Adrenal response of male rats exposed to prenatal stress and early postnatal stimulation

Stress in pregnant rats caused by chronic immobilization alters the pattern of secretion of corticosterone and modifies the hypothalamic-pituitary-adrenal axis (HPA) of the fetus. Early postnatal handling, however, may reverse the effects of increased secretion of corticosterone. We investigated the effects of prenatal stress and postnatal handling on the activity of the HPA axis of male offspring of stressed female rats. Male 90-day-old rats from four groups were investigated: prenatally stressed animals without postnatal handling, prenatally stressed animals with postnatal handling, unstressed control animals with postnatal handling, and unstressed control animals without postnatal handling. After sacrifice, the adrenal glands were weighed to determine the adrenal-somatic index. Apoptosis was evaluated by TUNEL assay and active caspase-3 expression. We found that the adrenal gland cortex:medulla ratio increased in animals with prenatal stress and that eventually the stress caused apoptosis. Handling newborns to simulate maternal activity ameliorated some of the negative effects of prenatal stress.

Specific jarosite biomineralization by Purpureocillium lilacinum, an acidophilic fungi isolated from Río Tinto

Río Tinto (Huelva, southwestern Spain) is an extreme environment with a remarkably constant acidic pH and a high concentration of heavy metals, conditions generated by the metabolic activity of chemolithotrophic microorganisms thriving in the rich complex sulfides of the Iberian Pyrite Belt (IPB). Fungal strains isolated from the Tinto basin were characterized morphologically and phylogenetically. The strain identified as Purpureocillium lilacinum specifically induced the formation of a yellow-ocher precipitate, identified as hydronium-jarosite, an iron sulfate mineral which appears in abundance on the banks of Río Tinto. The biomineral was characterized by X-ray diffraction (XRD) and its formation was observed with high-resolution transmission electron microscopy (TEM) and scanning electron microscopy (SEM) coupled to energy-dispersive X-ray spectroscopy (EDX) microanalysis. Jarosite began to nucleate on the fungal cell wall, associated to the EPS, due to a local increase in the Fe(3+) /Fe(2+) ratio which generated supersaturation. Its formation has been also observed in non-viable cells, although with much less efficiency. The occurrence of P. lilacinum in an ecosystem with high concentrations of ferric iron and sulfates such as Río Tinto suggests that it could participate in the process of jarosite precipitation, helping to shape and control the geochemical properties of this environment.

331 OPTIMIZATION OF BRANCHED 25kDa POLYETHYLENIMINE FOR EFFICIENT GENE DELIVERY IN BOVINE FETAL FIBROBLASTS

Cost-effective, highly efficient, and noncytotoxic transfection of bovine fetal fibroblasts (BFF) has proven difficult to achieve by regular chemical and physical methods. The aims of this study were to evaluate transient transfection efficiency and toxicity of commercially available branched 25 kDa polyethylenimine (25 kDa PEI, Sigma-Aldrich, St. Louis, MO, USA) and to optimize the transfection conditions leading to high percentages of PEI-transfected fibroblasts with minimum cytotoxic effects. Bovine fetal fibroblast (BFF) cells were seeded a day before transfection in 24-well plates at a density of 3 × 104 cells per well in DMEM with antibiotics and 10% SFB. When 70 to 90% confluence was reached, cells were washed with PBS and incubated in DMEM without antibiotics or SFB. For the transfection-mix preparation, increasing amounts of plasmidic DNA (pZsGreen1; 2 to 6 µg) were added to 50 µL of DMEM without antibiotics or SFB, incubated for 5 min at room temperature, and complexed with 0.5 to 4 µg of PEI (from 1 mg mL–1 solution) in 50 µL of PBS for 10 min. This transfection mix was added to the cell cultures and, 2 h later, 500 µL of DMEM with antibiotics and 10% SFB was added to each well. Detection of green fluorescent protein (GFP) expression by flow cytometry (reported as percentage of green fluorescent cells) was performed 48 h after transfection. Results were analysed by ANOVA and Tukey test and expressed as mean ± SEM (P < 0.05). We found no significant difference between the percentage of GFP-positive cells transfected with 1 or 2 µg of 25 kDa PEI at 2 µg of DNA/well (15.2 ± 1.3 v. 16.9 ± 0.9%, respectively; P > 0.05), whereas cells transfected with 1 or 2 µg of low-molecular-weight PEI (2 kDa) showed extremely low transfection efficiencies. Increasing the DNA load up to 6 µg significantly enhanced cell transfection (3.5- and 6-fold comparing 2 µg v. 4 µg and 6 µg of DNA, respectively; P < 0.05) at 1 and 2 µg of 25 kDa PEI/well. In order to evaluate the cytotoxic effect of PEI, cell viability was determined using the MTT assay in 96-well plates (cells/well), with each condition scaled down to replicate the effect of 2 kDa or 25 kDa PEI in a 24-well plate. The MTT results (expressed as % of the control) indicated that PEI became cytotoxic at concentrations equivalent to 2 and 4 µg/well (54.7 ± 3.4 and 18.5 ± 5.7, respectively), whereas 1 µg/well produced a slight detrimental effect on cell viability (90.0 ± 2.6). No evidence of cytotoxicity was observed when the BFF were incubated with 0.5 µg/well of 25 kDa PEI and 1 or 2 µg/well of 2 kDa PEI. To study if a combination of low- and high-molecular-weight PEI could improve transfection efficiency and reduce toxicity, we tested a mixture (1 : 1) of 2 kDa and 25 kDa PEI. Even though the 1 : 1 mixture was less cytotoxic, the efficiency of gene delivery was not improved. We conclude that, under our experimental conditions, the highest percentage of GFP-expressing cells with good viability was obtained when 1 µg of 25 kDa PEI was added per well. Therefore, branched 25 kDa PEI transfection represents an efficient, simple, and cost-effective alternative for gene delivery in bovine fibroblast cells in culture.

Usefulness of consecutive biomarkers measurement in the management of community-acquired pneumonia

The aim of this study was to investigate whether procalcitonin (PCT), neopterin, C-reactive protein (CRP), and mid regional pro-atrial natriuretic peptide (MR-proANP) levels at admission and during the clinical course can be useful for the management of patients with pneumonia. The study population consisted of 75 patients with clinical and radiological diagnosis of pneumonia. Serum samples were collected at admission and during hospitalization. Complications were defined as intensive care unit (ICU) admission or death. The levels of PCT were significantly higher in pneumonia of definite bacterial origin in comparison to probable bacterial or unknown origin. The PCT levels were higher in pneumococcal pneumonia. The PCT and MR-proANP levels increased significantly according to the Pneumonia Severity Index (PSI). All biomarkers levels are higher in patients developing complications and who were dying. The serial levels of MR-proANP remain significantly elevated in patients developing complications and in patients classified in PSI and CURB-65 risk groups. In patients not developing complications, there is a significant decrease in the PCT levels. PCT can be useful for identifying pneumonia etiology. PCT and MR-proANP levels correlate with pneumonia severity rules. PCT and MR-proANP serial measurements can be useful for predicting short-term prognosis. Systemic biomarkers can provide additional information regarding clinical evolution, because these are dynamic and can be measured daily.

Chemokine response induced by Chlamydia trachomatis in prostate derived CD45+ and CD45- cells

The role of innate cells and their receptors within the male genital tract remains poorly understood. Much less is known about the relative contribution of different genital tract cells such as epithelial/stromal cells and resident leucocytes. In this study, we examined innate immune responses to Chlamydia trachomatis by prostate epithelial/stromal cells and prostate resident leucocytes. Murine prostate primary cultures were performed and leucocyte and epithelial/stromal cells were sorted based on surface protein expression of CD45 by magnetism-activated cell sorting or fluorescence-activated cell sorting. Prostate derived CD45- and CD45+ cells were infected with C. trachomatis and chemokine secretion assayed by ELISA. Similar experiments were performed using prostate CD45+ and CD45- cells from myeloid differentiation factor 88 (Myd88(-/-)) mice or toll-like receptor (Tlr2(-/-)) and Tlr4(mutant) double-deficient mice. Moreover, a TLR-signalling pathway array was used to screen changes in different genes involved in TLR-signalling pathways by real-time PCR. Prostate derived CD45- and CD45+ cells responded to chlamydial infection with the production of different chemokines. Both populations expressed genes involved in TLR signalling and required to respond to pathogen-associated molecular patterns and to C. trachomatis infection. Both populations required the adaptor molecule MYD88 to elicit chemokine response against C. trachomatis. TLR2-TLR4 was essential for chemokine production by CD45+ prostate derived cells, but in their absence, CD45- cells still produced significant levels of chemokines. We demonstrate that C. trachomatis is differentially recognised by prostate derived CD45+ and CD45- cells and suggest that diverse strategies are taking place in the local microenvironment of the host in response to the infection.

From Río Tinto to Mars: the terrestrial and extraterrestrial ecology of acidophiles

The recent geomicrobiological characterization of Río Tinto, Iberian Pyrite Belt (IPB), has proven the importance of the iron cycle, not only in generating the extreme conditions of the habitat (low pH, high concentration of toxic heavy metals) but also in maintaining the high level of microbial diversity, both prokaryotic and eukaryotic, detected in the water column and the sediments. The extreme conditions of the Tinto basin are not the product of industrial contamination but the consequence of the presence of an underground bioreactor that obtains its energy from the massive sulfide minerals of the IPB. To test this hypothesis, a drilling project was carried out to intersect ground waters that interact with the mineral ore in order to provide evidence of subsurface microbial activities and the potential resources to support these activities. The oxidants that drive the system appear to come from the rock matrix, contradicting conventional acid mine drainage models. These resources need only groundwater to launch microbial metabolism. There are several similarities between the vast deposits of sulfates and iron oxides on Mars and the main sulfide-containing iron bioleaching products found in the Tinto. Firstly, the short-lived methane detected both in Mars' atmosphere and in the sediments and subsurface of the IPB and secondly, the abundance of iron, common to both. The physicochemical properties of iron make it a source of energy, a shield against radiation and oxidative stress as well as a natural pH controller. These similarities have led to Río Tinto's status as a Mars terrestrial analogue.

Alternatives for biosurfactants and bacteriocins extraction from Lactococcus lactis cultures produced under different pH conditions

AIMS

Study of the potential of Lactococcus lactis CECT-4434 as a biosurfactants and nisin (the only bacteriocin allowed to be used in the food industry) producer for industrial applications, exploiting the possibility of recovering separately both metabolites, taking into account that L. lactis is an interesting micro-organism with several applications in the food industry because it is recognized as GRAS.

METHODS AND RESULTS

The results showed the ability of this strain to produce cell-bound biosurfactants, under controlled pH, and cell-bound biosurfactants and bacteriocins, when pH was not controlled. Three extraction procedures were designed to separately recover these substances.

CONCLUSIONS

The strain L. lactis CECT-4434 showed to be a cell-bound biosurfactants and bacterocins producer when fermentations were carried out under uncontrolled pH. Both products can be recovered separately.

SIGNIFICANCE AND IMPACT OF THE STUDY

Development of a convenient tool for the extraction of cell-bound biosurfactants and bacteriocins from the fermentation broth.

Spanish radiobiological pattern of care in lung cancer: a GOECP/SEOR study

INTRODUCTION

A survey regarding radiobiological questions in the treatment of lung cancer (LC) was done to study the clinical aspects of radiotherapy in Spain, in order to standardise treatment decisions.

METHODS AND MATERIALS

From November 2007 to March 2008, a survey was performed among radiation oncologists in Spain specialising in LC treatment via e-mail, which included questions regarding different radiobiological aspects of radiotherapy LC treatment. The extent of the resulting material made it necessary to divide it into two parts; the first is presented in this article. The second, which includes items about alpha/beta-NTCP/TCP values and reirradiation criteria, will be reported elsewhere.

RESULTS

Thirty-one radiation therapists from 29 radiation oncology departments answered the survey. 77.4-93.5% of responders used the basic formula from the linear-quadratic model and/or computer software for radiobiological calculations; 100% used lung (mostly V20, median <30%) and spinal cord constraints (mostly a median of physical maximum dose <45.5 Gy); and 90.3% used heart and oesophagus constraints (very heterogeneous parameters in both organs).

CONCLUSIONS

Radiobiological considerations are clearly present in the planning process of radiotherapy of LC in Spain, with a high coincidence with the literature regarding lung and spinal cord constraints. The heterogeneity shown for oesophagus and heart results demonstrates the need for continuing investigation into the standardisation of clinical, dosimetric and radiobiologic aspects of the treatment of this cancer.

Cutaneous leishmaniasis due to Leishmania chagasi/Le. infantum in an endemic area of Guarico State, Venezuela

This study reports cutaneous leishmaniasis (CL) caused by Leishmania chagasi/Le. infantum in Venezuela, with some atypical characteristics. Out of 63 cases of CL in the suburbs of Altagracia de Orituco, Guarico State, Venezuela, 30 presented clinical, parasitological, immunological and epidemiological features different from those of the classical CL known in the country. The initial lesion was small and nodular, which, if not treated, might progress to a superficial ulcer. No secondary infection was observed. The identification of the isolates was carried out by molecular techniques. Twelve species of phlebotomine sandflies were caught, the most abundant being Lutzomyia evansi and Lu. longipalpis s.l., known vectors of Le. chagasi/Le. infantum. The existence of Le. chagasi/Le. infantum and its vectors in an endemic area of CL has implications and we suggest that epidemiological studies should be carried out to obtain a clearer picture of the extent of this CL form in Venezuela.