1α,25-dihydroxyvitamin D(3) mechanism of action: modulation of L-type calcium channels leading to calcium uptake and intermediate filament phosphorylation in cerebral cortex of young rats

The involvement of calcium-mediated signaling pathways in the mechanism of action of 1α,25-dihydroxyvitamin D(3) (1,25D) is currently demonstrated. In this study we found that 1,25D induces nongenomic effects mediated by membrane vitamin D receptor (VDRm) by modulating intermediate filament (IF) phosphorylation and calcium uptake through L-type voltage-dependent calcium channels (L-VDCC) in cerebral cortex of 10 day-old rats. Results showed that the mechanism of action of 1,25D involves intra- and extracellular calcium levels, as well as the modulation of chloride and potassium channels. The effects of L-VDCCs on membrane voltage occur over a broad potential range and could involve depolarizing or hyperpolarizing coupling modes, supporting a cross-talk among Ca(2+) uptake and potassium and chloride channels. Also, the Na(+)/K(+)-ATPase inactivation by ouabain mimicked the 1,25D action on (45)Ca(2+) uptake. The Na(+)/K(+)-ATPase inhibition observed herein might lead to intracellular Na(+) accumulation with subsequent L-VDCC opening and consequently increased (45)Ca(2+) (calcium, isotope of mass 45) uptake. Moreover, the 1,25D effect is dependent on the activation of the following protein kinases: cAMP-dependent protein kinase (PKA), Ca(2+)/calmodulin-dependent protein kinase (PKCaMII), phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase p38 (p38(MAPK)). The modulation of calcium entry into neural cells by the 1,25D we are highlighting, might take a role in the regulation of a plethora of intracellular processes. Considering that vitamin D deficiency can lead to brain illness, 1,25D may be a possible candidate to be used, at least as an adjuvant, in the pharmacological therapy of neuropathological conditions.     

Detection of the first incidence of Akodon paranaensis naturally infected with the Jabora virus strain (Hantavirus) in Brazil

We characterised hantaviruses circulating in different Akodon rodent species collected in midwestern Santa Catarina (SC), southern Brazil, where the Jabora hantavirus (JABV) strain was first identified in Akodon montensis. Genetic and phylogenetic analyses based on a partial S segment indicated that, in SC, Akodon paranaensis and A. montensis carried the same type of hantavirus. Additionally, we conducted the first genomic characterisation of the complete S segment from the Brazilian JABV strain. This is the first report of A. paranaensis infected with the JABV.     

Quercetin as a shuttle for labile iron

The antioxidant activity of flavonoids may involve their ability to complex body iron in non-redox-active forms. In this study, it was found that the catechol flavonoids rutin and quercetin are able to suppress redox-active labile plasma iron (LPI) in both buffered solution and in iron-overloaded sera. Both flavonoids are effective in loading the metal into the iron-transport protein transferrin. Iron derivatives of quercetin and rutin are able to permeate cell membranes, however, only free quercetin is able to gain access to the cytosol and decrease intracellular labile iron pools. These results suggest that the antioxidant activity of quercetin may be dependent on its ability to shuttle labile iron from cell compartments followed by its transfer to transferrin.     

Trends in prevalence, awareness, treatment, and control of hypertension, and the risk of mortality among middle-aged Lithuanian urban population in 1983-2009

ABSTRACT: BACKGROUND: Arterial hypertension (AH) is a main risk factor for the risk from cardiovascular (CVD) and stroke mortality. Only few data was published on prevalence, awareness and management of AH in Lithuania. Development of objective approaches to the treatment and control of AH reduces the risk of mortality. The aim of this study was to evaluate time trends, the prevalence, awareness, treatment and control of AH and risk of mortality among Lithuanian urban population aged 45--64 years during the period of 1983--2009. METHODS: Time trends of AH and risk of mortality were examined in three MONICA health surveys in 1983, 1986, 1992, and in one health survey according to MONICA protocol in 2002 included randomly recruited of 2,218 men and 2,491 women. AH was defined as systolic blood pressure (BP) [GREATER-THAN OR EQUAL TO]140 mmHg and/or diastolic BP of [GREATER-THAN OR EQUAL TO]90 mmHg or current use of antihypertensive medication. The main outcome measures were all-cause mortality, mortality from CVD, coronary heart disease (CHD) and stroke. The mean duration of follow-up was 11.8 [PLUS-MINUS SIGN] 9.2 years. All survey periods were age standardized to the year 2006 of Kaunas population. The estimates of hazard ratio and 95% confidence interval were based on the multivariate Cox proportional hazards regression. RESULTS: In men during 1983--2002 period hypertension prevalence was 52.1--58.7% and did not significantly change whereas in women decreased from 61.0 to 51.0%. There was a significant increase in hypertension awareness among hypertensive men and women (45.0 to 64.4% and 47.7 to 72.3%, respectively) and in treated hypertensives (55.4 to 68.3% in men and 65.6 to 86.2% in women). Adjusted Cox proportional hazard regression analyses revealed a strong dose--response association between blood-pressure level and all-cause, CVD, CHD and stroke-mortality risk in both men and women groups. CONCLUSION: In Lithuanian urban population the prevalence of hypertension remains high. Despite positive changes in hypertension awareness and treatment, hypertension control remains poor. A strong dose--response association between the level of BP and all-cause, CVD, CHD and stroke mortality risk was indicated.     

Proteomic profiling of the rat hypothalamus

Background

The hypothalamus plays a pivotal role in numerous mechanisms highly relevant to the maintenance of body homeostasis, such as the control of food intake and energy expenditure. Impairment of these mechanisms has been associated with the metabolic disturbances involved in the pathogenesis of obesity. Since rodent species constitute important models for metabolism studies and the rat hypothalamus is poorly characterized by proteomic strategies, we performed experiments aimed at constructing a two-dimensional gel electrophoresis (2-DE) profile of rat hypothalamus proteins.

Results

As a first step, we established the best conditions for tissue collection and protein extraction, quantification and separation. The extraction buffer composition selected for proteome characterization of rat hypothalamus was urea 7?M, thiourea 2?M, CHAPS 4%, Triton X-100 0.5%, followed by a precipitation step with chloroform/methanol. Two-dimensional (2-D) gels of hypothalamic extracts from four-month-old rats were analyzed; the protein spots were digested and identified by using tandem mass spectrometry and database query using the protein search engine MASCOT. Eighty-six hypothalamic proteins were identified, the majority of which were classified as participating in metabolic processes, consistent with the finding of a large number of proteins with catalytic activity. Genes encoding proteins identified in this study have been related to obesity development.

Conclusion

The present results indicate that the 2-DE technique will be useful for nutritional studies focusing on hypothalamic proteins. The data presented herein will serve as a reference database for studies testing the effects of dietary manipulations on hypothalamic proteome. We trust that these experiments will lead to important knowledge on protein targets of nutritional variables potentially able to affect the complex central nervous system control of energy homeostasis.     

Essential-oil diversity of three Calamintha species from Greece

The aim of the present study was to contribute to the knowledge of the essential-oil composition of the Calamintha officinalis-nepeta complex in Greece and to clarify the main patterns of its variation. The oils obtained from 22 wild-growing populations of C. glandulosa, C. nepeta, and C. menthifolia were studied. They could be classified into two different chemotypes, which correspond to the main biosynthetic routes of the C(3)-oxygenated p-menthane compounds. Chemotype I includes oils rich in trans-piperitone oxide, cis-piperitone oxide, and piperitenone oxide, while Chemotype II comprises oils rich in pulegone and menthone or menthone and isomenthone. Within both chemotypes, quantitative fluctuations of the main components were observed. Comparison with published data showed that the presence of Chemotype II has not been observed before in C. menthifolia, while Chemotype I has been reported in C. nepeta plants from Greece for the first time.     

Essential Oils of Micromeria dalmatica Benth., a Balkan Endemic Species of Section Pseudomelissa

The essential oils of 13 Greek populations of Micromeria dalmatica, a Balkan endemic species and member of the section Pseudomelissa, were examined for the first time. Among the studied populations, two main oil types could be distinguished. Type I was found to be rich in β‐pinene, limonene, and germacrene D (accounting for 55.6–70.2% of the total oil), and Type II was characterized by the preponderance of p‐menthane compounds (accounting for 64.2–89.9% of the oil). The latter oil type could be further divided into two subtypes, one comprising oils with predominance of piperitenone and piperitenone oxide and another composed of oils containing high proportions of pulegone, menthone, and isomenthone. The abundance of p‐menthane compounds is a common feature of the oils of all members of the section Pseudomelissa studied to date. However, the existence of oils of Type I has not been previously reported for M. dalmatica, neither for other members of the section Pseudomelissa.     

Molecular cloning and analysis of apple HcrVf resistance gene paralogs in a collection of related Malus species

Few complete genes belonging to the receptor-like protein class of plant resistance (R) genes (called HcrVf genes in Malus) have been cloned from apple cultivars. To date, the HcrVf2 gene from the Rvi6 locus of ??Florina??, a derivative of Malus?×?floribunda 821, is the only cloned apple scab R gene with a proven function. The breakdown of the Rvi6 scab resistance in several apple growing regions has forced the search for new resistance sources for R gene pyramiding through traditional and biotechnological breeding. Marker-assisted breeding is aimed at the selection of the desired R gene combinations but might be extended for monitoring putative risks of resistance breakdown in potential scab R gene donors. Here we report on a marker-based screen of Rvi6 homologues supplemented by a polymerase chain reaction (PCR)-based full-length cloning of HcrVf paralogs. Known Rvi6 markers were analysed in a sub-set of accessions selected by a preceding SSR-based genetic relationship analysis from a large Malus species germplasm collection, which has been evaluated for scab resistance in an unsprayed orchard for a period of 3?years. The Rvi6 breakdown in several M. × floribunda accessions was confirmed, and several other Malus species putatively related to M. × floribunda were also infected by scab. The selected sub-cluster consisting of 40 accessions, including all M. × floribunda, two Malus?×?micromalus and two Malus baccata accessions, was screened for Rvi6 markers CH-Vf1-SSR and AL07-SCAR and for the presence of HcrVf2 by using gene-specific primers. The two M. × micromalus accessions, which proved to be identical genotypes, were found to be closely related to M. × floribunda. They also displayed the Rvi6 markers and could be infected by race (5,6,7) scab isolate Vi158. To verify the assumed existence of the HcrVf2 gene in M. × micromalus, a PCR-based cloning method was used to clone full-length HcrVf paralogs from this species and additionally from a scab-susceptible M. baccata genotype also showing the Rvi6 markers. The M. × micromalus gene MAM31 was identified as an identical copy of HcrVf2. Another HcrVf-like gene (MAM6) newly cloned from M. × micromalus showed 95 % similarity to HcrVf2. MAM6 was chosen for the development of a gene-specific PCR marker, which was analysed in the selected apple group and additionally mapped in an apple progeny derived from a cross with M. × micromalus. The cloning method described in this paper might be used in future to mine for more HcrVf gene variants to develop highly specific markers for R gene deployment in traditional breeding and to use cloned genes for gene transfer and functional studies.     

Intensification of high cell-density cultivations of rE. coli for production of S. pneumoniae antigenic surface protein, PspA3, using model-based adaptive control

This work proposes an innovative methodology to control high density fed-batch cultures of E. coli, based on measurements of the concentration of dissolved oxygen and on estimations of the cellular specific growth rate (μ), of the yield of biomass/limiting substrate (Y (xs)) and of the maintenance coefficient (m). The underlying idea is to allow cells to grow according to their metabolic capacity, without the constraints inherent to pre-set growth rates. Cellular concentration was assessed on-line through a capacitance probe. Three configurations of the control system were compared: (1) pre-set value for the three control parameters; (2) continuously updating μ; (3) updating μ, Y (xs) and m. Implementation of an efficient noise filter for the signal of the capacitance probe was essential for a good performance of the control system. The third control strategy, within the framework of an adaptive model-based control, led to the best results, with biomass productivity reaching 9.2?g(DCW)/L/h.     

Folic acid-decorated nanocomposites prepared by a simple solvent displacement method

A biodegradable nanocarrier system based on PLGA applicable for FR targeting is described. PEI-based conjugates with covalently coupled folic acid are synthesized, characterized with regard to their composition and used for DNA complexation. The preparation of composites is performed by a solvent displacement technique, assuming an electrostatic interaction of PEI-based polyplexes with PLGA. The synthesis of a folic acid-PEG3kDa-PEI25kDa conjugate is achieved. Blending of PLGA with polyplexes results in spherical nanoparticles with sizes ≤ 250 nm. Incorporation of polyplexes and the localization of folic acid on the particle surface, performed by antibody binding, is confirmed. The method is suitable for the preparation of nanosized, folic-acid-decorated nanoparticles.