Leiomyosarcomas of the oral cavity: report of a radiation-associated and a metastatic case

Background

Leiomyosarcoma is rare in the oral cavity, where it may arise as primary, radiation-associated, or metastatic tumor. This article reports two cases of oral leiomyosarcoma, discussing the range of clinicopathological features and the significance of these presentations.

Case report

One case is a radiation-associated leiomyosarcoma arising in the tongue of a 71-year-old male occurring 22?years after radiation therapy for tonsil squamous cell carcinoma that was surgically treated. The other one is a mandible metastasis from a retroperitoneal widespread leiomyosarcoma in a 69-year-old man, who was treated by surgery and chemotherapy but died from the disease.

Discussion

Post-radiotherapy sarcomas of the oral cavity and oral metastasis from soft tissue sarcomas are very uncommon, but based on patient??s clinical history, they should be considered by oral health care providers in order to allow an early diagnosis and proper and timely management. Finally, to the best of our knowledge, this seems to be the first reported case of tongue leiomyosarcoma arising in a previously irradiated field.     

Micromorphology of the Dental Pulp Is Highly Preserved in Cancer Patients Who Underwent Head and Neck Radiotherapy

Introduction

Teeth are often included in the radiation field during head and neck radiotherapy, and recent clinical evidence suggests that dental pulp is negatively affected by the direct effects of radiation, leading to impaired sensitivity of the dental pulp. Therefore, this study aimed to investigate the direct effects of radiation on the microvasculature, innervation, and extracellular matrix of the dental pulp of patients who have undergone head and neck radiotherapy.

Methods

Twenty-three samples of dental pulp from patients who finished head and neck radiotherapy were analyzed. Samples were histologically processed and stained with hematoxylin-eosin for morphologic evaluation of the microvasculature, innervation, and extracellular matrix. Subsequently, immunohistochemical analysis of proteins related to vascularization (CD34 and smooth muscle actin), innervation (S-100, NCAM/CD56, and neurofilament), and extracellular matrix (vimentin) of the dental pulp was performed.

Results

The morphologic study identified preservation of the microvasculature, nerve bundles, and components of the extracellular matrix in all studied samples. The immunohistochemical analysis confirmed the morphologic findings and showed a normal pattern of expression for the studied proteins in all samples.

Conclusions

Direct effects of radiotherapy are not able to generate morphologic changes in the microvasculature, innervation, and extracellular matrix components of the dental pulp in head and neck cancer patients.     

Cd modifies hepatic Zn deposition and modulates δ-ALA-D activity and MT levels by distinct mechanisms

Cadmium (Cd) is a pollutant that is harmful to human and animals. The liver is a target for Cd accumulation and it can disrupt Zn homeostasis. Here we examined the interaction of Zn and Cd to determine how these two metals could affect δ-aminolevulinate-dehydratase (δ-ALA-D) and metallothionein (MT), two potential molecular endpoints for Cd hepatotoxicity. Cd exposure (0.25 and 1 mg kg1 body weight, i.p., for 10 days) caused a marked increase in hepatic Zn deposition, which was not modified by treatment with Zn (2 mg kg1 , i.p.). Cd caused a dose-dependent increase in hepatic Cd content that was not modified by Zn. Zn and/or Cd treatment increased hepatic δ-ALA-D activity, although the increase caused by Cd was less marked. Reactivation index of δ-ALA-D by DTT was decreased by Zn and Cd exposure, which indicates that Zn protects enzyme from oxidation. Hepatic MT was increased only after exposure to 1 mg kg(-1) Cd and Zn reduced the stimulation of MT synthesis. The results presented here indicate that Cd can redistribute Zn from non-hepatic tissues to liver and the increase in hepatic Zn deposition can account for the increase in hepatic δ-ALA-D activity after Cd exposure. However, Zn blocked the increase in hepatic MT levels caused by Cd. Thus, the modulation of the two molecular endpoints of Cd toxicity used here was distinct, which indicates that the mechanism(s) involved in Zn and Cd distribution, δ-ALA-D and MT regulation are not coincident.     

Cinnamaldehyde induces changes in the protein profile of Salmonella Typhimurium biofilm

The effect of cinnamaldehyde against biofilm cells of Salmonella Typhimurium ATCC 14028 was evaluated. We also assessed differential protein patterns that were expressed by biofilms compared with planktonic cells and protein expression by cinnamaldehyde-treated biofilms cells. This compound decreased biofilm biomass and metabolic activity of biofilms at both concentrations tested. Cinnamaldehyde treatment reduced the number of attached cells in polypropylene, reflected by colony count and scanning electron microscopy. The proteomic analysis of biofilms compared with planktonic cells indicated that several proteins were upregulated or downregulated, especially proteins that are involved in energy metabolism. Peroxiredoxin, ATP synthase alpha chain protein, conjugal transfer nickase/helicase TraI and elongation factor G were upregulated in untreated-biofilm cells, and their expression decreased as a function of cinnamaldehyde treatment. Cinnamaldehyde had antibiofilm activity, and several differentially expressed proteins identified provide potential and interesting targets to explore new control strategies for S. Typhimurium biofilms.     

New methodology for evaluating osteoclastic activity induced by orthodontic load

Orthodontic tooth movement (OTM) is a dynamic process of bone modeling involving osteoclast-driven resorption on the compression side. Consequently, to estimate the influence of various situations on tooth movement, experimental studies need to analyze this cell.

Objectives

The aim of this study was to test and validate a new method for evaluating osteoclastic activity stimulated by mechanical loading based on the fractal analysis of the periodontal ligament (PDL)-bone interface.

Material and Methods

The mandibular right first molars of 14 rabbits were tipped mesially by a coil spring exerting a constant force of 85 cN. To evaluate the actual influence of osteoclasts on fractal dimension of bone surface, alendronate (3 mg/Kg) was injected weekly in seven of those rabbits. After 21 days, the animals were killed and their jaws were processed for histological evaluation. Osteoclast counts and fractal analysis (by the box counting method) of the PDL-bone interface were performed in histological sections of the right and left sides of the mandible.

Results

An increase in the number of osteoclasts and in fractal dimension after OTM only happened when alendronate was not administered. Strong correlation was found between the number of osteoclasts and fractal dimension.

Conclusions

Our results suggest that osteoclastic activity leads to an increase in bone surface irregularity, which can be quantified by its fractal dimension. This makes fractal analysis by the box counting method a potential tool for the assessment of osteoclastic activity on bone surfaces in microscopic examination.     

Assessment of dental age estimation methods applied to Brazilian children: a systematic review and meta-analysis

Objectives:To review the scientific literature of studies on dental age estimation methods applied to Brazilian children.Methods:A systematic literature review was designed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and registered in PROSPERO (CRD42020136170). Six scientific databases were used as primary search sources (PubMed, Scopus, LILACS, SciELO, Embase and Web of Science) and two databases (Open Grey and Open Thesis) were searched to partially select the “grey literature.” Only cross-sectional studies were included. The risk of bias was assessed by means of Joanna Briggs Institute Critical Appraisal Tools for Systematic Reviews. The standardized mean difference (SMD) between the estimated dental and chronological ages was meta-analysed via random effects model.Results:The search resulted in 2,527 studies, from which 13 met the eligibility criteria. Out of the eligible studies, 76.92% had low risk of bias and high methodological quality. Ten studies provided proper information to be included in the meta-analysis.The methods and their SMD between estimated and chronological ages were: Willems’=0.05, Lilequist and Lundberg’s = −0.11, Nolla’s = 0.22, Mornstad’s = 0.27, Cameriere’s = −0.31, Demirjian’s = 0.74 and Haavikko’s = −0.87.Conclusion:Although originally trained in populations worldwide, most of the international methods for radiographical dental age estimation had optimal performance in Brazilian children.     

A safe-by-design approach to the development of gold nanoboxes as carriers for internalization into cancer cells

Gold nanomaterials are currently raising a signi?cant interest for human welfare in the ?eld of clinical diagnosis, therapeutics for chronic pathologies, as well as of many other biomedical applications. In particular, gold nanomaterials are becoming a promising technology for developing novel approaches and treatments against widespread societal diseases such as cancer. In this study, we investigated the potential of proprietary gold nanoboxes (AuNBs) as carriers for their perspective translation into multifunctional, pre-clinical nano-enabled systems for personalized medicine approaches against lung cancer. A safe-by-design, tiered approach, with systematic tests conducted in the early phases on uncoated AuNBs and more focused testing on the coated, drug-loaded nanomaterial toward the end, was adopted. Our results showed that uncoated AuNBs could effectively penetrate into human lung adenocarcinoma (A549) cells when in simple (mono-cultures) or complex (co- and three-dimensional-cultures) in vitro microenvironments mimicking the alveolar region of human lungs. Uncoated AuNBs were biologically inert in A549 cells and demonstrated signs of biodegradability. Concurrently, preliminary data revealed that coated, drug-loaded AuNBs could efficiently deliver a chemotherapeutic agent to A549 cells, corroborating the hypothesis that AuNBs could be used in the future for the development of personalized nano-enabled systems for lung cancer treatment.     

Phylogenetic analysis of rabies viruses isolated from cattle in southern Brazil

Virus Genes - Bats and dogs are the main reservoirs of rabies virus (RABV) in Latin America and are responsible for the maintenance of different cycles of infection. In the two neighbour and most...