Marina Azevedo

Immunohistochemical expression of matrix metalloprotease‐2 and matrix metalloprotease‐9 in the disks of patients with temporomandibular joint dysfunction

PURPOSE Matrix metalloproteases (MMPs) are tissue-remodeling enzymes that function during the remodeling process, such as in immune-inflammatory diseases. Metalloprotease-2 (MMP-2) and metalloprotease-9 (MMP-9) are gelatinases that degrade several types of extracellular matrix collagen. It is hypothesized that in temporomandibular joint (TMJ) dysfunction, MMP-2 and MMP-9 expression levels may be elevated. Therefore, the objective of this study is to determine the association of MMP-2 and MMP-9 expression with temporomandibular joint dysfunction using an immunohistochemical approach to evaluate the joint disk. MATERIAL AND METHODS A total of 45 human temporomandibular joint samples were collected, with 36 samples in the test group (patients with anterior disk displacement with reduction (n = 29) and without reduction (n = 7)) and nine samples in the control group. The immunostaining of the TMJ disks was statistically compared between the groups (P < 0.05). RESULTS There was a statistically significant difference for the area of MMP-2 immunostaining between the control group and the displacement disks with reduction group (ADDwR) (P = 0.048) and between the groups with disk displacement and without reduction (ADDwoR) (P = 0.029). The expression of MMP-2 was significantly elevated in the ADDwoR group. CONCLUSION No statistically significant difference was found between the variable area of MMP-9 expression in the disk with and without disk displacement, as determined by immunohistochemical analysis. However, there was an elevation of MMP-2 expression in the disks of patients with displacement and without reduction (more severe alteration).

FasL expression in articular discs of human temporomandibular joint and association with osteoarthrosis

BACKGROUND Apoptosis is a programme of cell death which does not induce an inflammatory response. Recent previous research has suggested a correlation between temporomandibular internal derangement and apoptosis. Fas ligand (FasL) is an apoptosis-inducing factor, known to trigger apoptosis through distinct signal pathways. This study aims to examine, by immunohistochemistry, the expression of FasL in temporomandibular joint (TMJ) articular discs of patients with anterior disc displacement with reduction (ADDwR) and without reduction (ADDwoR) in patients with and without osteoarthrosis (OA). METHODS Forty-two (n = 42) TMJ articular discs were divided into two cut-offs: (i) 8 control, 17 ADDwR, 17 ADDwoR, and (ii) without OA (n = 25) and with OA (n = 17). The area of immunostaining was compared statistically between groups (P < 0.05). RESULTS Statistically significant differences were found in the expression of FasL in TMJ discs between the three groups (P = 0.001). ADDwR presented significant higher FasL expression when compared with ADDwoR (P < 0.001). Significant higher FasL expression was observed in the group without OA (P = 0.001). All patients without OA presented ADDwR, while all the patients with OA presented ADDwoR. CONCLUSION A higher area of in situ immunostaining of FasL was found in temporomandibular discs with reduction, which is the less severe condition. Moreover, a reduced expression of FasL in the discs of patients with osteoarthrosis was found, suggesting that some aspects of apoptosis might underlie the progression of TMJ disorders.

Immunoexpression of GADD45β in the myocardium of newborns experiencing perinatal hypoxia

AIM Among the several organs affected by perinatal hypoxia, the heart plays a central role, with cell death caused mainly by apoptosis. One of the biomarkers most often linked to hypoxia-derived apoptosis of cardiomyocytes in animals is Gadd45β. From the published literature, Gadd45β is proposed as a biomarker of hypoxia-induced lesion in cardiomyocytes, both in vitro, as well as in animal models. Our study suggests that this protein can be used as an early biomarker of cell damage in neonates cardiomyocytes (humans specimens), a process that can ultimately lead to apoptosis. The aim is to determine levels of tissue immunoexpression of the Gadd45β biomarker in myocardium samples of newborns affected by hypoxia, and to correlate these results with clinical and anatomopathologic data. METHODS Myocardium samples from the left ventricle of newborns were used. The samples were collected from 78 autopsies performed in neonates of both genders, with hypoxia (Apgar score at five minutes below 6 and/or pH below 7.2 and/or autopsy with anatomopathological signs of hypoxia), who had died within the first day of life. All samples were organized in Tissue Microarray. Immunohistochemistry analysis, using anti-Gadd45β as the primary antibody, was performed on 3 multi-sample histological slides. There was no correlation between Gadd45β tissue immunoexpression and neonatal weight (p=0.93), gestational age (p=0.16), Apgar score at first minute (p=0.914), Apgar score at five minutes (p=0.988) and arterial blood pH (p=0.542). There was a relation between Gadd45β tissue immunoexpression and survival (p=0.02). The maximum peak of Gadd45β tissue immunoexpression was 8.43% HPF (high power field) and was observed around of six hours of life. CONCLUSION Gadd45β could be a suitable biomarker of cardiomyocytes apoptosis in newborns experiencing hypoxia in the first day of life, as its highest tissue immunoexpression around at the first six hours after birth.

The Impact of Uremic Toxicity Induced Inflammatory Response on the Cardiovascular Burden in Chronic Kidney Disease

Uremic toxin (UT) retention in chronic kidney disease (CKD) affects biological systems. We aimed to identify the associations between UT, inflammatory biomarkers and biomarkers of the uremic cardiovascular response (BUCVR) and their impact on cardiovascular status as well as their roles as predictors of outcome in CKD patients. CKD patients stages 3, 4 and 5 (n = 67) were recruited and UT (indoxyl sulfate/IS, p-cresil sulfate/pCS and indole-3-acetic acid/IAA); inflammatory biomarkers [Interleukin-6 (IL-6), high sensitivity C reactive protein (hsCRP), monocyte chemoattractant protein-1 (MCP-1), soluble vascular adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1) and soluble Fas (sFas)] and BUCVRs [soluble CD36 (sCD36), soluble receptor for advanced glycation end products (sRAGE), fractalkine] was measured. Patients were followed for 5.2 years and all causes of death was used as the primary outcome. Artery segments collected at the moment of transplantation were used for the immunohistochemistry analysis in a separate cohort. Estimated glomerular filtration rate (eGFR), circulating UT, plasma biomarkers of systemic and vascular inflammation and BUCVR were strongly interrelated. Patients with plaque presented higher signs of UT-induced inflammation and arteries from CKD patients presented higher fractalkine receptor (CX3CR1) tissue expression. Circulating IS (p = 0.03), pCS (p = 0.007), IL-6 (p = 0.026), sFas (p = 0.001), sCD36 (p = 0.01) and fractalkine (p = 0.02) were independent predictors of total mortality risk in CKD patients. Our results reinforce the important role of uremic toxicity in the pathogenesis of cardiovascular disease (CVD) in CKD patients through an inflammatory pathway.

Zika Virus Infection at Different Pregnancy Stages: Anatomopathological Findings, Target Cells and Viral Persistence in Placental Tissues

Zika virus (ZIKV) infection in humans has been associated with congenital malformations and other neurological disorders, such as Guillain-Barré syndrome. The mechanism(s) of ZIKV intrauterine transmission, the cell types involved, the most vulnerable period of pregnancy for severe outcomes from infection and other physiopathological aspects are not completely elucidated. In this study, we analyzed placental samples obtained at the time of delivery from a group of 24 women diagnosed with ZIKV infection during the first, second or third trimesters of pregnancy. Villous immaturity was the main histological finding in the placental tissues, although placentas without alterations were also frequently observed. Significant enhancement of the number of syncytial sprouts was observed in the placentas of women infected during the third trimester, indicating the development of placental abnormalities after ZIKV infection. Hyperplasia of Hofbauer cells (HCs) was also observed in these third-trimester placental tissues, and remarkably, HCs were the only ZIKV-positive fetal cells found in the placentas studied that persisted until birth, as revealed by immunohistochemical (IHC) analysis. Thirty-three percent of women infected during pregnancy delivered infants with congenital abnormalities, although no pattern correlating the gestational stage at infection, the IHC positivity of HCs in placental tissues and the presence of congenital malformations at birth was observed. Placental tissue analysis enabled us to confirm maternal ZIKV infection in cases where serum from the acute infection phase was not available, which reinforces the importance of this technique in identifying possible causal factors of birth defects. The results we observed in the samples from naturally infected pregnant women may contribute to the understanding of some aspects of the pathophysiology of ZIKV.

Expression of MMP-13 in Human Temporomandibular Joint Disc Derangement and Osteoarthritis

Abstract Objective: MMP-13 performs digestion of collagen, which is a primary component of the temporomandibular joint (TMJ) articular disc. This study evaluated the expression of MMP-13 in patients with anterior disc displacement with (ADDwR) and without reduction (ADDwoR), and in the presence of TMJ osteoarthrosis. Methods: Thirty-nine human temporomandibular joint disc samples were collected and divided in two ways: ADDwR (21 samples), ADDwoR (10 samples), and a control group (8 samples); and with osteoarthrosis (10 samples) and without osteoarthrosis (29 samples). Immunostaining of the TMJ discs was statistically compared between the groups. Results: There was no statistically significant difference for the area of MMP-13 immunostaining between the control group, ADDwR, and ADDwoR, nor between groups with and without osteoarthrosis. Conclusion: This study suggests MMP-13 is not significantly involved in collagen degradation in human TMJ disc displacement or osteoarthrosis.

Utilização de brocas trefina para a confecção de tissue microarray

Objetivos: Descrever e validar uma tecnica alternativa economica e eficiente para a confeccao de amostras teciduais com arranjo matricial (tissue microarrays, TMA). Materiais e metodos: Utilizou-se um motor, um micromotor, um contra-ângulo redutor 16:1 e brocas trefina de aco inoxidavel para osso. Analise histomorfometrica do volume das celulas acinares de glândulas parotidas foi realizada. Para testar marcadores imunoistoquimicos para celulas mioepiteliais, acinares e ductais das parotidas foram utilizados calponina e PCNA. Resultados: Na analise macroscopica e microscopica das lâminas, nao foi encontrada perda total do tissue e nem mesmo deslocamento (parcial e/ou total) deste, sendo as perdas teciduais observadas apenas parciais. Das 90 lâminas analisadas, 59 (65%) obtiveram de 50% a 100% do tissue com ausencia de artefato, deslocamento ou perda de tecido. Conclusao: O equipamento proposto pelos autores para a confeccao deamostras teciduais com arranjo matricial representa uma alternativa economica e eficiente.(AU) Objectives: To describe and validate an inexpensive and efficient alternative for the production of tissue microarrays (TMA). Materials and methods: An electric-motor, a hand-piece, a reducing contra-angle hand-piece 16:1 and trephine stainless steel drills for bones were used in this study. A histomorphometric assessment of the volume of the acinar cells of parotid glands was performed. Calponin and PCNA were used to test the immunohistochemical markers for myoepithelial, acinar and ductal cells of parotid glands. Results: During the macroscopic and microscopic analysis, total loss of sections was not observed in any slide as well as artifactual ungluing (total and/or partial) of the sections. The loss of sections was partial. Fifty nine (65%) out of 90 slides showed 50%-100% of the tissue without technical artifact, artifactual ungluing or loss of the section. Conclusion: The equipment proposed by the authors for the production of arrays represents an inexpensive and efficient alternative.(AU)