Browsing by Author "Solar, A"

Now showing 1 - 4 of 4
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    Bile secretory function in the obese Zucker rat: evidence of cholestasis and altered canalicular transport function
    (BMJ PUBLISHING GROUP, 2004) Pizarro, M; Balasubramaniyan, N; Solis, N; Solar, A; Duarte, I; Miquel, JF; Suchy, FJ; Trauner, M; Accatino, L; Ananthanarayanan, M; Arrese, M
    Background: Obese Zucker rats (ZR) have been used as an experimental model for non-alcoholic fatty liver disease and are particularly susceptible to various types of liver injury. Bile secretory function has not been assessed in ZR.
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    Congenital lipoid adrenal hyperplasia caused by a novel splicing mutation in the gene for the steroidogenic acute regulatory protein
    (ENDOCRINE SOC, 2004) Gonzalez, AA; Reyes, ML; Carvajal, CA; Tobar, JA; Mosso, LM; Baquedano, P; Solar, A; Venegas, A; Fardella, CE
    Steroidogenic acute regulatory protein (StAR) plays a crucial role in the transport of cholesterol from the cytoplasm to the inner mitochondrial membrane, facilitating its conversion to pregnenolone by cytochrome P450scc. Its essential role in steroidogenesis was demonstrated after observing that StAR gene mutations gave rise to a potentially lethal disease named congenital lipoid adrenal hyperplasia, in which virtually no steroids are produced. We report here a 2-month-old female patient, karyotype 46XY, who presented with growth failure, convulsions, dehydration, hypoglycemia, hyponatremia, hypotension, and severe hyperpigmentation suggestive of adrenal insufficiency. Serum cortisol, 17OH-progesterone, dehydroepiandrosterone sulfate, testosterone, 17OH-pregnenolone, and aldosterone levels were undetectable in the presence of high ACTH and plasma renin activity levels. Immunohistochemical analysis of testis tissues revealed the absence of StAR protein. Molecular analysis of StAR gene demonstrated a homozygous G to T mutation within the splice donor site of exon 1 (IVS1 + 1G>T). Her parents and one brother were heterozygous for this mutation. In vitro analysis of the mutation was performed in COS cells transfected with minigenes coding regions spanning exon-intron 1 to 3 carrying the mutant and the wild-type sequences. RT-PCR analyses of the mutant gene showed an abnormal mRNA transcript of 2430 bp (normal size 433 bp). Sequence analysis of the mutant mRNA demonstrated the retention of intron 1. Immunolocalization of the StAR minigene product detected the peptide in the mitochondria of COS cells transfected with the wild-type minigene but not in those transfected with the mutant minigene. We conclude that this mutation gives rise to a truncated StAR protein, which lacks an important N-terminal region and the entire lipid transfer domain.
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    Pathological characteristics of thyroid microcarcinoma. A review of 402 biopsies
    (2005) Fardella, C; Jimenez, M; Gonzalez, H; Leon, A; Goni, I; Cruz, F; Solar, A; Torres, J; Mosso, L; Gonzalez, G; Rodriguez, JA; Campusano, C; Lopez, JM; Arteaga, E
    Background: Thyroid microcarcinoma is a tumor of 10 mm or less. that should have a low risk of mortality. However a subgroup of these carcinomas is as aggressive as bigger tumors. Aim To describe the pathological presentation of these tumors.. and compare them with larger tumors. Material and methods. All Pathological samples of thyroid carcinoma that were obtained between 1992 and 2003, were studied. In all biopsies, the pathological type, tumor size. the focal or multifocal character the presence of lymph node involvement and the presence of lymphocytic thyroiditis or thyroid hyperplasia, were recorded. Results: One hundred eighteen microcarcinomas and 284 larger tumors were studied. The mean age of patients with microcarcinoma and larger tumors was 42.7 +/- 14 and 49.3 +/- 16 years respectively (p < 0,00.1) and 83% were female. without gender differences between tumor types. klean size of microcarcinomas was 8.6 mm and 116 (98%) were papillary carcinomas. Of these. 109 (94% were well differentiated and seven (6%) were moderatly differentiated. Thirty six(31%) were multifocal and in 10 (8,6%), there was lymph node involvement. The mean size of larger tumors was 23.8 mm and 241 (85%) were papillary carcinomas. Of these, 200 (83%) were well differentiated, and 41 (17%) were moderately differentiated.Eighty five (35%) were multifocal and in 44 (18%) there was lymph node involvement. The prevalence of thyroiditis and hyperplasia was significantly higher among microcardinomas than in larger tumors (15 and 2.5%, respectively, p < 0.001, for the former; 32.4 and 1.7%, respectively, p < 0.001, for the latter. Conclusions. In this series. one third of microcarcinomas were multifocal and 10% had lymph node involvement. Therefore, aggresiveness of these tumors is higher than what is reported in the literature and they should be treated with total thyroidectomy.
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    Thyroid microcarcinoma with an aggressive evolution. Report of one case
    (2005) Mosso, L; Jimenez, M; Gonzalez, H; Solar, A; Torres, J; Fardella, C; NCD Risk Factor Collaboration (NCD-RisC)
    The treatment of papillary thyroid carcinoma of less than 10 mm diameter is a matter of controversy. The incidental finding of papillary microcarcinomas in autopsies is frequent and some authors postulate that these tumors are biologically inactive and should only be observed. We report a 21 years old woman with a papillary thyroid cancer of 6x5x5 mm and bilateral paratracheal metastases, that leas subjected to a total thyroidectomy. She received 200 mCi of radioiodine. Two years after surgery, a new nodule of 9.6 Mm diameter was detected by ultrasound, that was treated with a new dose of 200 1,170 of radioiodine. One year later a suprasternal mass of 2 cm diameter and 3 enlarged lymph nodes were detected. She was subjected to a surgical lymph node dissection of the neck and the biopsy confirmed the presence of cancer. She received a new dose of 300 mCi of radioiodine. The mother of the patient had a 7 mm thyroid nodule that was also a papillary carcinoma.