Distinct populations of cortical pyramidal neurons mediate drug reward and aversion.

Processing within the anterior cingulate cortex (ACC) is crucial for the patterning of appropriate behavior, and ACC dysfunction following chronic drug use is thought to play a major role in drug addiction. However, cortical pyramidal projection neurons can be subdivided into two major types (intratelencephalic (IT) and pyramidal tract (PT)), with distinct inputs and projection targets, molecular and receptor profiles, morphologies and electrophysiological properties. Yet, how each of these cell populations modulate behavior related to addiction is unknown. We demonstrate that PT neurons regulate the positive features of a drug experience whereas IT neurons regulate the negative features. These findings support a revised theory of cortical function in addiction, with distinct cells and circuits mediating reward and aversion.

Survival and prognostic factors in patients with oral squamous cell carcinoma.

BACKGROUND: This study aimed to evaluate sociodemographic and clinical factors influencing overall survival (OS) in patients with oral squamous cell carcinoma (OSCC). MATERIAL AND METHODS: Medical charts of 547 patients with OSCC from a public hospital in northeastern Brazil seen between 1999 and 2013 were evaluated. Survival analysis was performed using the Kaplan-Meier method. The influence of age, sex, ethnicity, clinical stage, anatomical location, type of treatment, and comorbidities on the patients' prognosis was evaluated. Cox proportional hazards regression model was used to identify independent prognostic factors. RESULTS: The 5-year OS was 39%. Multivariate analysis showed that age < 40 years (HR = 2.20; 95%CI: 1.02-4.72) and a single treatment modality (HR = 1.91; 95%CI: 1.37-2.67) were associated with a poor prognosis, while early clinical stage resulted in better outcomes (HR = 0.38; 95%CI: 0.25-0.58). CONCLUSIONS: OSCC patients in advanced clinical stages, diagnosed at a younger age, and submitted to a single therapeutic modality have a poorer prognosis.

Intermittent but not continuous access to cocaine produces individual variability in addiction susceptibility in rats.

Drug addiction is a chronic disease defined by a complex set of characteristics, including loss of control over drug intake and persistent drug craving, which primarily affects a small percentage of people who try drugs. Although many models have been developed to study individual aspects of drug use, there is great translational value in having an animal model that encompasses multiple aspects of the human disease, including the variation in severity observed in humans. Here, we describe an intermittent access model of cocaine self-administration that produces a subset of rats that display many of the core features of addiction, including escalation of drug intake, a binge-like pattern of drug use, robust locomotor sensitization, and high levels of drug-seeking during cue-induced reinstatement. This group is compared with rats that have the same drug history but do not develop this pattern of drug-taking and drug-seeking, as well as rats that undergo a traditional continuous access paradigm. Finally, we observe that high levels of cocaine consumption produce long-term changes in intracellular calcium signaling in the dorsomedial striatum.

Desensitizing Toothpastes for Dentin Hypersensitivity: A Network Meta-analysis.

The goal of this systematic review and network meta-analysis was to compare the relative effects of toothpaste formulations for dentin hypersensitivity (DH), tested in randomized controlled trials (RCTs). We searched 7 databases to February 2019. Paired reviewers independently screened studies, extracted data, and performed risk of bias assessment. The outcome of interest was painful response measured through tactile, cold, and air stimuli. We conducted a random-effects Bayesian network meta-analysis using standardized mean difference (SMD) and their credible intervals (CIs) as the measure of effect for each pain stimuli. We assessed certainty of evidence using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. We included 125 RCTs (12,541 patients). For tactile stimulus, the following active ingredients showed large beneficial effects compared to fluoride with moderate certainty of evidence (SMD; 95% CI): potassium + stannous fluoride (SnF2) (3.05; 1.69-4.41), calcium sodium phosphosilicate (CSP) (2.14; 0.75-3.53), SnF2 (2.02; 1.06-2.99), potassium + hydroxyapatite (2.47; 0.3-4.64), strontium (1.43; 0.46-2.41), and potassium (1.23; 0.48-1.98). For cold stimulus, CSP showed large beneficial effects compared to fluoride (3.93; 0.34-7.53) with moderate certainty; for air stimulus, arginine (2.22; 1.45-2.99), potassium + hydroxyapatite (2.44; 0.33-4.55), potassium + SnF2 (2.28; 0.87-3.69), CSP (1.98; 0.99-2.98), and SnF2 (1.9; 1.03-2.77) showed large beneficial effects compared to fluoride with moderate to high certainty. Most toothpaste formulations showed evidence of superiority against placebo or fluorides (amine fluoride, sodium monofluorophosphate, or sodium fluoride). CSP was most beneficial for all 3 stimuli with high to moderate certainty. SnF2 alone and potassium combined with SnF2 or hydroxyapatite were beneficial for tactile and air stimulus with high to moderate certainty. Arginine was beneficial for air stimulus, and strontium and potassium were beneficial for tactile stimulus, with moderate certainty.

Children's perceptions regarding functional limitations due to oral problems.

AIM: To evaluate factors associated with difficulty eating and speaking due to oral problems according to the reports of children. METHODS: A cross-sectional study was conducted with 769 5-year-old children at preschools in a city in northeast Brazil. Parents/caretakers answered a questionnaire addressing socio-demographic data and a history of dental pain. The children answered the scale of oral health outcomes for 5-year-old children, which was used to evaluate the dependent variables. Clinical examinations of the children were performed by examiners who had undergone calibration exercises. Data analysis involved descriptive statistics and Poisson regression analysis (α = 5%). RESULTS: The prevalence of the perception of functional limitations on the part of the children was 35.5% for difficulty eating and 22.9% for difficulty speaking. Difficulty eating was associated with a history of dental pain (PR = 1.68; 95% CI 1.27-2.22) and the occurrence of traumatic dental injury (TDI) (PR = 1.23; 95% CI 1.01-1.52). Difficulty speaking due to oral problems was associated with studying at a public preschool (PR = 1.71; 95% CI 1.19-2.46), a history of dental pain (PR = 1.54; 95% CI 1.07-2.20), and the occurrence of TDI (PR = 1.52; 95% CI 1.12-2.06). CONCLUSIONS: Pain symptoms and the occurrence of TDI can exert an influence on the development of functional limitations. With regard to socioeconomic factors, studying at a public preschool can influence difficulty speaking in children.

Self-Perceptions of the Impact of Oral Problems on the Social Behavior of Preschoolers.

INTRODUCTION: Investigating preschool children's social behaviors and the association with oral health variables helps to understand child development. Besides that, different perceptions need to be explored regarding the impact of oral problems on the social behavior between the child's self-report and parent's/caregiver's proxy report. OBJECTIVE: To determine which socioeconomic and oral factors are associated with difficulty sleeping and playing and the avoidance of smiling in preschoolers. METHODS: A cross-sectional study was conducted with a representative random sample of 769 pairs of parents/caregivers and 5-y-old preschoolers. The preschoolers answered a questionnaire on difficulty sleeping, difficulty playing, and the avoidance of smiling for reasons related to oral problems. The parents/caregivers answered a questionnaire addressing socioeconomic characteristics as well as the use of dental services. Two calibrated dentists examined the children for the determination of dental caries, traumatic dental injury (TDI), malocclusion, and bruxism. Descriptive and Poisson regression analysis for complex samples with robust variance was used to test the associations (α = 5%). RESULTS: The variables associated with difficulty sleeping were low household income (confidence interval [CI]: 1.40-3.01), number of untreated dental caries (CI, 1.02-1.04), dental pain (CI, 1.76-3.59), TDI (CI, 1.08-2.11), and anterior open bite (CI, 1.11-2.20). Difficulty playing also was associated with the low household income (CI, 1.34-3.15), number of untreated dental caries (CI, 1.01-1.04), dental pain (CI,1.42-3.61), and TDI (CI, 1.13-2.33). The number of untreated dental caries (CI, 1.02-1.05), dental pain (CI, 1.03-2.88), anterior open bite (CI, 1.30-3.26), and not using dental services (CI, 1.13-2.73) were determinant factors for the avoidance of smiling. CONCLUSION: Socioeconomic, symptomatic, and/or oral esthetic problems exerted an impact on the social behavior of the preschoolers analyzed, such as playing, sleeping, and smiling. KNOWLEDGE TRANSFER STATEMENT: The results of the present study may help parents and clinicians to understand better the association of oral problems with the social behavior of preschool children. Moreover, this study shows the importance of listening to children in clinical decisions. These results also can help in the elaboration of oral health policies.

Efficacy of respiratory muscle training in weaning of mechanical ventilation in patients with mechanical ventilation for 48hours or more: A Randomized Controlled Clinical Trial. / Eficacia del entrenamiento muscular respiratorio en el destete de la ventilación mecánica en pacientes con ventilación mecánica por 48 o más horas: un ensayo clínico controlado.

OBJECTIVE: To evaluate the efficacy of respiratory muscular training in the weaning of mechanical ventilation and respiratory muscle strength in patients on mechanical ventilation of 48hours or more. DESIGN: Randomized controlled trial of parallel groups, double-blind. Ambit: Intensive Care Unit of a IV level clinic in the city of Cali. PATIENTS: 126 patients in mechanical ventilation for 48hours or more. INTERVENTIONS: The experimental group received daily a respiratory muscle training program with treshold, adjusted to 50% of maximal inspiratory pressure, additional to standard care, conventional received standard care of respiratory physiotherapy. MAIN INTEREST VARIABLES: weaning of mechanical ventilation. Other variables evaluated: respiratory muscle strength, requirement of non-invasive mechanical ventilation and frequency of reintubation. ANALYSIS: intention-to-treat analysis was performed with all variables evaluated and analysis stratified by sepsis condition. RESULTS: There were no statistically significant differences in the median weaning time of the MV between the groups or in the probability of extubation between groups (HR: 0.82 95% CI: 0.55-1.20 P=.29). The maximum inspiratory pressure was increased in the experimental group on average 9.43 (17.48) cmsH20 and in the conventional 5.92 (11.90) cmsH20 (P=.48). The difference between the means of change in maximal inspiratory pressure was 0.46 (P=.83 95%CI -3.85 to -4.78). CONCLUSIONS: respiratory muscle training did not demonstrate efficacy in the reduction of the weaning period of mechanical ventilation nor in the increase of respiratory muscle strength in the study population. Registered study at ClinicalTrials.gov (NCT02469064).

Antiphospholipid antibodies, steroid dose, arterial hypertension, relapses, and late-onset predict organ damage in a population of Colombian patients with systemic lupus erythematosus.

Organ damage predicts mortality, increased accrual of detriment, and poor quality of life in systemic lupus erythematosus patients. The objective of this study is to determine the damage-free survival and its predictive factors in a population of Colombian subjects. The method used in this study is the retrospective follow-up of a cohort; damage was measured with SLICC/ACR index. Predictors of impairment were assessed by logistic regression and survival analysis. One hundred sixty-one individuals were included; 28.9% suffered damage, primarily neuropsychiatric, renal, and vascular. Arterial hypertension, antiphospholipid antibodies, prednisone dose, and number of relapses were all predictors of detriment. Onset after age 50 and daily prednisone dose higher than 7.5 mg determined earlier occurrence of damage.

The prevalence of sleep bruxism and associated factors in children: a report by parents.

AIM: To evaluate the prevalence of sleep bruxism and associated factors among children aged 3-12 years as reported by parents via a questionnaire. METHODS: A cross-sectional study was conducted with a sample of 148 parents/caregivers of children aged 3-12 years treated at paediatric dentistry clinics. Parents/caregivers answered a questionnaire in the waiting room. Information on the gender and age of the child, age of parent/caregiver, meaning of bruxism and child's sleep (type of sleep, if he/she slept alone, hours of sleep per night and if nocturnal bruxism could affect his/her health) were collected. Descriptive statistics were performed and Poisson regression with robust variance was employed (p < 0.05). RESULTS: The prevalence of sleep bruxism was 32.4%. Most parents (64.2%) did not know the meaning of bruxism. In the final Poisson regression model, child's gender (PR 1.32; 95% CI 1.06-1.66) and restless sleep (PR 1.39; 95% CI 1.12-1.72) were significantly associated with sleep bruxism. CONCLUSION: The prevalence of sleep bruxism was high and was associated with gender and having restless sleep. Most parents/guardians did not know the meaning of bruxism.

Effects of GPI-anchored TNAP on the dynamic structure of model membranes.

Tissue-nonspecific alkaline phosphatase (TNAP) plays a crucial role during skeletal mineralization, and TNAP deficiency leads to the soft bone disease hypophosphatasia. TNAP is anchored to the external surface of the plasma membranes by means of a GPI (glycosylphosphatidylinositol) anchor. Membrane-anchored and solubilized TNAP displays different kinetic properties against physiological substrates, indicating that membrane anchoring influences the enzyme function. Here, we used Electron Spin Resonance (ESR) measurements along with spin labeled phospholipids to probe the possible dynamic changes prompted by the interaction of GPI-anchored TNAP with model membranes. The goal was to systematically analyze the ESR data in terms of line shape changes and of alterations in parameters such as rotational diffusion rates and order parameters obtained from non-linear least-squares simulations of the ESR spectra of probes incorporated into DPPC liposomes and proteoliposomes. Overall, the presence of TNAP increased the dynamics and decreased the ordering in the three distinct regions probed by the spin labeled lipids DOPTC (headgroup), and 5- and 16-PCSL (acyl chains). The largest change was observed for 16-PCSL, thus suggesting that GPI-anchored TNAP can give rise to long reaching modifications that could influence membrane processes halfway through the bilayer.

The ins and outs of the striatum: role in drug addiction.

Addiction is a chronic relapsing disorder characterized by the loss of control over drug intake, high motivation to obtain the drug, and a persistent craving for the drug. Accumulating evidence implicates cellular and molecular alterations within cortico-basal ganglia-thalamic circuitry in the development and persistence of this disease. The striatum is a heterogeneous structure that sits at the interface of this circuit, receiving input from a variety of brain regions (e.g., prefrontal cortex, ventral tegmental area) to guide behavioral output, including motor planning, decision-making, motivation and reward. However, the vast interconnectivity of this circuit has made it difficult to isolate how individual projections and cellular subtypes within this circuit modulate each of the facets of addiction. Here, we review the use of new technologies, including optogenetics and DREADDs (Designer Receptors Exclusively Activated by Designer Drugs), in unraveling the role of the striatum in addiction. In particular, we focus on the role of striatal cell populations (i.e., direct and indirect pathway medium spiny neurons) and striatal dopaminergic and glutamatergic afferents in addiction-related plasticity and behaviors.

Association between oral conditions and functional limitations in childhood.

The aim of this study was to evaluate the impact of oral conditions on functional limitations among preschoolers. A preschool-based, cross-sectional study was carried out with 843 preschoolers in Campina Grande, Brazil. Parents/caregivers answered a questionnaire addressing socio-demographic characteristics and perceptions regarding the general/oral health of their children as well as the Brazilian version of the Early Childhood Oral Health Impact Scale. The nonparametric Kruskal-Wallis test followed by Mann-Whitney test (α = 5%) was used to compare mean children's quality-of-life scores for each independent variable. Poisson regression analysis was used to test associations between the independent and dependent variables (difficulties eating, drinking and speaking) (α = 5%). The multivariate regression model involved a hierarchical approach with four levels (distal to proximal determinants): (i) socio-demographic aspects; (ii) health perceptions; (iii) oral conditions; and (iv) pain conditions. The prevalence of negative impact on function was 24.7% for eating/drinking and 8.0% for speaking. Significant associations were found between toothache and negative impact on eating/drinking (PR = 5.38; 95%CI: 3.20-9.02) as well as between high severity dental caries and negative impact on speaking (PR = 14.91; 95%CI: 1.98-112.32). Dental caries, traumatic dental injury and malocclusion were not significantly associated with a negative impact on eating or drinking. However, toothache was an indicator of negative impact on eating/drinking and dental caries severity was an indicator of negative impact on speaking.

Bovine herpesvirus type 5 infection regulates Bax/BCL-2 ratio.

Bovine herpesvirus 5 (BoHV-5) is an α-herpesvirus that causes neurological disease in young cattle and is also occasionally involved in reproductive disorders. Although there have been many studies of the apoptotic pathways induced by viruses belonging to the family Herpesviridae, there is little information about the intrinsic programmed cell death pathway in host-BoHV-5 interactions. We found that BoHV-5 is able to replicate in both mesenchymal and epithelial cell lines, provoking cytopathology that is characterized by cellular swelling and cell fusion. Viral antigens were detected in infected cells by immunofluorescence assay at 48 to 96 h post-infection (p.i.). At 48 to 72 h p.i., anti-apoptotic BCL-2 antigens were found at higher levels than Bax antigens; the latter is considered a pro-apoptotic protein. Infected cells had increased BCL-2 phenotype cells from 48 to 96 h p.i., based on flow cytometric analysis. At 48 to 96 h p.i., Bax mRNA was not expressed in any of the infected cell monolayers. In contrast, BCL-2 mRNA was found at high levels at all p.i. in both types of cells. BoHV-5 replication apparently modulates BCL-2 expression and gene transcription, enhancing production of virus progeny.

Dental trauma among Brazilian schoolchildren: prevalence, treatment and associated factors.

AIM: To assess the prevalence of traumatic dental injury (TDI), as well as associated factors, behaviour of affected schoolchildren and normative treatment needs. METHODS: The present cross-sectional study involved 590 children aged 7-14 years at state schools in Campina Grande, Brazil. The O'Brien classification [1994] was used for the diagnosis of TDI and the body mass index (BMI) was used as an indicator of overweight/obesity. Clinical tests were carried out by two duly calibrated examiners (intra-observer and inter-observer agreement: 0.87 and 0.90, respectively). The Chi-square test was used (5% level of significance) to determine whether TDI was associated with age, gender, ethnicity, overweight/obesity, lip seal and overjet. Backward stepwise multivariate regression analysis was performed. Normative treatment needs were determined based on the criteria of the International Association of Dental Traumatology (IADT). When the absence of treatment was detected, each child/adolescent was asked about the reason for non-treatment. RESULTS: The prevalence of TDI was 12.7%. The most common type of trauma was enamel fracture (67.0%), followed by enamel-dentine fracture (25.3%). TDI was 4.9-fold greater (95% CI: 1.6-14.4) among children aged 13 and 14 years, 1.9- fold greater (95% CI: 1.1-3.2) among males and 2.6-fold greater (95% CI: 1.2-5.4) among those with inadequate lip seal. The majority of schoolchildren did not undergo treatment (82.6%) due to a belief that it was unnecessary (53.2%). The normative clinical evaluation revealed that adhesive restoration was the most common form of treatment (84.0%). CONCLUSION: The prevalence of TDI was low. Age, gender and inadequate lip seal were associated with dental trauma. A significant number of schoolchildren did not receive treatment for dental trauma.

Evaluation of indigenous bacterial strains for biocontrol of the frogeye leaf spot of soya bean caused by Cercospora sojina.

AIMS: Assessment of biological control of Cercospora sojina, causal agent of frogeye leaf spot (FLS) of soya bean, using three indigenous bacterial strains, BNM297 (Pseudomonas fluorescens), BNM340 and BNM122 (Bacillus amyloliquefaciens). METHODS AND RESULTS: From cultures of each bacterial strain, cell suspensions and cell-free supernatants were obtained and assayed to determine their antifungal activity against C. sojina. Both mycelial growth and spore germination in vitro were more strongly inhibited by bacterial cell suspensions than by cell-free supernatants. The Bacillus strains BNM122 and BNM340 inhibited the fungal growth to a similar degree (I ≈ 52-53%), while cells from P. fluorescens BNM297 caused a lesser reduction (I ≈ 32-34%) in the fungus colony diameter. The foliar application of the two Bacillus strains on soya bean seedlings, under greenhouse conditions, significantly reduced the disease severity with respect to control soya bean seedlings and those sprayed with BNM297. This last bacterial strain was not effective in controlling FLS in vivo. CONCLUSIONS: Our data demonstrate that the application of antagonistic bacteria may be a promising and environmentally friendly alternative to control the FLS of soya bean. SIGNIFICANCE AND IMPACT OF THE STUDY: To our knowledge, this is the first report of biological control of C. sojina by using native Bacillus strains.

Limb amputation among patients with surgically treated popliteal arterial injury: analysis of 15 years of experience in an urban trauma center in Cali, Colombia.

BACKGROUND: Popliteal arterial injuries carry a high risk of amputation. The currently available literature from both civilian and military experiences is characterized by a wide variation of recommendations for surgical management. We questioned how these recommendations have been applied in our practice. Therefore, we aimed to identify predictors of amputation after popliteal arterial injury. METHODS: We conducted an observational study of 175 patients with popliteal arterial injuries who underwent surgical treatment from 1992 to 2006 at a level I trauma center in Cali, Colombia. Information on demographic characteristics, clinical information, and surgical management was collected from clinical records. The outcome measure was amputation within 30 days following the first surgical intervention. RESULTS: The amputation rate was 17.1%. A multivariable logistic regression model indicates that blunt mechanism (odds ratio [OR] 4.79, 95% confidence interval [CI] 1.49-15.42), signs of ischemia (OR 5.29, 95% CI 1.48-18.91), ligation of the popliteal vein of the compromised limb during surgical exploration (OR 3.83, 95% CI 1.20-12.18), and the development of arterial thrombosis (OR 56.51, 95% CI 12.36-258) were found to be independent predictors of amputation. Fractures, popliteal venous injuries, prolonged time between injury and surgery, fasciotomies, and graft arterial repair were not statistically significant predictors of amputation. CONCLUSIONS: Emphasis on the early assessment and prompt identification of signs of ischemia after popliteal arterial injury continue to be the most important factor for reducing the risk of amputation, especially in blunt trauma. Vascular trauma teams must emphasize the need for the specialized management of popliteal veins. Clinical research is needed in order to identify means of decreasing arterial thrombosis after popliteal repair.

Maxillofacial injuries and dental trauma in patients aged 19-80 years, Recife, Brazil

Objetivo: Se llevó a cabo un estudio retrospectivo para evaluar las causas de traumatismomaxilofacial en Recife, Pernambuco, Brasil.Método: Se hizo una revisión de 186 pacientes con lesiones maxilofaciales de 19 a 83 años atendidosy tratados en el Hospital da Restauração entre Enero y Diciembre 2006, analizándoles segúnedad, sexo, etiología, localización de la fractura, traumatismo dentoalveolar y abuso de alcohol.Se llevó a cabo el análisis en Epi Info, utilizando el Chi cuadrado y la prueba exacta de Fisher.Resultados: Resultó que las lesiones maxilofaciales fueron más frecuentes en los hombres (89,2%)y en el grupo de edad de 19-28 años (46,8%). Accidentes de tráfico/motocicleta (23,7%) y violenciafísica (20,4%) fueron los factores etiológicos más comunes. Las fracturas faciales fueron detectadasen 90,9%, con una diferencia estadisticamente significativa entre el sexo y la fractura facial(p = 0,000). La fractura facial más común fue maxilar (29,1%), seguida por la de la mandíbula(27,5%). Hubo una asociación positiva entre la presencia de la fractura facial y el consumo dealcohol (p = 0,002). El traumatismo dentoalveolar estuvo presente en el 7,5% de los pacientes.Conclusión: La incidencia de las fracturas faciales en la población Brasileña es similar a la informadapreviamente en otros lugares. Las fracturas fueron más comunes en pacientes masculinos,principalmente debidas a accidentes de tráfico/motocicletas y a la violencia física(AU)

Aim: A retrospective study was undertaken to assess causes of maxillofacial trauma inRecife, Pernambuco, Brazil.Method: A review of 186 patients with maxillofacial injuries aged 19 and 83 years old seenand treated at the Hospital da Restauração between January and December 2006 wasconducted and were analyzed according to age, sex, etiology, site of fracture, dentoalveolartrauma and alcohol abuse. Analysis was made in Epi Info using the Chi-square and Fisher’sExact Tests.Results: It was found that maxillofacial injuries were most frequent in males (89.2%) and inthe 19-28 year age group (46.8%). Traffic accidents/motorcycle (23.7%) and physical violence(20.4%) were the most common etiological factor. Facial fractures were detected in 90.9%and a statistically significant difference between sex and facial fracture was found (p =0.000). The most common facial fracture was maxilla (29.1%), followed by the mandible(27.5%). A positive association between the presence of facial fracture and alcoholconsumption was observed (p = 0.002). Dentoalveolar trauma was present in 7.5% ofpatients.Conclusion: The incidence of facial fractures in Brazilian population is similar thanpreviously reported elsewhere. There were most common in male patients, mainly due totraffic accidents/motorcycle and physical violence(AU)

Antifungal activity of selected indigenous pseudomonas and bacillus from the soybean rhizosphere.

The purpose of this study was to isolate and select indigenous soil Pseudomonas and Bacillus bacteria capable of developing multiple mechanisms of action related to the biocontrol of phytopathogenic fungi affecting soybean crops. The screening procedure consisted of antagonism tests against a panel of phytopathogenic fungi, taxonomic identification, detection by PCR of several genes related to antifungal activity, in vitro detection of the antifungal products, and root colonization assays. Two isolates, identified and designated as Pseudomonas fluorescens BNM296 and Bacillus amyloliquefaciens BNM340, were selected for further studies. These isolates protected plants against the damping-off caused by Pythium ultimum and were able to increase the seedling emergence rate after inoculation of soybean seeds with each bacterium. Also, the shoot nitrogen content was higher in plants when seeds were inoculated with BNM296. The polyphasic approach of this work allowed us to select two indigenous bacterial strains that promoted the early development of soybean plants.

Structural stability and reversible unfolding of recombinant porcine S100A12.

Porcine S100A12 is a member of the S100 proteins, family of small acidic calcium-binding proteins characterized by the presence of two EF-hand motifs. These proteins are involved in many cellular events such as the regulation of protein phosphorylation, enzymatic activity, protein-protein interaction, Ca2+ homeostasis, inflammatory processes and intermediate filament polymerization. In addition, members of this family bind Zn2+ or Ca2+ with cooperative effect on binding. In this study, the gene sequence encoding porcine S100A12 was obtained by the synthetic gene approach using E. coli codon bias. Additionally, we report a thermodynamic study of the recombinant S100A12 using circular dichroism, fluorescence and isothermal titration calorimetry. The results of urea and temperature induced unfolding and refolding processes indicated a reversible two-state process. Also, the ANS fluorescence studies showed that in presence of divalent ions the protein exposes hydrophobic sites which could facilitate the interaction with other proteins and trigger the physiological responses.

Assessment of the role of chemotaxis and biofilm formation as requirements for colonization of roots and seeds of soybean plants by Bacillus amyloliquefaciens BNM339.

This article correlates colonization with parameters, such as chemotaxis, biofilm formation, and bacterial growth, that are believed to be connected. We show here, by using two varieties of soybean plants that seeds axenically produced exudates, induced a chemotactic response in Bacillus amyloliquefaciens, whereas root exudates did not, even when the exudates, also collected under axenic conditions, were concentrated up to 200-fold. Root exudates did not support bacterial cell division, whereas seed exudates contain compounds that support active cell division and high cell biomass at stationary phase. Seed exudates of the two soybean varieties also induced biofilm formation. B. amyloliquefaciens colonized both seeds and roots, and plant variety significantly affected bacterial root colonization, whereas it did not affect seed colonization. Colonization of roots in B. amyloliquefaciens occurred despite the lack of chemotaxis and growth stimulation by root exudates. The data presented in this article suggest that soybean seed colonization, but not root colonization, by B. amyloliquefaciens is influenced by chemotaxis, growth, and biofilm formation and that this may be caused by qualitative changes of the composition of root exudates.