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Biomedical subjects

S Avila

Publications and source records attributed to S Avila.

At least 19 recordsLinked to original sources
PubMed2005

The transcription factor PLA-1/SKN-1A is expressed in human placenta and regulates the placental lactogen-3 gene expression.

Here we report the selective expression of two POU transcription factor genes, PLA-1 and OCT-1, in human placenta and choriocarcinoma cell lines JAR, JEG-3 and BeWo. Pla-1 protein binds to a POU-consensus DNA sequence in the human placental lactogen-3 (PL-3) promoter and it is capable of trans-activating its transcription up to 18-fold. Other tissue-specific or ubiquitous POU transcription factors such as Pit-1/GHF-1 or Oct-1 showed none or low levels of trans-activation of the PL-3 promoter. In addition, we identified an unique and highly charged region in the N-terminal portion of Pla-1 protein required for full trans-activation of the PL-3 promoter.

Binding Sites↗
PubMed2005

Application of solid phase microextraction to the determination of strychnine in blood.

A simple and rapid method based on solid phase microextraction (SPME) via direct immersion followed by gas chromatography coupled with electron impact ionization/mass spectrometry (GC/EI-MS) was developed for the determination of strychnine in blood. Papaverine was used as internal standard (I.S.). Two types of fibre coating were tested, 100 microm polydimethylsiloxane and 65 microm Carbowax/Divinylbenzene, the latter giving higher recoveries of the compound. The main factors affecting the SPME process, such as sample dilution (1:10), adsorption and desorption times (20 and 10 min, respectively), carry-over effect (not observed), pH and salt addition (no modifications on pH or salt concentration) were optimized. The procedure was validated in terms of linearity (r(2)=0.9992 for concentrations ranging from 0.10 to 5.00 microg/mL), intra and interday precision (0.93 and 4.62%, respectively at 0.50 microg/mL; 3.33 and 8.06%, respectively at 2.50 microg/mL), sensitivity (6.83 and 8.91 ng/mL for LOD and LOQ, respectively) and extraction recovery (0.54 and 0.39% at 0.50 and 2.50 microg/mL, respectively). The developed procedure was found suitable for forensic investigations and was considered a good alternative to the liquid-liquid extraction methods normally used for the determination of this compound in biological media.

Adsorption↗
PubMed2004

Results of 60 consecutive hepatectomies for pediatric living donor liver transplantation.

Several technical improvements have been made to increase donor pool for pediatric liver transplantation, including reduced-size grafts, split-liver, and recently living donors. The objective of the present study is to report our single-center experience with 60 hepatectomies for living donor liver transplantation in pediatric recipients between June 2000 and December 2002. Donor workup consisted of a complete history and physical examination followed by laboratory test and liver function tests. Graft size was estimated using computed tomography scan or abdominal ultrasound. Liver biopsy was performed in all donors. Arteriogram was performed to evaluate hepatic arterial anatomy. All donors survived the procedure. Only seven patients experienced complications (10.2%), most of which were short term. We conclude that liver living donation for pediatric population is a safe procedure.

Adolescent↗
PubMed2003

A fatal forensic intoxication with fenarimol: analysis by HPLC/DAD/MSD.

Fenarimol (Rubigan) is a pyrimidine ergosterol biosynthesis inhibitor used as a systemic fungicide. The authors present a fatal fenarimol intoxication case analysed in the Forensic Toxicology Service of the National Institute of Legal Medicine. The results were used to compare two different HPLC techniques, regarding selectivity and sensitivity: an HPLC system with a diode array detector (DAD) and an HPLC system with a DAD and a mass spectrometry detector (MSD) with an electrospray interface. All biological samples were submitted to a solid-phase extraction procedure. The detection and quantification limits of fenarimol, linearity, precision and accuracy were evaluated. The fenarimol concentration levels determined were of 89.0 mg/ml in gastric contents, 1.9 mg/g in liver and 0.4 mg/g in kidney. Blood was not available at autopsy. No published data related to fenarimol self-poisoning were found, so it was not possible to interpret the results obtained by comparison with toxic/lethal levels.

Chromatography, High Pressure Liquid↗
PubMed2002

Implications of estradiol and progesterone in pulmonary vasodilatation in cirrhotic patients.

The derangement of sex hormone serum levels in cirrhotic patients is well-delineated, and increased levels of progesterone and estradiol have been associated to hyperventilation in cirrhotic patients. These hormones have a well-known role in the regulation of vascular tone. The aim of this study was to evaluate whether sex hormone levels contribute to pulmonary vasodilatation (PV) and gas exchange abnormalities in cirrhosis. Contrast transesophageal echocardiography, arterial blood gases, parameters of liver function, pulmonary function test, estradiol and progesterone levels were determined in 45 male cirrhotic patients. Nineteen of 45 patients (42.2%) presented PV. Hyperventilation (pressure arterial of CO2< or =35 mmHg) was correlated to progesterone levels (p<0.05) and pressure arterial of CO2 was high in patients with PV (p<0.005) and Child class B and C (p<0.01). Hypoxemia (pressure arterial of O2<80 mmHg) had inverse correlation with progesterone (p<0.05) and estradiol (p<0.05) levels and pressure arterial of O2 was low in patients with Child class B and C (p<0.05). PV was present in patients with high estradiol levels (p<0.05), high progesterone levels (p<0.005) and Pugh class B and C (p<0.05). Logistic regression analysis identified progesterone as the sole independent factor associated to PV (p<0.0005). Multivariate linear regression showed that PV was the sole independent factor related to both pressure arterial of CO2 (p<0.05) and pressure arterial of O2 (p<0.01) levels. PV was independently associated to gas exchange abnormalities in cirrhosis. Progesterone and estradiol were related with PV in cirrhotic patients.

Carbon Dioxide↗
PubMed2002

Inter-test reliability of the anti-RESA indices based on ELISA tests using eluates from whole blood spots dried on filter paper.

The ring-infected erythrocyte surface antigen (RESA), is one of the falciparum malaria vaccine candidates rarely studied in Brazil. Fieldwork logistics to conduct serology studies is simplified when eluates from whole blood dried on filter paper can be used. Therefore, this study aimed to assess the inter-test reliability for the anti-RESA ELISA-based indices using eluates from filter paper and from serum samples. The study population consisted of 210 individuals (Brazil) from whom matched samples were collected. Anti-RESA ELISA-based index means (+/- S.D.) were 15.29% (+/-28.13%) for filter paper and 11.79% (+/-23.67%) for serum samples. The intra-class correlation coefficient was estimated to be 82.38%, indicating high test reliability. However, there was a significant tendency for filter paper test results to have higher values than serum sample test results (P < 0.001). Explanations for this finding may be the presence of haemoglobin in the eluates from filter paper, which may interfere with ELISA testing.

Adolescent↗
PubMed2002

Strangulated volvulus of the sigmoid colon with inviable mucosal appearance in a non-surgical patient. Endoscopic devolvulation.

Colonoscopy is presently always performed before surgical management of a volvulus in the sigmoid colon. It leads to know the viability of the mucosa and, when possible, to resolve the volvulus conservatively. Besides, with endoscopic control, we can place a decompression tube proximal to the volvulated sigmoid colon, favouring a non-surgical resolution. With this conservative approach it is possible to overcome the acute period, and to restore the viability of the sigmoid wall, waiting for a definitive surgical management with less morbidity and mortality. Only with endoscopy, revolvulation does occur in 35-50% of cases. We present the clinical case of a sigmoid volvulus with compromised sigmoid wall in an 82-year-old man with several clinical problems contraindicating surgery. Endoscopic devolvulation with tube placement was adequate to resolve this sigmoid volvulus.

Aged↗
PubMed2001

Three-year assessment of methicillin-resistant Staphylococcus aureus clones in Latin America from 1996 to 1998.

Four hundred ninety-nine methicillin-resistant Staphylococcus aureus (MRSA) isolates recovered from 1996 to 1998 from 22 hospitals in five countries of Latin America-Argentina, Brazil, Chile, Uruguay and Mexico-were examined for antimicrobial susceptibility and clonal type in order to define the endemic clones in those hospitals. The hybridization of ClaI restriction digests with the mecA- and Tn554-specific DNA probes combined with pulsed-field gel electrophoresis of chromosomal SmaI digests (ClaI-mecA::ClaI-Tn554::PFGE clonal types) documented not only the predominance and persistence of the Brazilian clone (XI::B::B) in Brazil (97%) and Argentina (86%) but also its massive dissemination to Uruguay (100%). Moreover, a close relative of the Brazilian clone (XI::kappa::B) was highly represented in Chile (53%) together with a novel clone (47%) (II::E'::F) resistant to pencillin, oxacillin, ciprofloxacin, chloramphenicol, clindamycin, erythromycin, and gentamicin. A unique clonal type (I::NH::M) was detected in Mexico among pediatric isolates and was resistant to penicillin, oxacillin, and gentamicin only. This study clearly documented the very large capacity for geographic expansion and the persistence of the Brazilian clone, contributing not only to the increasing uniformity of the MRSA in South America but worldwide as well.

Anti-Bacterial Agents↗
PubMed2000

Serum prostate-specific antigen concentrations are not useful for monitoring the treatment of hirsutism with oral contraceptive pills.

Prostate-specific antigen (PSA) is produced in several female tissues, under the regulation of steroid hormones. Serum PSA levels are increased in women with hirsutism, and they correlate with serum androgen levels. Therefore, as a marker of androgen excess, measurement of serum PSA may play a role in monitoring the treatment of hirsutism with contraceptive pills. Sixteen hirsute patients were included in the study. Clinical and biochemical variables, including serum PSA (using an ultrasensitive chemiluminescent immunoassay), total testosterone, sex hormone-binding globulin, androstenedione, dehydroepiandrosterone-sulfate, estradiol, and gonadotropin concentrations were recorded at baseline and after 3 and 6 cycles of treatment with a monophasic contraceptive pill containing ethynylestradiol and desogestrel. Twenty-seven healthy women served as controls for serum PSA level and for the serum androgen profile. Serum PSA levels were higher in hirsute patients, as compared with healthy women (mean +/- SEM: 0.014 +/- 0.003 vs. 0.006 +/- 0.001 microg/L, P < 0.02). Despite a marked decrease in serum androgens (total testosterone and androstenedione, calculated free testosterone and free androgen index; and dehydroepiandrosterone-sulfate) and in the hirsutism score, and a marked increase in sex hormone-binding globulin levels, serum PSA levels did not change and remained detectable in all the hirsute patients after 3 and 6 cycles of treatment with contraceptive pills. In conclusion, the increased serum PSA levels present in hirsute patients do not change during treatment with contraceptive pills and do not parallel the amelioration in hirsutism and the decrease in serum androgen concentrations that occur during this treatment. Thus, serum PSA measurements have no apparent role in the management of hirsute patients on oral contraceptive treatment, at least with the ultrasensitive assays currently available.

Adult↗
PubMed2000

A prospective study of the prevalence of the polycystic ovary syndrome in unselected Caucasian women from Spain.

We prospectively estimated the prevalence of the polycystic ovary syndrome (PCOS), as defined by the NIH/NICHHD 1990 endocrine criteria, in a population of 154 Caucasian women of reproductive age reporting spontaneously for blood donation. Anthropometric data; the presence of hirsutism, acne, and androgenic alopecia; and the menstrual history were recorded by a single investigator. In 145 women, blood samples were also obtained for measurement of serum androgen levels. PCOS was defined by the presence of 1) oligomenorrhea, 2) clinical and/or biochemical hyperandrogenism, and 3) exclusion of hyperprolactinemia, thyroid disorders, and nonclassic 21-hydroxylase deficiency. Hirsutism was defined by a modified Ferriman-Gallwey score of 8 or more, acne was considered as a sign of hyperandrogenism when persistent after the second decade of life, and hyperandrogenemia was defined by an increase in circulating testosterone or dehydroepiandrosterone sulfate or an increase in the free androgen index above the 95th percentile of the control values derived from the nonhirsute, nonacneic women having regular menses who were not receiving hormonal therapy. PCOS was present in 10(6.5%), hirsutism was present in 11 (7.1%), and acne was present in 19 (12.3%) of the 154 women. Our results demonstrate a 6.5% prevalence of PCOS, as defined, in a minimally biased population of Caucasian women from Spain. The polycystic ovary syndrome, hirsutism, and acne are common endocrine disorders in women.

Adult↗
PubMed1998

The increased circulating prostate-specific antigen concentrations in women with hirsutism do not respond to acute changes in adrenal or ovarian function.

Serum prostate-specific antigen (PSA) is produced in several female tissues and appears to be up-regulated by androgens. We have studied serum PSA concentrations in women with different forms of hyperandrogenism, focusing on the influence of changes in ovarian and adrenal function on these concentrations. Thirty-seven hirsute women were studied in the follicular phase of the menstrual cycle. Basal and ACTH-stimulated plasma samples were obtained, and sampling was repeated 1 (gonadal stimulation) and 21 (gonadal suppression) days after receiving a single im 3.75-mg dose of triptorelin. Eleven nonhyperandrogenic women served as controls. Hirsute women had increased PSA levels compared to controls. When considering the source of the hyperandrogenism, ovarian patients (those with increased serum androgen levels that normalized during gonadal suppression) and adrenal patients (those with increased androgen levels that remained elevated during gonadal suppression) presented increased PSA values, whereas hirsute patients without hyperandrogenemia had normal PSA levels. PSA levels did not change during ovarian or adrenal stimulation or during gonadal suppression with respect to initial values. Basal PSA levels showed significant correlations with basal total testosterone (r = 0.59; P < 0.001), free androgen index (r = 0.68; P < 0.001), sex hormone-binding globulin (r = -0.58; P < 0.001), dehydroepiandrosterone sulfate (r = 0.39; P < 0.01), 17-hydroxyprogesterone (r = 0.32; P < 0.05), and age (r = -0.33; P < 0.05) when patients and controls were considered as a whole. In conclusion, basal PSA levels are increased in hirsute patients and correlate with the degree of hyperandrogenism when patients and controls are considered as a whole. The adrenal and the ovary do not appear to be the source of PSA, suggesting that hyperandrogenism induces PSA secretion in tissues other than the adrenal and the ovary.

Adolescent↗
PubMed1997

[Delayed reposition of gastrostomy tube using Savary's dilators].

The delay in substituting a gastrostomy tube after removal leads to the gastrocutaneous tract closure and to the impossibility of putting other nourishment tube without needing another complete endoscopic procedure. We have used the technique described by Tsang through the one which and using Savary's dilators, the stenosed gastrocutaneous tract after accidental removal of the tube, is dilated permitting to put in a simple way a new one. We accomplished the procedure in three patients that attended by removal of the probe and severe stenosis of the stoma. In all they and under endoscopic control we put a new tube in a way rapid and without complications.

Aged↗
PubMed1995

[Transpapillary endoscopic drainage of pancreatic pseudocyst].

Drainage of pancreatic pseudocysts can be achieved by means of endoscopy. In this paper we report a case of a pancreatic pseudocyst of ten centimeters in diameter, that was successfully managed by insertion of a nasocystic drainage through the papilla of Vater. The procedure was simple and complications were absent. Transpapillary drainage of pancreatic pseudocysts is an effective procedure.

Ampulla of Vater↗