233 resultados para Wingerd, Mary Lethert
Resumo:
Background: It has been well documented over past decades that interaction of pathogens with the extracellular matrix (ECM) plays a primary role in host cell attachment and invasion. Adherence to host tissues is mediated by surface-exposed proteins expressed by the microorganisms during infection. The mechanisms by which pathogenic leptospires invade and colonize the host remain poorly understood since few virulence factors contributing to the pathogenesis of the disease have been identified. Whole-genome sequencing analysis of L. interrogans allowed identification of a repertoire of putative leptospiral surface proteins. Results: Here, we report the identification and characterization of a new leptospiral protein that exhibits extracellular matrix-binding properties, called as Lsa21 (leptospiral surface adhesin, 21 kDa). Compatible with its role in adhesion, the protein was shown to be surface-exposed by indirect immunofluorescence. Attachment of Lsa21 to laminin, collagen IV, and plasma fibronectin was specific and dose dependent. Laminin oxidation by sodium metaperiodate reduced the protein-laminin interaction in a concentration-dependent manner, indicating that laminin sugar moieties are crucial for this interaction. The gene coding for Lsa21 is present in pathogenic strains belonging to the L. interrogans species but was not found in the saprophytic L. biflexa serovar Patoc strain Patoc 1. Loss of gene expression occurs upon culture attenuation of pathogenic strains. Environmental factors such as osmolarity and temperature affect Lsa21 expression at the transcriptional level. Moreover, anti-Lsa21 serum labeled liver and kidney tissues of human fatal cases of leptospirosis. Conclusion: Our data suggest a role of Lsa21 in the pathogenesis of leptospirosis.
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Entry inhibitor is a new class of drugs that target the viral envelope protein. This region is variable; hence resistance to these drugs may be present before treatment. The aim of this study was to analyze the frequency of patients failing treatment with transcriptase reverse and protease inhibitors that would respond to the entry inhibitors Enfuvirtide, Maraviroc, and BMS-806. The study included 100 HIV-1 positive patients from one outpatient clinic in the city of Sao Paulo, for whom a genotype test was requested due to treatment failure. Proviral DNA was amplified and sequenced for regions of gp120 and gp41. A total of 80 could be sequenced and from those, 73 (91.3%), 5 (6.3%) and 2 (2.5%) were classified as subtype B, F, and recombinants (B/F and B/C), respectively. CXCR4 co-receptor use was predicted in 30% of the strains. Primary resistance to Enfuvirtide was found in 1.3%, following the AIDS Society consensus list, and 10% would be considered resistant if a broader criterion was used. Resistance to BMS-806 was higher; 6 (7.5%), and was associated to non-B strains. Strikingly, 27.5% of samples harbored one or more mutation among A316T, I323V, and S405A, which have been related to decreased susceptibility of Maraviroc; 15% of them among viruses predictive to be R5. A more common mutation was A316T, which was associated to the Brazilian B strain harboring the GWGR motif at the tip of V3 loop and their derivative sequences. These results may be impact guidelines for genotype testing and treatment in Brazil.
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It has been demonstrated that human adipose tissue-derived mesenchymal stem cells (hASCs) enhance vascular density in ischemic tissues, suggesting that they can differentiate into vascular cells or release angiogenic factors that may stimulate neoangiogenesis. Moreover, there is evidence that shear stress (SS) may activate proliferation and differentiation of embryonic and endothelial precursor stem cells into endothelial cells (ECs). In this work, we investigated the effect of laminar SS in promoting differentiation of hASCs into ECs. SS (10 dyn/cm(2) up to 96 h), produced by a cone plate system, failed to induce EC markers (CD31, vWF, Flk-1) on hASC assayed by RT-PCR and flow cytometry. In contrast, there was a cumulative production of nitric oxide (determined by Griess Reaction) and vascular endothelial growth factor (VEGF; by ELISA) up to 96 h of SS stimulation ( NO(2)(-) in nmol/10(4) cells: static: 0.20 +/- 0.03; SS: 1.78 +/- 0.38, n = 6; VEGF in pg/10(4) cells: static: 191.31 +/- v35.29; SS: 372.80 +/- 46.74, n = 6, P < 0.05). Interestingly, the VEGF production was abrogated by 5 mM N(G)-L-nitro-arginine methyl ester (L-NAME) treatment (VEGF in pg/10(4) cells: SS: 378.80 +/- 46.74, n = 6; SS + L-NAME: 205.84 +/- 91.66, n = 4, P < 0.05). The results indicate that even though SS failed to induce EC surface markers in hASC under the tested conditions, it stimulated NO-dependent VEGF production.
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Background: We aimed to compare plasma concentrations of carbon dioxide (CO(2)) in dogs that underwent intra- and preperitoneal CO(2) insufflation. Materials and Methods: Thirty dogs were studied. Ten formed a control group, 10 underwent intraperitoneal CO(2) insufflation, and 10 underwent preperitoneal CO(2) insufflation. General anesthesia with controlled ventilation was standardized for all dogs. After stabilizing the anesthesia, blood samples were collected at predetermined times and were sent for immediate gasometric analysis. Analysis of variance was used for comparing variables. Results: The plasma CO(2) concentration in the intraperitoneal insufflation group increased significantly more than in the preperitoneal insufflation group and was significantly greater than in the control group (P < 0.05). The pH values in the intraperitoneal group were lower than in the preperitoneal group (P < 0.05). Conclusion: The data from this study suggest that a greater plasma concentration of CO(2) is achieved by insufflation at constant pressure into the intraperitoneal space than into the preperitoneal space.
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Objective: We compared temperament and character traits in children and adolescents with bipolar disorder (BP) and healthy control (HC) subjects. Method: Sixty nine subjects (38 BP and 31 HC), 8-17 years old, were assessed with the Kiddie Schedule for Affective Disorders and Schizophrenia-Present and Lifetime. Temperament and character traits were measured with parent and child versions of the Junior Temperament and Character Inventory. Results: BP subjects scored higher on novelty seeking, harm avoidance, and fantasy subscales, and lower on reward dependence, persistence, self-directedness, and cooperativeness compared to HC(all p < 0.007), by child and parent reports. These findings were consistent in both children and adolescents. Higher parent-rated novelty seeking, lower self-directedness, and lower cooperativeness were associated with co-morbid attention-deficit/hyperactivity disorder (ADHD). Lower parent-rated reward dependence was associated with co-morbid conduct disorder, and higher child-rated persistence was associated with co-morbid anxiety. Conclusions: These findings support previous reports of differences in temperament in BP children and adolescents and may assist in a greater understating of BP children and adolescents beyond mood symptomatology.
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Clinical trials using dendritic cells (DCs) to treat cancer patients have generated promising results in recent years. However, even simple aspects of this therapy are still not well understood, including the storage and distribution of manufactured vaccines. These processes are essential and must be elucidated in order to reduce costs. We evaluated the effects of different storage conditions on vaccine functionality using mixed lymphocyte reaction (MLR). Vaccine storage at 4 degrees C for up to 72 h had no significant effect on vaccine activity. Shipping to distant places is possible, if vaccines are kept at 4 degrees C and used up to 3 days after manufacture date.
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Objectives: Adults with major depressive disorder (MDD) are reported to have reduced orbitofrontal cortex (OFC) volumes, which could be related to decreased neuronal density. We conducted a study on medication naive children with MDD to determine whether abnormalities of OFC are present early in the illness course. Methods: Twenty seven medication naive pediatric Diagnostic and Statistical Manual of Mental Disorders, 4(th) edition (DSM-IV) MDD patients (mean age +/- SD = 14.4 +/- 2.2 years; 10 males) and 26 healthy controls (mean age +/- SD = 14.4 +/- 2.4 years; 12 males) underwent a 1.5T magnetic resonance imaging (MRI) with 3D spoiled gradient recalled acquisition. The OFC volumes were compared using analysis of covariance with age, gender, and total brain volume as covariates. Results: There was no significant difference in either total OFC volume or total gray matter OFC volume between MDD patients and healthy controls. Exploratory analysis revealed that patients had unexpectedly larger total right lateral (F = 4.2, df = 1, 48, p = 0.05) and right lateral gray matter (F = 4.6, df = 1, 48, p = 0.04) OFC volumes compared to healthy controls, but this finding was not significant following statistical correction for multiple comparisons. No other OFC subregions showed a significant difference. Conclusions: The lack of OFC volume abnormalities in pediatric MDD patients suggests the abnormalities previously reported for adults may develop later in life as a result of neural cell loss.
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The aim of this study was to examine the incidence and factors associated with the severity of liver fibrosis in 234 coinfected patients in Brazil. Patients were cared for in our clinic, from 1996 to 2004. Eligible patients were defined as patients with documented HIV and hepatitis C virus (HCV) infections and had previously undergone a liver biopsy. Patients with persistently normal alanine aminotransferase (ALT) were also included. The variables selected for study were age, gender, risk category, history of high alcohol consumption, CD4(+) T cell count, antiretroviral therapy usage, HCV genotype and duration of HCV infection. Stage of fibrosis was scored as follows: F0, no fibrosis; F1, portal fibrosis with no septa; F2, portal fibrosis with few septa; F3, bridging fibrosis with many septa; and F4, cirrhosis. The liver fibrosis stage was F3 in 39 (16.6%) and F4 in 20(8.5%) patients. Among patients with normal ALT, the liver fibrosis stage was F3-F4 in three patients (5.6%). Predictors of severe liver fibrosis (17344) by multivariate analysis were age (older patients) and genotype 3 (genotype I odds ratio [OR], 0.28; 95% confidence interval [0], 0.12 0.65). In summary, in the present study severe liver fibrosis was found in 25% of our patients and was associated with an age of more than 38 years at the time of liver biopsy as well as, HCV genotype 3. No differences were found with respect to CD4(+) T cell counts although patients with a CD4(+) T cell count greater than 50 were excluded.
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Objective: The striatum, including the putamen and caudate, plays an important role in executive and emotional processing and may be involved in the pathophysiology of mood disorders. Few studies have examined structural abnormalities of the striatum in pediatric major depressive disorder (MDD) patients. We report striatal volume abnormalities in medication-naive pediatric MDD compared to healthy comparison subjects. Method: Twenty seven medication-naive pediatric Diagnostic and Statistical Manual of Mental Disorders, 4(th) edition (DSM-IV) MDD and 26 healthy comparison subjects underwent volumetric magnetic resonance imaging (MRI). The putamen and caudate volumes were traced manually by a blinded rater, and the patient and control groups were compared using analysis of covariance adjusting for age, sex, intelligence quotient, and total brain volumes. Results: MDD patients had significantly smaller right striatum (6.0% smaller) and right caudate volumes (7.4% smaller) compared to the healthy subjects. Left caudate volumes were inversely correlated with severity of depression in MDD subjects. Age was inversely correlated with left and right putamen volumes in MDD patients but not in the healthy subjects. Conclusions: These findings provide fresh evidence for abnormalities in the striatum of medication-naive pediatric MDD patients and suggest the possible involvement of the striatum in the pathophysiology of MDD.
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Purpose: To evaluate the effects of Triesence (R) (TRI), a new preservative-free triamcinolone approved by the U. S. Food and Drug Administration (FDA) for intraocular use, on human retina pigment epithelial (ARPE-19) and rat neurosensory (R28) cells in culture. Methods: ARPE-19 and R28 cell cultures were treated 24 h with 1,000, 500, 200, or 100 mu g/mL of crystalline (cTRI) or 1,000, 500, or 200 mu g/mL of solubilized (sTRI). TRI was solubilized by centrifuging the drug, discarding the supernatant containing the vehicle and then resuspending the drug pellet in an equivalent amount of Dimethyl sulfoxide to achieve the same concentration as the commercial preparation. Percentage of cell viability (CV) was evaluated by a trypan blue dye-exclusion assay. The mitochondrial membrane potential (Delta Psi m) was analyzed with the JC-1 assay. The caspase-3/7 activity was measured by a fluorochrome assay. Results: In the ARPE-19 cultures, the cTRI caused a decrease in CV at 1,000 mg/mL (13.03 +/- 6.51; P < 0.001), 500 mu g/mL (28.87 +/- 9.3; P < 0.001), 200 mu g/mL (54.93 +/- 5.61; P < 0.001), and 100 mu g/mL (82.53 +/- 0.65; P < 0.005) compared with the untreated controls (96.98 +/- 0.16). In R28 cultures, the cTRI treatment also reduced CV values significantly (P < 0.001) for the 1,000 mu g/mL (22.73 +/- 2.44), 500 mu g/mL (34.63 +/- 1.91), 200 mu g/mL (58.70 +/- 1.39), and 100 mu g/m (75.33 +/- 2.47) compared with the untreated controls (86.08 +/- 3.54). Once the TRI was solubilized (sTRI), the CV and Delta Psi m remained similar to the untreated controls for both ARPE-19 and R28 cells. The sTRI treatment with 1,000, 500, and 200 mu g/mL increased in caspase-3/7 activity in ARPE-19 cells (P < 0.01) and in R28 cells (P < 0.05) compared with dimethyl sulfoxide equivalent controls. Conclusion: The crystalline form of TRI (cTRI) can cause a significant decrease in CV to cultured retinal cells. Once the TRI is solubilized (sTRI), at the same concentrations, the cells remain viable with no decrease in CV or Delta Psi m. The sTRI can, however, increase caspase-3/7 activity, thus suggesting some degree of apoptosis.
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Adipose tissue-derived stem cells (ASCs) are among the more attractive adult stem cell options for potential therapeutic applications. Here, we studied and compared the basic biological characteristics of ASCs isolated from humans (hASCs) and mice (mASCs) and maintained in identical culture conditions, which must be examined prior to considering further potential clinical applications. hASCs and mASCs were compared for immunophenotype, differentiation potential, cell growth characteristics, senescence, nuclear morphology, and DNA content. Although both strains of ASCs displayed a similar immunophenotype, the percentage of CD73(+) cells was markedly lower and CD31(+) was higher in mASC than in hASC cultures. The mean population doubling time was 98.08 +/- 6.15 h for hASCs and 52.58 +/- 3.74 h for mASCs. The frequency of nuclear aberrations was noticeably lower in hASCs than in mASCs regardless of the passage number. Moreover, as the cells went through several in vitro passages, mASCs showed changes in DNA content and cell cycle kinetics (frequency of hypodiploid, G0/G1, G2/M, and hyperdiploid cells), whereas all of these parameters remained constant in hASCs. Collectively, these results suggest that mASCs display higher proliferative capacity and are more unstable than hASCs in long-term cultures. These results underscore the need to consider specificities among model systems that may influence outcomes when designing potential human applications.
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Objectives: To analyze the effects of low-level laser therapy (LLLT), 670 nm, with doses of 4 and 7 J/cm(2), on the repair of surgical wounds covered by occlusive dressings. Background Data: The effect of LLLT on the healing process of covered wounds is not well defined. Materials and Methods: For the histologic analysis with HE staining, 50 male Wistar rats were submitted to surgical incisions and divided into 10 groups (n=5): control; stimulated with 4 and 7 J/cm(2) daily, for 7 and 14 days, with or without occlusion. Reepithelization and the number of leukocytes, fibroblasts, and fibrocytes were obtained with an image processor. For the biomechanical analysis, 25 rats were submitted to a surgical incision and divided into five groups (n=5): treated for 14 days with and without occlusive dressing, and the sham group. Samples of the lesions were collected and submitted to the tensile test. One-way analysis of variance was performed, followed by post hoc analysis. A Tukey test was used on the biomechanical data, and the Tamhane test on the histologic data. A significance level of 5% was chosen (p <= 0.05). Results: The 4 and 7J/cm(2) laser with and without occlusive dressing did not alter significantly the reepithelization rate of the wounds. The 7 J/cm(2) laser reduced the number of leukocytes significantly. The number of fibroblasts was higher in the groups treated with laser for 7 days, and was significant in the covered 4 J/cm(2) laser group. Conclusions: Greater interference of the laser-treatment procedure was noted with 7 days of stimulation, and the occlusive dressing did not alter its biostimulatory effects.
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In this study, 222 genome survey sequences were generated for Trypanosoma rangeli strain P07 isolated from an opossum (Didelphis albiventris) in Minas Gerais State, Brazil. T. rangeli sequences were compared by BLASTX (Basic Local Alignment Search Tool X) analysis with the assembled contigs of Leishmania braziliensis, Leishmania infantum, Leishmania major, Trypanosoma brucei, and Trypanosoma cruzi. Results revealed that 82% (182/222) of the sequences were associated with predicted proteins described, whereas 18% (40/222) of the sequences did not show significant identity with sequences deposited in databases, suggesting that they may represent T. rangeli-specific sequences. Among the 182 predicted sequences, 179 (80.6%) had the highest similarity with T. cruzi, 2 (0.9%) with T. brucei, and 1 (0.5%) with L. braziliensis. Computer analysis permitted the identification of members of various gene families described for trypanosomatids in the genome of T. rangeli, such as trans-sialidases, mucin-associated surface proteins, and major surface proteases (MSP or gp63). This is the first report identifying sequences of the MSP family in T. rangeli. Multiple sequence alignments showed that the predicted MSP of T. rangeli presented the typical characteristics of metalloproteases, such as the presence of the HEXXH motif, which corresponds to a region previously associated with the catalytic site of the enzyme, and various cysteine and proline residues, which are conserved among MSPs of different trypanosomatid species. Reverse transcriptase-polymerase chain reaction analysis revealed the presence of MSP transcripts in epimastigote forms of T. rangeli.
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Aims: Surgical staple line dehiscence usually leads to severe complications. Several techniques and materials have been used to reinforce this stapling and thus reduce the related complications. The objective was to compare safety of two types of anastomotic reinforcement in open gastric bypass. Methods: A prospective, randomized study comparing an extraluminal suture, fibrin glue, and a nonpermanent buttressing material, Seamguard (R), for staple line reinforcement. Fibrin glue was excluded from the study and analysis after two leaks, requiring surgical reintervention, antibiotic therapy, and prolonged patient hospitalization. Results: Twenty patients were assigned to the suture and Seamguard reinforcement groups. The groups were similar in terms of preoperative characteristics. No staple line dehiscence occurred in the two groups, whereas two cases of dehiscence occurred in the fibrin glue group. No mortality occurred and surgical time was statistically similar for both techniques. Seamguard made the surgery more expensive. Conclusion: In our service, staple line reinforcement in open bariatric surgery with oversewing or Seamguard was considered to be safe. Seamguard application was considered to be easier than oversewing, but more expensive.
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Background Data: Photodynamic therapy (PDT) involves the photoinduction of cytotoxicity using a photosensitizer agent, a light source of the proper wavelength, and the presence of molecular oxygen. A model for tissue response to PDT based on the photodynamic threshold dose (Dth) has been widely used. In this model cells exposed to doses below Dth survive while at doses above the Dth necrosis takes place. Objective: This study evaluated the light Dth values by using two different methods of determination. One model concerns the depth of necrosis and the other the width of superficial necrosis. Materials and Methods: Using normal rat liver we investigated the depth and width of necrosis induced by PDT when a laser with a gaussian intensity profile is used. Different light doses, photosensitizers (Photogem, Photofrin, Photosan, Foscan, Photodithazine, and Radachlorin), and concentrations were employed. Each experiment was performed on five animals and the average and standard deviations were calculated. Results: A simple depth and width of necrosis model analysis allows us to determine the threshold dose by measuring both depth and surface data. Comparison shows that both measurements provide the same value within the degree of experimental error. Conclusion: This work demonstrates that by knowing the extent of the superficial necrotic area of a target tissue irradiated by a gaussian light beam, it is possible to estimate the threshold dose. This technique may find application where the determination of Dth must be done without cutting the tissue.