Alberto Schanaider

Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil

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Publications (50)89.5 Total impact

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    ABSTRACT: Acute pancreatitis (AP) is an inflammatory disorder that can affect adjacent and/or remote organs. Some evidence indicates that the production of reactive oxygen species is able to induce AP. Protein carbonyl (PC) derivatives, which can also be generated through oxidative cleavage mechanisms, have been implicated in several diseases, but there is little or no information on this biomarker in AP. We investigated the association between some inflammatory mediators and PC, with the severity of ischemia-reperfusion AP. Wistar rats (n = 56) were randomly assigned in the following groups : control; sham, 15- or 180-min clamping of splenic artery, with 24 or 72 h of follow-up. The relationships between serum level of PC and thiobarbituric acid reactive species (TBARS) to myeloperoxidase (MPO) activity in tissue homogenates and to cytokines in culture supernatants of pancreatic samples were analyzed. MPO activity was related to the histology scores and increased in all clamping groups. Tumor necrosis factor-alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin-6 were higher in the 180-min groups. Significant correlations were found between MPO activity and the concentrations of TNF-α and IL-1β. PC levels increased in the 15-min to 24-h group. TBARS levels were not altered substantially. MPO activity and TNF-α and IL-1β concentrations in pancreatic tissue are correlated with AP severity. Serum levels of PC appear to begin to rise early in the course of the ischemia-reperfusion AP and are no longer detected at later stages in the absence of severe pancreatitis. These data suggest that PC can be an efficient tool for the diagnosis of early stages of AP.
    Clinical and experimental medicine. 06/2014;
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    ABSTRACT: Mechanical ventilation with high positive end-expiratory pressure (PEEP) has been used in patients with acute respiratory distress syndrome (ARDS) and intra-abdominal hypertension (IAH), but the role of PEEP in minimizing lung injury remains controversial. We hypothesized that in the presence of acute lung injury (ALI) with IAH: 1) higher PEEP levels improve pulmonary morphofunction and minimize lung injury; and 2) the biological effects of higher PEEP are more effective in extrapulmonary (exp) than pulmonary (p) ALI.
    Critical care (London, England) 06/2014; 18(3):R121. · 4.72 Impact Factor
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    ABSTRACT: PURPOSE: To evaluate the early bone response to a nanotextured dental implant treated with sodium sulfate (Na2SO4), using a rabbit model. METHODS: Twelve animals were randomly divided into group 1 (Control) - machined implants and group 2 (Test) - nanotextured implants. Extra-oral incision was performed to provide access to intended surgical site where the dental implant was inserted immediately after the extraction of the mandibular first premolar. Implant surface characterization was performed by scanning electron microscopy attached to energy dispersive spectroscopy and interferometry. Three weeks after surgery, the animals were induced to death and undecalcified sections of the samples were prepared for histological and histomorphometrical analysis. RESULTS: Surface characterization of the implant demonstrated enhanced surface area of anodized group compared to Control group with 19.2% ± 6.2 versus 1.6 ± 0.7, respectively. Histological evaluation demonstrated new bone formation starting from the buccal and lingual cortical walls on both groups. After three weeks, significant higher bone contact of 27% (p<0.05) was observed to nanotextured compared to machined implants (Control group). CONCLUSION: The anodization with sodium sulfate nanostructures to the implant surface that resulted in faster osseointegration.
    Acta cirurgica brasileira / Sociedade Brasileira para Desenvolvimento Pesquisa em Cirurgia 06/2014; 29(6):376. · 0.48 Impact Factor
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    ABSTRACT: A simple experimental protocol applying a quantitative ultrasound (QUS) pulse-echo technique was used to measure the acoustic parameters of healthy femoral diaphyses of Wistar rats in vivo. Five quantitative parameters [apparent integrated backscatter (AIB), frequency slope of apparent backscatter (FSAB), time slope of apparent backscatter (TSAB), integrated reflection coefficient (IRC), and frequency slope of integrated reflection (FSIR)] were calculated using the echoes from cortical and trabecular bone in the femurs of 14 Wistar rats. Signal acquisition was performed three times in each rat, with the ultrasound signal acquired along the femur's central region from three positions 1 mm apart from each other. The parameters estimated for the three positions were averaged to represent the femur diaphysis. The results showed that AIB, FSAB, TSAB, and IRC values were statistically similar, but the FSIR values from Experiments 1 and 3 were different. Furthermore, Pearson's correlation coefficient showed, in general, strong correlations among the parameters. The proposed protocol and calculated parameters demonstrated the potential to characterize the femur diaphysis of rats in vivo. The results are relevant because rats have a bone structure very similar to humans, and thus are an important step toward preclinical trials and subsequent application of QUS in humans.
    Brazilian Journal of Medical and Biological Research 05/2014; 47(5):403-10. · 1.14 Impact Factor
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    ABSTRACT: Ultrasound parameters were proposed to characterize femur in vitro from rats. Six quantitative parameters (Apparent Integrated Ultrasonic Backscatter -AIB, Frequency Slope of Apparent Backscatter – FSAB, Temporal Slope Apparent Backscatter -TSAB, Integrated Reflection Coefficient -IRC, Slope and Frequency Integrated Reflection -FSIR and Temporal Slope Reflection Coefficient -TSRC) were applied to the echo from the cortical and trabecular bone in twelve femur diaphyses in vitro from Wistar rats. The US signal is acquired from 5 previous chosen positions along the femur. The results showed that their values statistically belong to the same group. This is an indication that the proposed method (from acquisition protocol to parameter estimation) has potential to characterize bone tissue in animal models.
    IWBBIO 2014; 01/2014
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    ABSTRACT: We sought to investigate whether mammalian or ascidian Styela plicata heparin enemas could diminish inflammation in experimental diversion colitis. Wistar-specific pathogen-free rats were submitted to a Hartmann's end colostomy and treated with enemas containing mammalian or Styela plicata heparin, or saline. Enemas were administered 3 times a week in the excluded colon segment from 4 to 8 weeks after operation. The effect of treatment was evaluated using video-endoscopic and histologic scores, measuring the cytokines interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and transforming growth factor-β production in organ cultures by enzyme-linked immunosorbent assay, quantifying T cells and macrophages, and investigating nuclear factor-kappa B (NF-κB) and external mitogen-activated protein kinase (pERK) activation. Treatment with either mammalian or Styela plicata heparins decreased colonoscopic and histologic scores (P < .02) and restored the densities of collagen fibers and the number of goblet cells (P < .03) in the diverted colon. Both heparin treatments decreased the accumulation of T cells and macrophages (P < .03), and the activation of NF-κB and pERK (P < .04) in the diverted colon. The high levels of cytokines IL-1β, TNF-α, and IL-6 from the diversion colitis explants decreased (P < .05) to near normal values with heparin treatments. The improvement of experimental diversion colitis with heparin treatments indicates the anti-inflammatory effect of these compounds, even after topical administration. Further studies with the nonhemorrhagic heparin obtained from the invertebrate Styela plicata will be necessary to confirm its efficacy for the treatment of human diversion colitis and possibly other forms of colitis.
    Surgery 11/2013; · 3.37 Impact Factor
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    ABSTRACT: The P2X7 receptor (P2X7-R) is a non-selective ATP-gated cation channel present in epithelial and immune cells, and involved in inflammatory response. Extracellular nucleotides released in conditions of cell stress or inflammation may function as a danger signal alerting the immune system from inflammation. We investigated the therapeutic action of P2X7-R blockade in a model of inflammatory bowel disease. Rats with trinitrobenzene sulfonic acid-induced colitis were treated with the P2X7-R antagonists A740003 or brilliant blue G (BBG) through intra-peritoneal (IP) or intra-colonic (IC) injection prior to colitis induction. Clinical and endoscopic follow-up, histological scores, myeloperoxidase activity, densities of collagen fibers and goblet cells were evaluated. P2X7-R expression, NF-kappa B and Erk activities, and densities of T-cells and macrophages were analyzed by immunoperoxidase. The inflammatory response was determined by measuring inflammatory cytokines in cultures of colon explants, by ELISA. Colonic apoptosis was determined by the TUNEL assay. IP-BBG significantly attenuated the severity of colitis, myeloperoxidase activity, collagen deposition, densities of lamina propria T-cells and macrophages, while maintaining goblet cells densities. IP-BBG inhibited the increase in P2X7-R expression in parallel with apoptotic rates. TNF-α and interleukin-1β stabilized in low levels, while TGF-β and interleukin-10 did not change following IP-BBG-therapy. Colonic NF-kappa-B and Erk activation were significantly lower in IP-BBG-treated animals. Prophylactic IP-A740003 also protected rats against the development of TNBS-colitis. Prophylactic systemic P2X7-R blockade is effective in the prevention of experimental colitis, probably due to a systemic anti-inflammatory action, interfering with a stress-inflammation amplification loop mediated by P2X7-R.
    Biochimica et Biophysica Acta 10/2013; · 4.66 Impact Factor
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    ABSTRACT: To evaluate the use of a new spherical particle of polyvinyl alcohol and polyvinyl acetate (PVA-PVAc) for uterine artery embolization in patients with myoma with surgical indication. twelve patients underwent uterine myoma embolization with PVA-PVAc particles. Three to nine months later, they were submitted to laparotomy with myomectomy. We analyzed the following parameters: volume of the uterus and of the bigger myoma; concentrations of follicle stimulating hormone and hemoglobin; menstrual bleeding (number of days and used absorbents), signs and symptoms before treatment, after embolization and after myomectomy. The mean age was 37 years and mean uterine volume prior to treatment, 939.3 cc. Three years after embolization, there was reduction in uterine volume (p = 0.0005), increase in hemoglobin concentration after embolization (p = 0.0004), without variation after the myomectomy. There was no significant variation of the follicle stimulating hormone (p = 0.17). There was no case of ovarian failure, but one of the patients had endometrial atrophy. Two patients became pregnant, with good obstetric indicators. Signs and symptoms improved after embolization, and remained after myomectomy. Arterial embolization with spherical PVA-PVAc particles is promising in the preparation for myoma surgery, since it was associated with a reduction in uterine volume, decrease in intraoperative bleeding and made possible the use of smaller incisions, increasing the chance of preserving the uterus.
    Revista do Colégio Brasileiro de Cirurgiões 10/2013; 40(5):386-391.
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    ABSTRACT: Endoscopic ultrasound (EUS) imaging of the colon is an important diagnostic tool for early neoplasia, although usually restricted to the rectum in inflammatory bowel disease (IBD). This study aimed to evaluate the ability of an endoluminal ultrasound biomicroscopic (eUBM) system to detect and characterize lesions simulating Crohn's disease in the colon of rats in vivo. Colitis was induced with trinitrobenzene sulfonic acid instillated in the distal colon. Eighteen Wistar rats were submitted to eUBM in three time points: week 1 group (18 animals examined on day 3 after colitis induction), week 2 group (12 animals on days 3 and 10), and week 3 group (7 animals on days 3, 10, and 17). This design yielded distinct inflammation intensities. Three untreated rats were used for acquisition of control images. Scores were used for comparison with histology. Scores for eUBM and histology in the different moments of examination achieved a Spearman's rank correlation coefficient of 0.87 (p < 0.001). Findings of wall thickening presented positive predictive value (PPV) and sensitivity of 94 and of 100 %, respectively. Superficial and deep ulcers presented a PPV of 89 and 80 %, respectively, and negative predictive values of 100 and 85 %, respectively. Accurate detection and analysis of the lesions was achieved. The model is essential for the clinical development of the technique and a reproducible method for the evaluation of experimental colitis. eUBM might be applicable in different segments of the gut, developing into a novel adjunct method for IBD evaluation.
    International Journal of Colorectal Disease 08/2013; · 2.24 Impact Factor
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    ABSTRACT: To evaluate, in large abdominal wall defects surgically shaped in rats, if a synthetic polypropylene nonwoven prosthesis could be used as a therapeutic option to conventional polypropylene mesh. Twenty four (24) Wistar rats were enrolled into three groups. Group 1 (Simulation group) with an abdominal wall defect of 3 X 3 left untreated and Groups 2 and 3, respectively treated with a conventional polypropylene mesh and a polypropylene nonwoven (NWV) prosthesis to cover the breach. At the 45th postoperatively day, adhesion (area and strength) and vascularization of Groups 2 and 3 were evaluated. The histological preparations with Hematoxylin-Eosin, Tricromium of Masson, Pricrosirius red and polarization with birefringence, and also the structural analysis of the prostheses carried on by Thermogravimetry and Differential Scanning Calorimetry were also assessed. There were no significant differences between the Groups 2 and 3. In rats, the polypropylene nonwoven prosthesis showed to be safe and has to be considered as an alternative to conventional mesh manufactured by weaving in the treatment of great defects of the abdominal wall.
    Acta cirurgica brasileira / Sociedade Brasileira para Desenvolvimento Pesquisa em Cirurgia 10/2012; 27(10):671-80. · 0.48 Impact Factor
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    ABSTRACT: To investigate whether butyrate or glutamine enemas could diminish inflammation in experimental diversion colitis. Wistar specific pathogen-free rats were submitted to a Hartmann's end colostomy and treated with enemas containing glutamine, butyrate, or saline. Enemas were administered twice a week in the excluded segment of the colon from 4 to 12 wk after the surgical procedure. Follow-up colonoscopy was performed every 4 wk for 12 wk. The effect of treatment was evaluated using video-endoscopic and histologic scores and measuring interleukin-1β, tumor necrosis factor-alpha, and transforming growth factor beta production in organ cultures by enzyme linked immunosorbent assay. Colonoscopies of the diverted segment showed mucosa with hyperemia, increased number of vessels, bleeding and mucus discharge. Treatment with either glutamine or butyrate induced significant reductions in both colonoscopic (P < 0.02) and histological scores (P < 0.01) and restored the densities of collagen fibers in tissue (P = 0.015; P = 0.001), the number of goblet cells (P = 0.021; P = 0.029), and the rate of apoptosis within the epithelium (P = 0.043; P = 0.011) to normal values. The high levels of cytokines in colon explants from rats with diversion colitis significantly decreased to normal values after treatment with butyrate or glutamine. The improvement of experimental diversion colitis following glutamine or butyrate enemas highlights the importance of specific luminal nutrients in the homeostasis of the colonic mucosa and supports their utilization for the treatment of human diversion colitis.
    World Journal of Gastroenterology 08/2012; 18(32):4278-87. · 2.55 Impact Factor
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    ABSTRACT: This study evaluated the effectiveness of treating pseudarthrosis in rats by using bone marrow cell suspensions or cultures of bone marrow mesenchymal stromal cells Thirty-eight specific pathogen-free (SPF) animals were randomly assigned to four groups: Group 1, Control, without surgical intervention; Group 2 (Placebo), experimental model of femoral pseudarthrosis treated only with saline solution; Group 3, experimental model of femoral pseudarthrosis treated with heterologous bone marrow cells suspension; Group 4, experimental model of femoral pseudarthrosis treated with cultures of heterologous mesenchymal stromal cells from bone marrow. When pseudarthrosis was confirmed by simple radiological studies, digital radiography and histopathology after a 120-day postoperative period, Groups 2, 3 and 4 were treated as above. At 30, 60 and 90 days after the treatment, all animals were evaluated by simple radiological studies, and at the end of the experiment, the animals were assessed by computed axial tomography and anatomopathological and histomorphometric examinations. Injected cells were detected in the areas affected by pseudarthrosis using scintigraphy within the first 24 hours after their administration. After 60 days, the animals of Group 3 showed callus formation while the animals of Group 4 presented periosteal reaction and had some consolidated areas. In contrast, Group 2 showed a predominance of fibro-osteoid tissue. After 90 days, bone consolidation and remodeling was observed in all animals from Group 3 whereas animals from Group 4 exhibited partial consolidation and those ones from Group 2 persisted with pseudarthrosis. The treatment with heterologous bone marrow cells suspension proved to be effective in the treatment of pseudarthrosis whereas cultures of heterologous bone marrow mesenchymal stromal cells did not show the same potential to aid bone healing.
    Journal of Translational Medicine 03/2012; 10:51. · 3.46 Impact Factor
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    ABSTRACT: In this work, an ultrasound (US) pulse-echo method was proposed to characterize long bone diaphysis of in vivo animal model. Two quantitative parameters (Integrated Reflection Coefficient ?? IRC and Frequency slope integrated reflection - FSIR) related to US reflection, were applied to the echo from the muscle/bone interface in both femurs of five Wistar rats. FSIR is proposed here is the fraction of the apparent reflection corresponding to each frequency. The US signal is acquired from 3 previous chosen positions, one millimeter apart from each other, along the femur central region. The parameters were estimated for the three positions than averaged to represent the femur. The results showed that their values statistically belong to the same group. This is indication that the proposed method (from acquisition protocol to parameter estimation) has potential to characterize normal in vivo long bones in animal models.
    Health Care Exchanges (PAHCE), 2012 Pan American; 01/2012
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    ABSTRACT: Mesenchymal stromal cells (MSCs) were shown to have immunomodulatory activity and have been applied for treating immune-mediated disorders. We compared the homing and therapeutic action of cryopreserved subcutaneous adipose tissue (AT-MSCs) and bone marrow-derived mesenchymal stromal cells (BM-MSCs) in rats with trinitrobenzene sulfonic acid (TNBS)-induced colitis. After colonoscopic detection of inflammation AT-MSCs or BM-MSCs were injected intraperitoneally. Colonoscopic and histologic scores were obtained. Density of collagen fibres and apoptotic rates were evaluated. Cytokine levels were measured in supernatants of colon explants. For cell migration studies MSCs and skin fibroblasts were labelled with Tc-99m or CM-DiI and injected intraperitonealy or intravenously. Intraperitoneal injection of AT-MSCs or BM-MSCs reduced the endoscopic and histopathologic severity of colitis, the collagen deposition, and the epithelial apoptosis. Levels of TNF-α and interleukin-1β decreased, while VEGF and TGF-β did not change following cell-therapy. Scintigraphy showed that MSCs migrated towards the inflamed colon and the uptake increased from 0.5 to 24 h. Tc-99m-MSCs injected intravenously distributed into various organs, but not the colon. Cm-DiI-positive MSCs were detected throughout the colon wall 72 h after inoculation, predominantly in the submucosa and muscular layer of inflamed areas. Intraperitoneally injected cryopreserved MSCs home to and engraft into the inflamed colon and ameliorate TNBS-colitis.
    PLoS ONE 01/2012; 7(3):e33360. · 3.53 Impact Factor
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    ABSTRACT: The present work tested the capability of ultrasound biomicroscopy (UBM), at 45 MHz, to provide cross-sectional images with appropriate resolution and contrast to detect tumors and determine their penetration depths on the colon of mice, Mus musculus (Linnaeus 1758), treated with carcinogen for colon tumor induction. B-mode images were obtained, in vitro, from each animal (13 treated and 4 untreated) colon opened longitudinally and immersed in saline solution at room temperature. Prior to UBM inspection, all animals were also examined by colonoscopy. The layers of normal colon identified by UBM are: mucosa (hyperechoic), muscularis mucosae (hypoechoic), submucosa (hyperechoic) and muscularis externa (hypoechoic). UBM images of colon lesions presented structures corresponding to tumors (hyperechoic), lymphoid hyperplasia (hypoechoic) and polypoid tumors (hyperechoic). Additionally, tumoral lesion invasion through the colon was also identified. When compared with histopathologic analysis, all colon lesions detected by UBM were confirmed, while colonoscopic findings had two false negatives.
    Ultrasound in medicine & biology 12/2011; 37(12):2086-95. · 2.46 Impact Factor
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    ABSTRACT: Analyze the morphological and structural outcomes of a patch of expanded polytetrafluoroethylene in the treatment of an iatrogenic injury of the common bile duct. In Group 1 (Sham), 7 dogs underwent 3 laparotomies with intervals of 30 days between them. In Group 2, 10 dogs underwent transient common bile duct obstruction. After 30 days, this biliary occlusion was undone and a patch of expanded polytetrafluoroethylene replaced a fragment removed from the duct's wall. Thirty days after this last surgery, cholangiographic assessment of prosthesis patency and macro and microscopic evaluation of the biliary tract were performed. Daily clinical inspection completed the study outcomes. The Wilcoxon non-parametric test was used for statistical analysis. In all dogs enlargement of the biliary tree diameter was observed 30 and 60 days after the first surgical procedure. Partial adhesion of the patch to the common bile duct as a free luminal foreign body was found in 6 dogs. The prosthesis was completely integrated to surrounding tissue in the remaining four. Although a feasible option for the treatment of biliary duct iatrogenic lesions, the expanded polytetrafluoroethylene prosthesis must be used with caution considering the potential risks for complications.
    Acta cirurgica brasileira / Sociedade Brasileira para Desenvolvimento Pesquisa em Cirurgia 08/2011; 26(4):247-52. · 0.48 Impact Factor
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    ABSTRACT: To describe an experimental, unprecedented model that mimics the abdominal compartment syndrome (ACS). twenty rats were randomly divided into four groups. To simulate ACS intra-abdominal hypertension (IAH) was induced by inserting cotton surgical dressing (Zobec ®), 15x15cm (intra-abdominal pressure constant and equal to 12 mmHg) associated with hypovolemia induced by withdrawing blood, keeping mean arterial pressure (MAP) around 60 mmHg (HYPO). To dissociate the effects of those IAH-induced hypovolemia per se, two other groups were analyzed: one with only with IAH and another with only hypovolemia. The simulation group (sham) underwent the same surgical procedure performed earlier, however, the levels of intra-abdominal pressure and MAP were kept in 3 mmHg and 90 mmHg, respectively. By analyzing the impact of IAH on the small intestine, we observed necrosis of the villi, congestion, and neutrophilic infiltration. Hypovolemia induced only inflammation and edema of the villi. However, the association of IAH and HYPO led to hemorrhagic infarction, besides worsening of the aforementioned parameters. This model was effective in inducing ACS expressed by the effects found in the small intestine.
    Revista do Colégio Brasileiro de Cirurgiões 01/2011; 38(6):417-21.
  • Gastroenterology 01/2011; 140(5). · 12.82 Impact Factor
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    ABSTRACT: The aim of this study was to describe an experimental surgical technique to be used in the evaluation of bone grafts in rabbits. The operative technique was performed in jaws, with external approach from the labial commissure to the last molar tooth. An incision about 1cm extended forward to the alveolar ridge, followed by a exposing the cervical region of the alveolar bone and dental elements was done. Thus, after extraction of first molar with forceps, the tooth socket left was filled with hydroxyapatite. The bone gain was analyzed by histopathological studies. The histological analyses indicated formed bone surrounding the biomaterial. The experimental model using the tooth socket of the rabbit molar is a feasible procedure for studies of bone grafts.
    Acta cirurgica brasileira / Sociedade Brasileira para Desenvolvimento Pesquisa em Cirurgia 01/2011; 26 Suppl 2:66-9. · 0.48 Impact Factor
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    ABSTRACT: Quantitative Ultrasound (QUS) is a new possibility for non-ionizing diagnosis and monitoring of bone diseases which are usually monitored by radiographs. In this work, an ultrasound (US) pulse-echo method was proposed to in vivo signal acquisition for long bone characterization in an animal model. Two parameters, one related to US backscattering from bone and the other to US reflection at the muscle/bone interface, were calculated in both femurs of seven rats and the results showed that their values statistically belong to the same group. This is indication that the proposed protocol has potential to characterize normal in vivo long bones in animal models.
    Health Care Exchanges (PAHCE), 2011 Pan American; 01/2011