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1.  Sublethal Microcystin Exposure and Biochemical Outcomes among Hemodialysis Patients 
PLoS ONE  2013;8(7):e69518.
Cyanobacteria are commonly-occurring contaminants of surface waters worldwide. Microcystins, potent hepatotoxins, are among the best characterized cyanotoxins. During November, 2001, a group of 44 hemodialysis patients were exposed to microcystins via contaminated dialysate. Serum microcystin concentrations were quantified with enzyme-linked immunosorbent assay which measures free serum microcystin LR equivalents (ME). We describe serum ME concentrations and biochemical outcomes among a subset of patients during 8 weeks following exposure. Thirteen patients were included; 6 were males, patients’ median age was 45 years (range 16–80), one was seropositive for hepatitis B surface antigen. The median serum ME concentration was 0.33 ng/mL (range: <0.16–0.96). One hundred thirty nine blood samples were collected following exposure. Patients’ biochemical outcomes varied, but overall indicated a mixed liver injury. Linear regression evaluated each patient’s weekly mean biochemical outcome with their maximum serum ME concentration; a measure of the extrinsic pathway of clotting function, prothrombin time, was negatively and significantly associated with serum ME concentrations. This group of exposed patients’ biochemical outcomes display evidence of a mixed liver injury temporally associated with microcystin exposure. Interpretation of biochemical outcomes are complicated by the study population’s underlying chronic disease status. It is clear that dialysis patients are a distinct ‘at risk’ group for cyanotoxin exposures due to direct intravenous exposure to dialysate prepared from surface drinking water supplies. Careful monitoring and treatment of water supplies used to prepare dialysate is required to prevent future cyanotoxin exposure events.
PMCID: PMC3722218  PMID: 23894497
2.  1-Aryl-3-[4-(thieno[3,2-d]pyrimidin-4-yloxy)phenyl]ureas as VEGFR-2 Tyrosine Kinase Inhibitors: Synthesis, Biological Evaluation, and Molecular Modelling Studies 
BioMed Research International  2013;2013:154856.
The vascular endothelial growth factor receptor-2 (VEGFR-2) is a tyrosine kinase receptor involved in the growth and differentiation of endothelial cells that are implicated in tumor-associated angiogenesis. In this study, novel 1-aryl-3-[4-(thieno[3,2-d]pyrimidin-4-yloxy)phenyl]ureas were synthesized and evaluated for the VEGFR-2 tyrosine kinase inhibition. Three of these compounds showed good VEGFR-2 inhibition presenting low IC50 values (150–199 nM) in enzymatic assays, showing also a significant proliferation inhibition of VEGF-stimulated human umbilical vein endothelial cells (HUVECs) at low concentrations (0.5–1 µM), using the Bromodeoxyuridine (BrdU) assay, not affecting cell viability. The determination of the total and phosphorylated (active) VEGFR-2 was performed by western blot, and it was possible to conclude that the compounds significantly inhibit the phosphorylation of the receptor at 1 µM pointing to their antiproliferative mechanism of action in HUVECs. The molecular rationale for inhibiting the tyrosine kinase domain of VEGFR-2 was also performed and discussed using molecular docking studies.
PMCID: PMC3722775  PMID: 23936775
3.  Dilated fetal bowel as indication for prenatal diagnosis of cystic fibrosis 
BMJ Case Reports  2010;2010:bcr0320102868.
Dilated fetal bowel is a sonographic finding that is associated to meconium ileus, a feature of cystic fibrosis (CF). Prenatal diagnosis of CF is possible through analysis of the cystic fibrosis transmembrane regulator gene mutations.
A male infant is described, who was referred to our Prenatal Diagnosis Center a 17th week of gestation with a dilated bowel loop on a prenatal scan. Amniocentesis was performed at 23rd week gestation and a homozygous F508del mutation was found. He was born at 38 weeks gestation, after an otherwise unremarkable pregnancy, and admitted to Neonatal Intensive Care Unit. He showed progressive abdominal distension without stools and was transferred to another Hospital to surgery. A total occlusion of terminal ileum with meconium and a microcolon were found, and resection of 8 cm of ileum and an ileostomy were performed.
The characteristic sonographic finding of a dilated bowel is an indication to search for CF mutations.
PMCID: PMC3027772
4.  Erectile tissue molecular alterations with aging—differential activation of the p42/44 MAP Kinase pathway 
Age  2010;33(2):119-130.
Erectile dysfunction (ED) is a common problem in aged men; however, the molecular events involved in aging ED remain unclear. To better characterize the effects of aging in the penis, we evaluated cavernosal tissue remodeling capability and the downstream activation of the intracellular signaling mediator mitogen-activated protein p42/44 kinase (p42/44 MAPK). We used male Wistar rats, which were divided in groups of 2, 6, 12, 18, and 24 months old. Penile tissues were harvested and processed for protein isolation and immunohistochemical analysis. Cavernosal viability was assessed by TUNEL assay, and proliferation was analyzed by immunohistochemical detection of proliferating cell nuclear antigen (PCNA). Immunolocalization of the activated form of p42/44 MAPK was evaluated by immunofluorescence, and changes in its phosphorylation status were quantified by western blotting. p42/44 phosphorylation profile was also assessed in situ in human young and elderly cavernosal samples. With the advancement of age, experimental cavernosal tissue remodeling was affected by an age-dependent unbalance between the rate of apoptosis and proliferation, in all erectile components. Moreover, this turnover alteration was accompanied by significant modifications in the activation profile of the downstream effector p42/44 MAPK. In the youngest corporeal samples, p42/44 was mostly activated at perivascular sites, potentially mediating cell survival/proliferation. However, in elderly experimental erectile tissue, p42/44 phosphorylation shifted to trabecular fibroblasts, indicating a potential role in extracellular matrix (ECM) production. More importantly, the same differential pattern of p42/44 activation was observed in human young and aged cavernosal fragments, suggesting a distinct function of this protein with aging. We provided evidence for the first time that with the advancement of age, there is a differential activation of p42/44 MAPK in cavernosal tissue, which may promote ECM expansion and fibrosis, therefore compromising erectile function in the elderly.
PMCID: PMC3127464  PMID: 20628826
Aging; Erectile dysfunction; Erectile tissue; Apoptosis; Proliferation; p42/44 kinase
5.  Implanted neonatal human dermal fibroblasts influence the recruitment of endothelial cells in mice 
Biomatter  2012;2(1):43-52.
The vascularization of new tissue within a reasonable time is a crucial prerequisite for the success of different cell- and material-based strategies. Considering that angiogenesis is a multi-step process involving humoral and cellular regulatory components, only in vivo assays provide the adequate information about vessel formation and the recruitment of endothelial cells. The present study aimed to investigate if neonatal human dermal fibroblasts could influence in vivo neovascularization. Results obtained showed that fibroblasts were able to recruit endothelial cells to vascularize the implanted matrix, which was further colonized by murine functional blood vessels after one week. The vessels exhibited higher levels of hemoglobin, compared with the control matrix, implanted without fibroblasts, in which no vessel formation could be observed. No significant differences were detected in systemic inflammation. The presence of vessels originated from the host vasculature suggested that host vascular response was involved, which constitutes a fundamental aspect in the process of neovascularization. Fibroblasts implanted within matrigel increased the presence of endothelial cells with positive staining for CD31 and for CD34 and the production of collagen influencing the angiogenic process and promoting the formation of microvessels. New strategies in tissue engineering could be delineated with improved angiogenesis using neonatal fibroblasts.
PMCID: PMC3849057  PMID: 23507785
angiogenesis; endothelial cells; fibroblasts; regenerative medicine; tissue engineering; vascular networks
6.  Tachykinin receptors antagonism for asthma: a systematic review 
Tachykinins substance P, neurokinin A and neurokinin B seem to account for asthma pathophysiology by mediating neurogenic inflammation and several aspects of lung mechanics. These neuropeptides act mainly by their receptors NK1, NK2 and NK3, respectively which may be targets for new asthma therapy.
This review systematically examines randomized controlled trials evaluating the effect of tachykinins receptors antagonism on asthma. Symptoms, airway inflammation, lung function and airway inflammation were considered as outcomes. We searched the Cochrane Airways Group Specialized Register of Asthma Trials, Cochrane Database of Systematic Reviews, MEDLINE/PubMed and EMBASE. The search is as current as June 2010. Quality rating of included studies followed the Cochrane Collaboration and GRADE Profiler approaches. However, data were not pooled together due to different measures among the studies.
Our systematic review showed the potential of NK receptor antagonist to decrease airway responsiveness and to improve lung function. However, effects on airway inflammation and asthma symptoms were poorly or not described.
The limited available evidence suggests that tachykinin receptors antagonists may decrease airway responsiveness and improve lung function in patients with asthma. Further large randomized trials are still required.
PMCID: PMC3163224  PMID: 21810226
7.  Anti-angiogenic effects of pterogynidine alkaloid isolated from Alchornea glandulosa 
Angiogenesis, a complex multistep process that comprehends proliferation, migration and anastomosis of endothelial cells (EC), has a major role in the development of pathologic conditions such as inflammatory diseases, tumor growth and metastasis. Brazilian flora, the most diverse in the world, is an interesting spot to prospect for new chemical leads, being an important source of new anticancer drugs. Plant-derived alkaloids have traditionally been of interest due to their pronounced physiological activities. We investigated the anti-angiogenic potential of the naturally occurring guanidine alkaloid pterogynidine (Pt) isolated from the Brazilian plant Alchornea glandulosa. The purpose of this study was to examine which features of the angiogenic process could be disturbed by Pt.
Human umbilical vein endothelial cells (HUVEC) were incubated with 8 μM Pt and cell viability, proliferation, apoptosis, invasion and capillary-like structures formation were addressed. Nuclear factor κB (NFκB), a transcription factor implicated in these processes, was also evaluated in HUVEC incubated with Pt. Quantifications were expressed as mean ± SD of five independent experiments and one-way analysis of variance (ANOVA) followed by the Dunnet test was used.
A significant decrease in proliferation and invasion capacity and an effective increase in apoptosis as assessed by bromodeoxyuridine (BrdU), double-chamber and terminal transferase dUTP nick end labeling (TUNEL) assay, respectively, have been found. Pt also led to a drastic reduction in the number of capillary-like structures formation when HUVEC were cultured on growth factor reduced-Matrigel (GFR-Matrigel) coated plates. In addition, incubation of HUVEC with Pt resulted in reduced NFκB activity.
These findings emphasize the potential use of Pt against pathological situations where angiogenesis is stimulated as tumor development.
PMCID: PMC2694145  PMID: 19463163
8.  Evidence for the Effects of Xanthohumol in Disrupting Angiogenic, but not Stable Vessels 
Angiogenesis is a complex multistep process that comprises proliferation, migration, and anastomosis of endothelial cells, followed by stabilization of the newly formed vessel through the attachment of support cells. This process is imbalanced in a large number of disorders, including cardiovascular disease, diabetes and cancer. Evidence indicates that xanthohumol (XN), a prenylated chalcone present in beer, exerts anti-angiogenic properties. However, its precise effect within the angiogenic steps is not accurately established. The purpose of the present study was to examine which features of the angiogenic process can be disturbed by XN. Human umbilical vein endothelial cells (HUVEC) and human fetal aortic smooth muscle cells (SMC) were incubated with xanthohumol at 5 and 10 μM, and cell viability, apoptosis, invasion and capillary-like structures formation were examined. Treatment with 10 μM XN significantly decreased viability and invasion capacity and increased apoptosis in both cell types as assessed by MTT, double-chamber assay and TUNEL assay respectively. The two concentrations of XN further led to a significant reduction in the number of capillary-like structures, when HUVEC were cultured on growth factor reduced-Matrigel-coated plates. Interestingly, XN exhibited the opposite effect when HUVEC were co-cultured with SMC, leading to an increase in the number of cord structures. In addition, incubation of both types of cells with XN resulted in reduced activity of NFκB, a transcription factor implicated in these cell fates. Given the absence of adverse effects in mature vasculature by XN, these findings emphasize the potential use of XN against pathological situations where angiogenesis is stimulated.
PMCID: PMC3614657  PMID: 23675054
angiogenesis; endothelium; matured vessels; neovessels; polyphenols; smooth muscle cells

Results 1-9 (9)