Antineoplastic activity of the DNA methyltransferase inhibitor 5-aza-2′-deoxycytidine in anaplastic large cell lymphoma

DNA methylation is an epigenetic mechanism establishing long-term gene silencing during development and cell commitment, which is maintained in subsequent cell generations. Aberrant DNA methylation is found at gene promoters in most cancers and can lead to silencing of tumor suppressor genes. The DNA methyltransferase inhibitor 5-aza-2′-deoxycytidine (5-aza-CdR) is able to reactivate genes silenced by DNA methylation and has been shown to be a very potent epigenetic drug in several hematological malignancies. In this report, we demonstrate that 5-aza-CdR exhibits high antineoplastic activity against anaplastic large cell lymphoma (ALCL), a rare CD30 positive non-Hodgkin lymphoma of T-cell origin. Low dose treatment of ALCL cell lines and xenografted tumors causes apoptosis and cell cycle arrest in vitro and in vivo. This is also reflected in genome-wide expression analyses, where genes related to apoptosis and cell death are amongst the most affected targets of 5-aza-CdR. Furthermore, we observed demethylation and re-expression of p16^INK4A after drug administration and senescence associated β-galactosidase activity. Thus, our data provide evidence that 5-aza-CdR is highly efficient against ALCL and warrants further clinical evaluation for future therapeutic use.     

Vertical gradient of climate change and climate tourism conditions in the Black Forest

Due to the public discussion about global and regional warming, the regional climate and the modified climate conditions are analyzed exemplarily for three different regions in the southern Black Forest (southwest Germany). The driving question behind the present study was how can tourism adapt to modified climate conditions and associated changes to the tourism potential in low mountain ranges. The tourism potential is predominately based on the attractiveness of natural resources being climate-sensitive. In this study, regional climate simulations (A1B) are analyzed by using the REMO model. To analyze the climatic tourism potential, the following thermal, physical and aesthetic parameters are considered for the time span 1961–2050: thermal comfort, heat and cold stress, sunshine, humid–warm conditions (sultriness), fog, precipitation, storm, and ski potential (snow cover). Frequency classes of these parameters expressed as a percentage are processed on a monthly scale. The results are presented in form of the Climate-Tourism-Information-Scheme (CTIS). Due to warmer temperatures, winters might shorten while summers might lengthen. The lowland might be more affected by heat and sultriness (e.g., Freiburg due to the effects of urban climate). To adapt to a changing climate and tourism, the awareness of both stakeholders and tourists as well as the adaptive capability are essential.     

Effects of Stimulation of Soluble Guanylate Cyclase on Diabetic Nephropathy in Diabetic eNOS Knockout Mice on Top of Angiotensin II Receptor Blockade

The prevalence of diabetes mellitus and its complications, such as diabetic nephropathy (DN), is rising worldwide and prevention and treatment are therefore becoming increasingly important. Therapy of DN is particularly important for patients who do not adequately respond to angiotensin receptor blocker (ARB) treatment. Novel approaches include the stimulation of soluble guanylate cyclase (sGC) as it is reported to have beneficial effects on cardiac and renal damage. We aimed to investigate the effects of the sGC stimulator riociguat and ARB telmisartan on kidney function and structure in a hypertensive model of diabetic nephropathy.Seventy-six diabetic male eNOS knockout C57BL/6J mice were randomly divided after having received streptozotocin: telmisartan (1 mg/kg/d), riociguat (3 mg/kg/d), riociguat+telmisartan (3+1 mg/kg/d), and vehicle. Fourteen mice were used as non-diabetic controls. Treatment duration was 11 weeks.Glucose concentrations were increased and similar in all diabetic groups. Telmisartan insignificantly reduced blood pressure by 5.9 mmHg compared with diabetic controls (111.2±2.3 mmHg vs. 117.1±2.2 mmHg; p = 0.071). Treatment with riociguat both alone and in combination with telmisartan led to a significant reduction of blood pressure towards diabetic vehicle (105.2±2.5 mmHg and 105.0±3.2 mmHg, respectively, vs. 117.1±2.2 mmHg). Combined treatment also significantly decreased albuminuria compared with diabetic controls (47.3±9.6 µg/24 h vs. 170.8±34.2 µg/24 h; p = 0.002) reaching levels similar to those of non-diabetic controls (34.4±10.6 µg/24 h), whereas the reduction by single treatment with either telmisartan (97.8±26.4 µg/24 h) or riociguat (97.1±15.7 µg/24 h) was not statistically significant. The combination treatment led to a significant (p<0.01) decrease of tissue immunoreactivity of malondialdehyde, as consequence of reduced oxidative stress.In conclusion, stimulation of sGC significantly reduced urinary albumin excretion in diabetic eNOS knockout mice treated already with ARB. Thus, this new drug class on top of standard ARBs administration may offer a new therapeutic approach for patients resistant to ARB treatment.     

Interspecific relationship of ten European orchid species as revealed by enzyme electrophoresis

Ten species of orchid plants belonging to the generaOrchis (7),Dactylorhiza (2), andGymnadenia (1) were analyzed by enzyme electrophoresis. Each species can be identified by a combination of enzyme bands different from those of all other species examined. The electrophoretic data were used for the construction of phenetic and phylogenetic trees with the help of computer programs. The trees were almost identical regardless which method was used. Our results differ considerably from a classification based on morphological evidence. The electrophoretic data indicate that the genusOrchis is not a monophyletic group.     

Effects of Staphylococcus aureus-hemolysin A on calcium signalling in immortalized human airway epithelial cells

Part of the innate defence of bronchial epithelia against bacterial colonization is secretion of salt and water which generally depends on coordinated actions of receptor-mediated cAMP- and calcium signalling. The hypothesis that Staphylococcus aureus-virulence factors interfere with endogenous signals in host cells was tested by measuring agonist-mediated changes in [Ca(2+)](i) in S9 cells upon pre-incubation with bacterial secretory products. S9 cells responded to mAChR-activation with calcium release from intracellular stores and capacitative calcium influx. Treatment of cells with culture supernatants of S. aureus (COL) or with recombinant alpha-hemolysin (Hla) resulted in time- and concentration-dependent changes in [Ca(2+)](i). High concentrations of Hla (2000 ng/ml) resulted in elevations in [Ca(2+)](i) elicited by accelerated calcium influx. A general Hla-mediated permeabilization of S9 cell membranes to small molecules, however, did not occur. Lower concentrations of Hla (200 ng/ml) induced a reduction in [Ca(2+)](i)-levels during the sustained plateau phase of receptor-mediated calcium signalling which was abolished by pre-incubation of cells with carboxyeosin, an inhibitor of the plasma membrane calcium-ATPase. This indicates that low concentrations of Hla change calcium signalling by accelerating pump-driven extrusion of Ca(2+) ions. In vivo, such a mechanism may result in attenuation of calcium-mediated cellular defence functions and facilitation of bacterial adherence to the bronchial epithelium.     

Supplemental feeding reduces natural selection in juvenile red deer

In red deer, variation in winter and spring weather conditions encountered by the mothers during pregnancy and during the first year of life are a main determinant for individual life-history as well as population dynamics. We tested the hypothesis that supplementary feeding which provides constant food supply throughout winter removes the selective pressure of winter harshness on nutrition-mediated phenotypic traits. We analysed cohort variation in body weight in calves in October, before their first winter, and in yearlings in June, after their first winter, in a food-supplemented population in the Eastern Austrian Alps. Over eleven years, cohort body weight varied between years in calves and yearlings. Contrary to studies on non-supplemented red deer populations we found neither short- nor long-term effects of winter weather on body weight. In calves, autumn body weight was negatively related to April–May and June temperatures, suggesting that cool weather during the main growth period retarded plant senescence and thereby prolonged the period of high protein content of summer forage. In yearlings, variation in June body weight, shortly after the end of the feeding period, was lower after a wet April–May, suggesting a negative effect of a prolonged period of supplemental feeding. For both calves and yearlings intra-cohort variation in body weight was higher, inter-cohort variation was lower as compared to non-supplemented red deer, suggesting that in their first year of life supplemented red deer are under reduced natural selection pressure.     

Posttraumatic Stress Disorder and Not Depression Is Associated with Shorter Leukocyte Telomere Length: Findings from 3,000 Participants in the Population-Based KORA F4 Study

Background

A link between severe mental stress and shorter telomere length (TL) has been suggested. We analysed the impact of Posttraumatic Stress Disorder (PTSD) on TL in the general population and postulated a dose-dependent TL association in subjects suffering from partial PTSD compared to full PTSD.

Methods

Data are derived from the population-based KORA F4 study (2006–2008), located in southern Germany including 3,000 individuals (1,449 men and 1,551 women) with valid and complete TL data. Leukocyte TL was measured using a quantitative PCR-based technique. PTSD was assessed in a structured interview and by applying the Posttraumatic Diagnostic Scale (PDS) and the Impact of Event Scale (IES). A total of 262 (8.7%) subjects qualified for having partial PTSD and 51 (1.7%) for full PTSD. To assess the association of PTSD with the average TL, linear regression analyses with adjustments for potential confounding factors were performed.

Results

The multiple model revealed a significant association between partial PTSD and TL (beta = −0.051, p = 0.009) as well as between full PTSD and shorter TL (beta = −0.103, p = 0.014) indicating shorter TL on average for partial and full PTSD. An additional adjustment for depression and depressed mood/exhaustion gave comparable beta estimations.

Conclusions

Participants with partial and full PTSD had significantly shorter leukocyte TL than participants without PTSD. The dose-dependent variation in TL of subjects with partial and full PTSD exceeded the chronological age effect, and was equivalent to an estimated 5 years in partial and 10 years in full PTSD of premature aging.