Development of novel microsatellite markers to identify the different invasive lineages in the Corbicula complex and to assess androgenesis

Reliable markers are needed to identify the lineages in the invasive clam genus Corbicula. Previous studies have demonstrated that mitochondrial (mt) DNA poorly resolves Corbicula phylogeny, owing to its androgenetic reproductive mode. Moreover, hybridization and mitochondrial/nuclear mismatches occur. We developed the first eleven polymorphic markers to detect these phenomena and to investigate the nuclear identity of Corbicula populations. These microsatellite loci revealed three main lineages in Western Europe. One locus allowed rapid discrimination of these three lineages on agarose gel, saving time and money. Moreover, the eleven markers were successfully cross-amplified in the invasive Corbicula lineages found in North America.     

At the core of survival: autophagy delays the onset of both apoptotic and necrotic cell death in a model of ischemic cell injury

Ischemic cell injury leads to cell death. Three main morphologies have been described: apoptosis, cell death with autophagy and necrosis. Their inherent dynamic nature, a point of no return (PONR) and molecular overlap have been stressed. The relationship between a defined cell death type and the severity of injury remains unclear. The functional role of autophagy and its effects on cell death onset is largely unknown. In this study we report a differential induction of cell death, which is dependent on the severity and duration of an ischemic insult. We show that mild ischemia leads to the induction of autophagy and apoptosis, while moderate or severe ischemia induces both apoptotic and necrotic cell death without increased autophagy. The autophagic response during mild injury was associated with an ATP surge. Real-time imaging and Fluorescence Resonance Energy Transfer (FRET) revealed that increased autophagy delays the PONR of both apoptosis and necrosis significantly. Blocking autophagy shifted PONR to an earlier point in time. Our results suggest that autophagic activity directly alters intracellular metabolic parameters, responsible for maintaining mitochondrial membrane potential and cellular membrane integrity. A similar treatment also improved functional recovery in the perfused rat heart. Taken together, we demonstrate a novel finding: autophagy is implicated only in mild injury and positions the PONR in cell death.     

Determining biological tissue turnover using stable isotopes: the reaction progress variable

The reaction progress variable is applied to stable isotope turnover of biological tissues. This approach has the advantage of readily determining whether more than one isotope turnover pool is present; in addition, the normalization process inherent to the model means that multiple experiments can be considered together although the initial and final isotope compositions are different. Consideration of multiple isotope turnover pools allows calculation of diet histories of animals using a time sequence of isotope measurements along with isotope turnover pools. The delayed release of blood cells from bone marrow during a diet turnover experiment can be quantified using this approach. Turnover pools can also be corrected for increasing mass during an experiment, such as when the animals are actively growing. Previous growth models have been for exponential growth; the approach here can be used for several different growth models. Electronic Supplementary Material The online version of this article () contains supplementary material, which is available to authorized users.     

Effect of ACTH (tetracosactide) on steroid hormone levels in the mare. Part B: effect in ovariectomized mares (including estrous behavior)

The mare is the only non-primate species known to display estrous signs after ovariectomy and adrenal hormones have been implicated as a possible cause. Moreover, in several species, estradiol seems to have a stimulatory effect on the hypothalamic-pituitary-adrenal axis. The aim of the present study was to compare the effect of ACTH (tetracosactide) on pertinent hormones [cortisol, progesterone, androstenedione, testosterone (intact and ovariectomized mares) and estradiol (ovariectomized mares only)] in intact mares in estrus with the same mares after ovariectomy (n=5). Blood samples were collected hourly from 12:00 until 14:00 h the following day (half-hourly between 14:00 and 17:00 h) on two occasions, with saline or ACTH treatment at 14:00 h (saline treatment day or ACTH treatment day). The mares, both when intact and after ovariectomy, showed a significant increase in all measured hormones, except estradiol (not measured in intact mares), after ACTH treatment, lasting at least 3h post-treatment (P<0.001). On the saline treatment day, cortisol levels in ovariectomized mares were lower than in intact mares in the evening (18:00-23:00 h), but higher at night (24:00-05:00 h). No differences in cortisol response between mares, when intact and after ovariectomy, were found after ACTH treatment (P=0.3). Androstenedione levels were lower (P<0.001) and increased less after ACTH treatment in ovariectomized mares, as compared to when intact (P<0.05). Progesterone concentrations were lower in the ovariectomized mares at night (24:00-05:00 h) on the saline treatment day and at all times on the ACTH treatment day (P<0.05). Testosterone concentrations were lower in ovariectomized mares on both treatment days, as compared to when intact (P<0.001). It was concluded that ovariectomy affected basal cortisol pattern. Ovarian androstenedione and testosterone contributed to the basal circulating levels and, in the case of androstenedione, was stimulated by ACTH. Endogenous estradiol did not act stimulatory on adrenal gland hormone production in the mare.     

Comparison of enterotoxigenic Escherichia coli isolated from surface water and diarrhoeal stool samples in Bangladesh

Enterotoxigenic Escherichia coli (ETEC) is a common cause of bacterial infection leading to acute watery diarrhea in infants and young children. Although the prevalence of ETEC is high in Bangladesh and infections can be spread through food and contaminated water, limited information is available about ETEC in the surface water. We carried out studies to isolate ETEC from surface water samples from ponds, rivers, and a lake from a site close to field areas known to have a high incidence of diarrhea in Dhaka, Bangladesh, and Matlab, Bangladesh. ETEC strains isolated from the water sources were compared with ETEC strains isolated from patients with diarrhea at two hospitals in these areas. ETEC were isolated from 30% (45 of 150) of the samples from the surface water sources and 19% (518 of 2700) of the clinical specimens. One hundred ETEC strains isolated from patients with similar phenotypes as the environmental strains were compared for phenotypic and genotypic properties. The most common O serogroups on ETEC were O6, O25, O78, O115, and O126 in both types of strains. Pulsed-field gel electrophoresis analyses of the ETEC strains showed that multiple clones of ETEC were present within each colonization factor type and that some clones detected in the environment were also isolated from the stools of patients. The strains showed multiple and similar antibiotic resistance patterns. This study shows that ETEC is prevalent in surface water sources in Bangladesh suggesting a possible reason for the endemicity of this pathogen in Bangladesh.     

Surface properties of bacteria sensitive and resistant to the class IIa carnobacteriocin Cbn BM1

Aims: Class IIa bacteriocins are small antimicrobial peptides synthesized by lactic acid bacteria. The proposed mechanisms of action for class IIa bacteriocins suggest that the physicochemical properties of the target bacterial surface govern the bacteriocin antimicrobial activity. The aim of this study is to decipher the relationship between both sensitivity and resistance to a class IIa bacteriocin, carnobacteriocin BM1 and physicochemical surface properties of bacteria. Methods and Results: The study was performed on 18 strains by a microbial adhesion to solvents process and with electrophoretic mobility measurements considering bacteria as soft particles. A large variation in bacterial surface properties is observed among the bacterial populations. Electro‐hydrodynamic parameters values appear to be more homogeneous for sensitive strains than for the resistant ones, which can exhibit more extreme values. Conclusions: Physicochemical surface properties of 18 strains determined show large variations between the strains. However, no direct link between these surface properties and the resistant/sensitive phenotypes of the strains can be stated. Significance and Impact of the Study: The surface physicochemical properties tested have a low predictive power to discriminate sensitive or resistant strains when determined at the bacterial population scale.     

Concentration- and stage-specific effects of nitrite on colon cancer cell lines

Colorectal cancer (CRC) is the second leading cause of cancer-related death in the United States. Nitrite in cured meats is thought to contribute to increased incidence of colon cancer. We sought to determine the effect of nitrite on human colon cancer cell lines at different stages. Our results indicate nitrite has no effect on proliferation of stage 1 SW116 colon cancer cells, while nitrite inhibits proliferation of stage 2 SW480 at 10 nM–100 μM and inhibits stage 3 HCT15 proliferation at 100 nM–1 μM, but promotes a significant increase in proliferation on stage 4 COLO205 cells at 100 μM. Furthermore, nitrite inhibited invasion into Matrigel® of stage 3 SW480 colon cancer cells in a concentration-dependent manner. However, it significantly promotes the invasion of stage 4 cells at 100 μM. Our FACS data demonstrated that nitrite decreased cell cycle progression in SW480 and HCT15 with arrested G2/M transition and delayed G1 phase entry in a concentration-dependent manner. However, 100 μM nitrite promoted cell cycle progression in COLO205 cells with increased S-phase entry. Taken together, our data indicate nitrite inhibits cancer cell progression at low concentrations and early stage but promotes cancer cell progression at higher concentrations in cells representing stage 4 colon carcinomas.     

Ischaemic preconditioning and TNF-alpha-mediated preconditioning is associated with a differential cPLA2 translocation pattern in early ischaemia

Both the cytokine tumour necrosis factor-alpha (TNF-alpha) and the enzyme cytosolic phospholipase A2 (cPLA2) have been implicated in ischaemic injury. Apart from the induction of apoptosis, TNF-alpha also mediates cytoprotection when present in low concentrations. However, the relationship between TNF-alpha and cPLA2 activities during cytoprotection is poorly understood. Therefore, we examined the role of cPLA2 in TNF-alpha-mediated (TNF-PC) and ischaemic preconditioning (IPC) in tolerance to ischaemia (SI) in C2C12 myotubes. Significant decreases in cPLA2 phosphorylation in SI compared with the preconditioned groups were observed. This was also mirrored by the p38 mitogen activated protein kinase (MAPK) phosphorylation pattern. These results correlated with fluorescence- and three-dimensional imaging, demonstrating increased translocation of phospho-cPLA2 to the nuclear region in SI compared to TNF-PC and IPC. These data suggest a p38 driven cPLA2 translocation pattern, with a possible role for cPLA2 in deciding cell fate.     

Lycopus europaeus (Gypsywort): effects on the thyroidal parameters and symptoms associated with thyroid function.

The aim of the prospective two-armed open study was to examine the effect of Lycopi europaei herba on thyroid function and on associated symptoms during a 3-month follow-up phase. The study population consisted of patients with a basal TSH<1.0 mU/l and hyperthyroidism-associated symptoms. For the first time, the T3/T4 excretion in 24h urine was measured as a primary objective parameter. As secondary parameters, further hormones, the general condition and the symptoms associated with hyperthyroidism were registered. The urinary T4 excretion was significantly increased in Lycopus europaeus-treated patients (p=0.032). It is supposed that renal mechanisms cause the increased T4 excretion either by a modification within the glomeruli or by impaired reabsorption. Symptoms being specific to the thyroid gland were diminished, as e.g. the increased heart rate in the morning. The Lycopus europaeus preparation showed a good tolerance. These findings confirm positive effects of Lycopus europaeus in slight forms of hyperthyroidism.     

Effect of alternative treatments on seed-borne Didymella lycopersici in tomato

Aims:  To quantify the phytotoxicity and effect of alternative seed treatments based on acidified nitrite and elicitors of plant resistance (Tillekur and Chitosan) against seed-borne inocula of Didymella lycopersici .
Methods and Results:  Treatments tested were: nitrite [sodium nitrite in citric acid buffer (pH 2)] at 30, 100 and 300 mmol l⁻¹ and three exposure times (10, 20 and 30 min); Tillekur (in water) at 12·5, 25, 50, 100 and 200 mg ml⁻¹; Chitosan (in 0·05% acetic acid) at 2·5, 5, 10 and 50 mg ml⁻¹. Efficacy of treatments was determined in growth chamber experiments. Nitrite at 300 mmol l⁻¹ was completely effective, as was the fungicide, at controlling disease when applied for less than 20 min. Tillekur was as effective as the fungicide postemergence, but proved to be phytotoxic pre-emergence. Chitosan was significantly less effective than the other treatments.
Conclusions:  The high efficacy and low cost of acidified nitrite indicates that it is a suitable alternative to fungicides.
Significance and Impact of the Study:  There is currently a lack of effective seed treatments that can be used in organic and low-input crops. Treatments identified in this study can be considered as an effective alternative to chemical control against seed-borne fungal pathogens.