Understanding the genetic diversity, spatial genetic structure and mating system at the hierarchical levels of fruits and individuals of a continuous Theobroma cacao population from the Brazilian Amazon

Understanding the mating patterns of populations of tree species is a key component of ex situ genetic conservation. In this study, we analysed the genetic diversity, spatial genetic structure (SGS) and mating system at the hierarchical levels of fruits and individuals as well as pollen dispersal patterns in a continuous population of Theobroma cacao in Para State, Brazil. A total of 156 individuals in a 0.56 ha plot were mapped and genotyped for nine microsatellite loci. For the mating system analyses, 50 seeds were collected from nine seed trees by sampling five fruits per tree (10 seeds per fruit). Among the 156 individuals, 127 had unique multilocus genotypes, and the remaining were clones. The population was spatially aggregated; it demonstrated a significant SGS up to 15m that could be attributed primarily to the presence of clones. However, the short seed dispersal distance also contributed to this pattern. Population matings occurred mainly via outcrossing, but selfing was observed in some seed trees, which indicated the presence of individual variation for self-incompatibility. The matings were also correlated, especially within ((r) over cap (p(m)) = 0.607) rather than among the fruits ((r) over cap (p(m)) = 0.099), which suggested that a small number of pollen donors fertilised each fruit. The paternity analysis suggested a high proportion of pollen migration (61.3%), although within the plot, most of the pollen dispersal encompassed short distances (28m). The determination of these novel parameters provides the fundamental information required to establish long-term ex situ conservation strategies for this important tropical species. Heredity (2011) 106, 973-985; doi:10.1038/hdy.2010.145; published online 8 December 2010

A decision support system to facilitate management of patients with acute gastrointestinal bleeding

Objective: To develop a model to predict the bleeding source and identify the cohort amongst patients with acute gastrointestinal bleeding (GIB) who require urgent intervention, including endoscopy. Patients with acute GIB, an unpredictable event, are most commonly evaluated and managed by non-gastroenterologists. Rapid and consistently reliable risk stratification of patients with acute GIB for urgent endoscopy may potentially improve outcomes amongst such patients by targeting scarce health-care resources to those who need it the most. Design and methods: Using ICD-9 codes for acute GIB, 189 patients with acute GIB and all. available data variables required to develop and test models were identified from a hospital medical records database. Data on 122 patients was utilized for development of the model and on 67 patients utilized to perform comparative analysis of the models. Clinical data such as presenting signs and symptoms, demographic data, presence of co-morbidities, laboratory data and corresponding endoscopic diagnosis and outcomes were collected. Clinical data and endoscopic diagnosis collected for each patient was utilized to retrospectively ascertain optimal management for each patient. Clinical presentations and corresponding treatment was utilized as training examples. Eight mathematical models including artificial neural network (ANN), support vector machine (SVM), k-nearest neighbor, linear discriminant analysis (LDA), shrunken centroid (SC), random forest (RF), logistic regression, and boosting were trained and tested. The performance of these models was compared using standard statistical analysis and ROC curves. Results: Overall the random forest model best predicted the source, need for resuscitation, and disposition with accuracies of approximately 80% or higher (accuracy for endoscopy was greater than 75%). The area under ROC curve for RF was greater than 0.85, indicating excellent performance by the random forest model Conclusion: While most mathematical models are effective as a decision support system for evaluation and management of patients with acute GIB, in our testing, the RF model consistently demonstrated the best performance. Amongst patients presenting with acute GIB, mathematical models may facilitate the identification of the source of GIB, need for intervention and allow optimization of care and healthcare resource allocation; these however require further validation. (c) 2007 Elsevier B.V. All rights reserved.

Vestibular rehabilitation with biofeedback in patients with central imbalance

Central Nervous System disorders may cause important functional unbalance in the maintenance of balance and posture. There is no effective rehabilitation for these symptoms until now. Objective: The aim of this paper is to evaluate the use of tongue electrotactile stimulation on patients with central imbalance using BrainPort. Materials and Methods: This is a prospective case series study. We evaluated 8 patients with central imbalance, 6 men and 2 women, with mean age of 67.75 years. The patients were submitted to Computed Dynamic Posturography (CDP) and then received 18 sessions of electrotactile stimulation by BrainPort (R) device for 20 minutes, twice a day. Then they were submitted to a new CDP test and to a self-perception scale to assess symptom remission, partial improvement and no improvement at all. Results: 75% of the patients reported being more stable. There was no improvement in the balance control of the mass center in these patients. Conclusion: The patients were able to use the electrotactile stimulus to improve their balance control.

Experimental Model of Isolated Lung Perfusion in Rats: First Brazilian Experience Using the IL-2 Isolated Perfused Rat or Guinea Pig Lung System

Introduction. Lung transplantation has become the mainstay therapy for patients with end-stage lung disease refractory to medical management. However, the number of patients listed for lung transplantation largely exceeds available donors. The study of lung preservation requires accurate, cost-effective small animal models. We have described a model of ex vivo rat lung perfusion using a commercially available system. Methods. Male Wistar rats weighing 250 g-300 g were anesthetized with intraperitoneal sodium thiopental (50 mg/kg body weight). The surgical technique included heart-lung block extraction, assembly, and preparation for perfusion and data collection. We used an IL-2 Isolated Perfused Rat or Guinea Pig Lung System (Harvard Apparatus, Holliston, Mass, United States; Hugo Sachs Elektronik, Alemanha). Results. Preliminary results included hemodynamic and pulmonary mechanics data gathered in the experiments. Conclusion. The isolated rat lung perfusion system is a reliable method to assess lung preservation.

Is Full Postpleurodesis Lung Expansion a Determinant of a Successful Outcome After Talc Pleurodesis?

Study objectives: To analyze and compare radiologic lung expansion after tale pleurodesis performed either by videothoracoscopy or chest tube and correlate it with clinical outcome. Secondary end points evaluated were its follows: clinical efficacy; quality of life; safety; and survival. Methods: Prospective randomized study that included 60 patients (45 women, 15 men; mean age, 55.2 years) with recurrent malignant pleural effusion between January, 2005 and January 2008. They were randomized into the following two groups: video-assisted thoracic surgery (VATS) talc poudrage; and tale slurry (TS) administered through a chest tube. Lung expansion was evaluated through chest CT scans obtained 0, 1, 3 and 6 months after pleurodesis. Complications, drainage time, hospital stay,and quality of life (Medical Outcomes Study 36-item short form and World Health Organization quality-of-life questionnaires) were also analyzed. Results: There were no significant differences in preprocedure clinical and pathologic variables between groups. The immediate total (ie, > 90%) lung expansion was observed in 27 patients (45%) and wits more frequent in the VATS group (60% vs 30%, respectively; p = 0.027). During follow-up, 71% of the patients showed unaltered or improved lung expansion and 9 patients (15%) needed new pleural procedures (VATS group, 5 recurrences; TS group, 4 recurrences; p = 0.999). No differences, were found between groups regarding quality of life, complications, drainage time, hospital stay, and survival. Immediate lung expansion (lid not correlate with radiologic recurrence, clinical recurrence, or complications (p = 0.60, 0.15, and 0.20, respectively). Conclusion: Immediate partial lung expansion was a frequent finding and was more frequent after TS. Nonetheless, no correlation between immediate lung expansion and clinical outcome was found in this study. (CHEST 2009; 136:361-368)

Sao Paulo Lung Transplantation Waiting List: Patient Characteristics and Predictors of Death

Introduction. Nowadays, lung transplantation (LTx) allocation in Brazil is based mainly oil waiting time. There is a need to evaluate the equity of the current lung allocation system. Objectives. We sought to (1) determine the characteristics of registered patients on the waiting list and (2) identify predictors of death on the list. Materials and Methods. We analyzed the medical records as well as clinical and laboratory data of 164 patients registered on the waiting list from 2001 to June 2008. Predictors of mortality were obtained using Cox proportional hazards analysis. Results. Patients who were registered on the waiting list showed a mean age of 36.1 +/- 15.0 vs. 42.2 +/- 15.7 years, considering those who did versus did not, die on the list, respectively (P = .054). Emphysema was the most prevalent underlying disease among the patients who did not die on the list (28.8%); its prevalence was low among the patients who died on the list (6.5%; P = .009). The following variables correlated with the probability of death on the waiting list: emphysema or bronchiectasis diagnosis (hazard ratio [HR] = 0.15; P = .002); activated partial thromboplastin time > 30 seconds (HR = 3.28; P = .002); serum albumin > 3.5 g/dL (HR = 0.41; P = .033); and hemoglobin saturation > 85% (HR = 0.44; P = .031). Conclusions. Some variables seemed to predict death on the LTx waiting list; these characteristics should be used to improve the LTx allocation criteria in Brazil.

NEW COUPLING SYSTEM FOR INTERFERENCE SCREWS: BIOMECHANICAL RESISTANCE TO TORSION

Objective: To introduce a new coupling system between screw driver and interference screw, and biomechanical tests that validate the safety of its application. Methods: The new system was submitted to biomechanical torsion assays. Two types of analysis were performed: maximum torque of manual insertion of the screws into bovine bone; destructive assays of torsion of the system using an INSTRON 55MT machine. The same tests were also performed on a control group, using a commercially available interference screw coupling system (Acufex (R)). Results: In the tests on manual insertion of screws in bovine femurs, the average values found with a digital torque meter were 1.958 N/m for Acufex (R) and 2.563 N/m for FMRP. Considering p>0.05, there were no statistical differences between the two groups (p=0.02) in the values for maximum torque of insertion, in the two systems studied. The average values for maximum torque of torsion resisted by the screw were 15N/m for the Acufex (R) screw and 13N/m for the FMRP screw, again with no statistical differences between the two groups (p>0.05). In the evaluation of angular deformation, there was also no significant difference between the two screw types (p=0.15). Conclusion: The new coupling system for interference screws developed at FMRP-USP revealed a torsion resistance that is comparable with the system already available on the market and regulated for international use.

THE PHOTOELASTIC ANALISYS OF VERTEBRAL FIXATION SYSTEM SCREWS

Introduction: The photoelasticity is used for assessing the tensions/deformations involved in photoelastic materials when submitted to a given load by the observation of optical effects. The screw performance and mechanical functions are directly associated to the quality of the screws fixation in the vertebrae. Photoelasticity is an important tool to perform comparative studies of this nature. Objective: The aim of this study was to compare, by using photoelasticity, internal stresses produced by the screw with an external diameter of 6 mm, when submitted to two different pullout strengths. Materials and Methods: For this, four photoelastic models were produced. The simulation was conducted by using two pullout strengths: 0.75 and 1.50 kgf. The maximum shear stresses were calculated on 19 points around the screws, using the Tardy compensation method. Results:The values of maximum shear stress were higher with the load of 1.50 kgf. Conclusion: Thus, the screw will be more susceptible to pullout when heavier loads are applied. According to our analysis, we also found that the site with the highest maximum shear stress was found to be at the peak of creast, particularly near the tips of the screws, regardless of the load employed.

Inhibition of the renin-angiotensin system prevents seizures in a rat model of epilepsy

The RAS (renin angiotensin system) is classically involved in BP (blood pressure) regulation and water electrolyte balance, and in the central nervous system it has been mostly associated with homoeostatic processes, such as thirst, hormone secretion and thermoregulation. Epilepsies are chronic neurological disorders characterized by recurrent epileptic seizures that affect 1-3% of the world`s population, and the most commonly used anticonvulsants are described to be effective in approx. 70% of the population with this neurological alteration. Using a rat model of epilepsy, we found that components of the RAS, namely ACE (angiotensin-converting enzyme) and the AT(1) receptor (angiotensin II type I receptor) are up-regulated in the brain (2.6- and 8.2-fold respectively) following repetitive seizures. Subsequently, epileptic animals were treated with clinically used doses of enalapril, an ACE inhibitor, and losartan, an AT(1) receptor blocker, leading to a significant decrease in seizure severities. These results suggest that centrally acting drugs that target the RAS deserve further investigation as possible anticonvulsant agents and may represent an additional strategy in the management of epileptic patients.

Toxoplasma gondii: The severity of toxoplasmic encephalitis in C57BL/6 mice is associated with increased ALCAM and VCAM-1 expression in the central nervous system and higher blood-brain barrier permeability

In order to investigate the differential ALCAM, ICAM-1 and VCAM-1 adhesion molecules mRNA expression and the blood-brain barrier (BBB) permeability in C57BL/6 and BALB/c mice in Toxoplasma gondii infection, animals were infected with ME-49 strain. It was observed higher ALCAM on day 9 and VCAM-1 expression on days 9 and 14 of infection in the central nervous system (CNS) of C57BL/6 compared to BALB/c mice. The expression of ICAM-1 was high and similar in the CNS of both lineages of infected mice. In addition, C57BL/6 presented higher BBB permeability and higher IFN-gamma and iNOS expression in the CNS compared to BALB/c mice. The CNS of C578L/6 mice presented elevated tissue pathology and parasitism. In conclusion, our data suggest that the higher adhesion molecules expression and higher BBB permeability contributed to the major inflammatory cell infiltration into the CNS of C57BL/6 mice that was not efficient to control the parasite. (C) 2010 Elsevier Inc. All rights reserved.

Mechanisms Involved in 3 `,5 `-Cyclic Adenosine Monophosphate-Mediated Inhibition of the Ubiquitin-Proteasome System in Skeletal Muscle

Although it is well known that catecholamines inhibit skeletal muscle protein degradation, the molecular underlying mechanism remains unclear. This study was undertaken to investigate the role of beta(2)-adrenoceptors (AR) and cAMP in regulating the ubiquitin-proteasome system (UPS) in skeletal muscle. We report that increased levels of cAMP in isolated muscles, promoted by the cAMP phosphodiesterase inhibitor isobutyl methylxanthine was accompanied by decreased activity of the UPS, levels of ubiquitin-protein conjugates, and expression of atrogin-1, a key ubiquitin-protein ligase involved in muscle atrophy. In cultured myotubes, atrogin-1 induction after dexamethasone treatment was completely prevented by isobutyl methylxanthine. Furthermore, administration of clenbuterol, a selective beta(2)-agonist, to mice increased muscle cAMP levels and suppressed the fasting-induced expression of atrogin-1 and MuRF-1, atrogin-1 mRNA being much more responsive to clenbuterol. Moreover, clenbuterol increased the phosphorylation of muscle Akt and Foxo3a in fasted rats. Similar responses were observed in muscles exposed to dibutyryl-cAMP. The stimulatory effect of clenbuterol on cAMP and Akt was abolished in muscles from beta(2)-AR knockout mice. The suppressive effect of beta(2)-agonist on atrogin-1 was not mediated by PGC-1 alpha (peroxisome proliferator-activated receptor-gamma coactivator 1 alpha known to be induced by beta(2)-agonists and previously shown to inhibit atrogin-1 expression), because food-deprived PGC-1 alpha knockout mice were still sensitive to clenbuterol. These findings suggest that the cAMP increase induced by stimulation of beta(2)-AR in skeletal muscles from fasted mice is possibly the mechanism by which catecholamines suppress atrogin-1 and the UPS, this effect being mediated via phosphorylation of Akt and thus inactivation of Foxo3. (Endocrinology 150: 5395-5404, 2009)

The ubiquitin-proteasome system in Strongyloididae. Biochemical evidence for developmentally regulated proteolysis in Strongyloides venezuelensis

Nematode parasites from the genus Strongyloides spp. are important pathogens of the intestinal mucosa of animals and humans. Their complex life cycles involve alternating developmental adaptations between larvae stages and the adult parthenogenetic female. Here, we report, primarily through homology-based searching, the existence of the major components of the ubiquitin-proteasome system in this genus, using the available EST data from S. ratti, S. stercoralis, and Parastrongyloides trichosuri. In this study, S. venezuelensis was used as our model organism for detection of proteasome activity and ubiquitinated substrates in cytosolic preparations from the L3 larvae and the adult female. Marked differences in proteasome capabilities were found when these two stages were compared. A preference for degradation of chymotryptic synthetic peptides was found in both stages with the adult exhibiting a higher rate of hydrolysis compared to the larvae. Due to the high evolutionary conservation of proteasome alpha subunits, an anti-human proteasome antibody was able to recognize proteasome subunits in these preparations by Western blotting, supporting the proposal that the activity of the ubiqutin-proteasome system is developmentally regulated in this nematode.

CCR2 receptor is essential to activate microbicidal mechanisms to control Toxoplasma gondii infection in the central nervous system

Chemokines comprise a structurally related family of cytokines that regulate leukocyte trafficking. Because infection with Toxoplasma gondii can induce an important inflammatory reaction that, if left uncontrolled, can lead to death, we investigated the role of the chemokine receptor CCR2 in T gondii infection. We orally infected CCR2(-/-) mice with five ME-49 T gondii cysts and monitored morbidity, survival, and immune response thereafter. The CCR2(-/-) mice displayed higher susceptibility to infection as all mice died on day 28 after infection. Despite similar Th1 responses, a more evident anti-inflammatory response was induced in the peripheral organs of CCR2(-/-) mice compared with wild-type C57BL/6 mice. Additionally, CCR2-/- mice presented greater parasitism and a milder inflammatory reaction in their peripheral organs with lesser CD4(+) and MAC-1(+) and greater CD8(+) cell migration. The parasite load decreased in these organs in CCR2(-/-) mice but remained uncontrolled in the central nervous system. Additionally, we observed down-regulated inducible nitric oxide synthase expression in peripheral organs from CCR2(-/-) mice that was associated with a small nitric oxide production by spleen macrophages. In conclusion, in the absence of CCR2, another mechanism is activated to control tissue parasitism in peripheral organs. Nevertheless, CCR2 is essential for the activation of microbicidal mediators that control T gondii replication in the central nervous system.

Participation of kallikrein-kinin system in different pathologies

The general description of kinins refers to these peptides as molecules involved in vascular tone regulation and inflammation. Nevertheless, in the last years a series of, evidences has shown that local hormonal systems, such as the kallikrein-kinin system, may be differently regulated and are of pivotal importance to pathophysiological control. The combined interpretations of many recent studies allow us to conclude that the kallikrein-kinin system plays broader and richer roles than those classically described until recently. In this review, we report findings concerning the participation of the kallikrein-kinin system in inflammation, cancer, and in pathologies related to cardiovascular, renal and central nervous systems. (c) 2007 Elsevier B.V. All rights reserved.