The neuroprotective agent, valproic acid, regulates the mitogen-activated protein kinase pathway through modulation of protein kinase A signalling in Dictyostelium discoideum

Activation of the mitogen-activated protein kinase (MAPK) cascade gives rise to a neuroprotective effect in a variety of cell types. The bipolar disorder treatment, valproic acid (VPA), increases the activity of this pathway by modulating extracellular signal-regulated kinase 2 (ERK2) phosphorylation through an unknown mechanism. To investigate the molecular basis of this effect, we have used the biomedical model system Dictyostelium discoideum to dissect this signalling pathway. We find that, similar to mammalian systems, VPA causes a transient increase in the activation of the MAPK signalling pathway, as shown by ERK2 phosphorylation. We show that the MAP kinase and phosphatase, protein kinase A (PKA) and glycogen synthase kinase signalling pathways all function in controlling the levels of phospho-ERK2 (pERK2). We find that VPA induces elevated pERK2 levels through attenuation of the PKA signalling pathway. Interestingly, pERK2 levels are also controlled by another bipolar disorder drug, lithium, providing a common effect of these two drugs. This work therefore suggests a conserved pathway in eukaryotes that is targeted by neuroprotective and bipolar disorder drugs and allows us to propose a model for this neuroprotective effect.     

Diagnostic value of cytokeratin 7 and parvalbumin in differentiating chromophobe renal cell carcinoma from renal oncocytoma

OBJECTIVE: To investigate the diagnostic value of cytokeratin 7 (CK7) and parvalbumin at mRNA and protein levels. STUDY DESIGN: CK7 and parvalbumin mRNA expression levels in 23 oncocytomas and 32 chromophobe renal cell carcinomas (RCCs) were examined using gene expression microarrays. Immunohistochemistry was performed using monoclonal antibodies specific for CK7 or parvalbumin in 41 chromophobe RCCs and 55 oncocytomas. RESULTS: CK7 mRNA was overexpressed in 18 of 32 chromophobe RCCs but only 3 of 23 oncocytomas. Parvalbumin mRNA was overexpressed in 15 of 32 chromophobe RCCs and only 4 of 23 oncocytomas. In contrast, CK7 mRNA underexpression was noted in 13 of 23 oncocytomas and only 6 of 32 chromophobe RCCs, while parvalbumin underexpression was seen in 14 of 23 oncocytomas but only 6 of 32 chromophobe RCCs. By immunohistochemistry, 27 of 41 (66%) chromophobe RCCs expressed CK7 diffusely compared to only 3 of 55 (5%) oncocytomas. Diffuse parvalbumin expression was seen in all 41 of 41 (100%) chromophobe RCCs and only in 26 of 55 (47%) oncocytomas. CONCLUSION: Both mRNA and protein expression levels of CK7 appear significantly higher in chromophobe RCC compared to oncocytoma (p < 0.001). Parvalbumin expression is less specific but often displays a patchy pattern in oncocytomas. Our study provides further evidence that CK7 and parvalbumin immunostains may be useful in differentiating oncocytoma from chromophobe RCC in problematic cases. Negative or patchy staining (< 50% cells) for CK7 and/or parvalbumin strongly favors the diagnosis of oncocytoma.     

Immunoexpression of aquaporins 1, 2, 3 and 4 in kidney of yak (Bos grunniens) on the Qinghai-Tibetan Plateau

Aquaporins (AQP) 1, 2, 3 and 4 belong to the aquaporin water channel family and play an important role in urine concentration by reabsorption of water from renal tubule fluid. Renal AQPs have not been reported in the yak (Bos grunniens), which resides in the Qinghai Tibetan Plateau. We investigated AQPs 1?4 expressions in the kidneys of Yak using immunohistochemical staining. AQP1 was expressed mainly in the basolateral and apical membranes of the proximal tubules and descending thin limb of the loop of Henle. AQP2 was detected in the apical plasma membranes of collecting ducts and distal convoluted tubules. AQP3 was located in the proximal tubule, distal tubule and collecting ducts. AQP4 was located in the collecting ducts, distal straight tubule, glomerular capillaries and peritubular capillaries. The expression pattern of AQPs 1?4 in kidney of yak was different from other species, which possibly is related to kidney function in a high altitude environment.     

An evaluation of five preservation techniques and conventional freezing temperatures of -20 degrees C and -85 degrees C for long-term preservation of Campylobacter jejuni

AIMS: This study aimed to identify a simple, inexpensive preservation technique that will allow a quick and reliable recovery of Campylobacter jejuni following long-term periods of preservation. METHODS AND RESULTS: Preservation techniques include (i) Cryobank microbial preservation system using hypertonic 'cryopreservative solution' and glass beads, (ii) Cryobank microbial preservation system using defibrinated lysed horse blood and glass beads, (iii) FBP medium, (iv) 15% glycerol/85% nutrient broth no. 2 culture, and (v) 50% glycerol/50% nutrient broth no. 2 culture. Each preservation technique was evaluated over a 1-year period at conventional freezing temperatures of -20 degrees C and -85 degrees C. Replacement of 'cryopreservative fluid' in commercially prepared vials of glass beads with lysed horse blood increased the duration of preservation of Camp. jejuni by up to 6 months. CONCLUSIONS: FBP medium proved the most successful preservation technique with 100 and 80% recovery after 1 year at -85 degrees C and -20 degrees C, respectively. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrated a simple inexpensive preservation method for long-term storage of Camp. jejuni.     

Kinetics of the Anti-oxidant Response to Salinity in the Halophyte Cakile maritima

The effects of NaCl stress on the activity of anti-oxidant enzymes (superoxide dismutase, catalase (CAT),peroxidase (POD),ascorbate peroxidase (APX), monodehydroascorbate reductase, dehydroascorbate reductase (DHAR), and glutathionereductase (GR)), anti-oxidant molecules (ascorbate and glutathione), and parameters of oxidative stress (malondialdehyde(MDA), electrolyte leakage, and H_2O_2 concentrations) were investigated in Cakile maritima, a halophyte frequent along theTunisian seashore. Seedlings were grown in the presence of salt (100, 200, and 400 mmol/L NaCI). Plants were harvestedperiodically over 20 days. Growth was maximal in the presence of 0-100 mmol/L NaCl. At 400 mmol/L NaCl, growthdecreased significantly. The salt tolerance of C. maritima, at moderate salinities, was associated with the lowest values ofthe parameters indicative of oxidative stress, namely the highest activities of POD, CAT, APX, DHAR, and GR and high tissuecontent of ascorbate and glutathione. However, prolonged exposure to high salinity resulted in a decrease in anti-oxidantactivities and high MDA content, electrolyte leakage, and H_2O_2 concentrations. These results suggest that anti-oxidantsystems participate in the tolerance of C. maritima to moderate salinities.     

Starch-based microspheres for sustained-release of curcumin: Preparation and cytotoxic effect on tumor cells

Curcumin (CUR) has been proved to be highly cytotoxic against different tumor cell lines. However, its poor solubility in aqueous medium and fast degradation in physiological pH are the common drawbacks preventing its efficient practical use. Herein, we report the development of original microspheres based on the biopolymer starch crosslinked with N,N-methylenebisacrylamide (MBA) to be applied as an efficient delivering system for CUR. The starch-based microspheres showed high loading efficiency even in loading solution with different CUR concentrations. In vitro release assays data showed that the CUR release is governed by anomalous transport (n = 0.73) and it is pH-dependent. Cytotoxicity assays showed that starch microspheres could improve the cytotoxicity of CUR toward Caco-2 and HCT-116 tumor cell lines up to 40 times than that found for pure CUR. This behavior was attributed to the slowly and sustained release of CUR from the microspheres.     

Reconstructing Indian-Australian phylogenetic link

Background  

An early dispersal of biologically and behaviorally modern humans from their African origins to Australia, by at least 45 thousand years via southern Asia has been suggested by studies based on morphology, archaeology and genetics. However, mtDNA lineages sampled so far from south Asia, eastern Asia and Australasia show non-overlapping distributions of haplogroups within pan Eurasian M and N macrohaplogroups. Likewise, support from the archaeology is still ambiguous.     

An overview of foodborne pathogen detection: In the perspective of biosensors

Food safety is a global health goal and the foodborne diseases take a major crisis on health. Therefore, detection of microbial pathogens in food is the solution to the prevention and recognition of problems related to health and safety. For this reason, a comprehensive literature survey has been carried out aiming to give an overview in the field of foodborne pathogen detection. Conventional and standard bacterial detection methods such as culture and colony counting methods, immunology-based methods and polymerase chain reaction based methods, may take up to several hours or even a few days to yield an answer. Obviously this is inadequate, and recently many researchers are focusing towards the progress of rapid methods. Although new technologies like biosensors show potential approaches, further research and development is essential before biosensors become a real and reliable choice. New bio-molecular techniques for food pathogen detection are being developed to improve the biosensor characteristics such as sensitivity and selectivity, also which is rapid, reliable, effective and suitable for in situ analysis. This paper not only offers an overview in the area of microbial pathogen detection but it also describes the conventional methods, analytical techniques and recent developments in food pathogen detection, identification and quantification, with an emphasis on biosensors.