Publications by authors named "Vinicius Faccin Bampi"

7 Publications

  • Page 1 of 1

Cortical thickness and subcortical volume abnormalities in male crack-cocaine users.

Psychiatry Res Neuroimaging 2021 Apr 23;310:111232. Epub 2020 Nov 23.

Department of Neuroscience, Pontifical Catholic University of Rio Grande do Sul, 90619900, Porto Alegre, Brasil.

Crack-cocaine offers a higher risk of abuse than intranasal and intravenous use of cocaine. Yet, current treatments remain disappointing and our understanding of the mechanism of crack-cocaine neurotoxicity is still incomplete. Magnetic resonance images studies on brain changes of crack-cocaine addicts show divergent data. The present study investigated gray matter (GM) abnormalities in crack-cocaine dependents (n = 18) compared to healthy controls (n = 17). MRI data was analysed using FreeSurfer and voxel-based morphometry (VBM). FreeSurfer analysis showed that CD had decreased cortical thickness (CT) in the left inferior temporal cortex (lTC), left orbitofrontal cortex (lOFC) and left rostro frontal cortex (lRFC), enlargement in left inferior lateral ventricle, and smaller GM volume in right hippocampus and right ventral diencephalon. VBM analysis showed that CD had significantly decreased GM volume in left Putamen and left nucleus accumbens. Furthermore, we found a negative correlation between duration of crack-cocaine use and lTC CT. These results provide compelling evidence for GM abnormalities in CD and also suggest that duration of crack-cocaine use may be associated with CT alterations.
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http://dx.doi.org/10.1016/j.pscychresns.2020.111232DOI Listing
April 2021

Effect of platelet-rich plasma on rat Achilles tendon healing is related to microbiota.

Acta Orthop 2017 08 15;88(4):416-421. Epub 2017 Mar 15.

a Department of Clinical and Experimental Medicine, Orthopedics , Linköping University , Linköping , Sweden.

Background and purpose - In 3 papers in Acta Orthopaedica 10 years ago, we described that platelet-rich plasma (PRP) improves tendon healing in a rat Achilles transection model. Later, we found that microtrauma has similar effects, probably acting via inflammation. This raised the suspicion that the effect ascribed to growth factors within PRP could instead be due to unspecific influences on inflammation. While testing this hypothesis, we noted that the effect seemed to be related to the microbiota. Material and methods - We tried to reproduce our old findings with local injection of PRP 6 h after tendon transection, followed by mechanical testing after 11 days. This failed. After fruitless variations in PRP production protocols, leukocyte concentration, and physical activity, we finally tried rats carrying potentially pathogenic bacteria. In all, 242 rats were used. Results - In 4 consecutive experiments on pathogen-free rats, no effect of PRP on healing was found. In contrast, apparently healthy rats carrying Staphylococcus aureus showed increased strength of the healing tendon after PRP treatment. These rats had lower [corrected] levels of cytotoxic T-cells in their spleens. Interpretation - The failure to reproduce older experiments in clean rats was striking, and the difference in response between these and Staphylococcus-carrying rats suggests that the PRP effect is dependent on the immune status. PRP functions may be more complex than just the release of growth factors. Extrapolation from our previous findings with PRP to the situation in humans therefore becomes even more uncertain.
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http://dx.doi.org/10.1080/17453674.2017.1293447DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5499334PMC
August 2017

The promoting effect of carbamide peroxide teeth bleaching gel in a preclinical model of head and neck cancer in hamster buccal pouch.

Clin Exp Otorhinolaryngol 2014 Sep 1;7(3):210-5. Epub 2014 Aug 1.

Department of Morphology Science, Federal University of Pelotas, Pelotas, Brazil.

Objectives: The aim of this study was to verify the promoting effect of carbamide peroxide on dimethylbenzanthracene (DMBA)-induced carcinogenesis in the hamster buccal pouch, in order to reduce the period of latency for tumor formation.

Methods: Sixteen hamsters were randomized into two groups of eight animals each. The hamsters of the group I had their right buccal pouches treated with 0.5% DMBA and 10% carbamide peroxide teeth bleaching gel for 55 days. The animals of the group II had their right pouches treated only with DMBA. After, six animals of each group had their pouches prepared for light microscopy. Histomorphometry was performed to assess the presence of keratinization, nuclear polymorphism, pattern of invasion, number of blood vessels, and inflammatory infiltrate in the tumor front. Furthermore, the newly formed lesions were graded according the Bryne's grading system. The remaining animals had the vascular system of the pouches casted by Mercox and qualitatively analyzed by scanning electron microscopy.

Results: Histopathological analysis of the buccal pouches treated with DMBA and carbamide peroxide exhibited formation of squamous cell carcinoma well-differentiated with a high degree of malignancy in all pouches. The development of this neoplasm was associated with a significant increase in the number of blood vessels, presence of keratin pearls, and inflammatory infiltrate. The pouches of the group II showed inflammation, epithelial hyperplasia, dysplasia, and squamous cell carcinoma in only three right pouches. The analysis of the electron micrographs of the pouches chemically inducted with DBMA and carbamide peroxide reveled formation of a new vascular network characteristic of squamous cell carcinoma.

Conclusion: The protocol presented here, using DMBA associated with carbamide peroxide, shortens the period of latency to produce squamous cell carcinoma in the hamster buccal pouch, decreasing the time and costs of the experiments.
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http://dx.doi.org/10.3342/ceo.2014.7.3.210DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4135158PMC
September 2014

The effect of the anti-angiogenic drug sunitinib malate on the vascular architecture of oral squamous cell carcinoma.

Microsc Res Tech 2014 Apr 23;77(4):250-6. Epub 2014 Jan 23.

Department of Surgery, Medical School, Pontifical Catholic University of Rio Grande do Sul, Av. Ipiranga, 6681, Porto Alegre/RS, CEP: 90619-900, Porto Alegre, Rio Grande do Sul, Brazil.

The effects of anti-angiogenic therapies in guiding tumor angioarchitecture prompted us to examine the modifications in the vascular network of the oral squamous cell carcinoma (SCC) produced by the multitargeted tyrosine kinase inhibitor sunitinib malate. Twelve Syrian hamsters had their right buccal pouches submitted to tumor induction with dimethylbenzanthracene and carbamide peroxide for 55 days. The animals were then divided into two groups of six animals each; group I was treated with sunitinib malate and group II (control) was remained untreated. After 4 weeks, the hamsters had their vascular networks casted by Mercox® resin and analyzed by scanning electron microscopy. The qualitative study of the vascular network of the control tumor-bearing pouches showed images of intussusception and sprouting angiogenesis, flattened blood vessels, abrupt variations in their diameter, and a tortuous course. The samples treated with sunitinib exhibited a qualitative reduction of the signs of vascular proliferation. In addition, these casts presented an attenuation of the morphological features observed in the untreated tumor-bearing pouches. Quantitative analysis demonstrated that the pouches treated with sunitinib did not show a decrease (P > 0.05) in the vascular diameter and intervessel distances when compared with the control group. The results of the present study suggest that sunitinib may act on the vascular network of oral SCC, normalizing the blood vessels. However, further experiments should be performed in order to determine a judicious dose of this anti-angiogenic therapy.
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http://dx.doi.org/10.1002/jemt.22336DOI Listing
April 2014

Morphological characterization of sprouting and intussusceptive angiogenesis by SEM in oral squamous cell carcinoma.

Scanning 2014 May-Jun;36(3):293-300. Epub 2013 Jun 25.

Department of Morphology Science, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil.

The word angiogenesis indicates the formation of new vascular segments from existing vessels such as capillaries and venules. Blood vessel formation in tumors is the result of rapid, disorganized vascular growth through two distinct mechanisms: sprouting and intussusceptive angiogenesis. The objective of this study was to elucidate the morphological aspects of these two vascular growth mechanisms in oral squamous cell carcinoma induced in hamster buccal pouch. Eight Syrian golden hamsters had their right buccal pouch treated with DMBA 0.5% and 10% carbamide peroxide for 90 days in order to produce squamous cell carcinoma in this site. Next, buccal pouches of the animals were submitted to the vascular corrosion technique and then analyzed by scanning electron microscopy. The vascular figures of sprouts were observed in the entire vascular network of the buccal pouches, as opposed to the intussusceptive angiogenesis that was predominantly observed in the sub-epithelial network. It was possible to differentiate the figures of sprouts from artifacts by the analysis of the blind ending of these structures. Intussusceptive angiogenesis was identified by the presence of holes trespassing the lumen of the capillaries. Vascular expansion occurred through intussusceptive angiogenesis in two ways: by the fusion of the pillars to form a new capillary and, by increasing the girth of the pillar to form meshes. The method of corrosion associated with scanning electron microscopy proved to be an excellent tool to study the two types of angiogenesis in oral squamous cell carcinoma in the hamster buccal pouch.
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http://dx.doi.org/10.1002/sca.21104DOI Listing
April 2015

Angioarchitecture of squamous cell carcinoma from hamster buccal pouch: a scanning electron microscopy study.

Scanning 2009 Sep-Oct;31(5):188-94

Department of Morphology Science, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil.

Tumoral angiogenesis has been widely studied by histochemical analysis but little has been done regarding morphology of these new vessels. The objective of this study was to perform a qualitative analysis of the angiogenic response to chemical induction with dimethylbenzanthracene (DMBA) and carbamide peroxide of squamous cell carcinoma in pouches of Syrian hamsters after different periods of treatment. Twenty-four Syrian golden hamsters, divided into three groups of eight animals each, had their right jugal pouches treated with a 5% DMBA solution three times a week and a 10% carbamide peroxide two times a week for 55, 70 and 90 days. The left pouch was considered the control. After tumor induction, five animals in each group had their pouches prepared for analysis under scanning electron microscopy and three animals for analysis under light microscopy. The control pouches showed a vascular system composed by few main vessels running parallel to the longest axis of the pouch with some branches. In the pouches submitted to tumor induction, a well-differentiated squamous cell carcinoma was present since 55 days induction in all samples. The new vascular system showed the presence of many tortuous vessels and the majority of them were veins and capillaries. Terminal loops were extremely sinuous adopting a glomerular or corkscrew shape. These tumor vessels are different from normal vessels, presenting irregular diameters, outpouchings and constrictions. Angiogenesis of sprouting and intussusceptive kind could be identified in the tumor pouches, and they were more frequent as the tumor developed.
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http://dx.doi.org/10.1002/sca.20161DOI Listing
March 2010