Scielo RSS <![CDATA[Revista médica de Chile]]> http://www.scielo.cl/rss.php?pid=0034-988720040005&lang=es vol. 132 num. 5 lang. es <![CDATA[SciELO Logo]]> http://www.scielo.cl/img/en/fbpelogp.gif http://www.scielo.cl <![CDATA[<B>Evaluación pre-analítica de dos métodos de extracción de ADN para la amplificación del gen de la pneumolisina (<I>PLY</I>) de <I>Streptococcus pneumoniae</I>, en muestras de hemocultivo</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000500001&lng=es&nrm=iso&tlng=es Background: Streptococcus pneumoniae is a common etiologic agent of invasive respiratory infections among children under 5 years of age and older adults. Isolation rates of S. pneumoniae by traditional culture techniques are low. Aim: To study the sensitivity and specificity of two different DNA extraction methods to amplify the ply gene, applied to three different types of blood culture broths, experimentally inoculated with S. pneumoniae. Material and methods: DNA was extracted from the cultures using an organic method or a technique that consists in dilution, washing with NaOH and concentration of the sample. This was followed by PCR amplification of a 355 pb fragment of the pneumolysin gene (ply). Results: The organic DNA extraction method inhibited the PCR reaction at all concetrations studied (0.6 to 10(6) colony forming units/mL). Using the NaOH extraction, ply gene amplification was positive in all three blood culture broths, but only at concentrations of 10³ colony forming units/mL or higher. Using the same DNA extraction method, PCR was negative when the broths were inoculated with seven other related bacterial species, which results in a 100% specificity. Conclusions: Detection of S. pneumoniae by amplification of ply gene from blood cultures using the protocol of NaOH for DNA extraction is specific and provides results in a short lapse. However, the diagnostic sensitivity is not optimal, wich limits its clinical use (Rev Méd Chile 2004; 132: 533-8). <![CDATA[<B>Cáncer colorrectal hereditario no poliposo</B>: <B>tratamiento quirúrgico y análisis de genealogías</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000500002&lng=es&nrm=iso&tlng=es ackground: Hereditary nonpolyposis colorectal cancer (HNPCC) accounts for 3 to 5% of all colorectal cancer (CC). It is an autosomal dominant syndrome with 80% of penetrance for this disease. Aim: To analyze the pedigree and surgical treatment of HNPCC. Patients and methods: We retrospectively analyzed our database of CC selecting patients with HNPCC according to clinical criteria (Amsterdam II). We characterized our patient's pedigrees with telephonic interviews. Results: From 1111 patients operated on with CC we identified 13 (1.17%) with HNPCC. The mean age at diagnosis was 41.6 years (range: 23-75). Sixty two percent presented in International Union Against Cancer (UICC) stages I or II and none in stage IV. Seventy one percent of tumors were proximal to splenic flexure. In 5 patients the diagnosis of HNPCC was made postoperatively, after diagnosis of CC in their relatives. In all but one of the 8 patients with preoperative diagnosis of HNPCC, we performed a total colectomy. From the remaining 6 patients with partial colectomy, 2 developed metachronic CC. Two patients died of cancer. From 101 persons in the 4 families, 25 have developed neoplasia: 18 CC, 3 endometrial cancer and 4 other tumors. Twenty eight relatives were eligible for colonoscopic screening, but only 21% of them have been screened appropriately. Conclusions: Preoperative diagnosis should change the surgical treatment of HNPCC, preventing metachronic disease. Primary colonoscopic screening allowed us to diagnose CC in early stages, nonetheless most of eligible relatives have not followed recommended frequency for colonoscopy (Rev Méd Chile 2004; 132: 539-47). <![CDATA[<B>Serotipos y susceptibilidad antimicrobiana de <I>Streptococcus agalactiae</B></I>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000500003&lng=es&nrm=iso&tlng=es Background : Streptococcus agalactiae or group B streptococcus, GBS, is the leading cause of neonatal and maternal infections and an opportunistic pathogen in adults with underlying disease. In the last decade, a dramatic increase in the resistance of this microorganism to erythromycin and clindamycin has been observed. Aim: To determine the serotype distribution and antimicrobial susceptibility of isolates of S agalactiae collected from infections and colonization and to assess the genetic mechanisms of macrolide and clindamycin resistance. Material and methods: A total of 100 GBS isolates were collected between 1998 and 2002, in Santiago, Chile. They were isolated from the amniotic fluid from patients with premature rupture of membranes (7 isolates), blood from neonatal sepsis (10 isolates), neonate colonizations (2 strains), skin and soft tissue infections (7 isolates), urinary tract infections (5 isolates), genital infections (3 isolates), articular fluid (one isolate), and 65 strains were recovered from vaginal colonization55. Results: Serotypes Ia, II and III were the predominant serotypes identified in our study, accounting for 90 (90%) of the strains. Five isolates belonged to serotypes Ib (5%) and two (2%) to serotype V respectively; no strains belonging to serotype IV were found. All strains were susceptible to penicillin G, ampicillin and cefotaxime, and four isolates (4%) were resistant to both erythromycin (MIC >64 µg/ml) and clindamycin (MIC >64 µg/ml). The strains had a constitutive macrolide-lincosamide-streptogramin (cMLSB) resistance phenotype and the erm(A) gene was present in the four isolates. Conclusions: Serotypes Ia, II and III were the predominant serotypes in this study. All strains were susceptible to penicillin G, ampicillin and cefotaxime, and four (4%) strains were resistant to both erythromycin and clindamycin. The cMLSB resistance phenotype, and the erm(A) gene was detected in resistant strains (Rev Méd Chile 2004; 132: 549-55). <![CDATA[<B>Cirugía paliativa mediante operación de Norwood en distintas formas de corazón univentricular</B>: <B>resultados quirúrgicos inmediatos</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000500004&lng=es&nrm=iso&tlng=es Background: Norwood procedure is used as the first stage in the palliative treatment of the hypoplastic heart syndrome and can be used, with some technical modifications, in other forms of univentricular heart with aortic stenosis or hypoplasia. These patients have a high mortality (50%), derived from the procedure itself and from their abnormal physiological status. Aim: To report our experience with the Norwood procedure. Patients and methods: Retrospective analysis of all patients subjected to the Norwood procedure between February 2000 and June 2003. Results: Thirteen patients (9 females, age range 5-60 days and median weight of 3.3 kg) were operated. Eight had hypoplastic heart syndrome and five had a single ventricle with aortic arch hypoplasia. The diagnosis was done in utero in eight patients. All technical variations, according to the disposition and anatomy of the great vessels, are described. Cardiac arrest with profound hypothermia was used in all and regional cerebral perfusion was used in nine. Three patients died in the perioperative period and three died in the follow up (two, four and 10 months after the procedure). Gleen and Fontan procedures were completed in five and one patients, respectively. Conclusions: Our results with the Norwood procedure are similar to other series. There is an important mortality in the immediate operative period and prior to the Glenn procedure (Rev Méd Chile 2004; 132: 556-63). <![CDATA[<B>Perfil epidemiológico y clínico de la invaginación intestinal en lactantes de la Región Metropolitana</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000500005&lng=es&nrm=iso&tlng=es Background. Intussusception (IS) is a potentially severe disease that affects an undetermined number of Chilean infants. The withdrawal of a rotavirus vaccine in 1999 due to its association with IS, highlighted the need for updated information on IS worldwide including Chile, before introduction of new vaccines. Aim: To estimate the incidence and to describe the epidemiology and clinical presentation of IS in the Metropolitan Area of Chile. Material and methods. IS cases occurring between 1996 and 2001 in the seven public pediatric hospitals and in six private clinics (during 2000 and 2001) were identified. Incidence rates were calculated using updated population estimates. A systematic review of the medical charts of IS cases occurring in the public hospitals for 2000-2001 was performed. Results. IS incidence rates for the Public Sector ranged from 32 to 39 per 100.000 children < 2 years of age. These figures did not vary significantly among the different Health Care Services, nor after inclusion of the private clinics. IS was more common in males (66%) and infants younger than 12 months (83%), with 67% of cases occurring between 3 and 8 months of age. The most common presenting symptoms were abdominal pain (90%), vomiting (86%), and rectal bleeding (75%). Ileocolic IS predominated (83%) and surgical correction was the preferred treatment (81%). No death occurred in this series. Conclusions: IS incidence rates were intermediate compared to other series, stable over time, and similar between the public and private sector. Clinical characteristics were similar to those previously reported with a disproportionately high use of surgical correction over enema, currently considered the preferred treatment option. (Rev Méd Chile 2004; 132: 565-72) <![CDATA[<B>Impacto biomédico de los viajes en adultos mayores chilenos</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000500006&lng=es&nrm=iso&tlng=es Background: In Chile there is a program named "Vacations for Elderly during Low Season". Aim: To characterize participants of this program and to measure the impact of traveling in their health and wellbeing. Material and methods: Two anonymous and voluntary questionnaires were applied to 4200 participants, before and after a ten days vacation package. Results: Before traveling, questionnaires were answered by 802 subjects, and after traveling by 4057 (69% women, 22% older than 75 years old, 15.8% living alone). The presence and maintaining of good health were most appreciated at this age and 59% classified their health as good or excellent. Twenty five percent referred sensory problems (seeing or hearing), 12% reported urinary incontinence and 21% presented falls in the last three months; depression screening (GDS-5) was positive in 16%. Chronic disease prevalence was similar to the general Chilean elderly population. After traveling they reported significant improvements in the items sociability, wellbeing, mood, appetite, insomnia and ostheoarthritic pain. Conclusions: Elderly who traveled were mainly women, who thought that maintaining good health is the most precious value. After traveling they improved significantly different aspects of wellbeing. Promotion of this kind of recreation programs is an important tool for integration and enhancement of quality of life in elderly subjects in our country (Rev Méd Chile 2004; 132: 573-8). <![CDATA[<B>Cambios recientes en la mortalidad por cáncer de próstata en Chile</B>: <B>estudio de tendencias en el período 1955-2001</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000500007&lng=es&nrm=iso&tlng=es Background: By the year 2000, prostate cancer became the second leading cause of cancer death in Chilean men of all ages and is the leading cause of cancer deaths in men of eighty years of age or older. Aim: To analyze the trends in mortality rates from prostate cancer in Chile in a fifty years series, estimating the rate of increase of such rates and their changes in time. Material and methods: A trend analysis for age standardized mortality rates was performed, using join point regression analysis, which allows estimation of the annual percent change of rates and to find significant changes in such trend. Results: Age standardized mortality rates in Chile reached their peak value in 1996, becoming apparently stable from then on. Crude rates have had a steady increase during the whole period. The trends analysis identified three different periods in the growth of the age standardized rates: a first one of slow increase in rates between 1955 and 1981 (0.9% annual increase), a second one of more aggressive growth starting in 1981 (2.6% annual increase), and a third period starting in 1996, in which rates slowly decline at an annual rate of 1%. Conclusions: The tendency of prostate cancer seen in Chile resembles that of industrialized countries, with an increase in its age standardized death rates that suffers a downturn by the end of the past decade. Besides early detection techniques, a substantial part of the reduction in mortality from prostate cancer could be explained by therapeutic improvements (Rev Méd Chile 2004; 132: 579-87). <![CDATA[<B>Neumonía neumocócica bacterémica en 45 adultos inmunocompetentes hospitalizados</B>: <B>Cuadro clínico y factores pronósticos</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000500008&lng=es&nrm=iso&tlng=es Background: The presence of bacteremia during a pneumococcal pneumonia is a sign of bad prognosis. Aim: To report a clinical experience with bacteremic pneumococcal pneumonia. Patients and methods: We reviewed the clinical and laboratory data from 45 adults (36 male, aged 17 to 97 years) with community acquired pneumonia (CAP) and Streptococcus pneumoniae bacteremia, hospitalized between January 1997 and August 2002 at the Puerto Montt Hospital (Southern Chile). Results: Eighty four percent of patients had underlying aggravating conditions, mainly alcoholism (40%), chronic obstructive lung disease (17.8%) and renal failure (17.8%). Seven percent were homeless. Fever, cough, dyspnea and sputum were the most common presenting symptoms. Five patients had pleural involvement. Four strains (8.9%) of S. pneumoniae had diminished susceptibility to penicillin. Nine patients died (case-fatality rate of 20%), but mortality was attributed to pneumonia in only three of them. Main factors associated with a higher mortality were renal failure, absence of cough, an arterial pH <7.3 on admission, ICU hospitalization, shock, mechanical ventilation and an APACHE score >16. Conclusions: The high death rate of these patients could be explained mainly by underlying conditions. ICU management and higher cost preventive measures could reduce this rate (Rev Méd Chile 2004; 132: 588-94). <![CDATA[<B>Validez de la escala de Braden para predecir úlceras por presión en población femenina</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000500009&lng=es&nrm=iso&tlng=es Background: Pressure ulcers are a common complication among elderly patients confined to bed for long periods. The Braden scale is a commonly used risk assessment tool. Aim: To evaluate the use of Braden scale. Patients and methods: Seventy women aged 61 to 96 years, admitted to the Internal Medicine Service of Barros Luco-Trudeau Hospital, were studied. Their risk was evaluated using the Braden scale. The presence of pressure ulcer was diagnosed according to the National Pressure Ulcer Advisory Panel on admition, two weeks later and at discharge. Results: On admission, mean Braden scale score was 16.6±2.8 and 34 women had a score of 16 or less, that is considered of risk. Twenty five women (20 with a score of 16 or less) developed pressure ulcers, mostly superficial. The odds ratio of a score of 16 or less for the development of ulcers was 4.2 (95% CI 1.8-11.7, p <0.001). The sensitivity and specificity of such score were 80 and 69% respectively. Conclusions: The Braden scale predicts the risk of developing pressure ulcers with a good sensitivity and specificity in female elderly patients (Rev Méd Chile 2004; 132: 595-600). <![CDATA[<B>Diálisis con albúmina MARS (Molecular Adsorbent Recirculating System) como puente para el trasplante hepático en insuficiencia hepática fulminante</B>: <B>presentación de 3 casos</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000500010&lng=es&nrm=iso&tlng=es The most successful therapy for acute liver failure is liver transplantation. However, due to the low number of donors, organ support therapies need to be used as a bridge to liver transplantation. Molecular Adsorbents Recirculating System (MARS) is a dialysis treatment that uses a recirculating dialysate containing albumin. This allows the removal of both hydrosoluble and albumin-related substances. This system improves hepatic encephalopathy, renal dysfunction and some clinical parameters in acute liver failure, but there is no clear decrease in mortality. We report three women aged 23, 21 and 61 years, that were subjected to liver transplantation, in whom this therapy was successfully used (Rev Méd Chile 2004; 132: 601-7). <![CDATA[<B>Taquicardia recíproca de la unión auriculoventricular</B>: <B>características electrofisiológicas en un paciente con la variedad paroxística. Caso clínico</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000500011&lng=es&nrm=iso&tlng=es Junctional reciprocating tachycardia is an atrioventricular reentrant tachycardia whose anterograde conduction occurs via the His Purkinje and the retrograde conduction via an accessory pathway with slow conduction. The most common form is incessant tachycardia but a paroxysmal form also exists. We report a 35 years old female with recurrent paroxysmal tachycardia, that underwent electrophysiological evaluation. A left posterolateral accessory pathway was documented. Reciprocating paroxysmal tachycardia was induced by electrical stimulation and a successful pathway ablation was performed (Rev Méd Chile 2004; 132: 608-13). <![CDATA[<B>Epidermólisis bulosa distrófica recesiva</B>: <B>Caso clínico</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000500012&lng=es&nrm=iso&tlng=es We report a female newborn with a dystrophic epidermolysis bullosa. The diagnosis was made by electron microscopy of a bullous skin lesion. The importance of reaching a specific diagnosis is underscored. Close relatives can therefore be informed and educated about prognosis, etiology and the possibility of having new affected offspring. An accurate diagnosis can be reached through electronic microscopy or modern immunohistochemical techniques. Further complementary information given by conventional histology is required. A complete study is recommended to minimize errors in the intepretation of morphology (Rev Méd Chile 2004; 132: 614-8). <![CDATA[<B>Integrones y cassettes genéticos de resistencia</B>: <B>estructura y rol frente a los antibacterianos</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000500013&lng=es&nrm=iso&tlng=es Bacteria have developed sophisticated and successful genetic mechanisms to evade the action of antimicrobials. Bacterial multiresistance has caused serious problems in the treatment of nosocomial infections. Integrons and gene cassettes are considered the main genetic elements in the evolution of plasmids and transposons that actively participate in the mobilization of genes, codifying different bacterial resistance mechanisms. This article reviews the historical and structural aspects of integrons and resistance gene cassettes and the presence of these structures in Gram negative bacteria isolated from Chilean hospitals in the last ten years (Rev Méd Chile 2004; 132: 619-26). <![CDATA[<B>Tumores neuroendocrinos del páncreas</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000500014&lng=es&nrm=iso&tlng=es All pancreatic neuroendocrine tumors derive from Langerhans islet cells and have a low incidence. Half of them are functioning tumors that produce diverse hormones and occasionally cause serious clinical endocrine syndromes. They may be malignant, but they have a better survival, if compared to pancreatic ductal adenocarcinoma. Insulinoma, gastrinoma, glucagonoma, VIPoma (VIP=vasoactive intestinal peptide), somatostatinoma and ACTHoma are functioning tumors and they may also be part of Multiple Endocrine Neoplasia type I (MEN 1) syndrome and of von Hippel-Lindau disease. Diagnosis of non-functioning tumors is usually late, when they reach a big size and have even developed nodal and hepatic metastases. Nowadays, there are effective medical treatments for the medical problems secondary to excessive hormone production. For example, the hypergastrinemia typical of the Zollinger-Ellison syndrome in gastrinoma, can be adequately managed. Surgical resection is the most advisable therapy for pancreatic endocrine tumors, especially when they are small, when long time survival is better. Pre and intra operative imagenology is a great aid to locate these tumors. There are several surgical alternatives, according to the tumor size and location within the pancreas. Furthermore, palliative therapy can be used in disseminated disease. Treatment success is the result of a multidisciplinary medical team work of endocrinologists, surgeons, gastroenterologists, pathologists and geneticists (Rev Méd Chile 2004; 132: 627-34). <![CDATA[<B>Bienestar y satisfacción de los médicos con el ejercicio de su profesión en un sistema de salud en proceso de reforma</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000500015&lng=es&nrm=iso&tlng=es The subjective wellbeing of physicians and the degree of dissatisfaction with their practice is nowadays an important issue in English speaking journals. There is an international perception of a growing and deepening crisis in health systems that is affecting the professional and personal life of physicians. A multidisciplinary group, from two main Universities in Chile, has been formed to investigate this situation locally. The results of this investigation will be published in successive issues of Revista Médica de Chile (Rev Méd Chile 2004; 132: 635-6). <![CDATA[<B>Cambios en el entorno del trabajo médico</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000500016&lng=es&nrm=iso&tlng=es Changes in medical practice have been very deep in the last 50 years. These changes have happened together with other external variations in the economy, demography, culture and information, generating a sense of uneasiness and unhappiness among the medical profession. This problem is visible when interviewing clinicians in a wide range of medical settings, independently of their contractual arrangement. The medical work model in Chile has changed from a situation in which there was a sole employer, the National Health Service, one single training school, the University of Chile, and a small minority of powerful and influential intellectual leaders. At the beginning of the XXI century, there are several modes of medical work, distant and unconnected among them. On the other side of the problem many factors add complexity, such as the demographic and epidemiological transition, technological advance, the dual rich-poor medical care, the emergence of malpractice procedures and the new, better informed and more demanding medical consumer. On top of this, different health care systems reform initiatives appear, providing more uncertainty to a nearly unbearable situation. This bibliographic review shows us that similar feelings are experienced in advanced countries and in developing societies such as Chile (Rev Méd Chile 2004; 132: 637-42). <![CDATA[<B>Propuesta para la formación de Hematólogos en Chile</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000500017&lng=es&nrm=iso&tlng=es Changes in medical practice have been very deep in the last 50 years. These changes have happened together with other external variations in the economy, demography, culture and information, generating a sense of uneasiness and unhappiness among the medical profession. This problem is visible when interviewing clinicians in a wide range of medical settings, independently of their contractual arrangement. The medical work model in Chile has changed from a situation in which there was a sole employer, the National Health Service, one single training school, the University of Chile, and a small minority of powerful and influential intellectual leaders. At the beginning of the XXI century, there are several modes of medical work, distant and unconnected among them. On the other side of the problem many factors add complexity, such as the demographic and epidemiological transition, technological advance, the dual rich-poor medical care, the emergence of malpractice procedures and the new, better informed and more demanding medical consumer. On top of this, different health care systems reform initiatives appear, providing more uncertainty to a nearly unbearable situation. This bibliographic review shows us that similar feelings are experienced in advanced countries and in developing societies such as Chile (Rev Méd Chile 2004; 132: 637-42). <![CDATA[<B>Citas de autores</B> <B>nacionales en la <I>Revista Médica de Chile</B></I>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000500018&lng=es&nrm=iso&tlng=es Changes in medical practice have been very deep in the last 50 years. These changes have happened together with other external variations in the economy, demography, culture and information, generating a sense of uneasiness and unhappiness among the medical profession. This problem is visible when interviewing clinicians in a wide range of medical settings, independently of their contractual arrangement. The medical work model in Chile has changed from a situation in which there was a sole employer, the National Health Service, one single training school, the University of Chile, and a small minority of powerful and influential intellectual leaders. At the beginning of the XXI century, there are several modes of medical work, distant and unconnected among them. On the other side of the problem many factors add complexity, such as the demographic and epidemiological transition, technological advance, the dual rich-poor medical care, the emergence of malpractice procedures and the new, better informed and more demanding medical consumer. On top of this, different health care systems reform initiatives appear, providing more uncertainty to a nearly unbearable situation. This bibliographic review shows us that similar feelings are experienced in advanced countries and in developing societies such as Chile (Rev Méd Chile 2004; 132: 637-42).