Scielo RSS <![CDATA[Revista médica de Chile]]> vol. 130 num. 1 lang. es <![CDATA[SciELO Logo]]> <![CDATA[Reflexiones frente a un nuevo año]]> The arrival of a new year stimulated the Editor to reflect on what has been recently accomplished in the Revista and on what is planned for its immediate future. In 2001 the electronic version at the website started to reproduce the full contents of most articles. Members of the International Advisory Committee submitted reviews and special articles by invitation. The input of manuscripts increased and most of them have been improved through the peer review process. A Symposium held in August stimulated the editors of a vast proportion of Chilean clinical and biomedical journals to interchange experiences. The 5 years tenure of the Editor in Chief was extended for a second period. For the year 2002, improvements will be made in the editorial process while the Revista commemorates 130 years of continuous publication, being among the 20 oldest medical journals in the world (Rev Med Chile 2001;130:7-8) <![CDATA[Cirugía de la insuficiencia mitral isquémica]]> Background. Ischemic mitral regurgitation (IMR) is a severe condition which may be best treated by surgery, nowithstanding a relatively high mortality rate. Objectives. To evaluate the results of mitral valve replacement or repair in patients with IMR. Patients and methods. Retrospective review of the clinical records in 29 patients with IMR who were surgically treated from 1990 to 1999. They represent 8% of surgical procedures on the mitral valve. Results. Mean age was 67 ± 9 years. Surgery was performed urgently in 19 patients (66,5%). NYHA functional class was 3.4 ± 0.8. The mechanism of IMR was annular dilatation and spreading of papillary muscles in 18 patients, papillary muscle rupture in 9 and fibrosis in 2. Mitral valve replacement was performed in 14 patients and mitral valve repair in 15. Twenty four patients (83%) had concomitant myocardial revascularization. Overall surgical mortality was 24%; 26% for mitral replacement and 13% for mitral valve repair (p=0.215). On follow up of 26±33 months, one year survival was 76±0.8% and 5 years survival was 59±12%. Excluding in hospital mortality, survival was 100% at one year and 78±14% at 5 years. Functional class improved in all survivors, to 1.4±0.5. Late echocardiographic evaluation of patients with mitral valve repair showed absence of mitral regurgitation in 58%, 1+ MR in 17% and 2+ MR in 25%. Conclusion. In spite of a high perioperative mortality, surgery for IMR is a valuable procedure for patients with an otherwise highly lethal disease (Rev Méd Chile 2002; 130: 9-16) <![CDATA[Radiación ultravioleta productora de eritema en Valdivia: Comparación entre inferencias satelitales, modelo de transferencia radiativa y mediciones desde Tierra]]> To evaluate dose rates and daily doses (DDE) at Valdivia in Southern Chile, ultraviolet irradiances recorded every 15 min from 1998 to 2000 with a high resolution spectroradiometer were weighted with an erythemal action spectrum. Exposure times to get one MED (210 J/m2) in Summer are 10, 12, 18 and 24 min for skin types I trough IV respectively. DDE estimations included in NASA Web products overestimate measurements by 16% on average in Summer, with an absolute uncertainty of 980 J/m2 at the 95% level. Observed dose rates for clear days are in fair agreement with the numerical output from a numerical model, suggesting that acute episodes can be predicted if total ozone can be forecasted and the population is instructed on corrections for cloud effects (Rev Méd Chile 2002; 130: 17-25) <![CDATA[Resistencia de <I>Streptococcus pneumoniæ</I> a penicilina y su asociación con factores clínicos y epidemiológicos: <I>Clinical and epidemiological aspects</I>]]> Background: Penicillin and third generation cephalosporin resistant pneumococcal isolates have emerged in Chile, mainly in the pediatric population. These isolates complicate therapeutic alternatives, specially among patients with central nervous system infections. Aim: To assess the frequency of penicillin and third generation cephalosporin resistance among isolates obtained from pediatric patients with invasive pneumococcal infections, and to study serotypes and clinical risk factors associated with resistance. Material and methods: Microbiological isolates obtained from children between April 1994 and May 1999 with pneumococcal invasive infections, were serotyped and analyzed according to their susceptibility to penicillin and cefotaxime by E-test and broth microdilution testing. Potential risk factors studied included patient's age, previous antibiotic use or admissions, comorbidity, and serotypes. Results: Seventy eight patients were studied. Penicillin-resistant pneumococcal isolates were detected in 35.9% of cases (21.8% with intermediate and 14.1% with high level resistance) without significant variation among different clinical conditions. Most of the high level penicillin-resistant pneumoccocal isolates had MIC ≥4 µg/mL (8 out of 11 strains). One third of penicillin-resistant isolates also expressed cefotaxime resistance. Multivariate analysis indicated an age ≤36 months (OR=6.8; IC 95%: 1.4 to 33.5) and serotype 14 (OR=6.3; IC 95%: 1.7 to 23.3) as factors associated with penicillin resistance. Conclusions: One third of the invasive pneumococcal isolates obtained from pediatric patients were resistant to penicillin. Risk factors involved a younger age and pneumococcal isolates belonging to serotype 14 (Rev Méd Chile 2002; 130: 26-34) <![CDATA[Asociación entre el fenotipo fisura labiopalatina no sindrómica y marcadores de microsatélites ubicados en 6p, 17q y 19q]]> Background: In the search of the major genes responsible for the genetic etiology of Nonsyndromic Cleft Lip and Palate (NSCLP), an association study between this malformation and four molecular markers, F13A1 and EDN1 (6p), D17S579 (17q) and BCL3 (19q), was done. Aim: To determine, in a Chilean population, the presence of NSCLP susceptibility regions, as proposed for Caucasian populations in the 6p, 17q and 19q chromosomal regions. Material and Methods: A sample of unrelated NSCLP patients, that belonged to Simplex (Sx) and Multiplex (Mx) families, was analyzed. Blood donors were used as a control group (Co). The DNA of the four markers was amplified by means of PCR, their products analyzed by PAGE denaturants and visualized by silver staining. Statistical analysis was performed using chi2 log ratio. Results: Allele frequency distribution of D17S579 was significantly different in all patients with NSCLP and their subgroups, when compared to control subjects. Significant differences in EDN1 frecuency were observed between the total groups of NSCLP patients and those pertaining to the Mx subgroup, when compared to controls. Differences in F13A1 distribution were only observed between NSCLP-Mx patients and controls. There was a slight difference in BCL3 distribution, between the total sample of NSCLP patients and controls. Conclusions: Our results support the hypothesis of the existence of cleft susceptibility regions in 6p and 17q. The small significance of BCL3, suggests that ethnicity can influence the interactions between involved genes (Rev Méd Chile 2002; 130: 35-44) <![CDATA[Metodología clásica y molecular en la identificación de especies de <I>Enterococcus spp</I>]]> Background: Enterococcus is a bacterial genus with low virulence. However, in the last years, the importance of some enterococcus species as nosocomial pathogens has increased, specially due to their resistance to some antimicrobial. Aim: To identify enterococcus strains using classical biochemical techniques and genomic amplification with Polymerase Chain Reaction (PCR). Material and methods: Three hundred and five enterococcus strains, isolated between 1996 and 1999, from different clinical specimens in hospitals and other centers of the VIIIth Region of Chile, were studied. The isolates were identified, to the species level, according to the scheme proposed by Carvalho et al. Identification of some strains was confirmed by PCR. Results: Eighty nine percent of isolates were identified as E fæcalis, 10.2% as E fæcium and 3.3% as other species. Conclusions: PCR is a fast and promising technique, useful in the identification of Enterococcus species (Rev Méd Chile 2002; 130: 45-49) <![CDATA[Gasto energético de reposo medido en obesos y no obesos: comparación con la estimación por fórmulas y ecuaciones propuestas para población chilena]]> The commonly used predictive equations to calculate resting energy expenditure (REE) can yield inaccurate results. Aim: To compare measured REE, with estimated REE in normal and obese adults. To develop specific predictive equations for our population. Patients and Methods: Eight hundred sixteen women aged 18 to 74 years old with a body mass index (BMI) between 18.5 and 69.7 kg/m² and 441 men aged 18 to 71 years old with a BMI between 185 and 67.9 kg/m2 were studied. REE was measured by indirect calorimetry and fat free mass by tetrapolar bioimpedance. REE was also estimated using FAO/WHO (F/W) and Harris-Benedict (H/B) equations. Results: Measured REE in controls was 20.7 ± 1.9 and 23.6 ± 3.3 kcal/kg/day in women and men respectively. The figures for overweight women and men were 19.8 ± 1.9 and 20.0 ± 2 kcal/kg/day, for obese women and men were 18.3 ± 1.7 and 19.0 ± 1.8 kcal/kg/day and for morbidly obese women and men, were 16.9 ± 1.8 and 16.1 ± 1.7 kcal/kg/day. When REE was corrected for fat free mass, no differences between controls and different degrees of obesity, were observed. The difference between estimated and measured REE ranged from -420 to 617 kcal in women and from -400 to 900 kcal in men. The equations derived using data obtained in the present study, showed a better predictive accuracy. Conclusions: An important error was detected when REE was predicted using FAO/WHO or Harris Benedict equations, in Chilean obese subjects. Therefore these equations must be used with caution, local equations must be devised or resting energy expenditure must be measured by indirect calorimetry (Rev Méd Chile 2002; 130: 51-60) <![CDATA[Prueba de Elisa en deposición para detectar infección por <I>Helicobacter pylori</I>]]> Background: Infection with Helicobacter pylori is frequent in Chile, and a good test for its diagnosis ideally should be non-invasive, fast, easy and inexpensive. Aim: To report the use of an immunoassay test, that detects antigens of Helicobacter pylori in stools. Material and methods: One hundred and four patients that required an upper gastrointestinal endoscopy were studied. Stool samples were analyzed using an enzymatic immunoassay. These results were compared with those obtained with the urease test and microscopic examination of smears taken from biopsies obtained during the diagnostic endoscopy. Results: In 81 of 83 patients considered to have the infection according to the endoscopic tests, the antigen was also present in the stools. The test was negative in 16 of 21 patients considered to be without the infection. The resulting sensitivity and specificity for the immunoassay was thus 97.6 and 76.2% respectively, with positive and negative predictive values of 92.4 and 88.9%, respectively. Conclusions: These results are in agreement with those reported in the literature. Further studies are needed to define its usefulness in massive screening, follow up after antibiotic treatments or the detection of coccoid forms of Helicobacter pylori (Rev Méd Chile 2002; 130: 61-65) <![CDATA[Duración de la amenorrea de lactancia en la población urbana de Temuco]]> Background: Studies done in Santiago, Chile show that menses return before the sixth month of puerperium in 50% of lactating women, even in those that continue with exclusive breast feeding. Aim: To study the length of lactational amenorrhea in a group of women living in Southern Chile. Material and methods: One hundred fourteen women giving exclusive breast feeding, were followed from the third postpartum month, to determine the length of lactational amenorrhea. Its relationship with general characteristics of the mothers and children and breast feeding pattern was also studied. Results: Sixty six women (58%) recovered their menses before the 6th postpartum month and their length of lactational amenorrhea was 101 ± 5 days. In the rest of the sample, the length was 277 ± 10 days. No differences in characteristics of the mothers and children or breast feeding pattern, were observed between these two groups. Conclusions: A short lactational amenorrhea is common in the Chilean population. Clinical characteristics or pattern of breast feeding do not explain the length of LA in this population ( Rev Méd Chile 2002; 130: 66-70) <![CDATA[Identificación de los determinantes de la estadía en Unidades de Cuidados Intensivos usando redes neuronales artificiales]]> The prediction of the length of stay at the moment of hospital admission is of outmost importance. Many studies have used lineal models to predict this variable, but there are inherent limitations to these models. The use of non lineal models has been scarce. Aim: To develop a non lineal model to predict length of stay in intensive care units. Material and methods: Retrospective analysis of 294 patients admitted to two intensive care units in Santiago, Chile. The severity of the disease motivating the admission was nominally quantified. This and other physiological variables were included in the model. The length of stay was modeled using Artificial Neural Networks. Results: The model yielded an error of 8.7% (3.6 ± 0.4 days, CI 95%) and a correlation coefficient of 0.9 (p <0.001) for the prediction of length of stay. Using net sensitivity analysis, the model determined that gastrointestinal diseases, infections and respiratory problems were the main causes of prolongation of intensive care unit stay. Conclusions: Intensive care units should have, in the future, computer systems that gather vital information to predict length of stay (Rev Méd Chile 2002; 130: 71-78) <![CDATA[Estados de hipercoagulabilidad heredados y trombosis venosa cerebral: Experiencia en 3 casos]]> Hereditary hypercoagulability has been identified as risk factor in approximately 30% of cerebral venous thrombosis cases. We report three females with this association. A 38 years old female with a history of deep venous thrombosis of the lower limb, presented with headache, vomiting and a generalized seizure. Magnetic resonance angiography showed a partial thrombosis of the left lateral and superior longitudinal venous sinuses. Coagulation study showed a resistance to activated C protein and factor V Leyden. A 42 years old woman with a history of deep venous thrombosis, presented a right hemiplegia during a hospitalization. Magnetic resonance showed a left lateral hemorrhagic infarction. Magnetic resonance angiography showed an absence of signal in three venous sinuses. Coagulation study showed a protein C deficiency. A 17 years old woman presented a right hemiparesis in the sixth day of puerperium. CAT scan showed a left frontoparietal subcortical venous infarction. Coagulation study showed an antithrombin III deficiency (Rev Méd Chile 2002; 130: 79-85) <![CDATA[Obstrucción de rama macular de arteria central de la retina]]> We report a 54 years old female on oral anticoagulant treatment with a mitral valve disease, with a history of two transient ischemic attacks and a decreased visual acuity. She was assessed by an ophthalmologist and signs of retinal vascular disease were found. During follow up, the patient experienced an acute unilateral loss of vision in the left eye. Fundoscopy revealed an obstruction of a macular branch of central retinal artery. Aspirin was added to oral anticoagulants and one month later, the patient experienced an upper gastrointestinal bleeding. After four months of follow up, there is no recovery of left eye vision (Rev Méd Chile 2002; 130: 86-89) <![CDATA[Hallazgo incidental de cáncer en saco herniario inguinal]]> The presence of cancer in a hernia sac is uncommon. The tumor can involve the hernia sac, the herniated mass or be external to the hernia sac. We report two cases with this condition. A 68 years old male was operated of a right inguinal hernia. During surgery, several white nodules were noted in the internal side of hernia sac. The same lesions were present in the mesentery. Pathological study revealed an adenocarcinoma. The primary tumor was not located and the patient died one and a half years after the procedure. A 62 years old male was operated due to an irreductible inguinal mass, seven months after a subtotal gastrectomy for gastric cancer. During the resection of the mass, metastasic implants in the mesenteric adipose tissue were noted. A mini laparotomy was performed and an extensive peritoneal tumor dissemination was found. The patient died two months after surgery (Rev Méd Chile 2002; 130: 91-95 <![CDATA[Ejercicio de la Medicina Interna en América Latina: Rol de médico internista]]> This article explores the causes of the crisis in the role of internists. As in the United States, the progressive specialization of internists lead to a dehumanized, expensive and technical practice of medicine. Aiming to better incomes and prestige, more than 60% of internists practice as specialists. Primary care physicians, with a very low rate of problem solving, cover 75% of consultations. Specialists, with increasing costs, cover the rest of consultations. Patients, medical schools and health organizations are claiming the return of the general internal medicine specialist. To increase the interest for general internal medicine, several strategies are applicable. Medical students interested in general internal medicine could receive a focused training, provided by these specialists. A greater emphasis should be put on primary care. More independent, secondary care diagnostic and treatment centers, should be created. Continuous medical education should be done with periodical re certification of physicians. The public health system should increase its wages and the generalist view should be maintained by physicians when practicing at their private offices (Rev Méd Chile 2002; 130: 96-100) <![CDATA[Pedro Laín Entralgo, médico y humanista<A HREF="#a1"><SUP>1</SUP></A>]]> This speech of the president of the Chilean Academy of Medicine, Dr Alejandro Goic, is a tribute to the memory of the Spanish physician, scholer, historian, writer and intellectual Dr. Pedro Laín Entralgo, who died in Madrid on June 4, 2001, at the age of 93. On that occasion, the Spanish newspaper "El Pais" defined him as the last humanist. The Spanish civil war started when Laín was 28 years old and he aligned with Franco's supporters. In 1940, when he founded the magazine "El Escorial", he was separated from the official party. He and other intellectuals declared themselves in an "interior exile". His autobiographical book, "Lightening the burden on the conscience" refers to his painful personal history. He obtained the History of Medicine chair, at the Complutense University, at the age of 34 and remained at that post until his retirement in 1978. His intellectual production is magnificent and calls to a mutual understanding, hope, friendship and love. Outstanding, among others, are his books "The wait and hope", "Theory and reality of the other", "Spain as a problem", "Medicine and history", "The clinical history", "Patient physician relationship", "Medical anthropology". He directed the collective work composed of seven volumes, called "Universal History of Medicine". He was a member of the Royal Academies for Language, History and Medicine. In Chile, he was named honorary member of the Faculty of Medicine of the University of Chile and of the Academies of Language, History and Medicine. He dictated a course of Medical Anthropology that had a profound impact on the thought of Chilean physicians. In 1949 he wrote that Chile was the most solid state of Latin America and that "Chile needs to leave his traditional calm, through a historical gesture, and create the river beds required by his magnificent spiritual and geographical gifts. There is a lack of a beautiful craziness". It was an invocation for an understanding with our neighboring countries "for ever and ever" (Rev Méd Chile 2002; 130: 101-6) <![CDATA[Mortalidad infantil e indicadores económicos en Chile: 1985-1999]]> Background: The link between economy and some public health indicators like Infant Mortality Rate (IMR) is widely demonstrated. Aim: To explore the relationship between some economic indicators and infant mortality in Chile between 1985 and 1999. Material and methods: An ecological study, obtaining information from Demographic Annual Reports edited by the National Institute of Statistics, Health Ministry, Planning Ministry and the Central Bank. Results: There is an inverse association between the Gross National Product, per capita and Real Salary Index and a direct relationship between inflation and unemployment rates with an increased infant mortality. Conclusions: The reduction in infant mortality observed in Chile depends more on socio demographic than on economical factors (Rev Méd Chile 2002; 130: 107-12) <![CDATA["El Mito de la autonomía"]]> Background: The link between economy and some public health indicators like Infant Mortality Rate (IMR) is widely demonstrated. Aim: To explore the relationship between some economic indicators and infant mortality in Chile between 1985 and 1999. Material and methods: An ecological study, obtaining information from Demographic Annual Reports edited by the National Institute of Statistics, Health Ministry, Planning Ministry and the Central Bank. Results: There is an inverse association between the Gross National Product, per capita and Real Salary Index and a direct relationship between inflation and unemployment rates with an increased infant mortality. Conclusions: The reduction in infant mortality observed in Chile depends more on socio demographic than on economical factors (Rev Méd Chile 2002; 130: 107-12)