Surgery in Bilateral Wilms Tumor-A Single-Center Experience

The treatment of bilateral Wilms tumors (BWT) involves curing the cancer, preserving long-term renal function, and maintaining a good quality of life. Established methods for achieving these goals include preoperative chemotherapy and nephron-sparing surgery (NSS). This study aimed to evaluate the experience of a single institution in treating patients with BWT. We analyzed cases of BWT treated at the Pediatric Oncology Institute-GRAACC-Federal University of São Paulo over a period of 35 years. Bleeding control was performed with manual compression of the renal parenchyma. Thirty-three patients were included in the study. Thirty cases were synchronous tumors. The mean age at diagnosis was 30.4 months (±22 m) and 66.7% were girls. The median follow-up period was 83 months. Neoadjuvant chemotherapy was the primary approach in most patients (87.9%), with a simultaneous upfront surgical approach performed in 84.8%. Most patients underwent bilateral NSS (70.4%). There were no early complications in this series, but 39.4% had clinical complications. The five-year survival rate was 76%. Therefore, it is clear that the surgical approach to BWT plays a crucial role in achieving good outcomes. However, it is difficult to standardize surgical techniques and technology may have the potential to enhance safety.

Survival analysis and prognostic factors in posterior fossa ependymomas in children and adolescents

OBJECTIVE

In this study, the authors aimed to analyze the overall survival (OS) and progression-free survival (PFS) of patients younger than 18 years of age who were diagnosed with posterior fossa ependymomas, and to identify prognostic factors such as the degree of resection, tumor topography, and involvement of the lesion in the hindbrain.

METHODS

The authors performed a retrospective cohort study of patients younger than 18 years of age, treated beginning in 2000, with a diagnosis of posterior fossa ependymoma. Ependymomas were separated into three groups: tumors restricted to the fourth ventricle, tumors inside the fourth ventricle and exiting from the foramen of Luschka, and tumors inside the fourth ventricle and completely surrounding the hindbrain. Furthermore, the tumors were classified by molecular group using the staining method for H3K27me3. Statistical analysis was performed using Kaplan-Meier survival curves, with p < 0.05 considered statistically significant.

RESULTS

Of 1693 patients who underwent surgical treatment between January 2000 and May 2021, 55 patients who met the inclusion criteria were included. The median age at diagnosis was 2.98 years. The median OS was 44 months, and the survival rates at 1, 5, and 10 years were 92.5%, 49.1%, and 38.3%, respectively. The cases were assigned to two posterior fossa ependymoma molecular groups: 35 (63.6%) cases to group A and 8 (14.5%) to group B. The median ages in groups A and B were 2.94 and 2.85 years and the median OS values were 44 and 38 months, respectively (p = 0.9245). Statistical analysis was performed on multiple variables, including age, sex, histological grade, Ki-67 expression, tumor volume, extent of resection, and adjuvant therapies. The median PFS of patients with dorsal-only involvement was 28 months; for dorsolateral involvement, it was 15 months; and for total involvement, it was 9.5 months (p = 0.0464). No statistically significant difference was found for OS. There was a statistically significant difference between the proportion of patients in whom gross-total resection was achieved in the dorsal-only involvement group (73.1%, 19/26) and those in the total involvement group (0%, 0/6) (p = 0.0019).

CONCLUSIONS

This study confirmed that the extent of resection has an impact on OS and PFS. The authors found that adjuvant radiotherapy resulted in a higher OS but did not prevent progression, that the pattern of involvement of the brainstem in the tumor at diagnosis could elicit important information regarding the patient's prognosis regarding PFS, and that the total involvement of the rhombencephalon impaired the gross-total resection of these tumors.

Gliomas in children and adolescents: investigation of molecular alterations with a potential prognostic and therapeutic impact

PURPOSE

Gliomas represent the most frequent central nervous system (CNS) tumors in children and adolescents. However, therapeutic strategies for these patients, based on tumor molecular profile, are still limited compared to the wide range of treatment options for the adult population. We investigated molecular alterations, with a potential prognostic marker and therapeutic target in gliomas of childhood and adolescence using the next-generation sequencing (NGS) strategy.

METHODS

We selected 95 samples with initial diagnosis of glioma from patients treated at Pediatric Oncology Institute-GRAACC/UNIFESP. All samples were categorized according to the 2021 World Health Organization Classification of Tumors of the CNS, which included 39 low-grade gliomas (LGGs) and 56 high-grade gliomas (HGGs). Four HGG samples were classified as congenital glioblastoma (cGBM). NGS was performed to identify somatic genetic variants in tumor samples using the Oncomine Childhood Cancer Research Assay^® (OCCRA^®) panel, from Thermo Fisher Scientific^®.

RESULTS

Genetic variants were identified in 76 of 95 (80%) tumors. In HGGs, the most common molecular alteration detected was H3F3A c.83A > T variant (H3.3 K27M) and co-occurring mutations in ATRX, TP53, PDGFRA, MET, and MYC genes were also frequently observed. One HGG sample was reclassified as supratentorial ependymoma ZFTA-fusion positive after NGS was performed. In LGGs, four KIAA1549-BRAF fusion transcripts were detected and this alteration was the most recurrent genetic event and favorable prognostic factor identified. Additionally, genetic variants in ALK and NTRK genes, which provide potential targets for therapy with Food and Drug Administration-approved drugs, were identified in two different cases of cGBM that were classified as infant-type hemispheric glioma, a newly recognized subgroup of pediatric HGG.

CONCLUSION

Molecular profiling by the OCCRA^® panel comprehensively addressed the most relevant genetic variants in gliomas of childhood and adolescence, as these tumors have specific patterns of molecular alterations, outcomes, and effectiveness to therapies.

Molecular profiling of pediatric and adolescent ependymomas: identification of genetic variants using a next-generation sequencing panel

PURPOSE

Ependymoma (EPN) accounts for approximately 10% of all primary central nervous system (CNS) tumors in children and in most cases, chemotherapy is ineffective and treatment remains challenging. We investigated molecular alterations, with a potential prognostic marker and therapeutic target in EPNs of childhood and adolescence, using a next-generation sequencing (NGS) panel specific for pediatric neoplasms.

METHODS

We selected 61 samples with initial diagnosis of EPN from patients treated at Pediatric Oncology Institute-GRAACC/UNIFESP. All samples were divided according to the anatomical compartment of the CNS - 42 posterior fossa (PF), 14 supratentorial (ST), and five spinal (SP). NGS was performed to identify somatic genetic variants in tumor samples using the Oncomine Childhood Cancer Research Assay® (OCCRA®) panel, from Thermo Fisher Scientific®.

RESULTS

Genetic variants were identified in 24 of 61 (39.3%) tumors and over 90% of all variants were pathogenic or likely pathogenic. The most commonly variants detected were in CIC, ASXL1, and JAK2 genes and have not been reported in EPN yet. MN1-BEND2 fusion, alteration recently described in a new CNS tumor type, was identified in one ST sample that was reclassified as astroblastoma. Additionally, YAP1-MAMLD1 fusion, a rare event associated with good outcome in ST-EPN, was observed in two patients diagnosed under 2 years old.

CONCLUSIONS

Molecular profiling by the OCCRA® panel showed novel alterations in pediatric and adolescent EPNs, which highlights the clinical importance in identifying genetic variants for patients' prognosis and therapeutic orientation.

Abstract 2167: Genomic profiling of pediatric and adolescent ependymomas: Underlying genetic alterations for prognosis and therapeutic orientation

Background: Ependymoma (EPN) is the third most common brain tumor in children and adolescents and is incurable in up to 40% cases, as chemotherapy is ineffective in most individuals and treatment remains challenging. A genetic panel based on next-generation sequencing (NGS) technology and developed exclusively for pediatric neoplasms is essential in order to determine prognosis and therapeutic managements in EPN, as this tumor comprise several molecular subgroups with unique clinical characteristics. We aimed to detect and investigate molecular alterations, with potential prognostic marker and therapeutic target in childhood and adolescence EPN, using the NGS strategy.

Methods: We selected 59 EPN samples from patients diagnosed and treated at Pediatric Oncology Institute-GRAACC/UNIFESP. All 59 EPN samples were divided according to the anatomical compartment of the Central Nervous System: 41 samples from the posterior fossa (PF), 13 supratentorial (ST) and 5 spinal (SP). NGS was performed to identify somatic genetic alterations in tumor samples using Oncomine Childhood Cancer Research Assay (OCCRA) panel, from Thermo Fisher, designed specifically for childhood and adolescence neoplasms. Our molecular findings were correlated with clinical and histopathological characteristics of the patients analyzed.

Results: A total of 59 EPN samples were sequenced in our institution and we identified somatic alterations in 24 of 59 (40.7%) tumors. We observed 14 altered genes and 16 genetic variants, which 43.8% were pathogenic and 37.5% have not been reported yet. The most commonly detected genetic alterations were involving ASXL1, CIC, JAK2, ABL2 and MDM4 genes. SNVs were the majority of all genetic alterations detected, accounting for 10 of 20 cases (50%). The pathogenic and synonymous mutation c.4533C&gt;T of CIC gene, previously reported as SNP, was the most frequent variant observed in EPN samples. CNVs were observed in ABL2 and MDM4 genes and were exclusively identified in PF-EPN samples. Gene fusions were found in 3 alive patients with age to diagnosis under 5 years and with ST-EPN and SP-EPN.

Conclusions: Molecular profile investigation, based on NGS panel specific for pediatric tumors, can provide information about potential prognostic biomarkers for EPN. Thus, genomic profiling of childhood and adolescence EPN that appropriately integrate the clinical, radiologic, and histologic aspects of this tumor, is essential in order to define therapeutic strategies.

Funding Source: São Paulo Research Foundation (FAPESP no. 2019/12074-5)

Citation Format: Débora Cabral de Corrêa, Indhira Dias Oliveira, Francine Tesser-Gamba, Maria Teresa de Seixas Alves, Nasjla Saba-Silva, Andrea Maria Capellano, Patrícia Dastoli, Sergio Cavalheiro, Silvia Regina Caminada de Toledo. Genomic profiling of pediatric and adolescent ependymomas: Underlying genetic alterations for prognosis and therapeutic orientation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2167.

Diagnostic Errors in Wilms' Tumors: Learning From Our Mistakes

Aim: This study aimed to analyze clinical characteristics and image findings in patients initially diagnosed with renal masses and treated on the Société Internationale d'Oncologie Pédiatrique (SIOP) 2001 protocol for Wilms tumor (WT) that eventually were diagnosed with different pathologies. Methods: We reviewed the preoperative symptoms, laboratory tests, and images of patients who were initially treated for WT and proved to have other diagnoses. Data from these patients were compared to those of the last 10 patients with WT and the last 10 patients with neuroblastoma (NBL) treated at a single institution. Results: From June 2001 to December 2020, we treated 299 patients with NBL and 194 with WT. Five patients treated with preoperative chemotherapy for WT were postoperatively diagnosed with NBL (one patient had bilateral renal masses and one with multifocal xanthogranulomatous pyelonephritis). Three underwent nephrectomy, two biopsies only, and one adrenalectomy due to intraoperative characteristics. Regarding clinical presentation, abdominal mass or swelling was very suggestive of WT (p = 0.011); pain, although very prevalent in the study group (67%), was not statistically significant, as well as intratumoral calcifications on computed tomography (CT) (67%). Urinary catecholamines were elevated in all patients mistreated for WT with the exception of the patient with pyelonephritis in which it was not collected. Conclusion: Some pathologies can be misdiagnosed as WT, especially when they present unspecified symptoms and dubious images. Diagnostic accuracy was 98.1%, which highlights the quality of the multidisciplinary team. Abdominal mass or swelling is highly suggestive of WT, especially in the absence of intratumoral calcifications on CT. If possible, urinary catecholamines should be collected at presentation as they help in the differential diagnosis of NBL.

Management of Pediatric Tumors With Vascular Extension

Background: Pediatric tumors can present with vascular extension to the inferior vena cava and right atrium, which impacts the surgical strategy and can be challenging during surgical treatment. Wilms tumor (WT) is the most common retroperitoneal tumor that can present with vascular extension, but also adrenal tumors, clear cell tumors from the kidney, and hepatoblastomas can present with this situation. Surgical aims include obtaining complete tumor resection without risk for patients, to avoid severe bleeding, cardiac arrest, and embolization, and to avoid cardiac bypass if possible. Objective: To describe and discuss the surgical strategies to deal with pediatric tumors with vascular extension and propose a protocol. Method: Retrospectivly review the experience of treating patients with vascular extension in a single institution, describing different scenarios and a decision making fluxogram based on the preoperative evaluation regarding the surgical techniques and the need for cardiac bypass that are adequate for each situation. Image studies are important to guide the surgical strategy. Depending on the quality of image available, computerized tomography (CT) or magnetic resonance imaging (MRI) can be enough to give the information needed for surgical decisions. Ultrasonography (US) with Doppler is helpful to confirm diagnosis and describes factors to guide the adequate surgical strategy, like the upper level extension and presence or absence of blood flow around the thrombus. Neoadjuvant chemotherapy is indicated in most cases, in order to reduce the upper level of extension (and avoid the need for cardiac bypass) and to lower the risk of embolization. The approach is based on the upper level of the thrombus and can include cavotomy or cavectomy, sometimes with cardiac bypass and cardiac arrest with hypothermia, when the thrombus reaches the diaphragmatic level or above. Pathology analysis of the thrombus can guide staging and the need for radiotherapy postoperatively. Results: A decision making fluxogram protocol is presented focusing on the surgical treatment of such condition. Conclusion: Surgery strategy is highly impacted by the presence of vascular extension in pediatric tumors. Surgeons should be aware of potential complications and how to prevent them. Such cases should be treated in reference centers.

Abnormal spindle-like microcephaly-associated (ASPM) gene expression in posterior fossa brain tumors of childhood and adolescence

PURPOSE

In neurogenesis, ASPM (abnormal spindle-like microcephaly-associated) gene is expressed mainly in the ventricular zone of posterior fossa and is the major determinant in the cerebral cortex. Besides its role in embryonic development, ASPM overexpression promotes tumor growth, including central nervous system (CNS) tumors. This study aims to investigate ASPM expression levels in most frequent posterior fossa brain tumors of childhood and adolescence: medulloblastoma (MB), ependymoma (EPN), and astrocytoma (AS), correlating them with clinicopathological characteristics and tumor solid portion size.

METHODS

Quantitative reverse transcription (qRT-PCR) is used to quantify ASPM mRNA levels in 80 pre-treatment tumor samples: 28 MB, 22 EPN, and 30 AS. The tumor solid portion size was determined by IOP-GRAACC Diagnostic Imaging Center. We correlated these findings with clinicopathological characteristics and tumor solid portion size.

RESULTS

Our results demonstrated that ASPM gene was overexpressed in MB (p = 0.007) and EPN (p = 0.0260) samples. ASPM high expression was significantly associated to MB samples from patients with worse overall survival (p = 0.0123) and death due to disease progression (p = 0.0039). Interestingly, two patients with AS progressed toward higher grade showed ASPM overexpression (p = 0.0046). No correlation was found between the tumor solid portion size and ASPM expression levels in MB (p = 0.1154 and r = - 0.4825) and EPN (p = 0.1108 and r = - 0.3495) samples.

CONCLUSION

Taking in account that ASPM gene has several functions to support cell proliferation, as mitotic defects and premature differentiation, we suggest that its overexpression, presumably, plays a critical role in disease progression of posterior fossa brain tumors of childhood and adolescence.

Identification of genetic alterations in childhood and adolescence glioblastoma (GBM) using next generation sequencing strategy

e14547

Background: Glioblastoma (GBM) is the most aggressive brain malignancy with a heterogeneity molecular profile and accounts for no more than 3-5% of Central Nervous System tumors in children. Despite its rarity, pediatric GBM pertain different molecular genetics, outcome and effectiveness to therapies and remains an equally lethal tumor in children. Identification of genetic alterations in GBM of childhood and adolescence is important to refine molecular classification, define prognosis and therapeutic strategies. We aimed to detect and investigate molecular changes with potential prognostic marker and therapeutic target in GBM, using next generation sequencing (NGS) strategy. Methods: We selected 41 GBM samples from patients treated at Pediatric Oncology Institute/GRAACC. NGS was performed to identified genetic alterations in tumor samples using Oncomine Childhood Cancer Research Assay (OCCRA) panel, specific genetic panel for childhood and adolescence neoplasms. Results: We selected 41 GBM samples and identified 33 mutated genes. The most commonly detected genetic alterations were involving TP53, PDGFRA, PIK3CA, NF1, MYC, MET and genes with histone-related functions, including H3F3A and ATRX. Mutations in H3F3A K28M, ATRX and TP53 were most recurrent. ATRX alterations, either nonsense substitution or frameshift deletion, were exclusively found in patients with H3F3A K28M mutations. TP53 loss-of-function was exclusive in 9 of 41 (22%) tumors. In 7 of 9 cases (78%) harboring both H3F3A and TP53 mutations, patients died due to disease progression . In these patients, H3F3A-TP53 mutation is suggested to be unfavorable prognostic factor. Copy number alterations were found in 30% of GBM cases and PDGFRA-amplifications were the most frequent. PDGFRA-amplification was exclusively found in patients with H3F3A K28M mutations and 75% of these patients did not survived longer than two years. Conclusions: Molecular profiling based on NGS genetic panel, specific for pediatric tumors, can provide information about potential prognostic biomarkers for GBM of childhood and adolescence. Thus, wider understanding about GBM biologic heterogeneity may lead to personalized therapeutic strategies for pediatric patients.

The impact of burial period on compact bone microstructure: Histological analysis of matrix loss and cell integrity in human bones exhumed from tropical soil

Human bone histological analysis is a useful tool to assess post mortem diagenesis and to predict successful nuclear DNA typing of forensic material. This study is part of a series of studies developed by the authors intended to improve the understanding of post mortem diagenesis and to develop applications for DNA analysis of skeletal species from tropical soils, in order to optimize genetic and anthropological protocols. The aim of this study was to analyze the impact of burial period on the integrity of exhumed compact bone microstructure from tropical climate. In fragments of exhumed human femora from 39 individuals from the same cemetery (exhumed group) and 5 fresh femora from routine autopsies (control group), sections stained by hematoxylin-eosin were analyzed in order to measure bone microstructural integrity. We found that bone integrity index in exhumed group was negatively influenced by the period of burial (r = -0.37, p < 0.05) and highly significantly decreased (p < 0.0001) in comparison to control group. The period of burial and nitric acid decalcification time was positively correlated (r = 0.51; p < 0.01), leading to imply a bone petrification process during inhumation. Exhumed group showed higher level of matrix bone loss (p < 0.001), as expected, and 87% of cases analyzed were "tunneled" as described by Hackett. Bone integrity index and bone matrix tend to decrease in bones buried in tropical soil between 8-14 years of inhumation. This period is short if we consider cases in which there are preserved bones interred for longer periods in other environments. These data must be considered in cases where genetic identification of exhumed skeletons from tropical environment is required. The diagenesis in these bones and the variations of results found are discussed, clarifying some challenges for forensic laboratories, especially in DNA analysis.

Irinotecan and vincristine for the treatment of refractory desmoplastic small round cell tumor in a developing country: a case report

Introduction

Desmoplastic small round cell tumor is an extremely rare and aggressive cancer that affects mainly adolescents and young adults. Despite multiple therapeutic strategies, most patients have resistant disease with very poor survival rates.

Case presentation

We present a case of a 10-year-old Caucasian boy with a desmoplastic small round cell tumor refractory to conventional treatment who exhibited a good response to alternative treatment. With use of irinotecan and vincristine in association with radiation therapy, a reduction of 96.9% of the dimensions of the target lesions compared with the initial image was observed.

Conclusion

This chemotherapy regimen, in association with radiation therapy, demonstrated efficacy for refractory desmoplastic small round cell tumor in our patient, and it is cost-effective.

Changes in the expression of matrix extracellular genes and TGFB family members in rotator cuff tears

Lack of synthesis of extracellular matrix compounds may contribute to degeneration of the tendons. Thus, we aimed to evaluate the expression of extracellular matrix and TGFB family members in ruptured and non-ruptured tendons of the rotator cuff, as well as the effect of clinical factors on gene expression in tendon samples, and the relationship between histological findings and altered gene expression. Injured and non-injured supraspinatus tendon samples and subscapular non-injured tendon samples were collected from 38 patients with rotator cuff tears. Non-injured supraspinatus tendons were obtained from eight controls. Specimens were used for histological evaluation, quantification of collagen fibers, and mRNA and protein expression analyses. Increased COL1A1, COL1A2, COL3A1, COL5A1, FN1, TNC, and TGFBR1 mRNA expression was observed in the tear samples (p < 0.05). Duration of symptoms was correlated with the levels of collagen type I/III fibers (p = 0.032; ρ = 0.0447) and FN1 immunostaining (p = 0.031; ρ = 0.417). Smoking was associated with increased frequency of microcysts, myxoid degeneration, and COL5A1, FN1, TNC, and TGFB1 mRNA expression (p < 0.05). FN1 immunostaining was correlated with the number of years of smoking (p = 0.048; ρ = 0.384). Lower levels of collagen type I/III fibers were detected in samples with fissures (0 = 0.046). High frequency of microcysts was associated with increased COL5A1, FN1, and TNC expression (p < 0.05, for all comparisons). Neovascularization was associated with reduced FN1 (p = 0.035) and TGFBR1 expression (p = 0.034). Our findings show differential expression of matrix extracellular genes and TGFB family members in the degeneration process involved in rotator cuff tears. These molecular alterations are influenced by clinical factors. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2542-2553, 2018.

The influence of cell concentration at cryopreservation on neutrophil engraftment after autologous peripheral blood stem cell transplantation

BACKGROUND

Peripheral blood stem cell concentrations are traditionally adjusted to 20-40 × 106 leukocytes/mL prior to freezing. This low cell concentration at cryopreservation implies larger volumes with more dimethyl sulfoxide being used, and higher cost and toxicity at the time of transplant. Higher cell concentrations have been reported but this is not widely accepted. Moreover, the influence of cell concentration on engraftment has not been well documented. Therefore, this study retrospectively analyzed the influence of peripheral blood stem cell concentration at freezing on engraftment after autologous hematopoietic stem cell transplantation.

METHOD

Leukapheresis products were plasma-depleted and cryopreserved with 5% dimethyl sulfoxide, 6% hydroxyethylamide solution and 4% albumin in a -80 °C freezer. Individual patient data from hospital records were reviewed.

RESULTS

Fifty consecutive patients with oncological diseases underwent 88 leukaphereses. Median age was six years (range: 1-32 years) and median weight was 19 kg (range: 8-94 kg). Median leukocyte concentration was 109 × 106/mL at collection and 359 × 106 (range: 58-676 × 106) at freezing with 78% viability (range: 53-95%); leukocyte recovery after thawing was 95% (range: 70-100%). In multivariate analysis, cell concentration (p-value = 0.001) had a negative impact on engraftment. Patients infused with bags frozen with <200 × 106 leukocytes/mL engrafted after a median of nine days (range: 8-12 days), 200-400 × 106 leukocytes/mL after 11 days (range: 9-20 days); 400-600 × 106 leukocytes/mL after 12 days (range: 8-19 days) and with cell concentrations >600 × 106 leukocytes/mL, engraftment was after 14 days (range: 13-22 days).

CONCLUSION

In patients with adequate CD34 cell collections, total leukocyte concentrations of 282 × 106/mL, freezing with 5% dimethyl sulfoxide and 6% hydroxyethylamide solution without a controlled-rate freezer, and storing cells at -80 °C yielded excellent engraftment. Further increases in cell concentration may delay engraftment, without affecting safety.

CYP genes in osteosarcoma: Their role in tumorigenesis, pulmonary metastatic microenvironment and treatment response

Osteosarcoma (OS) is the most common malignant bone tumor in children and adolescents. The present study investigated the expression of Cytochrome P-450 (CYP) genes: CYP1A2, CYP3A4 and CYP3A5 by qRT-PCR in 135 specimens obtained from OS patients, including biopsy (pre-chemotherapy), tumor resected in surgery (post-chemotherapy), adjacent bone to tumor (nonmalignant tissue), pulmonary metastasis and adjacent lung to metastasis (nonmalignant tissue). Normal bone and normal lung tissues were used as control. We also investigated in five OS cell lines the modulation of CYPs expression by cisplatin, doxorubicin and methotrexate. As result, the adjacent lung specimens presented CYP1A2 overexpression compared to the normal lung (p=0.0256). Biopsy specimens presented lower CYP3A4 expression than normal bone (p=0.0314). The overexpression of both CYP1A2 and CYP3A4 in post-chemotherapy specimens were correlated with better event free-survival (p=0.0244) and good response (p=0.0484), respectively. Furthermore, in vitro assays revealed that CYP1A2 was upregulated by doxorubicin (p=0.0034); CYP3A4 was upregulated by cisplatin, doxorubicin and methotrexate (p=0.0004, p=0.0024, p<0.0001, respectively); and CYP3A5 was downregulated by doxorubicin (p=0.0285) and upregulated in time-dependent manner by methotrexate (p=0.0239). In conclusion, our findings suggest that CYP genes play an important role in OS tumorigenesis, at primary and metastatic sites, as well in treatment response.

Epigenetic regulation of metalloproteinases and their inhibitors in rotator cuff tears

Rotator cuff tear is a common orthopedic condition. Metalloproteinases (MMP) and their inhibitors (TIMP) seem to play a role in the development of joint injuries and in the failure of tissue healing. However, the mechanisms of regulation of gene expression in tendons are still unknown. Epigenetic mechanisms, such as DNA methylation and microRNAs regulation, are involved in the dynamic control of gene expression. Here, the mRNA expression and DNA methylation status of MMPs (MMP1, MMP2, MMP3, MMP9, MMP13, and MMP14) and TIMPs (TIMP1-3) and the expression of miR-29 family members in ruptured supraspinatus tendons were compared with non-injured tendons of individuals without this lesion. Additionally, the gene expression and methylation status at the edge of the ruptured tendon were compared with macroscopically non-injured rotator cuff tendon samples from the anterior and posterior regions of patients with tendon tears. Moreover, the possible associations between the molecular alterations and the clinical and histologic characteristics were investigated. Dysregulated expression and DNA methylation of MMP and TIMP genes were found across the rotator cuff tendon samples of patients with supraspinatus tears. These alterations were influenced at least in part by age at surgery, sex, smoking habit, tear size, and duration of symptoms. Alterations in the studied MMP and TIMP genes may contribute to the presence of microcysts, fissures, necrosis, and neovascularization in tendons and may thus be involved in the tendon healing process. In conclusion, MMPs and their inhibitors are regulated by epigenetic modifications and may play a role in rotator cuff tears.

Venous Shunt Versus Venous Ligation for Vascular Damage Control: The Immunohistochemical Evidence

BACKGROUND

To evaluate the expression of immunohistochemical markers of tissue ischemia (iNOS, eNOS, and HSP70) in a vascular damage control experimental model to determine if a venous temporary vascular shunt insertion leads to a better limb perfusion when compared with the ligature of the injured vein.

METHODS

Experimental study in male Sus Scrofa weighting 40 Kg. Animals were distributed into 5 groups: group 1 animals were submitted to right external iliac artery (EIA) shunting and right external iliac vein (EIV) ligation; group 2 animals were submitted to right EIA shunting and right EIV shunting; group 3 animals were submitted to right EIV ligation; group 4 animals were submitted to right EIV shunting; group 5 animals were not submitted to vascular shunting or venous ligation. Transonic Systems flowmeters were used to measure vascular flow on right and left external iliac vessels, and i-STAT (Abbot) portable blood analyzer was used for EIVs blood biochemical analysis. An initial baseline register of invasive arterial pressure, iliac vessels flow, and venous blood analysis was performed. Arterial pressure and iliac vessels flow were taken immediately after right iliac vessels shunting or ligation. Then, hemorrhagic shock was induced by continuous 20 mL/min blood withdraw from the external right jugular vein whereas arterial blood pressure and iliac vessels flow registers were taken every 10 min, and blood samples from EIVs were obtained every 30 min until the vascular flow through right EIA (or through the shunt inserted into the right EIV for group 4 animals) became inexistent or until the animal's death. After the end of the experiments, bilateral hind limb's biopsies were obtained for immunohistochemical analysis. Using image editing and analysis software, the expression of iNOS, eNOS, and HSP70 (3 well-known ischemic associated immunohistochemical markers) was assessed. The mean expression of each marker in the right hind limb was compared between groups. For statistical analysis, Microsoft Office Excel 2007 and BioEstat 5.0 (2007) were used.

RESULTS

Immunohistochemical analysis showed no difference regarding the iNOS expression; nevertheless, both eNOS and HSP70 expression were statistically more intense (P < 0.05) on group 1 (eNOS = 1.32; HSP70 = 15.05) than on group 2 (eNOS = 0.018; HSP70 = 8.56).

CONCLUSIONS

The higher expression of eNOS and HSP70 in the right hind limbs of group 1 animals (arterial shunt and venous ligature) than group 2 animals (arterial shunt and venous shunt) suggests that venous ligation is associated with more intense ischemic histological findings than venous shunting.

Fusion Oncogenes Are the Main Genetic Events Found in Sporadic Papillary Thyroid Carcinomas from Children

BACKGROUND

Previous studies reported significant differences in the clinical presentation and outcomes of papillary thyroid carcinoma (PTC) in pediatric patients compared with adults. Previous studies have suggested that the clinicopathological differences observed between pediatric and adult PTCs may be due the existence of distinct genetic alterations. However, the knowledge of genetic events in pediatric PTCs is based primarily on studies in radiation-exposed PTCs or in the few studies that enrolled predominantly adolescent patients. The aim of this study was to characterize the known oncogenic alterations of the MAPK pathway found in adult and radiation-exposed PTCs in a cohort of predominantly sporadic pediatric PTC patients.

METHODS

Thirty-five pediatric PTCs were screened for the most prevalent fusions (RET/PTC1, RET/PTC2, RET/PTC3, ETV6-NTRK3, and AGK-BRAF) and point mutations (BRAFV600E and NRASQ61) described in sporadic pediatric PTCs. The mutational status was correlated with clinicopathological data.

RESULTS

Mutations were found in 20 out of 35 (57%) PTC cases. Fusion oncogenes were the main genetic alterations found. RET/PTC1-3 rearrangements were found in 13 (37%), ETV6-NTRK3 in 3 (9%), AGK-BRAF in 4 (11%), and BRAFV600E in 3 (9%). No mutation was found in NRASQ61. BRAFV600E was associated with older age and larger tumor size (p < 0.05), and RET/PTC3 was associated with a larger tumor size and multifocality (p < 0.05).

CONCLUSIONS

The genetic signature in this cohort was remarkably different than that observed in adults. Although observed at a lower prevalence, the spectrum of mutations was quite similar to that described in radiation-exposed pediatric PTCs. As mutations were unidentifiable in over 40% of the PTC cases, more comprehensive studies conducted in these patients will help to decipher the genetic landscape of sporadic pediatric PTCs.

Low-level laser therapy on bone repair of rat tibiae exposed to ionizing radiation

OBJECTIVE

The purpose of this study was to evaluate the effects of low-level laser therapy (LLLT) on the repair of rat tibiae exposed to ionizing radiation (IR).

BACKGROUND DATA

IR causes structural changes that delay bone tissue repair. Properly dosed, LLLT improves the bone repair process.

METHODS

Seventy-two healthy Wistar rats were distributed into the following groups: Group I, sham control; Group II, LLLT; Group III, IR; and Group IV, IR and LLLT. Groups III and IV received a single dose (30 Gy) of gamma radiation and underwent surgery 28 days later. A noncritical sized bone defect (diameter 2.5 mm) was surgically created in all groups. Groups II and IV received three applications of postsurgical LLLT (GaAlAs, 808 nm, 100 mW, 0.028 cm(2), 3.57 W/cm(2), 20 sec, 2 J,≅71.4 J/cm(2)) on alternate days. Histomorphometry was assessed following digital image analysis.

RESULTS

The samples were evaluated on days 7, 14, and 21 after surgery; the IR protocol resulted in a significant reduction (p<0.018) in bone formation in Group III compared with Group I. Significant increases (p<0.006) in newly formed bone were noted in Group IV compared with Group III. No significant differences were observed between Group I and Group IV.

CONCLUSIONS

LLLT increased the newly formed bone area during the initial phase of the tibiae repair process in rats exposed to IR.

Thyroid-Specific Genes Expression Uncovered Age-Related Differences in Pediatric Thyroid Carcinomas

Despite a more advanced stage of disease at presentation, a better response to radioiodine (RAI) therapy and a reduced overall mortality have been reported in pediatric differentiated thyroid cancer (DTC) in comparison to adult DTC. Few studies suggested that the better response to RAI therapy in pediatric patients might be associated with an increased expression of NIS. However, a marked heterogeneity within the pediatric group has been recognized. Children (<10 years old) usually present a more aggressive disease than adolescents (≥10-18 years old). By analyzing the expression of thyroid-specific genes in 38 sporadic pediatric tumors, we show that the expression of NIS, PDS, and TSHR was lower in children than adolescents (P < 0.05). A linear regression confirmed the association between NIS expression and age. Most significantly, NIS was expressed at similar levels in DTC from children and adults, whereas PDS and TSHR expression was even lower in DTC from children, compared to adolescents and adults. Our data suggest that biological behaviors of DTC in adolescents might differ from those in children and adults. Therefore, the premise that the expression of thyroid-specific genes is higher in tumors from pediatric patients than in adults is not entirely true and might be too oversimplified.

Investigation of IGF2, Hedgehog and fusion gene expression profiles in pediatric sarcomas

The childhood sarcomas are malignant tumors with high mortality rates. They are divided into two genetic categories: a category without distinct pattern karyotypic changes and the other category showing unique translocations that originate gene rearrangements. This category includes rhabdomyosarcoma (RMS), Ewing's sarcoma (ES) and synovial sarcoma (SS). Diverse studies have related development genes, such as; IGF2, IHH, PTCH1 and GLI1 and sarcomatogenesis.

OBJECTIVE

To characterize the RMS, ES and SS rearrangements, we quantify the expression of IGF2 IHH, PTCH1 and GLI1 genes and correlate molecular data with clinical parameters of patients.

DESIGN

We analyzed 29 RMS, 10 SS and 60 ES tumor samples by RT-PCR (polymerase chain reaction-reverse transcription) and qPCR (quantitative PCR).

RESULTS

Among the samples of ARMS, 50% had rearrangements of PAX3/7-FOXO1, 60% of ES samples were EWS-FLI1 positive and 90% of SS samples were positive for SS18-SSX1/2. In relation to the control reference samples (QPCR Human Reference Total RNA-Stratagene, Human Skeletal Muscle Total RNA-Ambion, Universal RNA Human Normal Tissues-Ambion), RMS samples showed a high IGF2 gene expression (p<0.0001). Moreover, ES samples showed a low IGF2 gene expression (p<0.0001) and high IHH (p<0.0001), PTCH1 (p=0.0173) and GLI1 (p=0.0113) gene expressions.

CONCLUSIONS

The molecular characterization of IGF and Hedgehog pathway in these pediatric sarcomas may collaborate to enable a better understanding of the biological behavior of these neoplasms.

Analysis of KIAA1549-BRAF fusion gene expression and IDH1/IDH2 mutations in low grade pediatric astrocytomas

Low-grade astrocytomas comprise about 30 % of the central nervous system tumors in children. Several investigations have searched a correlation between the BRAF gene fusions alterations and mutations at IDH1 and IDH2 genes in low grade pediatric astrocytomas. This study identified the expression of KIAA1549-BRAF fusion gene and BRAF V600E mutation, mutations at exon 4 of the IDH1 and IDH2 genes in samples of pilocytic astrocytomas (PA) and grade-II astrocytomas (A-II) pediatric patients. The correlation between these alterations and the clinical profile of the patients was also evaluated. Eighty-two samples of low-grade astrocytomas (65 PA and 17 A-II) were analyzed by PCR and sequencing for each of the targets identified. We identified the KIAA1549-BRAF fusion transcript in 45 % of the samples. BRAF V600E and BRAFins598T mutations were detected in 7 and 1 % of the samples, respectively. Mutations in the R132/R172 residues of the IDH1/IDH2 genes were detected in only two samples, and the G105G polymorphism (rs11554137:C>T) was identified in ten patients. Additionally, we observed two mutations out of the usual hotspots at IDH1 and IDH2 genes. We observed a smaller frequency of mutations in IDHs genes than previously described, but since the prior studies were composed of adult or mixed (adults and children) samples, we believe that our results represent a relevant contribution to the growing knowledge in low grade childhood astrocytomas.

Investigation of PAX3/7-FKHR fusion genes and IGF2 gene expression in rhabdomyosarcoma tumors

The purpose of our study was to investigate the prevalence of the PAX3/7-FKHR fusion genes and quantify the IGF2 gene expression in rhabdomyosarcoma (RMS) samples. Soft tissue sarcomas account 5% of childhood cancers and 50% of them are RMS. Morphological evaluation of pediatric RMS has defined two histological subtypes, embryonal (ERMS) and alveolar (ARMS). Chromosomal analyses have demonstrated two translocations associated with ARMS, resulting in the PAX3/7-FKHR rearrangements. Reverse transcriptase-polymerase chain reaction (RT-PCR) is extremely useful in the diagnosis of ARMS positive for these rearrangements. Additionally, several studies have shown a significant involvement of IGF pathway in the pathogenesis of RMS. The presence of PAX3/7-FKHR gene fusions was studied in 25 RMS samples from patients attending the IOP-GRAACC/UNIFESP and three RMS cell lines by RT-PCR. IGF2 gene expression was quantified by qPCR and related with clinic pathological parameters. Of the 25 samples, nine (36%) were ARMS and 16 (64%) were ERMS. PAX3/7-FKHR gene fusions expression was detected in 56% of ARMS tumor samples. IGF2 overexpression was observed in 80% of samples and could indicate an important role of this pathway in RMS biology.

Establishment and cytogenetic characterization of a cell line from a pulmonary metastasis of osteosarcoma

Osteosarcoma (OS) is the most frequent malignant bone tumour in children and adolescents. In metastatic patients, the most common site of metastasis is the lung. There are relatively few cell lines of metastatic OS reported in the literature and the cytogenetic aspects of OS metastases are still controversial and inconclusive. Here we describe the establishment of a new OS cell line, M-OS, from a pulmonary metastasis of a typical osteoblastic OS of an 11-year-old boy with metastatic OS at diagnosis. M-OS cells have been maintained in culture for over 50 passages for more than 1 year. M-OS was characterized by immunohistochemistry, conventional cytogenetics and fluorescence in situ hybridization (FISH). In order to evaluate in vitro cell modification, the immunohistochemical analysis was performed in three different moments of the cell line: 10th, 30th and 50th passages. The conventional cytogenetic analysis revealed the ploidy of M-OS cell line as near-diploid, with most metaphases hyperdiploid and tetraploid. We found a copy number gain of MDM2 gene as the most frequent alteration in the FISH analysis. The immunohistochemical analysis confirmed that M-OS cell line maintained the osteogenic nature even after all passages for the cell line establishment in vitro.

MAPK7 and MAP2K4 as prognostic markers in osteosarcoma

Osteosarcoma is a class of cancer originating from the bone, affecting mainly children and young adults. Cytogenetic studies showed the presence of rearrangements and recurrent gains in specific chromosomal regions, indicating the possible involvement of genes located in these regions during the pathogenesis of osteosarcoma. These studies investigated expression of 10 genes located in the chromosomal region involved in abnormalities in osteosarcoma, 1p36, 17p, and chromosome 19. The purpose of this study was to investigate the expression profile of genes located in regions involved in chromosomal rearrangements in osteosarcoma. We used quantitative real-time polymerase chain reaction to investigate the expression of 10 genes located in 1p36.3 (MTHFR, ERRFI1, FGR, E2F2), 17p (MAPK7, MAP2K4), and chromosome 19 (BBC3, FOSB, JUND, and RRAS), in 70 samples taken from 30 patients (30 prechemotherapy, 30 postchemotherapy, and 10 metastases specimens) and 10 healthy bones as a control sample. The most interesting results showed a strong association between the expression levels of MAPK7 and MAP2K4 genes and clinical parameters of osteosarcoma. Overexpression of these genes was significantly associated to a poor response to treatment (P = .0001 and P = .0049, respectively), tumor progression, and worse overall survival (P = .0052 and P = .0085, respectively), suggesting that MAPK7 and MAP2K4 could play an important role in osteosarcoma tumorigenesis. Thus, these genes could be good markers in assessing response to treatment and development of osteosarcoma.

Overuse of training increases mechanoreceptors in supraspinatus tendon of rats SHR

The presence of mechanoreceptors in tendon after overuse activities can be a further step to learn about tendinopathy and overuse. Studies of tendons mechanoreceptors in rats are rare. We studied 12 isogenic spontaneous hypertensive rats (SHR), which underwent an overuse protocol consisting of an hour per daily session of treadmill running at a speed of 17 m/min, 5 times/week for 4 months. Supraspinatus tendons were evaluated with immunohistochemistry using S100 protein antibodies and histological protocol. Supraspinatus tendons at the end of 4 months of overuse protocol had a high number of media mechanoreceptors (4.3) than controls (0.6). The overexpression of S100 protein antibody in overuse activities maybe could represent a adaptative effort to tendon before the tear.

Bone deposition, bone resorption, and osteosarcoma

Bone deposition and bone resorption are ongoing dynamic processes, constituting bone remodeling. Some bone tumors, such as osteosarcoma (OS), stimulate focal bone deposition. OS is the most common primary bone tumor in children and young adults. A complex network of genes regulates bone remodeling and alterations in its expression levels can influence the genesis and progression of bone diseases, including OS. We hypothesized that the expression profiles of bone remodeling regulator genes would be correlated with OS biology and clinical features. We used real-time PCR to evaluate the mRNA levels of the tartrate-resistant acid phosphatase (ACP5), colony stimulating factor-1 (CSF1R), bone morphogenetic protein 7 (BMP7), collagen, type XI, alpha 2 (COL11A2), and protein tyrosine phosphatases zeta 1 (PTPRZ1) genes, in 30 OS tumor samples and correlated with clinical and histological data. All genes analyzed, except CSF1R, were differentially expressed when compared with normal bone expression profiles. In our results, OS patients with high levels of COL11A2 mRNA showed worse overall (p = 0.041) and event free survival (p = 0.037). Also, a trend for better overall survival was observed in patients with samples showing higher expression of BMP7 (p = 0.067). COL11A2 overexpression and BMP7 underexpression could collaborate to OS tumor growth, through its central role in bone remodeling process.

Correlations between radiographic, magnetic resonance and histological examinations on the degeneration of human lumbar intervertebral discs

CONTEXT AND OBJECTIVE

There is controversy regarding which imaging method is best for identifying early degenerative alterations in intervertebral discs. No correlations between such methods and histological finds are presented in the literature. The aim of this study was to correlate the thickness of intervertebral discs measured on simple radiographs with the degree of degeneration seen on magnetic resonance images and the histological findings relating to nerve ends inside the discs.

DESIGN AND SETTING

Cross-sectional correlation study on the lumbar spines of human cadavers, at Universidade Federal de São Paulo (Unifesp), São Paulo, Brazil.

METHODS

Ten lumbar spinal columns were extracted from human cadavers and subjected to magnetic resonance imaging and simple radiography. They were classified according to the degree of disc degeneration seen on magnetic resonance, and the thickness of the discs was measured on radiographs. The intervertebral discs were then extracted, embedded in paraffin and analyzed immunohistochemically with protein S100, and the nerve fibers were counted and classified.

RESULTS

No correlation was observed between the thickness of the intervertebral discs and the degree of degeneration seen on magnetic resonance images. Only the uppermost lumbar discs (L1/L2 and L2/L3) presented a correlation between their thickness and type I and IV nerve endings.

CONCLUSION

Reduced disc thickness is unrelated to increased presence of nerve ends in intervertebral discs, or to the degree of disc degeneration.

Prognostic factors and outcomes for osteosarcoma: an international collaboration

We aimed to evaluate the prognostic significance of traditional clinical predictors in osteosarcoma through an international collaboration of 10 teams of investigators (2680 patients) who participated. In multivariate models the mortality risk increased with older age, presence of metastatic disease at diagnosis, development of local recurrence when the patient was first seen, use of amputation instead of limb salvage/wide resection, employment of unusual treatments, use of chemotherapeutic regimens other than anthracycline and platinum and use of methotrexate. It was also influenced by the site of the tumour. The risk of metastasis increased when metastatic disease was present at the time the patient was first seen and also increased with use of amputation or unusual treatment combinations or chemotherapy regimens not including anthracycline and platinum. Local recurrence risk was higher in older patients, in those who had local recurrence when first seen and when no anthracycline and platinum were used in chemotherapy. Results were similar when limited to patients seen after 1990 and treated with surgery plus combination chemotherapy. This large-scale international collaboration identifies strong predictors of major clinical outcomes in osteosarcoma.

Estudo sobre a associação de cerâmica a plasma rico em plaquetas na coluna vertebral de ratos

OBJETIVO: Analisar o efeito osteoindutor dos fatores de crescimento contidos no plasma rico em plaquetas (PRP) quando associados a cerâmicas no processo de fusão na coluna vertebral de ratos. MATERIAL E MÉTODO: Laminectomia lombar foi realizada em 16 ratos Lewis isogênicos para implantar cerâmica. O PRP foi preparado no ato operatório a partir do sangue de outras duas cobaias.os grupos estudo e controle foram estabelecidos por randomização, recebendo o grupo estudo cerâmica associada a PRP e o controle apenas cerâmica. Os animais foram sacrificados após 10 semanas e as colunas enviadas para análise histopatológica. RESULTADOS: Intensa atividade osteoblástica e osteoclástica e completa reabsorção da cerâmica foram achados no grupo estudo. No grupo controle havia ilhotas de osso em meio a tecido fibroso e cerâmica não reabsorvida. Discussão: Os fatores de crescimento liberados pelas plaquetas agem ligando-se à superfície de osteoblastos e fibroblastos, estimulando a síntese de colágeno para formação de matriz óssea. macrófagos ativados continuam secretando os fatores de crescimento e estimulando a osteogênese. CONCLUSÃO: O uso de PRP associado a cerâmica mostrou maior atividade osteoblástica e osteoclástica e completa reabsorção da cerâmica em relação à enxertia da mesma isoladamente na coluna vertebral de ratos.

Estudo comparativo dos mecanorreceptores dos discos intervertebrais normais e degenerados da coluna lombar de humanos pela radiografia, ressonância magnética e estudo anatomopatológico

Os autores fizeram um estudo da coluna lombar de humanos, objetivando avaliar e determinar os diferentes tipos de fibras nervosas no disco intervertebral normal e no degenerado. Foram usadas dez colunas lombares de cadáveres com aproximadamente 48 a 72 horas de óbito. As peças foram submetidas a exames de radiografia simples e ressonância magnética. Após os exames, os discos foram classificados em normais e degenerados. Em seguida, foram dissecados, divididos em regiões anterior e posterior, incluídos em parafina e realizado estudo de imuno-histoquímica com a proteína S100. Com o auxílio de um programa de computador Image-Pro Plus (media cybernetics®), as fibras nervosas tiveram seu diâmetro medidos em micrômetros e classificadas em quatro tipos de fibras. Foram encontrados quatro tipos de fibras nervosas nas diferentes regiões discais. O número e o tipo de fibras variaram de acordo com a região e grau de degeneração do disco intervertebral. Concluíram que as fibras do tipo III são mais freqüentes na região anterior; as fibras dos tipos II e IV são mais freqüentes na região posterior, e as fibras do tipo I não apresentaram diferenças entre a região anterior e a posterior; além disso, o disco degenerado tem mais fibras nervosas que o disco normal.

[Inhibition of peridural fibrosis after laminectomy using biological sheet in rat model]

The prevention of fibrosis after lumbar and thoracic laminectomies by avoiding herniation of muscular tissue was studied using Wistar-EPM rats with a biological membrane made of decorticated bone of bovine material. The rats were sacrificed after eight, sixteen and twenty four weeks and the material was sent to anatomopathological study. This membrane proved to be biocompatible and its efficacy was seen by allowing formation of bone and preventing muscular tissue invasion of the epidural space and avoiding adherences.

Análise por tomografia computadorizada do enxerto autógeno na cirurgia de "sinus lift"

OBJETIVO: Quantificar a formação óssea nos enxertos com e sem plasma rico em plaquetas, obtido pelos métodos de centrifugação e aférese, comparando os três tipos de enxertos realizados por meio de análise tomográfica. MATERIAIS E MÉTODOS: Este estudo prospectivo, duplo cego, utilizou uma amostra composta de 34 pacientes adultos, de ambos os sexos, com idade média de 48 anos e 8 meses, portadores de pneumatização unilateral ou bilateral dos seios maxilares, que necessitavam de enxertos ósseos, com a finalidade de melhorar as condições locais para a colocação dos implantes dentários. Todos os pacientes realizaram tomografia computadorizada antes da cirurgia. Foram operados 53 seios maxilares, divididos em três grupos: enxerto de plasma rico em plaquetas obtido pelos métodos de aférese, centrifugação e enxerto apenas de osso autógeno. Após seis meses do procedimento cirúrgico foram realizados novos exames de imagem. RESULTADOS: Pela avaliação tomográfica, houve crescimento em altura e em largura nos três grupos quando foram comparados os momentos inicial e final, entretanto, não houve diferença estatística para a altura e para a largura. CONCLUSÃO: Evidências clínicas demonstram a eficácia dos enxertos autógenos, principalmente os associados a fatores indutores de crescimento ósseo, como o plasma rico em plaquetas, recuperando o arcabouço maxilofacial, necessário para a reconstrução protética e funcional por meio de implantes dentários.

O papel da proteína morfogenética óssea na reparação do tecido ósseo

Este estudo de revisão da literatura aborda os avanços do uso da proteína morfogenética óssea (BMP) na reparação do tecido ósseo e seus mecanismos de ação no tecido lesionado. As BMPs são moléculas pleiotrópicas que são envolvidas na quimiotaxia, mitose e diferenciação de células mesenquimais no tecido ósseo.