based phylogeny. Phylogenomic analysis of 658 genomes belonging to the newly proposed Epsilonbacteraeota suggests that the ancestor of this phylum was an autotrophic, motile, thermophilic chemolithotroph that likely assimilated nitrogen from ammonium taken up from the environment or generated from environmental nitrate and nitrite by employing a variety of functional redox modules. The emergence of chemoorganoheterotrophic lifestyles in several Epsilonbacteraeota families is the result of multiple independent losses of various ancestral chemolithoautotrophic pathways. Our proposed reclassification of this group resolves an important anomaly in bacterial systematics and ensures that the taxonomy of Proteobacteria remains robust, specifically as genome-based taxonomies become more common.