The buccal mucosa fenestrated graft for Bracka first stage urethroplasty: experimental study in rabbits

Objective To histologically evaluate, in an experimental study in rabbits, the integration process of the buccal mucosa fenestrated graft applied in the corpora cavernosa for Bracka first stage urethroplasty. Materials and Methods A urethral defect was surgically created in 16 male rabbits of the New Zealand breed through the excision of the penile urethra. The urethral defect was corrected by applying buccal mucosa fenestrated graft through two cruciform incisions in the distal portions of its longitudinal axis. The animals were sacrificed at 2, 4, 8 and 12 weeks post surgery and their genitals were subjected to clinical and histological assessment. Results The buccal mucosa fenestrated graft showed complete uptake in all groups, with keratinization squamous metaplasia and mucosal proliferation of the fenestrated areas. The fenestrated graft area represented an increase in length of 25% in length in relation to the original standard graft. Conclusions The fenestrated buccal mucosa graft presented total integration to the adjacent epithelia with re-epithelization of the incision areas of the graft (fenestrations) and no significant inflammatory or scarring reactions when compared to other mucosa transplanted areas; therefore its application is viable in cases of extensive urethral defect whenever the donating area might be insufficient.Federal University of São Paulo Departament of Urology (PO, HB, AR, UBjr, VO, AMjr) Department of Pathology (RD)UNIFESP, Departament of Urology (PO, HB, AR, UBjr, VO, AMjr) Department of Pathology (RD)SciEL

Keratinized versus non-keratinized preputial flap onlay urethroplasty: does it make any difference in the histological analysis? An experimental study in rabbits

Purpose: To compare the histological characteristics of keratinized versus non-keratinized onlay island flaps in an experimental rabbit model.Materials and Methods: Sixteen male rabbits were randomly allocated into two experimental groups: keratinized and non-keratinized onlay island flaps. A defect was created in the ventral aspect of the penile urethra. in the keratinized group, a longitudinal island flap was harvested from the external prepuce and rotated to cover the urethral defect. in the non-keratinized group a transverse island flap was harvested from the inner prepuce. the animals were sacrificed after 2, 4, 8 and 12 weeks.Results: the flaps were viable in all animals, and no deaths were associated with the procedure. Two urethrocutaneous fistulas were identified, one in each experimental group. A similar pattern of fibrosis was identified in both groups. the keratinized epithelium of the external prepuce kept its histological aspect and keratin production. Both keratinized and non-keratinized groups presented a slight decrease on the epithelial thickness, however without a statistically significant difference between groups.Conclusions: in this short-term rabbit model, we observed that the stratified squamous keratinized epithelium from the external prepuce kept its keratin production. There was no statistical influence of the flap type on the mean epithelial thickness.Universidade Federal de São Paulo UNIFESP, Div Urol, São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Div Urol, São Paulo, BrazilWeb of Scienc

Histopathological evaluation of urethroplasty with dorsal buccal mucosa: an experimental study in rabbits

PURPOSE: Buccal mucosa is a widely accepted tissue for urethroplasty. The exact healing and tissue integration process, mainly the histological characteristics of dorsal buccal mucosa graft urethroplasty when used dorsally to reconstruct the urethral plate has not previously been assessed, and thus we developed an experimental model to address this question. MATERIALS AND METHODS: In 12 New Zealand rabbits (weight 2.5 kg) we surgically created a dorsal penile urethral defect. A buccal mucosa graft was sutured to the corpora and tunica albuginea, and the ventral urethra anastomosed to this new urethral plate. The animals were divided in three groups and sacrificed 1, 3 and 6 weeks after surgery (groups 1, 2 and 3). A retrograde urethrogram was obtained at autopsy in the last group and the penis analyzed histologically with hematoxylin-eosin and Masson's staining. RESULTS: The urethrograms showed no evidence of fistula or stricture. In group 1 the histopathological analysis showed submucosal lymph-mononuclear inflammatory edema, numerous eosinophils and squamous epithelium integrated into the adjacent urothelium. In group 2 there was no evidence of an inflammatory response but rather complete subepithelial hyaline healing, which was more marked in group 3. CONCLUSION: Healing of buccal mucosa grafts to reconstruct the urethral plate can be achieved by total integration of the squamous epithelium with the urothelium, maintaining the original histological properties of the graft with no fibrosis or retraction.Federal University of São Paulo Divisions of UrologyFederal University of São PauloUNIFESP, Divisions of UrologyUNIFESPSciEL

A preoperative diagnostic test that distinguishes benign from malignant thyroid carcinoma based on gene expression

Accurate diagnosis of thyroid tumors is challenging. A particular problem is distinguishing between follicular thyroid carcinoma (FTC) and benign follicular thyroid adenoma (FTA), where histology of fine-needle aspirates is not conclusive. It is often necessary to remove healthy thyroid to rule out carcinoma. in order to find markers to improve diagnosis, we quantified gene transcript expression from FTC, FTA, and normal thyroid, revealing 73 differentially expressed transcripts (Pless than or equal to.0001). Using an independent set of 23 FTCs, FTAs, and matched normal thyroids, 17 genes with large expression differences were tested by real-time RT-PCR. Four genes (DDIT3, ARG2, ITM1, and C1orf24) differed between the two classes FTC and FTA, and a linear combination of expression levels distinguished FTC from FTA with an estimated predictive accuracy of 0.83. Furthermore, immunohistochemistry for DDIT3 and ARG2 showed consistent staining for carcinoma in an independent set 59 follicular tumors (estimated concordance, 0.76; 95% confidence interval, [0.59, 0.93]). A simple test based on a combination of these markers might improve preoperative diagnosis of thyroid nodules, allowing better treatment decisions and reducing long-term health costs.Universidade Federal de São Paulo, Mol Endocrinol Lab, Div Endocrinol, Dept Med, São Paulo, BrazilUniversidade Federal de São Paulo, Div Genet, Dept Morphol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pathol, São Paulo, BrazilDuke Univ, Med Ctr, Dept Biostat & Bioinformat, Durham, NC USAJohns Hopkins Univ, Sch Med, Dept Neurosurg, Baltimore, MD 21205 USAUniversidade Federal de São Paulo, Mol Endocrinol Lab, Div Endocrinol, Dept Med, São Paulo, BrazilUniversidade Federal de São Paulo, Div Genet, Dept Morphol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pathol, São Paulo, BrazilWeb of Scienc

AGK-BRAF gene fusion is a recurrent event in sporadic pediatric thyroid carcinoma

Thyroid cancer is the fastest increasing cancer worldwide in all age groups. Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer in both adults and children. PTC genomic landscape has been extensively studied in adults, but information regarding sporadic pediatric patients is lacking. Although BRAF V600E mutation is highly prevalent in adults, this mutation is uncommon in pediatric cases. As adult and pediatric PTC is a mitogen-activated protein kinase-driven cancer, this altered pathway might be activated by different genetic events. The aim of this study was to investigate the occurrence of AGK-BRAF fusion gene, recently described in radiation-exposed pediatric PTC, in a cohort of exclusively sporadic pediatric PTC. The series consisted of 30 pediatric PTC younger than 18 years of age at the time of diagnosis and 15 matched lymph node metastases (LNM). Primary tumors and matched LNM were screened for the presence of the AGK-BRAF fusion transcript by RT-PCR. To confirm the identity of the amplified products, randomly selected samples positive for the presence of the fusion transcripts were sequenced. Moreover, BRAF dual-color, break-apart probes confirmed BRAF rearrangement. Overall, the AGK-BRAF fusion gene was detected in 10% (3/30) of primary tumors. For one of these cases, paired LNM was also available, which also shows the presence of AGK-BRAF fusion gene. This study described, for the first time, the presence of AGK-BRAF in sporadic pediatric PTC. Understanding the molecular events underlying pediatric PTC may improve preoperative diagnosis, allow molecular prognostication and define a therapeutic approach toward sporadic PTC patients.Sao Paulo State Research Foundation (FAPESP)CNPqFAPESP scholarUniv Fed Sao Paulo, Dept Morphol & Genet, Div Genet, Genet Bases Thyroid Tumors Lab, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Pathol, Sao Paulo, SP, BrazilIrmandade Santa Casa Misericordia Sao Paulo, Dept Pediat, Sao Paulo, SP, BrazilIrmandade Santa Casa Misericordia Sao Paulo, Dept Med, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Morphol & Genet, Div Genet, Genet Bases Thyroid Tumors Lab, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Pathol, Sao Paulo, SP, BrazilFAPESP: 2012/02902-9FAPESP: 2013/03867-5FAPESP: 2014/06570-6CNPq: 470441/2013-5Web of Scienc

Adenomas hipofisários: relação entre invasividade e índice proliferativo tumoral Pituitary adenomas: relationship between invasiveness and proliferative cell nuclear index

Analisamos 76 pacientes com adenomas hipofisários do ponto de vista clínico, radiológico e tratamento cirúrgico. Todos os casos foram estudados por imuno-histoquímica e em 49 pacientes foi pesquisado o anticorpo monoclonal PCNA. Os adenomas bi-hormonais foram os mais frequentes seguidos dos prolactinomas e os adenomas não secretantes. Os adenomas bi-hormonais não secretantes e os produtores de subunidade alfa foram proporcionalmente mais invasivos pelos critérios radiológicos. A maioria dos pacientes (59) foi operada por via transeptoesfenoidal, em seis casos a via transcraniana foi realizada e em 11 pacientes houve necessidade das duas abordagens. A ressecção foi total em 32 pacientes, a maioria em microadenomas, subtotal em 15 e parcial em 29. A complicação endócrina mais frequente foi diabetes insipidus. Houve tendência de associação positiva para os adenomas secretantes e PCNA mais elevado, assim como relação positiva quando analisamos os adenomas invasivos pela tomografia computadorizada ou ressonância magnética e o PCNA 3 e 4. A melhora visual foi observada em 85% dos macroadenomas, mesmo quando a ressecção foi parcial ou subtotal.<br>We evaluated clinically, radiologically and surgically a series of 76 pituitary adenomas. All cases were assessed immunohistochemically and in 49 patients the PCNA monoclonal antibody was measured. The most frequent types found were the bihormonal adenomas, followed by prolactinomas and non secreting adenomas. The bihormonal adenomas, non secreting adenonas and the sub unit alfa producing adenomas were proportionally more invase as determined by radiological criteria (CTscan or MRI). In 59 patients a transphenoidal approach was used, six cases were operated on transcranially and in 11 patients we used a combination of both approach. Total resection were achieved in 32 cases, most of which were microadenomas, in 15 cases the resection was subtotal and partial in 29 cases. Diabetes insipidus was the most frequent endocrine complication. It was observed that secreting adenomas tend to be associated with an increased PCNA and invasive adenomas correlated with PCNA 3 and 4. An improvement in vision was observed in 85% of macroadenomas seen after a total, subtotal or partial resection