On the fine structure of the electrocyte of Electrophorus electricus L.

Summary The general ultrastructure of the electrocyte, the basic unit of the electric organs of Electrophorus electricus, is analyzed. Presented herein are detailed observations of the syncytial surface, its fibrillar coat, invaginations of the plasma membrane and synaptic terminals. Using Thiéry's method glycogen granules were identified in the syncytial cytoplasm and inside the synaptic terminals, their size and structure being compatible with the muscular origin of the electric organs, to which the filamentous meshwork found in the cytoplasm may be related. Among the perinuclear-organelles, are dense bodies with crystalline patterns. The mitochondrial matrix contains dense granules, their size and structure varying according to the organ to which they belong and to the fixation method used.This work has been supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Conselho de Ensino para Graduados da UFRJ and Banco Nacional de Desenvolvimento Econômico, FUNTEC-241     

Central poststroke pain: somatosensory abnormalities and the presence of associated myofascial pain syndrome

Background

Mild cognitive impairment (MCI), defined as a transitional zone between normal cognition and dementia, requires a battery of formal neuropsychological tests administered by a trained rater for its diagnosis. The objective of this study was to develop a screening tool for MCI.

Methods

One hundred ninety seven cognitively normal controls (NC), one hundred sixteen patients with amnestic MCI ?Csingle domain (aMCI-sd), one hundred ninety five patients with amnestic MCI-multiple domain (aMCI-md), and two hundred twenty eight patients with mild Alzheimer??s disease (AD) were evaluated by comprehensive neuropsychological tests and by the Memory and Executive Screening (MES).

Results

Correlation analysis showed that the three indicators of the MES were significantly negatively related with age (P<0.05), yet not related with education (P>0.05). There was no ceiling or floor effect. Test completion averaged seven minutes (421.14±168.31 seconds). The receiver operating characteristics (ROC) analyses performed on the aMCI-sd group yielded 0.89 for the area under the curve (AUC) (95% CI, 0.85?C0.92) for the MES-total score, with sensitivity of 0.795 and specificity of 0.828. There was 81% correct classification rate when the cut-off was set at less than 75. Meanwhile, the aMCI-md group yielded 0.95 for the AUC (95% CI, 0.93?C0.97) for the MES-total score, with sensitivity of 0.87 and specificity of 0.91, and 90% correct classification rate when the cut-off was set at less than 72.

Conclusion

The MES, minimally time-consuming, may be a valid and easily administered cognitive screening tool with high sensitivity and specificity for aMCI, with single or multiple domain impairment.     

Comparative antibacterial potential of selected aldehyde-based biocides and surfactants against planktonic Pseudomonas fluorescens

The antimicrobial efficacy of two aldehyde-based biocides (glutaraldehyde, GTA, and ortho-phthalaldehyde, OPA) and two surfactants (cetyltrimethyl ammonium bromide, CTAB, and sodium dodecyl sulphate, SDS) was tested against planktonic Pseudomonas fluorescens. The antimicrobial effects were evaluated by respiratory activity as a measure of the oxygen uptake rate, adenosine triphosphate (ATP) release, outer membrane proteins (OMP) expression and cellular colour changes. The results were compared with the bacterial characteristics without chemical treatment. Tests in the presence of bovine serum albumin (BSA), in order to mimic a disinfection process in the real situation under dirty conditions, were performed according to the European Standard EN-1276. P. fluorescens was completely inactivated with OPA (minimum bactericidal concentration, MBC = 0.5 mM) and CTAB (MBC = 5 mM) and was resistant to GTA and SDS. Only CTAB promoted cellular disruption and consequent ATP release. The antimicrobial action of the chemicals tested was significantly reduced when BSA was introduced into the bacterial cultures, increasing markedly the MBC values. Additionally, the presence of BSA acted as a disruption protective agent when CTAB was applied and stimulated the bacterial respiratory activity when lower concentrations of SDS were tested. The OMP of the bacterial cells was affected by the application of both surfactants. OMP expression remained unaltered after biocide treatment. Bacterial colour change was noticed after treatment with biocides and surfactants. In summary, P. fluorescens was extremely resistant to GTA and SDS, with antimicrobial action being quenched markedly by the reaction with BSA.     

Polymorphism in the promoter region of the mannose-binding lectin gene among human T-cell lymphotropic virus infected subjects

The present study investigated the frequency of the mutations at positions -550 and -221 of the mannose-binding lectin (MBL) gene in a sample of 75 human T-cell lymphotropic virus (HTLV) infected patients and 96 HTLV seronegative controls, in order to evaluate the occurrence of a possible association between the polymorphism and HTLV infection. A sequence specific primer-polymerase chain reaction was used for discrimination of the polymorphism. The analysis of allele frequencies at position -550 did not show any significant differences between HTLV infected group and controls, but there was a significant difference at position -221. The comparative analysis of haplotypes frequencies were not significant, but the genotype frequencies between the two groups, revealed a higher prevalence of genotype LYLX (25.3%), associated with medium and low MBL serum levels among HTLV infected subjects. The odds ratio estimation demonstrated that the presence of genotype LYLX was associated with an increased risk of HTLV infection (p = 0.0096; 1.38 < or = IC95% < or = 7.7605). There was no association between proviral load and the promoter polymorphism, but when promoter and exon 1 mutations were matched, it was possible to identify a significant higher proviral load among HTLV infected individuals carrying haplotypes correlated to low serum levels of MBL. The present study shows that the polymorphism in the promoter region of the MBL gene may be a genetic marker associated with HTLV infection, and emphasizes the need for further studies to determinate if the present polymorphism have any impact on diseases linked to HTLV infection.     

Miltefosine in the treatment of cutaneous leishmaniasis caused by Leishmania braziliensis in Brazil: a randomized and controlled trial

Background

Cutaneous leishmaniasis (CL) is treated with parenteral drugs for decades with decreasing rate cures. Miltefosine is an oral medication with anti-leishmania activity and may increase the cure rates and improve compliance.

Methodology/Principal Findings

This study is a randomized, open-label, controlled clinical trial aimed to evaluate the efficacy and safety of miltefosine versus pentavalent antimony (Sb^v) in the treatment of patients with CL caused by Leishmania braziliensis in Bahia, Brazil. A total of 90 patients were enrolled in the trial; 60 were assigned to receive miltefosine and 30 to receive Sb^v. Six months after treatment, in the intention-to-treat analyses, the definitive cure rate was 53.3% in the Sb^v group and 75% in the miltefosine group (difference of 21.7%, 95% CI 0.08% to 42.7%, p = 0.04). Miltefosine was more effective than Sb^v in the age group of 13–65 years-old compared to 2–12 years-old group (78.9% versus 45% p = 0.02; 68.2% versus 70% p = 1.0, respectively). The incidence of adverse events was similar in the Sb^v and miltefosine groups (76.7% vs. 78.3%). Vomiting (41.7%), nausea (40%), and abdominal pain (23.3%) were significantly more frequent in the miltefosine group while arthralgias (20.7%), mialgias (20.7%) and fever (23.3%) were significantly more frequent in the Sb^v group.

Conclusions

This study demonstrates that miltefosine therapy is more effective than standard Sb^v and safe for the treatment of CL caused by Leishmania braziliensis in Bahia, Brazil.

Trial Registration

Clinicaltrials.gov Identifier {"type":"clinical-trial","attrs":{"text":"NCT00600548","term_id":"NCT00600548"}}NCT00600548     

Top 10 plant pathogenic bacteria in molecular plant pathology

Many plant bacteriologists, if not all, feel that their particular microbe should appear in any list of the most important bacterial plant pathogens. However, to our knowledge, no such list exists. The aim of this review was to survey all bacterial pathologists with an association with the journal Molecular Plant Pathology and ask them to nominate the bacterial pathogens they would place in a 'Top 10' based on scientific/economic importance. The survey generated 458 votes from the international community, and allowed the construction of a Top 10 bacterial plant pathogen list. The list includes, in rank order: (1) Pseudomonas syringae pathovars; (2) Ralstonia solanacearum; (3) Agrobacterium tumefaciens; (4) Xanthomonas oryzae pv. oryzae; (5) Xanthomonas campestris pathovars; (6) Xanthomonas axonopodis pathovars; (7) Erwinia amylovora; (8) Xylella fastidiosa; (9) Dickeya (dadantii and solani); (10) Pectobacterium carotovorum (and Pectobacterium atrosepticum). Bacteria garnering honourable mentions for just missing out on the Top 10 include Clavibacter michiganensis (michiganensis and sepedonicus), Pseudomonas savastanoi and Candidatus Liberibacter asiaticus. This review article presents a short section on each bacterium in the Top 10 list and its importance, with the intention of initiating discussion and debate amongst the plant bacteriology community, as well as laying down a benchmark. It will be interesting to see, in future years, how perceptions change and which bacterial pathogens enter and leave the Top 10.     

Biofilm Formation by Salmonella Enterica Serovar 1,4,[5],12:i:- Portuguese Isolates: A Phenotypic,Genotypic, and Socio-geographic Analysis

Biofilm-forming ability is well established as an important virulence factor. However, there are no studies available regarding biofilm formation of Salmonella Typhimurium 1,4,[5],12:i:-, the new pandemic serovar in Europe. To address this problem, biofilm expression by Salmonella 1,4,[5],12:i:- was evaluated using 133 isolates from clinical, environmental and animal origins, collected in Portugal from 2006 to 2011. Biofilm detection was performed by phenotypic and genotypic methods, such growth characterization in agar and broth medium, optical density determination by microtiter assays and direct observation by fluorescent in situ hybridization. Biofilm-related genes adrA, csgD and gcpA were detected by PCR. A socio-geographic characterization of strains as biofilm producers was also performed. Results showed that biofilm formation in monophasic Salmonella is widely distributed in Portuguese isolates and could be one of the reasons for its dissemination in this country. Biofilm expression varies between locations, showing that isolates from some regions like Lisboa or Ponta Delgada have an increased ability to persist in the environment due to an enhanced biofilm production. Biofilm formation also varies between risk groups, with a higher prevalence in isolates from salmonellosis infections in women. Therefore, the analysis of the socio-geographic distribution of biofilm-forming bacteria should be considered for the establishment of more adequate regulatory measures or therapeutics regimens, especially important due to the continuous increase of infections caused by antimicrobial resistant microorganisms.     

Effect of curcumin-nanoemulsion associated with photodynamic therapy in breast adenocarcinoma cell line

Curcumin, a natural compound has several antineoplastic activities and is a promising natural photosensitizer used in photodynamic therapy. However, its low solubility in physiological medium limit the clinical use of curcumin. This study aimed to analyze the action of curcumin-nanoemulsion, a new and well-designed Drug Delivery System (DDS+) molecule, used as a photosensitizing agent in photodynamic therapy in an in vitro breast cancer model, MCF-7 cells. The empty nanoemulsion fulfils all necessary requirements to be an excellent DDS. Furthermore, the use of curcumin-nanoemulsion in photodynamic therapy resulted in a high phototoxic effect after activation at 440?nm, decreasing to <10% viable tumor cells after two irradiations and increasing the reactive oxygen species (ROS) production. The use of curcumin-nanoemulsion associated with photodynamic therapy resulted in an increase in the levels of caspase 3/7 activity for the studied MCF-7 cell model, indicating that this therapy triggers a cascade of events that lead to cell death, such as cellular apoptosis. In conclusion, curcumin-nanoemulsion proved to be efficient as a photosensitizing agent, had phototoxic effects, significantly decreased the proliferation of MCF-7 cells and stimulating the ROS production in combination with photodynamic therapy, so, this formulation has a great potential for use in treatment of breast cancer.