Browsing by Author "Martinez, Constanza"

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    FOXO1 regulates wound-healing responses in human gingival fibroblasts
    (2024) Rojas, Leticia; Tobar, Nicolas; Espinoza, Javier; Rios, Susana; Martinez, Constanza; Martinez, Jorge; Graves, Dana T.; Smith, Patricio C.
    Background and objective: Forkhead box-O 1 (FOXO1) is a transcription factor actively involved in oral wound healing at the epithelial barrier. However, less is known regarding the role of FOXO1 during the tissue repair response in the connective tissue compartment. This study explored the involvement of FOXO1 in the modulation of fibroblast activity related to wound healing. Methods: Primary cultures of human gingival fibroblasts were obtained from four healthy young donors. Myofibroblastic differentiation, collagen gel contraction, cell migration, cell spreading, and integrin activation were evaluated in the presence or absence of a FOXO1 inhibitor (AS1842856). Variations in mRNA and proteins of interest were evaluated through qRT-PCR and western blot, respectively. Distribution of actin, alpha-smooth muscle actin, and beta 1 integrin was evaluated using immunofluorescence. FOXO1 and TGF-beta 1 expression in gingival wound healing was assessed by immunohistochemistry in gingival wounds performed in C57BL/6 mice. Images were analyzed using ImageJ/Fiji. ANOVA or Kruskal-Wallis test followed by Tukey's or Dunn's post-hoc test was performed. All data are expressed as mean +/- SD. p < .05 was considered statistically significant. Results: FOXO1 inhibition caused a decrease in the expression of the myofibroblastic marker alpha-SMA along with a reduction in fibronectin, type I collagen, TGF-beta 1, and beta 1 integrin mRNA level. The FOXO1 inhibitor also caused decreases in cell migration, cell spreading, collagen gel contraction, and beta 1 integrin activation. FOXO1 and TGF-beta 1 were prominently expressed in gingival wounds in fibroblastic cells located at the wound bed. Conclusion: The present study indicates that FOXO1 plays an important role in the modulation of several wound-healing functions in gingival fibroblast. Moreover, our findings reveal an important regulatory role for FOXO1 on the differentiation of gingival myofibroblasts, the regulation of cell migration, and collagen contraction, all these functions being critical during tissue repair and fibrosis.
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    Glycated Collagen Stimulates Differentiation of Gingival Myofibroblasts.
    (2017) Retamal, Ignacio N.; Hernández, Romina; Melo Ledermann, Francisco Javier; Zapata, Paulina; Martinez, Constanza; Martínez, Jorge; Smith, Patricio C.
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    Oral polio vaccine in infants does not interfere in detection of enterovirus in blood
    (SOC CHILENA INFECTOLOGIA, 2013) Gonzalez, Marcela; Sandoval, Carmen; Valenzuela, Patricia; Montecinos, Luisa; Martinez, Constanza; Godoy, Paula; Abarca, Katia
    Introduction: There is not known if a viraemia post-oral polio vaccine (OPV) is detectable by modern molecular techniques. Such viraemia could affect the performance of the real time-polymerase chain reaction (PCR) for non polio enterovirus (EV) detection, technique of growing clinical use for the study of febrile infants. Objective: To determine viraemia post-first dose of OPV in healthy infants, by molecular techniques. Patients and Methods: 50 infants less than three months without previous VPO were randomized in 5 groups: a control group with prevaccination blood sample (BS), group 1 BS at day 2, group 2 BS at day 4, group 3, BS at day 6 and group 4, BS at day 8 post-vaccination. Conventional and specific PCR for poliovirus and real time PCR for non polio EV were performed in BS and in OPV samples. Results: No genetic material of poliovirus was detected in any infant, while in 9 of them (18%) non polio EV was identified. Real time PCR for EV did not amplify poliovirus from OPV samples. Discussion: Results suggest that no post VPO viraemia detectable by molecular methods exists. Considering that real time PCR for EV does not allow to identify polio virus, no false positives of the test are expected as a result of a recent VPO vaccination. We documented presence of non polio EV in blood of healthy asymptomatic infants.
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    Platelet Count in Patients with Mild Disease at Admission is Associated with Progression to Severe Hantavirus Cardiopulmonary Syndrome
    (2019) Lopez, Rene; Vial, Cecilia; Graf, Jeronimo; Calvo, Mario; Ferres, Marcela; Mertz, Gregory; Cuiza, Analia; Agueero, Begonia; Aguilera, Dante; Araya, Diego; Pailamilla, Ignacia; Paratori, Flavia; Torres-Torres, Victor; Vial, Pablo A.; Abarca, Juan; Miguel Noriega, Luis; Valdivieso, Francisca; Delgado, Iris; Martinez, Constanza; Carlos Chamorro, Juan; Hernandez, Jury; Pino, Marcelo; Vega, Ivonne; Otarola, Irisol; Ortega, Carlos; Daube, Elizabeth; Castillo, Constanza; Mardones, Jovita; Sanhueza, Ligia; Inostroza, Jaime; Donoso, Solange; Navarrete, Maritza; Araneda, Andres; Aguilera, Teresa; Osorio, Carola; Yobanolo, Veronica; Scholz, Luis; Riquelme, Raul; Riquelme, Mauricio; Munoz, Miriam
    Background: Hantavirus cardiopulmonary syndrome (HCPS) has a mortality up to 35-40% and its treatment is mainly supportive. A variable to predict progression from mild to severe disease is unavailable. This study was performed in patients with documented infection by Andes orthohantavirus, and the aim was to find a simple variable to predict progression to moderate/severe HCPS in patients with mild disease at admission. Methods: We performed a retrospective analysis of 175 patients between 2001 and 2018. Patients were categorized into mild, moderate, and severe disease according to organ failure and advanced support need at hospital admission (e.g., mechanical ventilation, vasopressors). Progression to moderate/severe disease was defined accordingly. Clinical and laboratory variables associated with progression were explored. Results: Forty patients with mild disease were identified; 14 of them progressed to moderate/severe disease. Only platelet count was different between those who progressed versus those that did not (37 (34-58) vs. 83 (64-177) K/mm(3), p < 0.001). A ROC curve analysis showed an AUC = 0.889 (0.78-1.0) p < 0.001, with a platelet count greater than 115K /mm(3) ruling out progression to moderate/severe disease. Conclusions: In patients with mild disease at presentation, platelet count could help to define priority of evacuation to tertiary care centers.
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    Preparation and bioactive properties of novel bone-repair bionanocomposites based on hydroxyapatite and bioactive glass nanoparticles
    (WILEY, 2012) Valenzuela, Francisco; Covarrubias, Cristian; Martinez, Constanza; Smith, Patricio; Diaz Dosque, Mario; Yazdani Pedram, Mehrdad
    Bionanocomposites based on ceramic nanoparticles and a biodegradable porous matrix represent a promising strategy for bone repair applications. The preparation and bioactive properties of bionanocomposites based on hydroxyapatite (nHA) and bioactive glass (nBG) nanoparticles were presented. nHA and nBG were synthesized with nanometric particle size using solgel/precipitation methods. Composite scaffolds were prepared by incorporating nHA and nBG into a porous alginate (ALG) matrix at different particle loads. The ability of the bionanocomposites to induce the crystallization of the apatite phase from simulated body fluid (SBF) was systematically evaluated using X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray analysis, and Fourier transform infrared spectroscopy. Both nHA/ALG and nBG/ALG composites were shown to notably accelerate the process of crystallization and growth of the apatite phase on the scaffold surfaces. For short immersion times in SBF, nBG (25%)-based nanocomposites induced a higher degree of apatite crystallization than nHA (25%)-based nanocomposites, probably due to the more reactive nature of the BG particles. Through a reinforcement effect, the nanoparticles also improve the mechanical properties and stability in SBF of the polymer scaffold matrix. In addition, in vitro biocompatibility tests demonstrated that osteoblast cells are viable and adhere well on the surface of the bionanocomposites. These results indicate that nHA- and nBG-based bionanocomposites present potential properties for bone repair applications, particularly oriented to accelerate the bone mineralization process. (c) 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 100B: 16721682, 2012.
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    Tooth loss and depression in Chilean participants of the National Health Survey 2016-2017: Oral and social functions mediation analysis
    (2024) Ortuno, Duniel; Martinez, Constanza; Caneo, Constanza; Paredes, Fabio; Soto, Mario; Gonzalez, Maria Ines; Vargas, Juan Pablo; Koller, Garrit
    Background: Previous studies have indicated the association between poor oral health and depression in adults. This study evaluated oral and social functions contribution to the association between tooth loss and depressive symptoms in Chilean individuals. Methods: We used data from the Chilean National Health Survey. The number of remaining teeth (<= 19 versus >= 20 teeth) and anterior tooth losses were the exposure variables. Outcome was depression, measured through a self-report question and with the Composite International Diagnostic Interview - Short Form (CIDI SF). Mediating variables were determined by five questions, including problems regarding "speaking", "pain and suffering", "eating", "daily activities", and "social relationships". We performed logistic regression models adjusted by multiple confounders variables. Finally, we calculated indirect, direct effect, total effect, and the proportion mediated (PM). Results: We included 5383 participants. The self-reported depression and suspected depression prevalence were 22,1 % and 14,0 % respectively. The total effect of fewer remaining teeth (<= 19) on self-reported depression was 1.21 (95 % CI 1.02-1.44), and 1.09 (95 % CI 0.90-1.33) for suspected depression. All five variables of oral and social functions significantly mediated the association between tooth loss and depression. Feeling uncomfortable when speaking or eating discomfort were the most significant mediators. Limitations: The mediation analysis should be interpreted with caution due to the cross-sectional design. Conclusions: Deterioration of oral and social functions was a significant mediator in the association between tooth loss and depression, in particular feeling uncomfortable when speaking or eating. This mechanism should be considered in interventions to improve mental health.