Scielo RSS <![CDATA[Revista médica de Chile]]> http://www.scielo.cl/rss.php?pid=0034-988720010008&lang=es vol. 129 num. 8 lang. es <![CDATA[SciELO Logo]]> http://www.scielo.cl/img/en/fbpelogp.gif http://www.scielo.cl <![CDATA[Identificación de mutaciones en el gen CFTR en pacientes chilenos con fibrosis quística]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001000800001&lng=es&nrm=iso&tlng=es Background: Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the CFTR gene, that codes for a chloride channel located in the apical surface of epithelial cells. The main role of this protein is the regulation of chloride transport, and secondarily, of sodium and water to the extracellular space. More than 900 gene mutations have been described, and their relative frequency in different populations depends on their ethnic origin. Aim: To report the findings of Chilean patients with cystic fibrosis, in whom the presence of 20 common mutations was analyzed. Patients and methods: Fifty seven patients with established diagnosis or suspicion of CF were studied. The simultaneous identification of 20 mutations and the normal deltaF508 allele was done using polymerase chain reactions with a commercial assay. Results: Eight mutations were found. Fifty patients fulfilled diagnostic criteria proposed by the Consensus Panel of the CF Foundation and 66% of alleles were identified in this group. ∆F508 mutation was found in 45%. We did not identify mutations in any of the remaining 7 patients. Conclusions: Our results suggest that the majority of undetected mutations are associated with atypical phenotypes or that some patients in this series could have other diseases. We recommend to include mutation analysis in the evaluation of Chilean patients with CF. It is useful to establish prognosis and genetic counselling (Rev Méd Chile 2001; 129: 841-7). <![CDATA[Hipovitaminosis D en mujeres postmenopáusicas con masa ósea baja en la Región Metropolitana]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001000800002&lng=es&nrm=iso&tlng=es Background: Low vitamin D levels are a risk factor for osteoporosis. In the Northern hemisphere, a high frequency of low vitamin D levels has been detected. The correction of this deficit is associated with a lower fracture risk. Aim: To measure serum vitamin D levels in postmenopausal women with low bone mineral density. Material and methods: 25-hydroxyvitamin D levels were measured in 40 postmenopausal women aged 50 to 74 years old, with a spine bone mineral density of less than 2 standard deviation of the values for young individuals. Serum calcium, phosphorus and calcium dietary intake were also measured. Results: Mean serum 25-hydroxyvitamin D levels were 32.2 ± 12.5 ng/ml. No correlation between vitamin D levels and other measured variables was observed. Using a cutoff value of 15 ng/ml, two women had low 25-hydroxyvitamin D levels. Conclusion: In this sample of postmenopausal women, vitamin D deficiency was infrequent (Rev Méd Chile 2001; 849-52). <![CDATA[Subtipos "no clásicos" de diabetes mellitus]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001000800003&lng=es&nrm=iso&tlng=es Background: Some adult, obese and diabetic patients, initiate their disease with a severe diabetic ketoacidosis without a precipitating factor and do not require insulin thereafter. These patients are classified as having a "non classical" diabetes mellitus. Aim: To study the clinical, immunological, genetic and metabolic features of patients with non classical diabetes mellitus. Patients and methods: Ten patients (9 men, aged 45±12 years old) with non classical diabetes mellitus were studied. Anti islet and anti glutamic acid decarboxylase antibodies (ICA and anti GAD), HLA DQ a arginine 52 and non aspartic ß57 were measured. Insulin secretion was measured by C peptide after glucagon injection and with the minimal model of Bergman. The latter model was also used to determine insulin sensitivity. Results: Three patients were immunologically classified as type 1, since they had positive ICA or antiGAD antibodies and type 1 genetics (neutral or susceptible HLA DQ a and ß). They had insulin secretion after glucagon stimulus (C peptide ranging from 2.2 to 7.5 pmol/ml), but an almost absent response to a glucose load. They were also insulin resistant (a sensitivity index ranging from 0.05 to 1.67 x 10-4 min/µU x ml). These three cases could be categorized as latent type 1. The other seven patients were ICA negative and antiGAD negative. Five had a susceptible HLA genotype for type 1 diabetes and two were neutral. All had insulin secretion after glucagon stimulation and a variable response to glucose. Six were insulin resistant (sensitivity index ranging from 0.32 to 1.29 x 10-4 min/µU x ml). One patient was insulin sensitive (sensitivity index of 3.83 x 10-4 min/µU x ml). Therefore all these patients were classified as type two diabetics with an atypical debut. Conclusions: Not all diabetics presenting with a severe diabetic ketoacidosis are type I. Among these, there are subjects with a latent type 1 diabetes or with an atypical type 2 diabetes (Rev Med Chile 2001; 129: 853-60). <![CDATA[Estudio comparativo de la angioplastia coronaria en pacientes con diabetes.: Resultados clínicos y angiográficos inmediatos y evolución clínica en el primer año]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001000800004&lng=es&nrm=iso&tlng=es Background: The success of revascularization procedures for coronary artery disease could be lower in diabetic patients. Aim: To report the results of coronary angioplasty in diabetic and non diabetic patients. Patients and methods: All angioplasty procedures performed between 1996 and 1999 were recorded. Demographic data, procedure details, hospital outcome and evolution at one year of follow up were analyzed. Results: During the study period, 358 patients were treated; of these, 79 were diabetics. Despite the greater severity of coronary lesions among diabetic patients the clinical success of the procedure was 92.4% in diabetics and 91.8% in non diabetics. Hospital mortality was 1.3% in diabetics and 0.7% in non diabetics. Major complications occurred in 3.8% of diabetics and 3.2% in non diabetics. One year survival was 95.9% for diabetics and 98% in non diabetics. There were five late cardiac deaths among non diabetics and 3 among diabetics during the year of follow up. The frequency of new revascularization procedures was 4.3% in diabetics and 8.3% in non diabetics. Event-free survival was 95.6% in diabetics and 89.2% in non diabetics. Conclusions: Results of angioplasty were similar in diabetic and non diabetic patients in terms of hospital outcome and late follow-up (Rev Méd Chile 2001; 129: 861-70). <![CDATA[Validación del criterio de evaluación nutricional global del adulto mayor]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001000800005&lng=es&nrm=iso&tlng=es Background: The Chilean Ministry of Health proposed the use of "Mini Nutritional Assessment", to identify elders at nutritional risk. This score considers anthropometric, dietary and quality of life items. Aim: To assess the concordance of the mini nutritional assessment with body mass index and dietary parameters in Chilean free living elders. Material and methods: Subjects aged 70 years old or more, coming from four public outpatient clinics were studied. In all, the mini nutritional assessment, dietary intake using 24 h recalls and anthropometric parameters, were measured. Energy intake was evaluated using FAO/WHO/UNU guidelines. Micronutrient intake was evaluated using the Dietary Recommended Intakes (DRI) from USA. Kappa index was used to determine diagnostic concordance. Results: Forty three percent of subjects were overweight or obese. There was a substandard intake of calcium, folate, zinc, vitamin A, C, E, B6, B12 and energy. Seventy nine percent of subjects had a deficient or regular food intake. Mini nutritional assessment score was normal in 66% of subjects. Fifty eight percent of those with a deficient food intake had a normal mini nutritional assessment. On the other hand, 73% of those considered at nutritional risk, had a normal or excessive weight. Conclusions: Mini nutritional assessment did not identify elders at nutritional risk in this sample (Rev Méd Chile 2001; 129: 871-6). <![CDATA[Perfil de resistencia a los antimicrobianos en agentes causantes de infección del tracto urinario en niños chilenos: Programa de vigilancia PRONARES]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001000800006&lng=es&nrm=iso&tlng=es Background: PRONARES (Programa Nacional de Vigilancia de Resistencia) is a national surveillance program for antimicrobial susceptibility, focused in different syndromes and among these, urinary tract infections. The work is done in a laboratory net that uses common protocols and whose data are centrally analyzed using the WHONET program. Aim: To analyze the pattern of antimicrobial susceptibility of agents causing urinary infections in children in the period 1997-1999. Material and methods: In the study period, 5,525 strains were analyzed. Of these, 2,307 came from pediatric patients (1,495 hospitalized and 803 ambulatory). Results: The most common causative agent was E. coli in 74,2% of cases, followed by Klebsiella spp in 8,2% and other agents in a lower frequency. Of E. coli strains, 74% were resistant to ampicillin, 52% to clotrimoxazole and 30% to first generation cephalosporins. These strains were sensitive to second and third generation cephalosporins, aminoglycosides, ciprofloxacin and nitrofurantoin. Strains from nosocomial or community infections had similar antimicrobial susceptibility. Klebsiella spp had a high rate of antimicrobial resistance (over 40%), that was even higher among nosocomial strains. It was 90% susceptible to ciprofloxacin and 100% to imipenem. All centers from which strains came had a similar pattern of susceptibility, with the exception of a pediatric center that had significantly higher resistance levels. Conclusions: The current therapeutic recommendations for urinary tract infections in children caused by E coli, are still pertinent, but the use of first generation cephalosporins must be cautious. The treatment of Klebsiella spp requires an individual antibiogram (Rev Méd Chile 2001; 129: 877-885). <![CDATA[Seguimiento prospectivo de una población infectada por VIH con y sin posibilidades de terapia anti-retroviral: impacto en sobrevida y complicaciones]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001000800007&lng=es&nrm=iso&tlng=es Background: Three-drug antiretroviral therapy (ART-3) has reduced complications and improved survival in HIV+ patients. The Chilean Public Health System began dual therapy (ART-2) in 1997, covering approximately 40% of patients in need. Aim: To report the results of a follow-up of patients with and without access to ART in a Chilean public hospital. Patient and Methods: Prospective follow-up of patients with ART-2 and 3 (cases) and patients with no access to ART (controls). All patients needed ART but it was available to a minority of them. Selection for ART was at random. Follow-up was between 6-24 months (11/96 to 3/99). Basal and periodic clinical and laboratory parameters were determined. Mortality and occurrence of new AIDS-defining events (ADE) were compared statistically using chi square. Results: One hundred and fifty cases (106 ART2, 28 ART3 and 16 ART2 expanded to ART3) and 166 controls were studied. Basal parameters were similar except prior ART (32.7 and 18.7% in cases and controls respectively). Close to 1/3 patients had AIDS. Cases had a mean follow up of 527 days; controls, 478. Six cases (4%) (5 in ART-2) and 17 controls (10%) died. Mortality x 100/pts/yr was 2.7 in cases and 7.7 in controls, p <0.05. ADE per 100/pts/yr was 21 in cases (24.4 in ART2, 15.1 in TAR3) and 54.5 in controls, p <0.05. Cases had a reduction of: esophageal candidiasis (84%), tuberculosis (75%), cryptococcosis and toxoplasmosis (66%), P carinii pneumonia (55%) and bacterial pneumonia (46%) and they had fewer hospitalizations (73%). Late assessment: 70 of 101 ART-2 patients had changed to ART-3 (1 death); 22 of 101 kept original ART-2 (12 dead, 10 alive), 39 of 43 ART-3 patients were alive and 1 died. Conclusions: Short-term ART-2 and 3 significantly reduced mortality (60% and 73%) ADE (65% and 76% respectively) and hospitalizations. Benefits of ART-2 were short lived. Resource-constrained countries cannot depend on weaker than standard ART for proper care of people with HIV disease. (Rev Méd Chile 2001; 129: 886-94) <![CDATA[Malformaciones congénitas en Chile.: Un problema emergente (período 1995-1999)]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001000800008&lng=es&nrm=iso&tlng=es Background: The Latin American collaborative study of congenital malformations (ECLAMC) is a surveillance program designed to monitor the frequency of congenital malformations and detect abrupt changes in their frequency, look for the cause of such change and implement primary prevention measures. Aim: To construct a secular trend curve with the frequency of congenital malformations in Chile. Material and methods: Using the ECLAMC protocol, every malformed newborn or stillbirth, weighting more than 500 g at birth is registered using a standard protocol, and the next non malformed child of the same sex born in the same hospital is assigned as control. Using the gathered data, secular trend curves of congenital malformations were constructed. Results: Between 1982 and 1999, there is a secular tendency in the rate of congenital malformations and maternal age, with a correlation coefficient of 0.8 and slope of 13.5 (p<0.05). The rates of congenital malformations at the moment of birth are higher at the University of Chile Clinical Hospital than in the rest of Chilean hospitals and other Latin American Hospitals. Anencephalia is a defect with a high frequency in Concepción and spina bifida has a high frequency in Rancagua, Viña del Mar, Concepción and Valdivia. There is an impressive increase in malformations dependent on prenatal diagnosis such as kidney agenesis, polycystic kidney and diaphragmatic hernia. Conclusions: Congenital malformations are having an increasing importance as causes of morbidity or mortality in the newborn. (Rev Méd Chile 2001; 129: 895-904). <![CDATA[Formulación de una mezcla vitamínica intravenosa para nutrición parenteral total pediátrica]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001000800009&lng=es&nrm=iso&tlng=es Background: No intravenous multivitamin formulation is available at the Chilean market that fulfills the requirements of pediatric patients on total parenteral nutrition. Therefore, adult formulations must be used. Aim: To prepare a parenteral aqueous multivitamin solution, to be used in pediatric patients. Material and methods: The solution was prepared, mixing vitamins according to their stability and compatibility, in a horizontal laminar flow hood. The quality control for this formulation at times zero and 30 days consisted of an organoleptic analysis, microbiologic and pyrogen controls and vitamin quantification. In addition, the effect of vitamin solution incorporation on the stability of total parenteral nutrition formulae was evaluated. The approximated production cost was calculated. Results: The ampoules did not show changes on the organoleptic characteristics. No bacterial contamination or pyrogens were detected. Total parenteral nutrition solutions were not modified after the incorporation of the vitamins. The vitamin solution was stable for one month at 4°C. Conclusions: The manufacture of this formulation results in significant savings, because it has a low manufacturing cost and fulfills pediatric requirements (Rev Méd Chile 2001; 129: 905-10) <![CDATA[Gemcitabina en 4 pacientes con colangiocarcinoma: <I>Report of four cases</I>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001000800010&lng=es&nrm=iso&tlng=es Cholangiocarcinoma is a biliary tree cancer of unknown etiology, whose symptoms are unspecific and is usually detected in advanced stages. Surgery continues to be the only curative therapy. Median survival in patients with inoperable tumors ranges between 5 and 8 months. There are few studies on the effects of chemotherapy, with a very small response. We report four patients with advanced cholangiocarcinoma, treated with gemcitabine 1000 mg/m2, weekly for 3 weeks every 28 days. There was a stabilization of tumor size and symptoms were alleviated. Toxicity was low and there was a probable prolongation of survival (Rev Méd Chile 2001; 911-6). <![CDATA[Síndrome de Münchausen por poder: una presentación inusual]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001000800011&lng=es&nrm=iso&tlng=es We report a 12 year old girl that first consulted for fever with bilateral knee arthralgias. A neurological workout was started due to a progressive gait disturbance, but all results were incongruent with nerve or nerve root lesions, leading to the diagnosis of a functional paralysis. The patient worsened to the point of prostration. Due to the suspicion that the mother was inducing the symptoms, the patient was admitted to the hospital, where she improved notably. She was discharged walking. The improvement during hospital stay confirmed the diagnosis of a Münchausen by proxy syndrome, mimicking a disabling neurological condition (Rev Méd Chile 2001; 129: 917-20). <![CDATA[Cirugía radioguiada en hiperparatiroidismo primario.: Caso clínico]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001000800012&lng=es&nrm=iso&tlng=es Primary hyperparathyroidism is the main cause of hypercalcemia in ambulatory patients. Classic surgical resolution of this disease includes bilateral cervical exploration with exhibition of the four parathyroid glands and evaluation of the suspicious gland with a rapid biopsy. We report a 79 years old female with a primary hyperparathyroidism in whom the adenoma causing the disease was located with the help of an intraoperatory gamma-probe that detected the zone of higher radiation counting of Tc99m Sestamibi, that was injected preoperatively. The patient was discharged with normal serum calcium and phosphate levels (Rev Méd Chile 2001; 129: 921-4). <![CDATA[Tendencias en la generación y reproducción del conocimiento sobre evaluación económica y salud]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001000800013&lng=es&nrm=iso&tlng=es This paper identifies the trends and recent progress in the generation and reproduction of knowledge on health economic evaluation. Analysis is organized along nine public health action fields, namely: health determinants and predictors, economic value of health, healthcare demand, healthcare supply, microeconomic evaluation of healthcare, healthcare market balance, evaluation of policy instruments, general evaluation of the health system, and healthcare planning, regulation and supervision. Each action field is defined to place the reader in the proper setting and level of analysis. In addition, thematic research topics developed in each action field are proposed and discussed. The generation and reproduction of knowledge on the different action fields was based on the review of the bibliographic databases MEDLINE and LILACS for the 1992-2000 period. Results lead to the conclusion that development and application of economic evaluation of healthcare has been uneven across different countries and that there is a growing increase of applications starting in 1994, the year of initiation of healthcare reform in Latin America (Rev Méd Chile 2001; 129: 925-34) <![CDATA[Acreditación de Escuelas de Medicina.: Trabajando para la calidad y la confiabilidad pública]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001000800014&lng=es&nrm=iso&tlng=es Important advances in the accreditation of higher education institutions and programs have occurred in Chile. A definite step forward had been the accreditation of three of the six Medical Schools, considered in the agreement subscribed between the Chilean Medical Faculties Association and the National Committee for Undergraduate Program Accreditation (CNAP). According to this understanding, educational quality was evaluated using international standards and its improvement was encouraged. The accreditation procedure carried out at the University of Chile Medical School is described. Its observation has revealed the difficulties of accreditation procedures and the early benefits obtained after they have been completed. The careful observation of the evaluation procedure will help to improve the used model and to design an effective accreditation instrument that will ultimately improve undergraduate teaching programs (Rev Méd Chile 2001; 129: 935-43) <![CDATA[Situación del VIH/SIDA en Latinoamérica al final del siglo XX: Análisis de las diferencias entre países]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001000800015&lng=es&nrm=iso&tlng=es The aim of this article is to analyze the current situation of AIDS in Latin American countries. Specifically, to compare their situation with other geographic areas of the planet, the prevalence index per countries, distribution per sex and age and, finally, the main ways of transmission in each country. The most recent data published by OMS and demographic data obtained from the Latin American and Caribean Demographic Center (CELADE) was used. This analysis reflects that in Latin America it is impossible to talk about AIDS in a homogeneous way since the differences between countries are remarkable (Rev Méd Chile 2001; 129: 944-54). <![CDATA[Computadores en investigación biomédica: I. Análisis de señales bioeléctricas]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001000800016&lng=es&nrm=iso&tlng=es A personal computer equipped with an analog-to-digital conversion card is able to input, store and display signals of biomedical interest. These signals can additionally be submitted to ad-hoc software for analysis and diagnosis. Data acquisition is based on the sampling of a signal at a given rate and amplitude resolution. The automation of signal processing conveys syntactic aspects (data transduction, conditioning and reduction); and semantic aspects (feature extraction to describe and characterize the signal and diagnostic classification). The analytical approach that is at the basis of computer programming allows for the successful resolution of apparently complex tasks. Two basic principles involved are the definition of simple fundamental functions that are then iterated and the modular subdivision of tasks. These two principles are illustrated, respectively, by presenting the algorithm that detects relevant elements for the analysis of a polysomnogram, and the task flow in systems that automate electrocardiographic reports (Rev Méd Chile 2001; 129: 955-62) <![CDATA[Comentarios sobre Etica Biomédica]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001000800017&lng=es&nrm=iso&tlng=es A personal computer equipped with an analog-to-digital conversion card is able to input, store and display signals of biomedical interest. These signals can additionally be submitted to ad-hoc software for analysis and diagnosis. Data acquisition is based on the sampling of a signal at a given rate and amplitude resolution. The automation of signal processing conveys syntactic aspects (data transduction, conditioning and reduction); and semantic aspects (feature extraction to describe and characterize the signal and diagnostic classification). The analytical approach that is at the basis of computer programming allows for the successful resolution of apparently complex tasks. Two basic principles involved are the definition of simple fundamental functions that are then iterated and the modular subdivision of tasks. These two principles are illustrated, respectively, by presenting the algorithm that detects relevant elements for the analysis of a polysomnogram, and the task flow in systems that automate electrocardiographic reports (Rev Méd Chile 2001; 129: 955-62) http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001000800018&lng=es&nrm=iso&tlng=es http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001000800019&lng=es&nrm=iso&tlng=es <![CDATA[<B>FE DE ERRATA</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001000800020&lng=es&nrm=iso&tlng=es A personal computer equipped with an analog-to-digital conversion card is able to input, store and display signals of biomedical interest. These signals can additionally be submitted to ad-hoc software for analysis and diagnosis. Data acquisition is based on the sampling of a signal at a given rate and amplitude resolution. The automation of signal processing conveys syntactic aspects (data transduction, conditioning and reduction); and semantic aspects (feature extraction to describe and characterize the signal and diagnostic classification). The analytical approach that is at the basis of computer programming allows for the successful resolution of apparently complex tasks. Two basic principles involved are the definition of simple fundamental functions that are then iterated and the modular subdivision of tasks. These two principles are illustrated, respectively, by presenting the algorithm that detects relevant elements for the analysis of a polysomnogram, and the task flow in systems that automate electrocardiographic reports (Rev Méd Chile 2001; 129: 955-62)