Mariana Montenegro de Melo Lira

Biocompatibility of the bacterial cellulose hydrogel in subcutaneous tissue of rabbits

PURPOSE To evaluate the biocompatibility and local sensibility reaction to bacterial cellulose hydrogel (0.8%) implanted in subcutaneous tissue of rabbits. METHODS Fifteen New Zeland rabbits were randomly allocated into three groups: T1, 7 days, T2, 21 days, and T3, 84 days. The new material was implanted in the subcutaneous tissue of the ear; on the scalp over the periosteum; and on the outer and inner surfaces of the thighs, in the aponeurosis of the muscle. At 7, 21 and 84 postoperative days, the material was collected for histological study. The clinical signs, inflammatory response, angiogenesis and fibrogenesis were variables used for analysis of the biocompatibility and biological reactivity to BCH. Analyses were performed with an AXIO(r) Imager. The statistical tests were performed using the GraphPad Prism 5.0 program(r) RESULTS The intensity of the inflammatory infiltrate, considering the different cell types (PMN, LMN and GC), was statistically significant, with group T1 different from groups T2 and T3 (p = 0.0124 and p <0.0001, respectively) and T2 different from the T3 group (p = 0.0007). Fibrogenesis grade 1 was the most prevalent in groups T1 (55.4%) and T2 (44.6%). The formation of neovascularization in the group was identified in 84.4% of samples. CONCLUSION Bacterial cellulose hydrogel (0.8%) is biocompatible, integrating with the subcutaneous tissue of rabbits and inducing tissue remodeling.

The Biocompatibility of a Cellulose Exopolysaccharide Implant in the Rabbit Bladder When Compared With Dextranomer Microspheres Plus Hyaluronic Acid

OBJECTIVE To evaluate biocompatibility of a cellulosic exopolysaccharide (CEC) as bulking agent in rabbit urinary bladder. MATERIALS AND METHODS The experimental study was developed at the Nucleus for Experimental Surgery or UFPE. The new agent was injected into the bladder of the adult rabbits using a small abdominal incision. Animals were injected with 0.2 mL of dextranomer microspheres (Dx) plus hyaluronic acid and CEC. The animals were studied after 3 days (G1), 90 days (G2), and 11 months (G3). The biocompatibility was evaluated according to the histologic parameters (presence of blood vessels, inflammatory reaction, and collagen deposition) by a quantitative analysis. The Student paired t test was used for continuous variables, and the scores were compared through the chi-square test. RESULTS Both materials were structurally homogeneous and free from inflammatory cells or blood vessels (G1). In 3-month samples (G2), CEC areas were densely invaded by fibroblasts and blood vessels. Dx areas were fragmented but still homogeneous and free from cells or blood vessels. Samples from 3 and 11 months showed a significant difference in favor of CEC especially concerning preservation of material in the implant site, as well as the presence of neovascularization. This experimental study represents a positive outcome in terms of reflux resolution in the long term. Further studies may be necessary to confirm its efficacy when in clinical use. CONCLUSION The CEC exhibited low inflammatory response and integrated with the host tissue better than Dx in the long-term follow-up.

Effect of sugarcane biopolymer in vocal fold of rabbits. Comparative study with calcium hydroxyapatite

PURPOSE To compare the inflammatory reaction caused by the injection of a sugarcane biopolymer (SCB) into the vocal fold of rabbits with that caused by calcium hydroxyapatite (CaH). METHODS CaH (Radiesse(r)) and SCB gel were injected respectively into the right and left vocal cords of thirty rabbits. The rabbits were distributed into two equal groups and sacrificed at three and twelve weeks after injection. We then evaluated the intensity of the inflammatory reaction, plus levels of neovascularization, fibrogenesis and inflammatory changes in the vocal mucosa. RESULTS The vocal cords injected with CaH had a stronger inflammatory reaction by giant cells in both study periods. The SCB group had a more intense inflammatory involvement of polymorphonuclear cells three weeks after injection. SCB caused a higher level of neovascularization compared with CaH three weeks after the procedure. CONCLUSION Whereas calcium hydroxyapatite triggers a more intense and lasting inflammatory reaction mediated by giant cells, sugarcane biopolymer causes a greater response from polymorphonuclear leukocytes, as well as higher levels of vneoascularization three weeks after injection.

Comparing the Immunoexpression of FUT3 and FUT6 between Prostatic Adenocarcinoma and Benign Prostatic Hyperplasia.

Prostatic Adenocarcinoma (PA) and Benign Prostatic Hyperplasia (BPH) have their etiology not fully understood mainly in glycidic aspects. Glycan changes are associated with cell alterations where glycosylation is carried out by glycosyltransferases, such as fucosyltransferases (FUTs). These enzymes catalyze the insertion of L-fucose residues in a variety of glycan structures often in the final stage of glycosylation. The present study aimed to investigate the expression of FUT3 and FUT6 in PA and BPH as well as to correlate immunostaining of these transferases with PA clinic-histopathologic data. The FUT3 and FUT6 expressions were evaluated by immunohistochemistry in formalin-fixed, paraffin-embedded biopsies of PA (n=40) and BPH (n=40). FUT3 and FUT6 showed a high expression in both prostatic diseases, especially FUT6. FUT6 was more immunoexpressed in PA cases than the FUT3 (p<0.0001) as well as in BPH cases but in a not significant way (p=0.0661). Besides, FUT3 was more expressed in BHP lesion than in PA cases (p<0.0001). Our study presented a new data about FUT3 and FUT6 expression in PA and BPH, revealing high FUT6 expression in both lesions and FUT3 overexpression in BHP in relation to PA, proposing that this enzyme could be a promising biomarker for benign prostate alterations.

Bacterial cellulose to reinforce urethrovesical anastomosis. A translational study

PURPOSE To evaluate the efficacy of the cellulosic exopolysaccharide membrane (CEM) as a urethral reinforcement for urethrovesical anastomosis. METHODS Twenty eight rabbits were submitted to urethrovesical anastomosis with or without CEM reinforcement. The animals were divided into 4 groups: C7, CEM7, C14 and CEM14: (C= only anastomosis or CEM = anastomosis + CEM), evaluated after 7 weeks, and 14 weeks. The biointegration and biocompatibility of CEM were evaluated according to stenosis, fistula, urethral wall thickness, urethral epithelium, rate of inflammation and vascularization. RESULTS Between the two experimental groups, the difference in the number of stenosis or urinary fistula was not statistically significant. The morphometric analysis revealed preservation of urethral lumen, well adhered CEM without extrusion, a controlled inflammatory process and implant vascularization. The urothelium height remained constant over time after CEM reinforcement and the membrane wall was thicker, statistically, after 14 weeks. CONCLUSION The absence of extrusion, stenosis or urinary fistula after 14 weeks of urethrovesical anastomosis demonstrates cellulosic exopolysaccharide membrane biocompatibility and biointegration with tendency to a thicker wall.

DNA Repair Defect and RAS Mutation in Two Patients With Schistosoma mansoni–Associated Colorectal Cancer: Carcinogenesis Steps or Mere Coincidence?

Besides CRC, S japonicum has also been implicated in liver cancer development. In addition, an association between S haematobium and bladder cancer has also been described. However, the association between S mansoni and CRC is scarce in the literature. InpatientswithSmansoni– associated CRC, patients are younger, their tumors are multicentric and present with mucinous histology, and there is a greater risk of lymph node metastasis and microsatellite instability (MSI). We report two patients with concurrent diagnosis of CRC and intestinal schistosomiasis and the potentially implicated carcinogenesis steps.