CESAR ISAAC
Projetos de Pesquisa
Unidades Organizacionais
LIM/04 - Laboratório de Microcirurgia, Hospital das Clínicas, Faculdade de Medicina - Líder
11 resultados
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- Treatment of extrinsic ectropion on burned face with facial suspension technique(2014) VANA, Luiz Philipe Molina; ISAAC, Cesar; ALONSO, NivaldoThe extrinsic ectropion is a condition with low prevalence characterized by an ectropion with normal eyelid and anatomy unchanged and the cause is found in tissues adjacent orbits. There are not many studies in the literature regarding their treatment, especially without addressing the eyelid respecting its anatomical integrity. Purpose: To evaluate the outcome of 8 extrinsic ectropions secondary to facial burns treated with facial suspension technique. Patients and methods: Five patients were evaluated with sequelae of facial burns and extrinsic unilateral or bilateral ectropion, a total of 8 ectropions. The technique used was the endoscopic facial suspension with or without release of the facial scar retraction. We evaluated the position of the lower lid over medium-pupillary line, symptoms, complications and patient satisfaction in a 24 months follow-up. Results: 6 Peri-orbital regions showed good results and two moderate results, all cases had clinical improvement of the ectropion, the symptoms and the esthetic aspect; there was not any complication or reoperation. There was a gain of 2.2-26.2% of the lower eyelid margin position in relation to the horizontal mid-pupillary line. Conclusion: The endoscopic facial suspension proved to be a surgical technique with low morbidity and efficient treatment in 8 facial extrinsic ectropion.
- Short-term effects of 7-ketocholesterol on human adipose tissue mesenchymal stem cells in vitro(2014) LEVY, Debora; RUIZ, Jorge Luis Maria; CELESTINO, Andrea Turbuck; SILVA, Suelen Feitoza; FERREIRA, Adilson Kleber; ISAAC, Cesar; BYDLOWSKI, Sergio PauloOxysterols comprise a very heterogeneous group derived from cholesterol through enzymatic and nonenzymatic oxidation. Among them, 7-ketocholesterol (7-KC) is one of the most important. It has potent effects in cell death processes, including cytoxicity and apoptosis induction. Mesenchymal stem cells (MSCs) are multipotent cells characterized by self-renewal and cellular differentiation capabilities. Very little is known about the effects of oxysterols in MSCs. Here, we describe the short-term cytotoxic effect of 7-ketocholesterol on MSCs derived from human adipose tissue. MSCs were isolated from adipose tissue obtained from two young, healthy women. After 24 h incubation with 7-KC, mitochondrial hyperpolarization was observed, followed by a slight increase in the level of apoptosis and changes in actin organization. Finally, the IC50 of 7-KC was higher in these cells than has been observed or described in other normal or cancer cell lines.
- Evaluation of Radiosterilized Glyercerolated Amniotic Membranes as a Substrate for Cultured Human Epithelial Cells(2020) PAGGIARO, Andre O.; MATHOR, Monica B.; TEODORO, Walcy R.; ISAAC, Cesar; CAPELOZZI, Vera L.; GEMPERLI, RolfHuman amniotic membrane (HAM) is a biomaterial with biological properties beneficial to tissue repair, serving as a substrate for cell cultivation. Irradiation is used for tissue sterilization, but can damage the HAM structure. The objective of this paper was to construct a skin substitute, composed of human keratinocytes cultured on glycerolated HAMs, and to evaluate the influence radiation on subsequent cell culture growth. Four batches of HAMs were glycerolated, and half of them were radio-sterilzed with 25 kGy. Non-irradiated glycerolated HAM (ni-HAM) and irradiated glycerolated HAM (i-HAM) samples were then de-epithelized and analyzed using optical microscopy (Picrossirius staining), immunofluorescence and electron microscopy. Subsequently, keratinocytes were cultured on ni- and i-HAMs, and either immersed or positioned at the air-liquid interface. The basement membranes of the ni-HAM group remained intact following de-epithelialization, whereas the i-HAM group displayed no evidence or remnant presence of these membranes. Concerning the keratinocyte cultures, the ni-HAM substrate promoted the growth of multi-layered and differentiated epithelia. Keratinocytes cultured on i-HAM formed epithelium composed of three layers of stratification and discrete cell differentiation. The glycerolated HAM was compatible with cultured epithelia, demonstrating its potential as a skin substitute. Irradiation at 25 kGy caused structural damage to the amnion.
- Clinical Trial Comparing 3 Different Wound Dressings for the Management of Partial-Thickness Skin Graft Donor Sites(2011) CARVALHO, Viviane Fernandes de; PAGGIARO, Andre Oliveira; ISAAC, Cesar; GRINGLAS, Julio; FERREIRA, Marcus CastroPURPOSE: A review of the literature reveals a lack of consensus regarding local management of skin graft donor sites. This study was undertaken to determine the effects of 3 different dressings on healing of donor sites and patient discomfort related to donor sites. DESIGN: This study is a comparison cohort study. SUBJECTS AND SETTING: We recruited 34 burn patients scheduled for partial-thickness skin grafts; their mean age was 36 +/- 18 years (mean +/- SD, range 20 to 54 years), and 63% were male. All subjects were managed at Burn Unity Care, located in Sao Paulo, Brazil. MATERIALS AND METHODS: Subjects were randomly allocated to 1 of 3 groups: (1) a study group (group A) whose donor sites were dressed with a bovine collagen calcium-alginate dressing covered with transparent polyurethane film; (2) a second intervention group (group B), whose donor sites were dressed only with transparent polyurethane film dressing; and (3) a control group whose donor sites were dressed with rayon soaked in 0.9% saline (group C). Two independent observers assessed donor site wounds for epithelialization, scabbing, quantity and characteristics of exudate, and complications. Pain was measured using the visual analog scale, the brief pain inventory, and Index of Pain Management. RESULTS: Subjects managed with the bovine collagen calcium-alginate dressing covered with transparent polyurethane film (group A) achieved the greatest epithelialization (6.3 vs 8.2 for thin film dressing only P < .02 and 6.3 vs 11.7 days for control group P < .01). Patients managed with the bovine collagen calcium-alginate dressing covered with transparent polyurethane film also reported less pain that subjects allocated to the control (group C) or thin film only group (group B), (P < .05). Ninety percent of subjects allocated to the calcium alginate covered with thin film dressing reported mild pain intensity on the Visual Analog Scale, 85% of did not report pain localized to the donor site on the brief pain inventory, and scores on the Index of Pain Management ranged from 23 to 11. CONCLUSION: Study findings suggest that use of a collagen calcium-alginate dressing with a transparent film covering reduces the time for complete epithelialization and may reduce pain related to skin graft donor sites.
- Sistematização de curativos para o tratamento clínico das feridas(2012) SMANIOTTO, Pedro Henrique de Souza; FERREIRA, Marcus Castro; ISAAC, Cesar; GALLI, RafaelThe treatment of cutaneous wounds includes both medical and surgical methods; dressing is one of the most commonly used clinical treatments. An extensive therapeutic toolkit comprising passive dressings or dressings with active principles can help repair wounds in various situations. Dressings are used to improve the conditions of the wound bed and may occasionally be considered the definitive treatment, whereas in some cases, they may be considered an intermediate step to surgical treatment. Intelligent and biological wound dressings are currently classified as dermal substitutes and will not be discussed in this article. Dressings should be selected on the basis of knowledge of the pathophysiology of wound healing and tissue repair while keeping the systemic problems of the patient in mind.
- Construção de substituto da pele composto por matriz de colágeno porcino povoada por fibroblastos dérmicos e queratinócitos humanos: avaliação histológica(2012) ISAAC, Cesar; REGO, Francinni M. P.; LADEIR, Pedro Ribeiro Soares de; ALTRAM, Silvana C.; OLIVEIRA, Renata C. de; ALDUNATE, Johnny L. C. B.; PAGGIARO, André O.; FERREIRA, Marcus CastroBACKGROUND: In the case of extensive lesions, the use of autologous grafts is limited by the extent of the donor area and the clinical condition of patients. Allografts collected from cadavers or volunteers are usually rejected after 1 to 2 weeks, thus serving only as temporary cover for these lesions. Treating major cutaneous lesions with reconstructed autologous skin is an attractive alternative, because it is possible to obtain cultures of cells that multiply rapidly and can be cryopreserved from a small fragment of the patient's skin, thereby facilitating its indefinite use in new treatments. This study evaluated the histological behavior of cultured human keratinocytes and fibroblasts on a collagen matrix derived from porcine small intestinal submucosa. METHODS: Cells from human epidermis and dermis were grown separately and seeded on porcine collagen matrix, which was maintained in a controlled environment for 21 days before being subjected to histological analysis. RESULTS: Fibroblasts invaded and colonized the collagen matrix, whereas keratinocytes were organized in laminated and stratified layers on the surface on which they were seeded. CONCLUSIONS: The use of porcine collagen matrix as a support for human skin cells is feasible, and the organization of these cells resembles the architecture of human skin.
- Comparative study of Silver Sulfadiazine with other materials for healing and infection prevention in burns: A systematic review and meta-analysis(2019) NIMIA, Heloisa Helena; CARVALHO, Viviane Fernandes; ISAAC, Cesar; SOUZA, Francisley Avila; GEMPERLI, Rolf; PAGGIARO, Andre OliveiraThe aim of this systematic review with meta-analysis was to compare the effect of Silver Sulfadiazine (SSD) with other new dressings, with or without silver, on healing and infection prevention in burns. The electronic search was carried out in the electronic databases of Pubmed, ScienceDirect, Lilacs and BVS. The articles included were randomized clinical trials about burn treatment with SSD, which evaluated the healing and infection of burn wounds in humans. The exclusion criteria included articles, editorials and letters published in the form of abstracts, unpublished reports and case series, cross-sectional, observational experimental studies, and the use of sulfadiazine for other types of wounds. The search identified 873 references, and 24 studies were included in accordance with the eligibility criteria. The results showed a statistically favorable difference related to the time of healing for silver dressings (p< 0.0001; MD 3.83; 95% CI 2.03-5.62) and dressings without silver (p< 0.007; MD 2.9; 95% CI 0.81-5.00) in comparison with SSD. The rate of infection showed no difference in the group treated with SSD compared with the group treated with dressings containing silver (p> 0.05). The rate of infection was significantly higher in the SSD group compared with the group treated with dressings without silver (p< 0.005; MD 25.29% and MD 12.97%). Considering the clinical trials conducted up to the present time, the authors concluded that new dressings withand without silver show better results than SSD for wound healing, and burn streated with dressings without silver are less likely to become infected than burns with SSD. No differences between SSD and new silver materials were observed in relation to infection prevention.
- Human fetal wound healing: a review of molecular and cellular aspects(2016) YAGI, Leticia Hitomi; WATANUKI, Larissa Martins; ISAAC, Cesar; GEMPERLI, Rolf; NAKAMURA, Yeda Midori; LADEIRA, Pedro Ribeiro SoaresThe physiological answer to after birth skin lesions is scarring, which compromises the function and the aesthetics of the injured area. However, fetuses in early gestation (24 weeks or less) respond to this damage with skin regeneration. To explain this difference, several factors are considered, such as increased production of collagen III in fetal fibroblasts and increased presence of this collagen in the skins of these fetuses. Increased hyaluronic acid in fetal matrix correlates with greater capacity for migration of fibroblasts in scarless repair. The fact that myofibroblasts in the wound appear only after the fetal stage of pregnancy which forms scars can also be correlated. Additionally, there is an increase in the amount of adhesion molecules in repair without scarring, which would multiply cell adhesion and migration. Lower levels of bTGF1 in fetal wound are correlated with reduced amounts of collagen I and may be the result of higher relative expression of bTGF3, which downregulates bTGF1. Amniotic fluid itself might be a stimulating factor to human skin's fibroblasts proliferation through cytokines such as bFGF and PDGF. A hypoxic environment in the fetal wound, associated with increased presence of Dot cells in blood, is also observed, and both facts can be related to a difference in the repair of the skin. Distinct gene expression guides those different responses and may also help to elucidate fetal skin regeneration. When the mechanisms responsible for the absence of scars in wounded fetuses are enlightened, it will be a significant mark in the studies of wound cicatrization and its therapeutic applications shall be extremely valuable.
- COMPARISONS OF THE RESULTS OF PERIPHERAL NERVE DEFECT REPAIR WITH FIBRIN CONDUIT AND AUTOLOGOUS NERVE GRAFT: AN EXPERIMENTAL STUDY IN RATS(2016) LONGO, Marco Vinicius Losso; FARIA, Jose Carlos Marques De; ISAAC, Cesar; NEPOMUCENO, Andre Coelho; TEIXEIRA, Nuberto Hopfgartner; GEMPERLI, RolfIntroduction: The standard treatment for nerve defects is nerve autograft. There is no conduit available that provides the same regenerative capacity of nerve autograft. This study evaluated the histological and functional recovery of nerve defects treated with fibrin conduit in comparison to the nerve autograft, in a rat model. Method: A sciatic nerve injury model (10-mm defect) was performed in 20 Wistar rats, nerve defect was reconstructed using a fibrin conduit (n=10). A nerve autograft was used as control (n=10). The walking behavior was measured by footprint analysis at 4, 8, and 12 weeks and sciatic function index was determined. After 12 weeks, histological analysis was performed to evaluate the regenerated nerve and measured axonal density. The triceps surae muscle weight was also evaluated. Results: The fibrin conduit group showed less improvement in walking behavior compared to nerve autograft (-53 +/- 2 vs. -36 +/- 2; P<0.001 at 12 weeks). The fibrin conduit group presented axonal density of 40.0 axons/10.995 mu m2 and the nerve autograft group had 67.2 axons/10.995 mu m2 (P<0.001). The triceps surae muscle weight ratio of the fibrin conduit group was 41 +/- 3% versus 71 +/- 4% of the nerve autograft group (P<0.001). Conclusion: The fibrin conduit could be used for nerve reconstruction following peripheral nerve injury in the rat model. However, the functional recovery in the fibrin conduit repair group was worse than that in nerve autograft group and the nerve repair with the fibrin conduit has less myelinated fibers when compared to the repair with nerve autograft. (C) 2015 Wiley Periodicals, Inc.
- Oxysterols in adipose tissue-derived mesenchymal stem cell proliferation and death(2017) SILVA, Suelen Feitoza; LEVY, Debora; RUIZ, Jorge Luis Maria; MELO, Thatiana Correa de; ISAAC, Cesar; FIDELIS, Maira Luisa; RODRIGUES, Alessandro; BYDLOWSKI, Sergio PauloMesenchymal stem cells (MSCs) are multipotent cells characterized by self-renewal and cellular differentiation capabilities. Oxysterols comprise a very heterogeneous group derived from cholesterol through enzymatic and non-enzymatic oxidation. Potent effects in cell death processes, including cytoxicity and apoptosis induction, were described in several cell lines. Very little is known about the effects of oxysterols in MSCs. 7-ketocholesterol (7-KC), one of the most important oxysterols, was shown to be cytotoxic to human adipose tissue-derived MSCs. Here, we describe the short-term (24 h) cytotoxic effects of cholestan-3 alpha-5 beta-6 alpha-triol, 3,5 cholestan-7-one, (3 alpha-5 beta-6 alpha)- cholestane-3,6-diol, 7-oxocholest-5-en-3 beta-ylacetate, and 5 beta-6 beta epoxy-cholesterol, on MSCs derived from human adipose tissue. MSCs were isolated from adipose tissue obtained from three young, healthy women. Oxysterols, with the exception of 3,5 cholestan-7-one and 7-oxocholest-5-en-3 beta-yl acetate, led to a complex mode of cell death that include apoptosis, necrosis and autophagy, depending on the type of oxysterol and concentration, being cholestan-3 alpha-5 beta-6 alpha-triol the most effective. Inhibition of proliferation was also promoted by these oxysterols, but no changes in cell cycle were observed.