Extraction of extracellular polymeric substances (EPS) from anaerobic granular sludges: comparison of chemical and physical extraction protocols

The characteristics of the extracellular polymeric substances (EPS) extracted with nine different extraction protocols from four different types of anaerobic granular sludge were studied. The efficiency of four physical (sonication, heating, cationic exchange resin (CER), and CER associated with sonication) and four chemical (ethylenediaminetetraacetic acid, ethanol, formaldehyde combined with heating, or NaOH) EPS extraction methods was compared to a control extraction protocols (i.e., centrifugation). The nucleic acid content and the protein/polysaccharide ratio of the EPS extracted show that the extraction does not induce abnormal cellular lysis. Chemical extraction protocols give the highest EPS extraction yields (calculated by the mass ratio between sludges and EPS dry weight (DW)). Infrared analyses as well as an extraction yield over 100% or organic carbon content over 1 g g⁻¹ of DW revealed, nevertheless, a carry-over of the chemical extractants into the EPS extracts. The EPS of the anaerobic granular sludges investigated are predominantly composed of humic-like substances, proteins, and polysaccharides. The EPS content in each biochemical compound varies depending on the sludge type and extraction technique used. Some extraction techniques lead to a slightly preferential extraction of some EPS compounds, e.g., CER gives a higher protein yield.     

Erythematous Oral Candidiasis in Patients with Controlled Type II Diabetes Mellitus and Complete Dentures

Diabetes mellitus (DM) is a systemic condition characterized by a deficient sugar metabolism, which affects the immune system and favors the development of yeasts. The aim of the present study was to perform biochemical, morphological, exoenzyme analyses of Candida species and the molecular identification (DNA) of C. albicans in patients with type II diabetes mellitus. The exoenzyme quantification was compared to non-diabetic patients as controls. Two hundred and seventy-four patients who make use of complete dentures were evaluated, 28 of whom had diabetes and erythematous oral candidiasis. Other thirty patients presented the same clinical feature but without diabetes. Samples were isolated for biochemical identification (auxonogram), morphological identification (production of germ tubes) and PCR molecular identification (DNA). The capability of the Candida samples in producing phospholipases and proteinases was also determined. The diabetic patients had a greater diversity of Candida species (Fischer’s exact test, P = 0.04). The production of proteinases by C. albicans in patients with diabetes was greater than in the control group (unpaired “t” test P < 0.003). However, there was no difference between groups for phospholipase production (unpaired “t” test P > 0.05). It was concluded that patients with controlled DM exhibited systemic conditions predisposing C. albicans proteinase increased production.     

Increase in Candida parapsilosis Fungemia in Critical Care Units: A 6-Years Study

Objectives

We aimed to asses possible clinically significant differences between C. parapsilosis and other candida species candidemia receiving care in the intensive care unit (ICU) setting.

Methods

The study included 118 adult patients diagnosed as candidemia after admission to the ICU of a university hospital between January 2004 and December 2009. Data about demographic characteristics, underlying diseases, and risk factors for ICU-related candidemia were collected.

Results

During the study period, 118 patients with candidemia were identified among 2,853 patients admitted into the ICU. Candidemia was seen in 41.4 cases per 1,000 ICU admissions. The overall incidence of candidemia in ICU patients during the study period was 2.09 per 1,000 hospital admissions. Of the isolates, 18.6% were C. albicans and 81.4% were C. non-albicans. The species most frequently isolated was C. parapsilosis (66.1%, 78/118). The distribution of other Candida spp. was as follows: 15 had C. tropicalis (12.7%) and 3 had C. glabrata (2.5%). By Statistical analysis, when patients with candidemia who had C. parapsilosis were compared with other Candida spp., the following factors were found to be significantly associated with C. parapsilosis fungemia; intravascular catheters (p = 0.008), malignity (p = 0.049) and age (p = 0.039). Relationship was found between C. tropicalis and hematologic malignancies (p = 0.001).

Conclusions

When infections with a high mortality such as candidemia is suspected in critically ill patients, it is important to know local risk factors and epidemiological distributions of causative agents in selection of empirical and effective antifungal treatment.     

Biodistribution of 137Cs in a mouse model of chronic contamination by ingestion and effects on the hematopoietic system

The aim of this work was to define the possible occurrence of hematological changes during the course of a chronic ingestion of ¹³⁷Cs. A mouse model was used, with ingestion through drinking water with a cesium concentration of 20 kBq l⁻¹. Ingestion started in parent animals before mating, and ¹³⁷Cs intake and its effect on the hematopoietic system was studied in offspring at various ages between birth and 20 weeks. ¹³⁷Cs content was measured in various organs, indicating that ¹³⁷Cs was distributed throughout the organism including lympho-hematopoietic organs, i.e., femurs, spleen and thymus. However, we did not observe any effect on the hematopoietic system, whatever the parameter used. In fact, blood cell counts, mononuclear cell counts and progenitor frequency in bone marrow and spleen, and Flt3-ligand, Erythropoietin, G-CSF and SDF-1 concentration in plasma remained unchanged when compared to control animals. Moreover, phenotypic analysis did not show any change in the proportions of bone marrow cell populations. These results indicate that, although ¹³⁷Cs was found in all organs implicated in the hematopoietic system, this did not induce any changes in bone marrow function.     

An alternative genotyping method using dye-labeled universal primer to reduce unspecific amplifications

We proposed a modification the procedure of genotyping based in labeled universal primer and tailed primer. In the standard protocol, three primers are used in the same PCR reaction, a forward primer with tail added at the 5′ end of the identical sequence to labeled universal primer with dye-fluorescent and a reverse primer. Unfortunately, the choice of a labeled primer characterized by a large number of complementary sequences in target genomes (which is more probable in larger genomes) result in unspecific amplifications (false positive) can cause absence or decrease amplification of the locus of interest and also false interpretation of the analysis. However, identification of possible homologies between the primer chosen for labelling and the genome is rarely possible from the available DNA data bases. In our approach, cycling is interrupted for the addition of the labeled primer only during the final cycles, thus minimizing unspecific amplification and competition between primers, resulting in the more fidelity amplification of the target regions.     

Effects of anti-TNF therapy on glucose metabolism in patients with ankylosing spondylitis,psoriatic arthritis or juvenile idiopathic arthritis

The objective of this study was to evaluate the influence of anti-tumor necrosis factor (anti-TNF) in juvenile idiopathic arthritis (JIA), ankylosing spondylitis (AS) or psoriatic arthritis (PsA). Sixty-two patients were investigated: 7 JIA; 37 AS; and 18 PsA. Caucasian race accounted for 79% and 29% were female. Mean age was 40.4 ± 12.6years. None of the patients had a history of diabetes, and none had used oral hypoglycemic agents or insulin. Treatment was with adalimumab, infliximab and etanercept. Glucose, inflammatory markers and prednisone dose were assessed at baseline, as well as after three and six months of treatment. The mean erythrocyte sedimentation rate was significantly lower at three months and six months than at baseline (13.7 ± 18.0 and 18 ± 22.5 vs. 27.9 ± 23.4 mm; p = 0.001). At baseline, three months and six months, we found the following: mean C-reactive protein levels were comparable (22.1 ± 22.7, 14.5 ± 30.7 and 16.0 ± 23.8 mg/L, respectively; p = 0.26); mean glucose levels remained unchanged (90.8 ± 22.2 mg/dl, 89.5 ± 14.6 mg/dl and 89.8 ± 13.6 mg/dl, respectively; p = 0.91); and mean prednisone doses were low and stable (3.9 ± 4.9 mg/day, 3.7 ± 4.8 mg/day and 2.6 ± 4.0 mg/day, respectively; p = 0.23). During the first six months of treatment, anti-TNF therapy does not seem to influence glucose metabolism in JIA, AS or PsA.     

Slightly modifying pseudoproline dipeptides incorporation strategy enables solid phase synthesis of a 54 AA fragment of caveolin‐1 encompassing the intramembrane domain

This work contributes to highlight the benefits of pseudoproline dipeptides introduction in difficult SPPS. We show how a slight modification in the positioning choice conditioned the synthesis achievement of a 54 amino acid long caveolin‐1 peptide encompassing the intramembrane domain. Furthermore, we report a side reaction correlated with the coupling steps and generating truncated fragments with a mass deviation of + 42 Da. Considering the need of structural data for membrane proteins, most of which are considered as prevalent therapeutic targets, chemical synthesis provides an interesting alternative pathway to obtain hydrophobic domains by pushing back the frontiers of conventional RP methods of purification. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.     

Sylvatic and peridomestic populations of Triatoma pseudomaculata are not significantly structured by habitat,as revealed by two genetic markers

Chagas disease remains a public health concern in Brazil and other Latin American countries, mainly due to the potential domiciliation of native triatomine species. We analyzed the genetic variability of Triatoma pseudomaculata in sylvatic and peridomestic ecotopes throughout three localities in the northeastern state of Bahia, Brazil. We studied polymorphisms generated by random amplified polymorphic DNA (RAPD) and isoenzyme electrophoresis analyses. Based on RAPD analysis, each specimen was assigned to one of three genetic clusters. Although all sylvatic specimens from one locality were grouped into the same cluster, sylvatic and peridomestic specimens from the other two localities were broadly distributed between the remaining two clusters, suggesting that geographic population structuring was not occurring. Furthermore, isoenzyme analysis suggested that distinct populations were in Hardy‐Weinberg equilibrium. Low statistical values for Wright's Fst index also supported the absence of population structuring and suggested the occurrence of panmixia. We conclude that genetic flow occurs between sylvatic and peridomestic T. pseudomaculata populations, probably as a consequence of passive and active dispersion of the insects, associated with deforestation and anthropic transformations.     

Monitoring Cognitive and Emotional Processes Through Pupil and Cardiac Response During Dynamic Versus Logical Task

The paper deals with the links between physiological measurements and cognitive and emotional functioning. As long as the operator is a key agent in charge of complex systems, the definition of metrics able to predict his performance is a great challenge. The measurement of the physiological state is a very promising way but a very acute comprehension is required; in particular few studies compare autonomous nervous system reactivity according to specific cognitive processes during task performance and task related psychological stress is often ignored. We compared physiological parameters recorded on 24 healthy subjects facing two neuropsychological tasks: a dynamic task that require problem solving in a world that continually evolves over time and a logical task representative of cognitive processes performed by operators facing everyday problem solving. Results showed that the mean pupil diameter change was higher during the dynamic task; conversely, the heart rate was more elevated during the logical task. Finally, the systolic blood pressure seemed to be strongly sensitive to psychological stress. A better taking into account of the precise influence of a given cognitive activity and both workload and related task-induced psychological stress during task performance is a promising way to better monitor operators in complex working situations to detect mental overload or pejorative stress factor of error.