Publications by authors named "Marcelo Rodrigues Da Cunha"

This study evaluated the biocompatibility of dense and porous forms of Poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV), Poly(ε-caprolactone) (PCL), and their 75/25 blend for bone tissue engineering applications. The biomaterials were characterized morphologically using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), and the thickness and porosity of the scaffolds were determined. Functional assessments of mesenchymal stem cells (MSCs) included the MTT assay, alkaline phosphatase (ALP) production, and morphological and cytochemical analyses.

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Sickle cell anemia is a hereditary disease caused by sickle-shaped red blood cells that can lead to vaso-occlusive crises. Treatment options are currently limited, highlighting the need to develop new clinical approaches. Studies demonstrated that elevated levels of fetal hemoglobin (Hb F) are associated with a reduction of mortality and morbidity in sickle cell anemia patients.

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Osteomyelitis is an inflammation of bone tissue usually caused by pyogenic bacteria. The most recurrent clinical approach consists of bone debridement followed by parenteral administration of antibiotics. However, systemic antibiotic treatment has limitations regarding absorption rate and bioavailability over time.

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Severe loss of bone mass may require grafting, and, among the alternatives available, there are natural biomaterials that can act as scaffolds for the cell growth necessary for tissue regeneration. Collagen and elastin polymers are a good alternative due to their biomimetic properties of bone tissue, and their characteristics can be improved with the addition of polysaccharides such as chitosan and bioactive compounds such as jatoba resin and pomegranate extract due to their antigenic actions. The aim of this experimental protocol was to evaluate bone neoformation in experimentally made defects in the mandible of rats using polymeric scaffolds with plant extracts added.

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Background: Medical education has evolved based on the application of pedagogical actions that place the student as the protagonist of the learning process through the use of active teaching methodologies. Within this context, higher education teachers should use strategies that focus on the student and his/her context and avoid traditional teaching methods. Specifically in medical schools, there is an even greater challenge since the teaching methods of medical curricula differ from those used in previous schooling.

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Bone lesions have the capacity for regeneration under normal conditions of the bone metabolism process. However, due to the increasing incidence of major traumas and diseases that cause bone-mineral deficiency, such as osteoporosis, scaffolds are needed that can assist in the bone regeneration process. Currently, natural polymeric scaffolds and bioactive nanoparticles stand out.

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Natural polymers are increasingly being used in tissue engineering due to their ability to mimic the extracellular matrix and to act as a scaffold for cell growth, as well as their possible combination with other osteogenic factors, such as mesenchymal stem cells (MSCs) derived from dental pulp, in an attempt to enhance bone regeneration during the healing of a bone defect. Therefore, the aim of this study was to analyze the repair of mandibular defects filled with a new collagen/chitosan scaffold, seeded or not with MSCs derived from dental pulp. Twenty-eight rats were submitted to surgery for creation of a defect in the right mandibular ramus and divided into the following groups: G1 (control group; mandibular defect with clot); G2 (defect filled with dental pulp mesenchymal stem cells-DPSCs); G3 (defect filled with collagen/chitosan scaffold); and G4 (collagen/chitosan scaffold seeded with DPSCs).

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Quercetin is a dietary flavonoid present in vegetables, fruits, and beverages, such as onions, apples, broccoli, berries, citrus fruits, tea, and red wine. Flavonoids have antioxidant and anti-inflammatory effects, acting in the prevention of several diseases. Quercetin also has neuroprotective properties and may exert a beneficial effect on nervous tissue.

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Lesions with bone loss may require autologous grafts, which are considered the gold standard; however, natural or synthetic biomaterials are alternatives that can be used in clinical situations that require support for bone neoformation. Collagen and hydroxyapatite have been used for bone repair based on the concept of biomimetics, which can be combined with chitosan, forming a scaffold for cell adhesion and growth. However, osteoporosis caused by gonadal hormone deficiency can thus compromise the expected results of the osseointegration of scaffolds.

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: The spinous foramen (FS) of the skull is an opening located in the greater wing of the sphenoid bone at the base of the skull, and it includes the middle meningeal vessels and the meningeal branch of the mandibular trigeminal nerve. The FS is commonly used as an anatomical landmark in neurosurgical procedures and neuroimaging of the middle cranial fossa because of its relationship with other cranial foramina and surrounding vascular and nervous structures. Thus, specific knowledge of its topography and possible anatomical variations is important regarding some surgical interventions and skull imaging.

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Fibrin, derived from proteins involved in blood clotting (fibrinogen and thrombin), is a biopolymer with different applications in the health area since it has hemostasis, biocompatible and three-dimensional physical structure properties, and can be used as scaffolds in tissue regeneration or drug delivery system for cells and/or growth factors. Fibrin alone or together with other biomaterials, has been indicated for use as a biological support to promote the regeneration of stem cells, bone, peripheral nerves, and other injured tissues. In its diversity of forms of application and constitution, there are platelet-rich fibrin (PRF), Leukocyte- and platelet-rich fibrin (L-PRF), fibrin glue or fibrin sealant, and hydrogels.

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Biomaterials have been investigated as an alternative for the treatment of bone defects, such as chitosan/carbon nanotubes scaffolds, which allow cell proliferation. However, bone regeneration can be accelerated by electrotherapeutic resources that act on bone metabolism, such as low-level laser therapy (LLLT). Thus, this study evaluated the regeneration of bone lesions grafted with chitosan/carbon nanotubes scaffolds and associated with LLLT.

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Background & Aims: Creatine is a dietary supplement with potential capacity to stimulate the phosphocreatine pathway and protein synthesis, through the stimulation of the PI3-K/AKT and mTOR cascade, its use in populations with reduced muscle preservation capacity (such as the older adults) can be an interesting and low-cost alternative. The aim of the present study was to evaluate the morphological, stereological and morphometric effects of the use of creatine monohydrate for 8 weeks on the renal, hepatic and muscular tissues of 26-month-old Wistar rats.

Methods: Twelve Wistar rats were divided into two groups of six animals each.

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Cell-based therapy is a promising treatment to favor tissue healing through less invasive strategies. Mesenchymal stem cells (MSCs) highlighted as potential candidates due to their angiogenic, anti-apoptotic and immunomodulatory properties, in addition to their ability to differentiate into several specialized cell lines. Cells can be carried through a biological delivery system, such as fibrin glue, which acts as a temporary matrix that favors cell-matrix interactions and allows local and paracrine functions of MSCs.

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The aim of the present study was to evaluate the use of collagen, elastin, or chitosan biomaterial for bone reconstruction in rats submitted or not to experimental alcoholism. Wistar male rats were divided into eight groups, submitted to chronic alcohol ingestion (G5 to G8) or not (G1 to G4). Nasal bone defects were filled with clot in animals of G1 and G5 and with collagen, elastin, and chitosan grafts in G2/G6, G3/G7, and G4/G8, respectively.

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Article Synopsis
  • The study examined the epidemiological profiles of child violence in Brazil, focusing on victims, aggressors, and their socioeconomic factors before and during the COVID-19 pandemic.
  • A total of 609 cases were analyzed, revealing a high prevalence of sexual violence (63.2%), with female victims predominantly aged 2-9 and 14-18, and most incidents occurring in the home.
  • The study found no correlation between socioeconomic demographics and violence rates, but noted an increase in notifications during the pandemic, with a significant portion of physical violence involving self-harm.
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COVID-19 is a viral disease characterized as a pandemic by the World Health Organization in March 2020. Since then, researchers from all over the world have been looking for ways to fight this disease. Many cases of complications arise from insufficient immune responses due to low immunity, with intense release of pro-inflammatory cytokines that can damage the structure of organs such as the lung.

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Cobalt-base alloys (Co-Cr-Mo) are widely employed in dentistry and orthopedic implants due to their biocompatibility, high mechanical strength and wear resistance. The osseointegration of implants can be improved by surface modification techniques. However, complex geometries obtained by additive manufacturing (AM) limits the efficiency of mechanical-based surface modification techniques.

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Article Synopsis
  • Autologous bone grafts are the gold standard for treating extensive bone loss, but they have limitations related to donor area and complications, prompting the need for new biomaterials.
  • The study tested the effects of elastin and collagen matrices on bone repair in rats with critical size defects, comparing a control group with two groups using different biomaterials.
  • Results showed that both matrices significantly improved bone growth compared to the control group, with the porcine collagen matrix yielding the best outcomes.
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Article Synopsis
  • Spontaneous otogenic pneumocephalus is a rare condition resulting from air entering the brain due to erosion in the ear area, often linked to low pressure in the skull.
  • Surgical treatment typically involves repairing the defect, with lumbar drainage used to help relax the brain and reduce leaks during the procedure.
  • A case study of a 66-year-old man showed that while lumbar drainage was intended to help, it instead worsened his condition, leading to serious complications like brain herniation, which only improved after receiving intrathecal saline.
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Tissue engineering represents a promising alternative for reconstructive surgical procedures especially for the repair of bone defects that do not regenerate spontaneously. The present study aimed to evaluate the effects of the elastin matrix (E24/50 and E96/37) incorporated with hydroxyapatite (HA) or morphogenetic protein (BMP) on the bone repair process in the distal metaphysis of rat femur. The groups were: control group (CG), hydrolyzed elastin matrix at 50°C/24h (E24/50), E24/50 + HA (E24/50/HA), E24/50 + BMP (E24/50/BMP), hydrolyzed elastin matrix at 37°C/96h (E96/37), E96/37 + HA (E96/37/HA), E96/37 + BMP (E96/37/BMP).

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Objective: To study the anatomy of the brachial plexus in fetuses and to evaluate differences in morphology during evolution, or to find anatomical situations that can be identified as the cause of obstetric paralysis.

Methods: Nine fetuses (12 to 30 weeks of gestation) stored in formalin were used. The supraclavicular and infraclavicular parts of the brachial plexus were dissected.

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The use of biomaterials in medical and dental areas has become increasingly important due to the need to restore areas with bone loss or defects. This study analyzed the use of a new elastin polymer matrix combined with Bone Morphogenetic Protein for the repair of cranial defects in rats. Thirty rats were divided into five groups: control (C) defect without graft, E24 (defect filled with elastin matrix submitted to alkaline hydrolysis at 50°C for 24 h), E24/BMP (defect filled with elastin matrix treated at 50°C for 24 h plus BMP), E96 (defect filled with elastin matrix treated at 37°C for 96 h) and E96/BMP (defect filled with elastin matrix treated at 37°C for 96 h plus BMP).

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Polymeric biomaterials composed of extracellular matrix components possess osteoconductive capacity that is essential for bone healing. The presence of collagen and the ability to undergo physicochemical modifications render these materials a suitable alternative in bone regenerative therapies. The objective of this study was to evaluate the osteogenic capacity of collagen-based matrices (native and anionic after alkaline hydrolysis) made from bovine intestinal serosa (MBIS).

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Glutamate decarboxylase or glutamic acid decarboxylase (GAD) is a protein associated with autoimmune diseases, including type-1 diabetes. This disease is primarily associated with the occurrence of a specific isoform: GAD65. Conversely, some specific peptides of this protein may block autoimmunity in diabetes.

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