Lactic acid bacteria as bioprotective agents against foodborne pathogens and spoilage microorganisms in fresh fruits and vegetables

La present tesi doctoral es centra en l'aplicació dels bacteris de l'àcid lactic (BAL) com a agents bioprotectors davant microorganismes patògens i deteriorants.Es van aïllar i seleccionar BAL de fruites i hortalisses fresques i es van assajar in vitro davant 5 microorganismes fitopatògens i 5 patògens humans.Es van realitzar assajos d'eficàcia en pomes Golden Delicious amb tots els aïllats enfront les infeccions causades pel fong Penicillium expansum. La soca més eficaç era Weissella cibaria TM128, que reduïa el diàmetre de les infeccions en un 50%.Les soques seleccionades es van assajar enfront els patògens Salmonella typhimurium, Escherichia coli i Listeria monocytogenes en enciams Iceberg i pomes Golden Delicious.Els BAL interferien eficientment amb el creixemet de S. typhimurium, and L. monocytogenes, però van mostrar poc efecte enfront E. coli.Finalment, es van realitzar assajos dosi-resposta amb les soques Leuconostoc mesenteroides CM135, CM160 and PM249 enfront L. monocytogenes. De totes les soques assajades, la soca CM160 va ser la més efectiva.

Infestação e parasitismo natural de ninfas de Bemisia tabaci biótipo b (Hemiptera: Aleyrodidae) em soja-hortaliça e elaboração de chave de identificação de Encarsia spp. (Hymenoptera: Aphelinidae)

Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV

Eficácia dos fungos nematófagos Duddingtonia flagrans e Arthrootrys robusta na profilaxa das infecções naturais por nematódeos gastrointestinais em ovinos

Pós-graduação em Medicina Veterinária - FMVZ

Asthma control and exacerbations: two different sides of the same coin.

Purpose of review: Optimal asthma management includes both the control of asthma symptoms and reducing the risk of future asthma exacerbations. Traditionally, treatment has been adjusted largely on the basis of symptoms and lung function and for many patients, this approach delivers both excellent symptom control and reduced risk. However, the relationship between these two key components of the disease may vary between different asthmatic phenotypes and disease severities and there is increasing recognition of the need for more individualized treatment approaches.

Recent findings: A number of factors which predict exacerbation risk have been identified including demographic and behavioural features and specific inflammatory biomarkers. Type-2 cytokine-driven eosinophilic airways inflammation predisposes to frequent exacerbations and predicts response to corticosteroids, and the usefulness of sputum eosinophilia as both a marker of exacerbation risk and biomarker for adjustment of corticosteroid treatment has been established for some time. However, attempts to develop surrogate markers, which would be more straightforward to deliver in the clinic, have been challenging.

Summary: Some patients with asthma have persistent symptoms in the absence of type-2 cytokine driven-eosinophilic airways inflammation due to noncorticosteroid responsive mechanisms (T2-low disease). Composite biomarker strategies using easily measured surrogate indicators of type-2 inflammation (such as fractional exhaled nitric oxide, blood eosinophil count and serum periostin levels) may predict exacerbation risk better but it is unclear if they can be used to adjust corticosteroid treatment. Biomarkers will be used to target novel biologic treatments but additionally may be used to optimize corticosteroid treatment dose and act as prognostics for exacerbation risk and potentially other important longer term asthma outcomes.

Chronic action of association of zidovudine, lamivudine and ritonavir on pregnant rats. A biologic assay

Purpose: To evaluate at term the effects of a highly active antiretroviral (HAAR) drug association administered during the entire period of rat pregnancy. Methods: Three groups (n = 10 each) of adult pregnant rats were treated with an oral solution of HAAR (Exp 1 = 10/5/20 mg/kg b.w.; Exp 2 = 30/15/60 mg/kg b.w.; Exp 3 = 90/45/180 mg/kg b.w.) from day ""0"" up to the 20th day of pregnancy. A fourth group served as a control. At term (20th day) the rats were killed under deep anesthesia and the number of implantations, resorptions, living fetuses, placentae and intrauterine deaths were recorded. Results: The highest HAAR doses caused lower maternal weight gain, lower litter weights, and lower placental weights compared to the control group. Conclusions: HAAR during the entire period of rat pregnancy can reduce maternal body weight gain and lower term placental weight.

Periodontal and Prosthetic Biologic Considerations to Restore Biological Width in Posterior Teeth

\ The biologic width is an essential dental space that always needs to be maintained to ensure periodontal health in any dental prosthetic restorations. An iatrogenic partial fixed prosthesis constructed in lower posterior teeth predisposed the development of subgingival caries, which induced violation of the biologic width in involved teeth, resulting in an uncontrolled inflammatory process and periodontal tissue destruction. This clinical report describes a periodontal surgical technique to recover a violated biologic width in lower posterior teeth, by crown lengthening procedure associated with free gingival graft procedure, to ensure the possibility to place a modified partial fixed prosthesis in treated area. The procedure applied to recover the biologic width was crown lengthening with some modifications, associated with modified partial fixed prosthesis to achieve health in treated area. The modified techniques in both surgical and prosthetic procedures were applied to compensate the contraindications to recover biologic width by osteotomy in lower posterior teeth. The result, after 4 years under periodic control, seems to achieve the projected goal. Treating a dental diseased area is necessary to diagnose, eliminate, or control all etiologic factors involved in the process. When the traditional methods are not effective to recover destructed tissues, an alternative, compensatory, and adaptive procedure may be applied to restore the sequelae of the disease, applying a restorative method that respects the biology of involved tissues.

Biologic and genetics aspects of chagas disease at endemic areas

The etiologic agent of Chagas Disease is the Trypanosoma cruzi, transmitted through blood-sucking insect vectors of the Triatominae subfamily, representing one of the most serious public health concerns in Latin America. There are geographic variations in the prevalence of clinical forms and morbidity of Chagas disease, likely due to genetic variation of the T. cruzi and the host genetic and environmental features. Increasing evidence has supported that inflammatory cytokines and chemokines are responsible for the generation of the inflammatory infiltrate and tissue damage. Moreover, genetic polymorphisms, protein expression levels, and genomic imbalances are associated with disease progression. This paper discusses these key aspects. Large surveys were carried out in Brazil and served as baseline for definition of the control measures adopted. However, Chagas disease is still active, and aspects such as host-parasite interactions, genetic mechanisms of cellular interaction, genetic variability, and tropism need further investigations in the attempt to eradicate the disease. Copyright 2012 Marilanda Ferreira Bellini et al.

Increased vascularization during early healing after biologic augmentation in repair of chronic rotator cuff tears using autologous leukocyte- and platelet-rich fibrin (L-PRF): a prospective randomized controlled pilot trial

HYPOTHESIS We hypothesized that arthroscopic rotator cuff repairs using leukocyte- and platelet-rich fibrin (L-PRF) in a standardized, modified protocol is technically feasible and results in a higher vascularization response and watertight healing rate during early healing. METHODS Twenty patients with chronic rotator cuff tears were randomly assigned to 2 treatment groups. In the test group (N = 10), L-PRF was added in between the tendon and the bone during arthroscopic rotator cuff repair. The second group served as control (N = 10). They received the same arthroscopic treatment without the use of L-PRF. We used a double-row tension band technique. Clinical examinations including subjective shoulder value, visual analog scale, Constant, and Simple Shoulder Test scores and measurement of the vascularization with power Doppler ultrasonography were made at 6 and 12 weeks. RESULTS There have been no postoperative complications. At 6 and 12 weeks, there was no significant difference in the clinical scores between the test and the control groups. The mean vascularization index of the surgical tendon-to-bone insertions was always significantly higher in the L-PRF group than in the contralateral healthy shoulders at 6 and 12 weeks (P = .0001). Whereas the L-PRF group showed a higher vascularization compared with the control group at 6 weeks (P = .001), there was no difference after 12 weeks of follow-up (P = .889). Watertight healing was obtained in 89% of the repaired cuffs. DISCUSSION/CONCLUSIONS Arthroscopic rotator cuff repair with the application of L-PRF is technically feasible and yields higher early vascularization. Increased vascularization may potentially predispose to an increased and earlier cellular response and an increased healing rate.

Soluble FLT1 binds lipid microdomains in podocytes to control cell morphology and glomerular barrier function.

Vascular endothelial growth factor and its receptors, FLK1/KDR and FLT1, are key regulators of angiogenesis. Unlike FLK1/KDR, the role of FLT1 has remained elusive. FLT1 is produced as soluble (sFLT1) and full-length isoforms. Here, we show that pericytes from multiple tissues produce sFLT1. To define the biologic role of sFLT1, we chose the glomerular microvasculature as a model system. Deletion of Flt1 from specialized glomerular pericytes, known as podocytes, causes reorganization of their cytoskeleton with massive proteinuria and kidney failure, characteristic features of nephrotic syndrome in humans. The kinase-deficient allele of Flt1 rescues this phenotype, demonstrating dispensability of the full-length isoform. Using cell imaging, proteomics, and lipidomics, we show that sFLT1 binds to the glycosphingolipid GM3 in lipid rafts on the surface of podocytes, promoting adhesion and rapid actin reorganization. sFLT1 also regulates pericyte function in vessels outside of the kidney. Our findings demonstrate an autocrine function for sFLT1 to control pericyte behavior.

The biologic and signaling effects of Tiam1 overexpression in colorectal carcinoma

Cellular migration is essential to many normal cellular processes. In tumor cells, aberrant activation of the normal pathways regulating migration is one of the critical steps in the development of metastasis. Previously, I demonstrated for the first time that overexpression of Tiam1, a guanine nucleotide exchange factor (GNEF) for small G proteins in the Rho family, could alter migration in colorectal tumor cells. ^ This dissertation focuses on the roles of Tiam1 in promoting cell migration, survival, and metastasis of colorectal carcinoma cells, utilizing the model system I developed. To determine the in vivo phenotype of the migratory cell lines, athymic nude mice were injected with cells into the orthotopic site. Several of the mice injected with cells of increased migratory potential had metastases. Thus, the in vitro selection for increased migration resulted in increased metastatic potential in vivo, and therefore, the Tiam1-overexpressing cells provide a model to examine signal transduction pathways important to this process. ^ To examine effects of Tiam1 signaling on small G proteins critical to cellular functions associated with migration, I examined the activation status of the small G proteins Rac, Rho, and Cdc42. The cells of increased migratory potential have increased GTP-bound Rac and Rho, compared to control SW480 cells. Cells that overexpress Tiam1 are more migratory and are resistant to detachment-induced death, or anoikis. To determine which effects and phenotypes were Tiam1-specific, we utilized siRNA to downregulate Tiam1 expression. These results demonstrate that Tiam1 is sufficient but not required for the migration of colorectal carcinoma cells in our model system, and that the biologically selected cells have additional changes that promote migration besides the increase in Tiam1. I also show that Tiam1 protects colorectal carcinoma cells from detachment-induced death, but is not required for anoikis resistance in the biologically selected migratory cells. ^ In summary, my studies demonstrate a heretofore-unknown regulator of phenotypes critical to the development of colorectal carcinoma metastases, overexpression of Tiam1. Understanding the mechanism by which Tiam1 contributes to cellular migration and metastasis is crucial to developing desperately needed new therapies for colorectal carcinoma. ^

A second order control-volume finite-element least-squares strategy for simulating diffusion in strongly anisotropic media

An unstructured mesh �nite volume discretisation method for simulating di�usion in anisotropic media in two-dimensional space is discussed. This technique is considered as an extension of the fully implicit hybrid control-volume �nite-element method and it retains the local continuity of the ux at the control volume faces. A least squares function recon- struction technique together with a new ux decomposition strategy is used to obtain an accurate ux approximation at the control volume face, ensuring that the overall accuracy of the spatial discretisation maintains second order. This paper highlights that the new technique coincides with the traditional shape function technique when the correction term is neglected and that it signi�cantly increases the accuracy of the previous linear scheme on coarse meshes when applied to media that exhibit very strong to extreme anisotropy ratios. It is concluded that the method can be used on both regular and irregular meshes, and appears independent of the mesh quality.