Evaluation of apoptotic cells and immunohistochemical detection of FAS, FAS-L, Bcl-2, Bax, p53 and c-Myc in the skin of patients with chronic venous leg ulcers

In the present study we were interested, if apoptosis plays a role in the surrounding skin of venous ulcers, where microcirculatory disorders were already observed. For this purpose laser Doppler flow and partial oxygen pressure were measured in 17 patients at the ulcer edge, the transitional area of the lower leg and the thigh. Subsequently biopsies were taken from the respective sites and subjected to terminal deoxynucleotidyl transferase labelling (TUNEL) and immunohistochemistry using antibodies to determine the protein expression of Fas, Fas-L, Bax, Bcl-2, p53 and c-Myc. Laser Doppler flow was increased and transcutaneous oxygen partial pressure was decreased, with significant differences at the ulcer edge and the lower leg compared to the thigh. The skin biopsies did not show any differences when labelling for apoptotic cells. Keratinocytes of basal and spinous layer stained with antibodies against Fas, Fas-L and Bax in all probes of the three sites. c-Myc and p53 were negative in all keratinocytes of the skin probes. However, staining with Bcl-2 was significantly decreased at the ulcer edge in comparison to the lower leg and the thigh (p=0.017). Our study revealed that a disturbed microcirculation does not increase the number of apoptotic cells at the ulcer edge in patients with venous disease. The reduced staining pattern with Bcl-2 at the ulcer edge seems not to result in higher susceptibility to apoptosis, but it remains to be proven whether it is involved in epidermal acanthosis.     

Genomic evolution of the placenta using co-option and duplication and divergence

The invention of the placenta facilitated the evolution of mammals. How the placenta evolved from the simple structure observed in birds and reptiles into the complex organ that sustains human life is one of the great mysteries of evolution. By using a timecourse microarray analysis including the entire lifetime of the placenta, we uncover molecular and genomic changes that underlie placentation and find that two distinct evolutionary mechanisms were utilized during placental evolution in mice and human. Ancient genes involved in growth and metabolism were co-opted for use during early embryogenesis, likely enabling the accelerated development of extraembryonic tissues. Recently duplicated genes are utilized at later stages of placentation to meet the metabolic needs of a diverse range of pregnancy physiologies. Together, these mechanisms served to develop the specialized placenta, a novel structure that led to expansion of the eutherian mammal, including humankind.     

Bacteria-induced natural product formation in the fungus Aspergillus nidulans requires Saga/Ada-mediated histone acetylation

Sequence analyses of fungal genomes have revealed that the potential of fungi to produce secondary metabolites is greatly underestimated. In fact, most gene clusters coding for the biosynthesis of antibiotics, toxins, or pigments are silent under standard laboratory conditions. Hence, it is one of the major challenges in microbiology to uncover the mechanisms required for pathway activation. Recently, we discovered that intimate physical interaction of the important model fungus Aspergillus nidulans with the soil-dwelling bacterium Streptomyces rapamycinicus specifically activated silent fungal secondary metabolism genes, resulting in the production of the archetypal polyketide orsellinic acid and its derivatives. Here, we report that the streptomycete triggers modification of fungal histones. Deletion analysis of 36 of 40 acetyltransferases, including histone acetyltransferases (HATs) of A. nidulans, demonstrated that the Saga/Ada complex containing the HAT GcnE and the AdaB protein is required for induction of the orsellinic acid gene cluster by the bacterium. We also showed that Saga/Ada plays a major role for specific induction of other biosynthesis gene clusters, such as sterigmatocystin, terrequinone, and penicillin. Chromatin immunoprecipitation showed that the Saga/Ada-dependent increase of histone 3 acetylation at lysine 9 and 14 occurs during interaction of fungus and bacterium. Furthermore, the production of secondary metabolites in A. nidulans is accompanied by a global increase in H3K14 acetylation. Increased H3K9 acetylation, however, was only found within gene clusters. This report provides previously undescribed evidence of Saga/Ada dependent histone acetylation triggered by prokaryotes.     

Achieving Ultra-Low Friction with Diamond/Metal Systems in Extreme Environments

In the search for achieving ultra-low friction for applications in extreme environments, we evaluate the interfacial processes of diamond/tungsten sliding contacts using an on-line macro-tribometer and a micro-tribometer in an ultra-high vacuum. The coefficient of friction for the tests with the on-line tribometer remained considerably low for unlubricated sliding of tungsten, which correlated well with the relatively low wear rates and low roughness on the wear track throughout the sliding. Ex situ analysis was performed by means of XPS and SEM-FIB in order to better understand the underlying mechanisms of low friction and low-wear sliding. The analysis did not reveal any evidence of tribofilm or transferfilm formation on the counterface, indicating the absence of significant bonding between the diamond and tungsten surfaces, which correlated well with the low-friction values. The minimal adhesive interaction and material transfer can possibly be explained by the low initial roughness values as well as high cohesive bonding energies of the two materials. The appearance of the wear track as well as the relatively higher roughness perpendicular to the sliding indicated that abrasion was the main wear mechanism. In order to elucidate the low friction of this tribocouple, we performed micro-tribological experiments in ultra-high vacuum conditions. The results show that the friction coefficient was reduced significantly in UHV. In addition, subsequently to baking the chamber, the coefficient of friction approached ultra-low values. Based on the results obtained in this study, the diamond/tungsten tribocouple seems promising for tribological interfaces in spacecraft systems, which can improve the durability of the components.     

Identification of soluble APO-1 in supernatants of human B- and T-cell lines and increased serum levels in B- and T-cell leukemias

The cell-surface protein APO-1 is a member of the nerve growth factor (NGF)/tumor necrosis factor (TNF) receptor superfamily. APO-1 mediates apoptosis in susceptible cells upon stimulation with the monoclonal antibody anti-APO-1 or upon binding of its natural ligand. Soluble receptors had previously been identified for most members of the NGF/TNF receptor superfamily. Recently, a soluble form of APO-1 (sAPO- 1) was described. We established a sandwich enzyme-linked immunosorbent assay to detect sAPO-1 in culture supernatants of human cell lines and in human sera. sAPO-1 was found in culture supernatants of different human B- and T-cell lines. Molecular weights of sAPO-1 and membrane APO- 1 were similar. In addition, in comparison to healthy donors, sera from patients with different high- and low-grade malignant B- and T-cell leukemias and lymphomas contained increased levels of sAPO-1. These findings may have implications for the growth of leukemias and the diagnostic monitoring of individual patients.     

Impaired Quality of Life,Work, and Activities Among Adults with <Emphasis Type="Italic">Clostridium difficile</Emphasis> Infection: A Multinational Survey

Background

Evidence of humanistic detriments of Clostridium difficile infection (CDI) remains limited.

Aims

To assess humanistic burden associated with CDI.

Methods

Self-reported National Health and Wellness Survey data between 2013 and 2016 were analyzed for the USA, five European countries, China, and Brazil. Outcome measures included SF-36v2^® for health-related quality of life (HRQoL) and Work Productivity and Activity Impairment questionnaire. Respondents (≥?18 years old) were classified as (1) currently treated doctor-diagnosed CDI (C-CDI), (2) doctor-diagnosed prior CDI (P-CDI), or (3) never experienced CDI (NO-CDI). Regression modeling assessed the association between CDI status and outcomes, adjusting for potential confounders.

Results

Of 352,780 respondents, 299, 2111, and 350,370 met the criteria for C-CDI, P-CDI, and NO-CDI, respectively, with 45% of the total from the USA. C-CDI and P-CDI respondents were older, were less often employed and had more comorbidities than those with NO-CDI. After adjustment for covariates, C-CDI and P-CDI had significantly lower HRQoL relative to NO-CDI for mental (MCS 39, 43 vs. 46) and physical (PCS 39, 41 vs. 46) component summary scores, and health utility (SF-6D 0.58, 0.64 vs. 0.71) (all p?<?0.05), meeting common thresholds for minimally important differences. Those with C-CDI and P-CDI reported missing more work (21, 16 vs. 8%), greater impairment while working (43, 34 vs. 22%), and more activity impairment (61, 49 vs. 34%) than those with NO-CDI (all p?<?0.05), respectively.

Conclusions

CDI is associated with meaningfully worse HRQoL and greater impairment to work and activities compared with NO-CDI. The impairment directly attributable to CDI requires further evaluation.

     

Claudin-3 regulates bile canalicular paracellular barrier and cholesterol gallstone core formation in mice

Background & Aims

Most cholesterol gallstones have a core consisting of inorganic and/or organic calcium salts, although the mechanisms of core formation are poorly understood. We examined whether the paracellular permeability of ions at hepatic tight junctions is involved in the core formation of cholesterol gallstones, with particular interest in the role of phosphate ion, a common food additive and preservative.

Modified Allergens for Immunotherapy

Purpose of Review

During the past few decades, modified allergens have been developed for use in allergen-specific immunotherapy (AIT) with the aim to improve efficacy and reduce adverse effects. This review aims to provide an overview of the different types of modified allergens, their mechanism of action and their potential for improving AIT.

Recent Findings

In-depth research in the field of allergen modifications as well as the advance of recombinant DNA technology have paved the way for improved diagnosis and research on human allergic diseases. A wide range of structurally modified allergens has been generated including allergen peptides, chemically altered allergoids, adjuvant-coupled allergens, and nanoparticle-based allergy vaccines. These modified allergens show promise for the development of AIT regimens with improved safety and long-term efficacy. Certain modifications ensure reduced IgE reactivity and retained T cell reactivity, which facilities induction of immune tolerance to the allergen. To date, multiple clinical trials have been performed using modified allergens. Promising results were obtained for the modified cat, grass and birch pollen, and house dust mite allergens.

Summary

The use of modified allergens holds promise for improving AIT efficacy and safety. There is however a need for larger clinical studies to reliably assess the added benefit for the patient of using modified allergens for AIT.