The German wildlife information system: population densities and development of European Hare (<Emphasis Type="Italic">Lepus europaeus</Emphasis> PALLAS) during 2002–2005 in Germany

The German Wildlife Information System, founded in 2001, is a long-term monitoring program documenting occurrence, number, and development of game populations throughout Germany. Population numbers are recorded by standardized counting methods in so-called reference areas. The population densities of the European hare are calculated by spotlight strip censuses in the reference areas each spring and autumn all across Germany. From 2002 to 2005, the censuses were carried out by local hunters in 510 to 676 reference areas each year. During these years, the calculated spring densities increased significantly from 11.0 (2002) to 14.5 hares/km² (2005) nationwide. The overall increase in spring densities was primarily caused by the population rise from spring 2003 to 2004, which correlates with the high net growth rate in 2003. In 2005, the number of counted hares varied between less than 1 and more than 107 hares/km² in spring and between 0 and more than 170 hares/km² in autumn. Because of differing landscapes in Germany, three regions were differentiated. In spring 2005, the average population densities (median) in East Germany (5.4 hares/km²) and Southwest Germany (14.6 hares/km²) were significantly lower than in Northwest Germany (23.9 hares/km²). These regional differences had been similarly distinct in former years.     

Do Aspergillus species produce biofilm?

Evaluation of: Mowat E, Butcher J, Lang S, Williams C, Ramage G: Development of a simple model for studying the effects of antifungal agents on multicellular communities of Aspergillus fumigatus. J. Med. Microbiol. 56, 1205-1212 (2007). Many microorganisms possess the innate ability for adhering to biotic and abiotic objects, and grow as benthic cells. The adhered cells produce an extracellular matrix in which the cells are embedded. The matrix-forming materials together with the cells form a biofilm often hundreds of micrometers in thickness. The biofilm provides the organism with a protective niche from the inhibitory effect of antimicrobial drugs, hence the production of biofilm is considered a survival mechanism. The pathogenic yeast Candida albicans is a well-known biofilm producer. The increasing incidence of antifungal drug resistance of bioprosthetic device infections in particular, and intravascular catheter-related infections of C. albicans is now largely attributed to biofilm formation. An intriguing question is whether the ability to produce biofilm is present in pathogenic filamentous fungi such as Aspergillus species. Mowat et al. describe the development of a simple in vitro model for studying the effects of antifungal drugs on a multicellular community of Aspergillus fumigatus.     

Colorimetric assay for sensitive poly(styrene sulfonate) quantification in a template directed polyelectrolyte-assembling process

Template directed Layer-by-layer (LbL) technology recently moved into the center of scientific attention, particularly as a versatile tool for bioencapsulation purposes. Its major advantages can be found in the striking simplicity of tuning wall properties and the complete control over layer thickness and permeability. Yet, for the most commonly applied pair of polyelectrolytes, poly(allylamine) hydrochloride (PAH) and poly(styrene sulfonate) sodium salt (PSS), the mandatory control of the successful deposition on plane and colloidal surfaces is currently only attainable by means of sophisticated and expensive equipment. Here we describe an alternative quantification method based on a simple colorimetric assay using the Bradford reagent, a cost-effective commercially available dye, and standard laboratory technical devices. The binding of the dye to PSS causes a distinct shift of the absorption maximum from 465 to 680 nm, providing a method for spectral quantification of submicrogram amounts of dissolved PSS during LbL coating with significant accuracy and excellent reproducibility. The method was successfully employed to quantify accurate polyelectrolyte loadings on several particles that have a general importance as LbL templates. Thus, this method can be recommended as standard laboratory technique for control of LbL encapsulation and will considerably broaden the applicability of this promising technology in biotechnology.     

Long-term effects of large-volume liposuction on metabolic risk factors for coronary heart disease

Abdominal obesity is associated with metabolic risk factors for coronary heart disease (CHD). Although we previously found that using liposuction surgery to remove abdominal subcutaneous adipose tissue (SAT) did not result in metabolic benefits, it is possible that postoperative inflammation masked the beneficial effects. Therefore, this study provides a long-term evaluation of a cohort of subjects from our original study. Body composition and metabolic risk factors for CHD, including oral glucose tolerance, insulin resistance, plasma lipid profile, and blood pressure were evaluated in seven obese (39 +/- 2 kg/m(2)) women before and at 10, 27, and 84-208 weeks after large-volume liposuction. Liposuction surgery removed 9.4 +/- 1.8 kg of body fat (16 +/- 2% of total fat mass; 6.1 +/- 1.4 kg decrease in body weight), primarily from abdominal SAT; body composition and weight remained the same from 10 through 84-208 weeks. Metabolic endpoints (oral glucose tolerance, homeostasis model assessment of insulin resistance, blood pressure and plasma triglyceride (TG), high-density lipoprotein (HDL)-cholesterol, and low-density lipoprotein (LDL)-cholesterol concentrations) obtained at 10 through 208 weeks were not different from baseline and did not change over time. These data demonstrate that removal of a large amount of abdominal SAT by using liposuction does not improve CHD metabolic risk factors associated with abdominal obesity, despite a long-term reduction in body fat.     

Primary sex ratio in fertilized chicken eggs (Gallus gallus domesticus) depends on reproductive age and selection

Recent studies of several avian species have shown that the primary sex ratio can change as a result of prevailing conditions, especially in the female bird's first reproductive season. In this study, we sought to determine the primary sex ratio of the first 15 eggs produced in chickens. The study compared chickens which had been commercially selected over many generations for egg-laying performance (Leghorns) with "fancy-bred" chickens selected for feather coloration. These fancy-bred chickens are known to reach reproductive maturity 4 weeks later than Leghorns. A group of precociously matured Leghorn chickens was produced by modification of diet and day length to investigate the effect of age at reproductive maturity on sex ratio. Sex diagnosis was performed on embryos which had died on or before embryonic day 10 by polymerase chain reaction (PCR). Living embryos were allowed to hatch before sex diagnosis. The group of precociously matured White Leghorns reached egg-laying age 3 weeks earlier than normal. In this group, the sex ratio of hatched chicks was in tendency skewed to females. In the White Leghorns maintained under normal conditions for commercial layers, sex ratio was balanced with a tendency to more males only in the first five eggs. In the group of fancy-bred chickens, the primary sex ratio was significantly biased toward more males and dependent on the laying sequence. Our data suggested a sex ratio bias toward males in the very first eggs at onset of reproduction in chickens depending on genetic background.     

Strong Association of a Common Dihydropyrimidine Dehydrogenase Gene Polymorphism with Fluoropyrimidine-Related Toxicity in Cancer Patients

Background

Cancer patients carrying mutations in the dihydropyrimidine dehydrogenase gene (DPYD) have a high risk to experience severe drug-adverse effects following chemotherapy with fluoropyrimidine drugs such as 5-fluorouracil (5-FU) or capecitabine. The pretreatment detection of this impairment of pyrimidine catabolism could prevent serious, potentially lethal side effects. As known deleterious mutations explain only a limited proportion of the drug-adverse events, we systematically searched for additional DPYD variations associated with enhanced drug toxicity.

Methodology/Principal Findings

We performed a whole gene approach covering the entire coding region and compared DPYD genotype frequencies between cancer patients with good (n = 89) and with poor (n = 39) tolerance of a fluoropyrimidine-based chemotherapy regimen. Applying logistic regression analysis and sliding window approaches we identified the strongest association with fluoropyrimidine-related grade III and IV toxicity for the non-synonymous polymorphism c.496A>G (p.Met166Val). We then confirmed our initial results using an independent sample of 53 individuals suffering from drug-adverse-effects. The combined odds ratio calculated for 92 toxicity cases was 4.42 [95% CI 2.12–9.23]; p (trend)<0.001; p (corrected) = 0.001; the attributable risk was 56.9%. Comparing tumor-type matched sets of samples, correlation of c.496A>G with toxicity was particularly present in patients with gastroesophageal and breast cancer, but did not reach significance in patients with colorectal malignancies.

Conclusion

Our results show compelling evidence that, at least in distinct tumor types, a common DPYD polymorphism strongly contributes to the occurrence of fluoropyrimidine-related drug adverse effects. Carriers of this variant could benefit from individual dose adjustment of the fluoropyrimidine drug or alternate therapies.     

Forchlorfenuron alters mammalian septin assembly, organization, and dynamics

Septins are filamentous GTPases that associate with cell membranes and the cytoskeleton and play essential roles in cell division and cellular morphogenesis. Septins are implicated in many human diseases including cancer and neuropathies. Small molecules that reversibly perturb septin organization and function would be valuable tools for dissecting septin functions and could be used for therapeutic treatment of septin-related diseases. Forchlorfenuron (FCF) is a plant cytokinin previously shown to disrupt septin localization in budding yeast. However, it is unknown whether FCF directly targets septins and whether it affects septin organization and functions in mammalian cells. Here, we show that FCF alters septin assembly in vitro without affecting either actin or tubulin polymerization. In live mammalian cells, FCF dampens septin dynamics and induces the assembly of abnormally large septin structures. FCF has a low level of cytotoxicity, and these effects are reversed upon FCF washout. Significantly, FCF treatment induces mitotic and cell migration defects that phenocopy the effects of septin depletion by small interfering RNA. We conclude that FCF is a promising tool to study mammalian septin organization and functions.     

Characterization of SNAREs determines the absence of a typical Golgi apparatus in the ancient eukaryote Giardia lamblia

Giardia is a eukaryotic protozoal parasite with unusual characteristics, such as the absence of a morphologically evident Golgi apparatus. Although both constitutive and regulated pathways for protein secretion are evident in Giardia, little is known about the mechanisms involved in vesicular docking and fusion. In higher eukaryotes, soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) of the vesicle-associated membrane protein and syntaxin families play essential roles in these processes. In this work we identified and characterized genes for 17 SNAREs in Giardia to define the minimal set of subcellular organelles present during growth and encystation, in particular the presence or not of a Golgi apparatus. Expression and localization of all Giardia SNAREs demonstrate their presence in distinct subcellular compartments, which may represent the extent of the endomembrane system in eukaryotes. Remarkably, Giardia SNAREs, homologous to Golgi SNAREs from other organisms, do not allow the detection of a typical Golgi apparatus in either proliferating or differentiating trophozoites. However, some features of the Golgi, such as the packaging and sorting function, seem to be performed by the endoplasmic reticulum and/or the nuclear envelope. Moreover, depletion of individual genes demonstrated that several SNAREs are essential for viability, whereas others are dispensable. Thus, Giardia requires a smaller number of SNAREs compared with other eukaryotes to accomplish all of the vesicle trafficking events that are critical for the growth and differentiation of this important human pathogen.     

EFA6 facilitates the assembly of the tight junction by coordinating an Arf6-dependent and -independent pathway

We have previously reported that EFA6, exchange factor for Arf6, is implicated upon E-cadherin engagement in the process of epithelial cell polarization. We had found that EFA6 acts through stabilization of the apical actin ring onto which the tight junction is anchored. Mutagenesis experiments showed that both the catalytic domain of EFA6 and its C-terminal domain were required for full EFA6 function. Here we address the contribution of the specific substrate of EFA6, the small G protein Arf6. Unexpectedly, depletion of Arf6 by RNA interference or expression of the constitutively active fast-cycling mutant (Arf6T157N) revealed that Arf6 plays an opposing role to EFA6 by destabilizing the apical actin cytoskeleton and the associated tight junction. However, in complementation experiments, when the C-terminal domain of EFA6 is co-expressed with Arf6T157N, it reverts the effects of Arf6T157N expressed alone to faithfully mimic the phenotypes induced by EFA6. In addition, we find that the two signaling pathways downstream of EFA6, i.e. the one originating from the activated Arf6GTP and the other one from the EFA6 C-terminal domain, need to be tightly balanced to promote the proper reorganization of the actin cytoskeleton. Altogether, our results indicate that to regulate the tight junction, EFA6 activates Arf6 through its Sec7 catalytic domain as it modulates this activity through its C-terminal domain.     

Flavonoids redirect PIN-mediated polar auxin fluxes during root gravitropic responses

The rate, polarity, and symmetry of the flow of the plant hormone auxin are determined by the polar cellular localization of PIN-FORMED (PIN) auxin efflux carriers. Flavonoids, a class of secondary plant metabolites, have been suspected to modulate auxin transport and tropic responses. Nevertheless, the identity of specific flavonoid compounds involved and their molecular function and targets in vivo are essentially unknown. Here we show that the root elongation zone of agravitropic pin2/eir1/wav6/agr1 has an altered pattern and amount of flavonol glycosides. Application of nanomolar concentrations of flavonols to pin2 roots is sufficient to partially restore root gravitropism. By employing a quantitative cell biological approach, we demonstrate that flavonoids partially restore the formation of lateral auxin gradients in the absence of PIN2. Chemical complementation by flavonoids correlates with an asymmetric distribution of the PIN1 protein. pin2 complementation probably does not result from inhibition of auxin efflux, as supply of the auxin transport inhibitor N-1-naphthylphthalamic acid failed to restore pin2 gravitropism. We propose that flavonoids promote asymmetric PIN shifts during gravity stimulation, thus redirecting basipetal auxin streams necessary for root bending.