Browsing by Author "Gejman, Roger"

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    Abnormal distribution of inositol 1,4,5-trisphosphate receptors in human muscle can be related to altered calcium signals and gene expression in Duchenne dystrophy-derived cells
    (FEDERATION AMER SOC EXP BIOL, 2010) Cardenas, Cesar; Juretic, Nevenka; Bevilacqua, Jorge A.; Garcia, Isaac E.; Figueroa, Reinaldo; Hartley, Ricardo; Taratuto, Ana L.; Gejman, Roger; Riveros, Nora; Molgo, Jordi; Jaimovich, Enrique
    Inositol 1,4,5-trisphosphate (IP3) receptors (IP(3)Rs) drive calcium signals involved in skeletal muscle excitation-transcription coupling and plasticity; IP3R subtype distribution and downstream events evoked by their activation have not been studied in human muscle nor has their possible alteration in Duchenne muscular dystrophy (DMD). We studied the expression and localization of IP3R subtypes in normal and DMD human muscle and in normal (RCMH) and dystrophic (RCDMD) human muscle cell lines. In normal muscle, both type 1 IP(3)Rs (IP(3)R1) and type 2 IP(3)Rs (IP(3)R2) show a higher expression in type II fibers, whereas type 3 IP(3)Rs (IP(3)R3) show uniform distribution. In DMD biopsies, all fibers display a homogeneous IP(3)R2 label, whereas 24 +/- 7% of type II fibers have lost the IP(3)R1 label. RCDMD cells show 5-fold overexpression of IP(3)R2 and down-regulation of IP(3)R3 compared with RCMH cells. A tetanic stimulus induces IP3-dependent slow Ca2+ transients significantly larger and faster in RCDMD cells than in RCMH cells as well as significant ERK1/2 phosphorylation in normal but not in dystrophic cells. Excitation-driven gene expression was different among cell lines; 44 common genes were repressed in RCMH cells and expressed in RCDMD cells or vice versa. IP3-dependent Ca2+ release may play a significant role in DMD pathophysiology.-Cardenas, C., Juretic, N., Bevilacqua, J. A., Garcia, I. E., Figueroa, R., Hartley, R., Taratuto, A. L., Gejman, R., Riveros, N., Molgo, J., Jaimovich, E. Abnormal distribution of inositol 1,4,5-trisphosphate receptors in human muscle can be related to altered calcium signals and gene expression in Duchenne dystrophy-derived cells. FASEB J. 24, 3210-3221 (2010). www.fasebj.org
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    Complete response to immunotherapy plus chemotherapy after an unusual clinical response to afatinib and stereotactic radiosurgery in a patient with metastatic EGFR-mutant non–small-cell lung cancer
    (2020) Pizarro, Gonzalo; Pinto, Mauricio P.; Muñoz-Medel, Matías; Cordova-Delgado, Miguel; Bravo, M. Loreto; Nervi, Bruno; Sánchez, César; Ibañez, Carolina; Peña, José; Walbaum, Benjamín; Madrid, Jorge; Briones, Juan; Koch, Erica; Valbuena, Jose; Gonzalez, Sergio; Gejman, Roger; Acevedo, Francisco; Mondaca, Sebastian; Garrido, Marcelo; Vines, Eugenio; Galindo, Hector
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    Dysferlinopathy in Chile: Evidence of Two Novel Mutations in the First Reported Cases
    (MARY ANN LIEBERT, INC, 2009) Bevilacqua, Jorge A.; Krahn, Martin; Pedraza, Luis; Gejman, Roger; Gonzalez, Sergio; Levy, Nicolas
    We describe two Chilean patients with dysferlinopathy, a 32-year-old man with Miyoshi's distal myopathy and a 29-year-old woman with a proximodistal phenotype. Absence of dysferlin in frozen muscle biopsy allowed diagnostic confirmation. In these two patients, two mutations not previously identified in other populations were found: a homozygous c.1948delC (p. Leu650TyrfsX6) was found in the male patient; the heterozygous mutation c.1276G>A (p.Gly426Arg) was found in the female patient in association with the previously reported c.2858dupT (p.Phe954ValfsX2). To our knowledge, this is the first time that mutations in DYSF are identified in native Chileans. Our findings suggest the possibility that mutations in the DYSF gene were present in the Native American population before colonization.
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    Virilization caused by an ovarian tumor. Report of one case
    (SOC MEDICA SANTIAGO, 2011) Salman M, Patricio; Cuello F, Mauricio; Kolbach, Marianne; Gejman, Roger; Arteaga U, Eugenio
    We report a 76-year-old woman with a virilization syndrome characterized by progressive androgenic alopecia, clitoris enlargement and hirsutism predominating in the face. Plasma testosterone was 711 ng/dl. Magnetic resonance imaging showed slightly enlarged ovaries with a cyst in the left. A bilateral oophorectomy was performed, demonstrating the presence of a Leydig cell hilar tumor in the right ovary. The patient had a good postoperative evolution with reduction of androgen levels and reversion of alopecia. (Rev Med Chile 2011; 139: 1066-1070).