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E Arteaga

Publications and source records attributed to E Arteaga.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Infection by Staphylococcus lugdunensis: clinico-microbiologic characterization of 25 cases].

INTRODUCTION: S. lugdunensis is a recently described staphylococcal species with morphologic characteristic similar to those of S. aureus. It has been associated to a variety of clinical infections. In this paper we present the clinical and microbiological features of S. lugdunensis isolates from 25 patients. MATERIALS AND METHODS: We have studied the S. lugdunensis isolates obtained from clinical specimens in our laboratory over a three-year period, 1994-96. For all isolates we determined the presence of clumping factor, Dnase, free coagulase in tube and ornithine decarboxylase (ODC). Full identification was performed with API ID32-Staph strips (bioMérieux) and antimicrobial susceptibility with commercial broth microdilution MIC panels (PASCO System, Difco). RESULTS: We obtained 38 S. lugdunensis isolates from 25 patients. The clinical specimens were: breast exudate/pus (8), blood (5), surgical wound (2), urine (2), nasal exudate (2), peritoneal fluid (1), pleural fluid (1), venous catheter (1), Tenckoff catheter (1), bartholin pus (1), ulcer (1). The isolates were considered clinically significant in 20 patients, whereas those of the remaining 5 patients were considered mere colonizers. All isolates were clumping factor (+), ODC (+), Dnase (-) and free coagulase (-). 16/23 (69.5%) were susceptible to penicillin and only one isolate was methicillin-resistant. CONCLUSIONS: We have isolated S. lugdunensis from a great variety of clinical specimens (blood, sterile body fluids, urine, skin, abscesses and nasal mucosa). It is specially remarkable the association with non-puerperal mastitis. The presence of clumping factor in all isolates can easily lead to misidentification as S. aureus. The ODC test appears as a good screening method for detecting S. lugdunensis. S. lugdunensis shows a good susceptibility to betalactamic an other antimicrobial agents.

Adult↗
PubMed1999

[Cushing syndrome by ectopic ACTH secretion: analysis of the physiopathologic mechanism of hypokalemia. Report of two cases].

We report a 42 years old male and a 66 years old female with a Cushing syndrome caused by ectopic ACTH secretion secondary to a carcinoid tumor. These patients had both severe hypokalemia, resistant to medical treatment and that subsided with bilateral adrenalectomy and supplementation with dexametasone. Cushing syndrome caused by ectopic ACTH secretion is characterized by a severe and rapidly evolving hypercortisolism. Hypokalemia is present in 90% of cases and is probably caused by a defect in 11 beta hydroxysteroid dehydrogenase, that limits the binding of cortisol to aldosterone receptor, metabolizing it to cortisone. Therefore, this alteration will increase the mineralocorticoid action of cortisol.

ACTH Syndrome, Ectopic↗
PubMed1999

[Detection of thyroglobulin autoantibodies and potential interference with serum thyroglobulin measurement].

BACKGROUND: Thyroglobulin measurement is useful for the follow up of patients subjected to total thyroidectomy for differentiated thyroid carcinoma. Thyroglobulin autoantibodies may interfere with its determination. AIM: To measure thyroglobulin autoantibodies and their interference with thyroglobulin determination. MATERIAL AND METHODS: The presence of thyroglobulin autoantibodies was investigated in 801 serum samples sent to the laboratory for measurement of thyroglobulin levels. A serum was considered positive for these autoantibodies when radioactivity corresponding to 125I-thyroglobulin bound to thyroglobulin autoantibodies, precipitated with human gamma globulin, exceeded in 1.4 times that of a negative sera pool. In positive sera, thyroglobulin autoantibody concentration was measured and its interference with thyroglobulin radioimmunoassay was assessed through a recuperation test using exogenous thyroglobulin. RESULTS: Thyroglobulin autoantibodies were detected in 149 sera (18.6%). Of these, 65 had a recuperation that fluctuated between 1 and 80%. Thyroglobulin autoantibody concentration was negatively correlated with recuperation percentages (r = -0.64; p < 0.001) but not with thyroglobulin concentrations (r = 0.08). Thyroglobulin was higher in positive sera with a recuperation over 80% than in sera with a recuperation of less than 80% (12.7 +/- 1.7 and 5.9 +/- 0.6 ng/ml, respectively; p < 0.001). CONCLUSIONS: Thyroglobulin autoantibodies interfere with thyroglobulin measurement by radioimmunoassay, sequestering variable amounts of thyroglobulin. The presence of these autoantibodies must be investigated prior to thyroglobulin determination.

Autoantibodies↗
PubMed1998

[Value of pericardial biopsy in the etiologic diagnosis of pericardial diseases].

PURPOSE: To determine the value of pericardial biopsy as a complementary exam in the etiology of pericardial effusion. METHODS: We analyzed retrospectively (from 1990 to 1997) 38 patients with pericardial effusion. The age ranged between 3 months and 79 years (mean 41.15 +/- 21.78 years). Pericardial biopsy was performed in all cases through a subxiphoid incision. RESULTS: In 4 patients (10.5%) the biopsy was able to define etiology, 2 had tuberculosis and 2 neoplasias (1 undetermined adenocarcinoma, 1 mesotelioma). In 34 patients the biopsy showed non-specific chronic pericarditis. CONCLUSION: Pericardial biopsy was not an effective method to determine the etiological diagnosis in pericardial effusion patients. We believe that we have to individualize the indication of pericardial biopsy especially if tuberculosis or neoplasia are suspected.

Adolescent↗
PubMed1998

[Cardiovascular diseases observed during follow-up of a group of patients with undetermined form of Chagas' disease].

PURPOSE: The aim of this study was to evaluate the cardiovascular outcome in patients with the undetermined form of Chagas' disease and whether or not it is related to the infectious disease in the long-term. METHODS: One hundred and sixty patients were prospectively followed-up at three month intervals for up to 177 months. RESULTS: Twenty and three (14.4%) patients developed hypertension complicated by ischemic stroke in two (1.2%) and symptomatic heart failure in one (0.6%). Cardiac arrhythmias occurred in four (2.4%) patients corresponding to isolated ventricular ectopic beats in two (1.2%), isolated supraventricular ectopic beats in one (0.6%) and an isolated episode of acute atrial fibrillation in another (0.6%). Two (1.2%) patients developed symptoms of coronary artery disease, one of them had one episode of acute chest pain diagnosed as myocardial infarction and the other had chronic chest pain diagnosed as angina. CONCLUSION: Hypertension is the most common cardiovascular disease occurring in the long-term follow-up of patients with the undetermined form of Chagas' disease. Cardiac rhythm disturbances and coronary artery disease were not more frequent than those generally found in a healthy population. These data confirm a favorable long-term prognosis in patients with the undetermined form of Chagas' disease.

Adolescent↗
PubMed1998

[Idiopathic chylopericardium].

We describe a case of a patient with idiopathic pericardial effusion that during investigation proved to be a chylopericardium. Lymphangiography showed the chylopericardium to be due to partial aplasia of the thoracic duct. A brief review the etiology, clinical feature, diagnostic procedures and therapeutic possibilities of chylopericardium is presented.

Adult↗
PubMed1998

Pharmacokinetic comparison between Conpremin (Premarin) and a generic preparation of conjugated estrogens.

OBJECTIVES: To determine the relative bioavailability of the estrogenic components of a generic brand of conjugated estrogens marketed in Chile in comparison to that of Conpremin (Premarin in the United States). METHODS: A randomized cross-over study was conducted on 16 healthy postmenopausal women receiving single oral doses of either two Conpremin 0.625-mg tablets or two 0.625-mg tablets of the generic brand, with a 14-day wash-out interval between doses. A gas chromatography tandem mass spectrometry assay was used to determine estrogen components. RESULTS: The peak plasma concentrations of unconjugated and total estrone and equilin, unconjugated 17 beta-dihydroequilin and 17 beta-estradiol were higher and occurred earlier with the generic conjugated estrogens than with Conpremin. The 90% confidence limits for both variables lay outside the accepted bioequivalence limits of 80-125%. Additionally, no measurable plasma concentration of unconjugated delta 8,9-dehydroestrone or 17 beta-delta 8,9-dehydroestradiol was seen after administration of the generic conjugated estrogens. CONCLUSIONS: These pharmacokinetic results indicate that the generic tablets do not have the modified-release characteristics of Conpremin tablets. In addition, the absence of delta 8,9-dehydroestrone and 17 beta-delta 8,9-dehydroestradiol in the plasma indicates that the generic form is not compositionally equivalent to Conpremin.

Adult↗
PubMed1998

In vitro effect of estradiol, progesterone, testosterone, and of combined estradiol/progestins on low density lipoprotein (LDL) oxidation in postmenopausal women.

OBJECTIVE: One of the mechanisms currently proposed to explain the cardioprotective effect of hormone replacement therapy (HRT) is the antioxidative property of estrogens. Considering that HRT involves the administration of an estrogen, usually combined with a progestin and sometimes with an androgen, we investigated the following in vitro: (1) the effect of estradiol, progesterone, and testosterone on the oxidation of low density lipoprotein; (2) the possible pro-oxidative effect of progesterone and testosterone on native low density lipoprotein; and (3) the possible modification of the antioxidant effect of estradiol on low density lipoprotein induced by progestins. DESIGN: Low density lipoprotein was isolated from blood samples obtained from 20 untreated postmenopausal women and divided in multiple aliquots, each containing 0.5 mg LDL protein. In Protocol 1 (n = 10) different doses of estradiol, progesterone, and testosterone ranging from 0 to 26 micrograms/ml were tested inducing oxidation with 15 microM copper sulfate. In Protocol 2 (n = 6) we studied the rate of oxidation of low density lipoprotein incubated with progesterone or testosterone without any oxidative induction. In Protocol 3 (n = 10) we studied the concomitant effect of 15 microM estradiol with four separate progestins (progesterone, medroxyprogesterone acetate, norethindrone, and norgestrel) in different doses (0, 5, 15, and 50 microM). After incubation for 4 h at 37 degrees C, malonaldehyde was measured as a marker of low density lipoprotein oxidation. The results were expressed in mean +/- SD. RESULTS: Protocol 1: Estradiol induced a dose-dependent decrease in malonaldehyde generation, from a baseline of 61.8 +/- 30.2 nmol/mg protein to 11.6 +/- 7.1 nmol/mg protein at the highest dose of estradiol tested (p < 0.0001). Progesterone or testosterone did not modify malonaldehyde generation. Protocol 2: Progesterone and testosterone did not show pro-oxidative action. Protocol 3: Estradiol 15 microM alone induced a 35% decrease in malonaldehyde generation, from a baseline of 75.4 +/- 25.4 to 49.3 +/- 18.8 nmol/mg protein (p < 0.0001). Norgestrel and norethindrone did not modify the antioxidant effect of estradiol (p > 0.05). Progesterone and medroxyprogesterone acetate induced a further reduction of malonaldehyde concentration to 37.2 +/- 20.8 and 38.6 +/- 18.2 nmol/mg protein, only at the highest dose tested (p < 0.02 and p < 0.01, respectively). CONCLUSIONS: Our results demonstrate that, in contrast with the potent antioxidant effect of estradiol, progesterone and testosterone did not show any pro- or antioxidant effect on low density lipoprotein in vitro. Furthermore, progestins did not counteract the antioxidant effect of estradiol in vitro.

Copper Sulfate↗
PubMed1998

[Comparison of the antioxidant effect of estriol and estradiol on low density lipoproteins in post-menopausal women].

BACKGROUND: Estradiol (E2) has a potent antioxidant effect on low density lipoproteins (LDL) in vitro and in vivo, which could be important in explaining the cardioprotective effect of hormone replacement therapy (HRT) in post menopausal women. Estriol (E3), on the other hand, is a weak estrogen with low metabolic effects on different tissues, and at present no cardioprotective effect has been attributed to this steroid. AIM: To study the antioxidant effect of E3 on LDL and to compare it with the potent antioxidant action exhibited by E2. SUBJECTS AND METHODS: After LDL was isolated by ultra centrifugation from plasma of 12 healthy untreated post menopausal women, it was divided into aliquots containing 0.5 mg of LDL protein. Estriol and E2 in doses of 0, 1, 5, 15 and 50 microM were incubated with different aliquots of LDL. CuSO4 15 microM was added to each aliquot to induce an oxidative stress. The aliquots were then incubated during 4 hours at 37 degrees C. Malonaldehyde (MDA) was measured as a marker of LDL oxidation, and expressed as nM/mg protein. RESULTS: (mean +/- SD): Estriol induced a dose-dependent decrease in MDA concentration (baseline 62.8 +/- 21.7; 1 microM: 61.5 +/- 23.0; 5 microM: 52.9 +/- 20.3; 15 microM 43.5 +/- 20.1 and 50 microM: 31.0 +/- 17.6 nM/mg protein; F = 92.4; p < 0.0001), reaching a mean decrease of 50.7% at the highest dose tested. Estradiol has a similar dose-dependent decrease in MDA concentration (F = 60.2; p < 0.0001), revealing a more potent effect than E3 (p < 0.05), with a mean decrease of 67.4% at the highest dose tested. CONCLUSIONS: Our results demonstrate that estriol shows an important antioxidant action of LDL in vitro, although its effect is less potent than estradiol. These results raise the possibility that estriol could have a cardioprotective effect in post menopausal women, possibility that has not been yet demonstrated.

Antioxidants↗
PubMed1997

[Maximal functional capacity and diastolic function in patients with cardiomyopathy due to Chagas' disease without congestive heart failure].

PURPOSE: To identify early cardiac dysfunctions in asymptomatic patients with Chagas' cardiomyopathy. METHODS: We studied 38 male individuals: control group consisting of 20 sedentary normal individuals and Chagas' group, of 18 asymptomatic patients with Chagas' disease, with suggestive electrocardiographic alterations and normal fractional shortening (FS) on echocardiogram. Both groups were submitted to evaluation of the maximal functional capacity, with measurements of maximal O2 consumption (VO2max), O2-pulse rate (PO2max), maximal ventilation (VEmax), maximal heart rate (HRmax), and anaerobic threshold of the VO2max (VO2-AT). Left ventricular diastolic function was evaluated by conventional echocardiography (E wave, A wave and E/A ratio). RESULTS: No significant differences occurred between the two groups with regard to FS (p = 0.212) and age means (p = 0.060). The 2 groups were significantly different (p < 0.001) regarding the parameters VO2max, PO2max, VEmax, HRmax and VO2-AT, E wave and E/A ratio. There was no difference (p = 0.520) in A wave. CONCLUSION: Impaired ventricular function may account for the above mentioned differences, a consequence of both systolic and diastolic dysfunctions.

Adult↗
PubMed1997

[Adrenal macrotumor diagnosed by computed tomography. Clinical experience of 33 cases].

BACKGROUND: Adrenal tumors of more than 6 cm diameter, also called macrotumors, cause diagnostic and therapeutic problems. AIM: To perform an analysis of adrenal macrotumors diagnosed by CAT scan between 1984 and 1995. PATIENTS AND METHODS: Thirty three patients aged 9 to 86 years old, 15 female, with an adrenal macrotumor diagnosed by CAT scan, were analyzed. RESULTS: Thirty percent of tumors were functioning (70% secreted cathecolamines and 30% cortisol). Eighty two percent had an adrenal localization and 18% were para-adrenal. Thirty four percent were malignant. These tumors were mostly non functioning, 70% occurred in men and 67% were metastatic. CONCLUSIONS: Most adrenal macrotumors in this series were non functioning and 36% were malignant.

Adolescent↗
PubMed1997

[Radiological findings in endomyocardial fibrosis].

PURPOSE: To determine through conventional radiology the type of ventricular involvement in endomyocardial fibrosis (EMF). METHODS: We analyzed 56 cases with EMF confirmed by angiocardiography and 9 by postmortem study, aged between 16 and 56 years (mean 32); there were 42 females. Only one radiologist analyzed X-rays without any knowledge of the cineangiography findings. RESULTS: The right side of the heart was primarily involved in 9 patients and the cardiac silhouette was characteristically globular and had oligemic pulmonary fields (66.66%). The cardiothoracic ratio was 0.62 +/- 0.11. Out of 9 patients, 8 were female. The left side of the heart was established as being primarily involved in 11 cases and simulated rheumatic mitral disease. The cardiothoracic ratio was 0.51 +/- 0.09 and there were increased pulmonary fields in 63.6%. The biventricular disease occurred in 36 cases. There were radiologic findings of right and left side. The cardiothoracic ratio was 0.63 +/- 0.06 and there was oligemic pulmonary fields in 38.8%, increased pulmonary fields in 33.3% and was normal in 27.7%. There were 4:1 females. CONCLUSION: The radiological study is fundamental in the initial diagnosis of EMF. The type of involvement could be done in 66.07% of all cases by chest X-ray.

Adolescent↗
PubMed1997

[Standardization of immunohistochemical techniques for detecting dengue virus antigens in paraffin-embedded tissues].

The immunohistochemical techniques may be very useful for the detection of antigens of the dengue virus in infected tissues. The results obtained with the use of 2 IHC methods: one direct and another indirect amplified with a biotin universal antibody and a streptavidin peroxidase system (LSAB) (the peroxidase enzyme is used in both) are shown in this paper. These methods were applied on paraffin-embedded tissues from mice that were inoculated with the dengue virus intracerebrally. Our objective is to have a technique at the laboratory allowing to identify these antigens in the tissues in order to apply them on the diagnosis and on the studies connected with the obtention of immunogens.

3,3'-Diaminobenzidine↗
PubMed1996

[Normal maximal functional capacity in patients with congestive heart failure due to Chagas' cardiomyopathy].

PURPOSE: To compare patients with heart failure due to Chagas' cardiomyopathy and maximal oxygen consumption greater than 20mL/kg-1/min-1 to normal individuals. METHODS: We studied 104 male patients with heart failure due to Chagas' cardiomyopathy, functional classe II-IV, age 18 to 65 years (40.3 +/- 9.0), and 23 normal sedentary male individuals (GI) age 17 to 51 years (35 +/- 8.7). Maximal oxygen consumption (VO2max) was obtained using a Beckman metabolic measurement cart, and left ventricular ejection fraction (EF) by conventional transthoracic echocardiography. Comparisons between means were made with t-test. RESULTS: Thirty seven patients (35.6%) presented VO2max above 20mL/kg-1/min-1 (G2), with values ranging from 20.5 to 30 (24.5 +/- 2.9) and EF between 19 and 63% (42 +/- 11.7). GI had VO2max between 21 and 42mL/kg-1/min-1 (33.3 +/- 5.6) and EF between 70 and 82% (75.1 +/- 3.2). Ages were not significantly different for the two groups (p = 0.1136). VO2max and EF were lower in G2, and this was statistically significant (p < 0.0001). CONCLUSION: These results indicate that patients with congestive heart failure due to Chagas disease may show values of VO2max, greater than 20mL/kg-1/min-1 which does not mean that they have normal maximal functional capacity.

Adolescent↗
PubMed1996

[Hip fracture: a case-control study in the metropolitan region I].

BACKGROUND: Hip fracture is a preventable cause of disability among elderly people AIM: To study factors associated to hip fractures in Chile. PATIENTS AND METHODS: Patients admitted to seven public hospitals in Chile, with hip fracture not due to major accidents, were considered as cases. To each, at least one age and sex matched hospitalized control, without or neoplastic diseases, was assigned. All patients were subjected to an inquiry, using an instrument devised by the WHO. RESULTS: Two hundred sixty eight cases and 501 controls were studied. Cases and controls has similar educational and labor histories. The right hip was fractures in 47% of cases and the left in the rest. Compared with controls, cases had a higher body mass index, loss of height during life, rate of hysterectomy, incidence of smoking and a lower consumption of diary products. Cases had higher risk of falls inside their homes and controls outside. CONCLUSIONS: The obtained information may contribute to the development of preventive measures and reduce the public health impact of hip fracture.

Aged↗
PubMed1996

[Comparative yield of fine needle biopsy and cytology of solid thyroid nodules].

BACKGROUND: The correct management of thyroid nodules requires an accurate histological diagnosis to discard carcinoma. AIM: To assess the diagnostic value of fine needle aspiration biopsy of thyroid nodules as compared to cytology of the same sample and surgical biopsy. PATIENTS AND METHODS: One hundred and forty three thyroid nodules were punctured with a 21 G needle under continuous aspiration obtaining a sample for cytological and histological diagnosis. Fifty patients were subjected to a thyroidectomy. RESULTS: The age of studied patients ranged from 12 to 78 years old and 94% were female. Mean nodule diameter was 2.7 +/- 1.4 cm. Two percent of procedures were complicated with local hematomas, that subsided spontaneously. A diagnosis of cancer was reached in 16% of all patients and 46% of operated patients. Cytology had a 50% sensitivity, 87.5% specificity, a 89.4% positive predictive value and a 87.5% negative predictive value. The figures for fine needle aspiration biopsy were 82.6, 100, 100 and 87% respectively. CONCLUSIONS: Fine needle aspiration biopsy has a better diagnostic accuracy than cytology and is a simple and safe procedure.

Adolescent↗
PubMed1996

[Dissolution velocity of different calcium preparations used in the clinical field].

BACKGROUND: Prescription of calcium supplements is a frequent practice, considering that diet is insufficient to cover daily requirements of this mineral. AIM: To study the dissolution velocity in an acid solution, of different commercial calcium supplements. MATERIAL AND METHODS: Hydrochloric acid was added to distilled water in increasing amounts to obtain a final pH of 6.9, 3.0, 2.5, 2.0 and 1.5. Eighteen commercial calcium preparations were incubated in these solutions for 60 min and dissolution velocity was measured as the percentage of elemental calcium found in solution after this incubation period. RESULTS: Calcium carbonate preparations had a pH dependent dissolution velocity, ranging from 0.67 +/- 0.8% at pH 6.9 to 77.15 +/- 17.5% at pH 1.5. Using the solution with pH 1.5, the dissolution velocity of different preparations varied widely from 56 to 100%. Calcium acetate, followed by calcium citrate and dicalcic phosphate were the salts in tablets with better dissolution velocities. Among powders and effervescent preparations, those containing calcium lactogluconate and citrate had the better dissolution velocities (95 to 115%), that were independent of the solution's pH. A studied preparation with integral bone had a very low dissolution velocity, not surpassing 33 mg of calcium per tablet. CONCLUSIONS: The dissolution velocity of different calcium carbonate preparations varies greatly and, in conditions of achlorhydria, it is negligible. Calcium lactogluconate and citrate dissolution velocities are independent of the solution's pH.

Calcium↗