Scielo RSS <![CDATA[Revista médica de Chile]]> vol. 132 num. 11 lang. es <![CDATA[SciELO Logo]]> <![CDATA[<B>Helicobacter pylori</B>: <B>20 años después </B>]]> Twenty years ago Helicobacter pylori was identified in the gastric content and this finding stimulated a multitude of studies and publications that changed drastically our knowledge of common gastric conditions such as peptic ulcer and gastric cancer. This progress has affected significantly our practice and has resulted in great benefits for our patients. The relationship of the bacteria to the pathogenesis of gastritis, peptic ulcer, gastric cancer and gastric lymphoma was firmly established. A large number of individuals are infected (an estimated half of the world's population) while only a minority suffers of the above mentioned conditions, so it became clear that certain strains of the bacteria, susceptibility of the host and environmental factors interplay in causing the damage. The diagnosis of the infection became a standard practice and therapy and prevention of these common conditions has been drastically modified. Eradication of the bacteria resulted in the cure of ulcers, in a dramatic decrease in the rate of its complications and in the ocurrence of gastric cancer. Better sanitary conditions are part of the solution. Also it is successful in the management of certain gastric lymphomas. The treatment however, is expensive and not free of side effects. Further research work is needed to facilitate the diagnosis and less expensive treatments should be available to eradicate Helicobacter pylori throughout the world <![CDATA[<B>Relación de la genotipificación de <I>Helicobacter pylori</I> con la forma e intensidad de la gastritis en población adulta portadora de patología gástrica benigna </B>]]> Background: The damaging capacity of Helicobacter pylori is variable and depends, in part, on its genetic polymorphism. Aim: To study H pylori genes vacA, cagA and iceA and the relationship of these genotypes with the features of acute damage in chronic gastritis. Material and methods: Gastric endoscopic biopsies were obtained in 75 adults for pathological study and genetic typification of H pylori by specific PCR. Results: In only 64 cases, complete information was available. In 53 of these, there was H pylori infection demonstrated by PCR. Twenty one percent had infection by two or more H pylori strains, vacA gene had genotypes s2/m2, s1/m1 and s1/m2 in 36, 25 and 8% of cases respectively, cagA gene was present in 49% of infected patients. iceA gene had genotypes iceA 1 ad iceA 2 in 15 and 60% of patients respectively. The presence of cagA or alleles s1/m1 and s1/m2 of vacA gene was directly correlated with polymorphonuclear infiltration and the severity of epithelial damage. The genotype s2/m2 of vacA gene was significantly associated with a milder or absent mucosal damage. No association was found between iceA alleles and the pathological features of gastritis. Conclusions: Alleles of vacA and cagA genes of H pilory are associated with the severity of gastric mucosal damage <![CDATA[<B>Epidemiología de la Insuficiencia Renal Aguda grave</B>: <B>Un estudio prospectivo multicéntrico en la Región Metropolitana </B>]]> Background: There is a paucity of information about the epidemiology of acute renal failure in Chile. Aim: To perform a prospective multicentric survey of severe acute renal failure in Chile. Material and methods: All patients admitted to ten hospitals in Metropolitan Santiago, during a period of six months with severe acute renal failure, were studied. The criteria for severity was the requirement of renal replacement therapy. All patients information was gathered in special forms and the type of renal replacement therapy and evolution was registeres. Results: One hundred fourteen patients were studied (65 males, age range 18 to 87 years). The calculated incidence of acute renal failure was 1.03 cases per 1000 hospital discharges. The onset was nosocomial in 79 subjects (69%) and community acquired in the rest. Renal failure was oliguric in 64 cases (56%) and in 60% of patients it had two or more causative factors. Sepsis, isolated or combined with other causes, was present in 51 of patients. Other causes included ischemia in 47%, surgery in 26%, exogenous toxicity in 25%, endocenous toxicity in 11%, acute glomerular damage in 6% and obstructive uropathy in 6%. Cardiac surgery was responsible for 47% of post operative cases of acute renal failure. Intermittent conventional hemodialysis, continuous renal replacement techniques and daily prolonged hemodialysis were used in 66%, 29% and 2% of patients, respectively. Overall mortality was 45% and it was higher in oliguric patients. Gender, age, cause or the type of therapy did not influence survival. Nine percent of surviving patients had some degree of kidney dysfunction at discharge. Conclusions: There is still a great space for prevention of severe acute renal failure in Chile, considering the main etiologies found in this study <![CDATA[<B>Variaciones del índice de masa corporal (IMC) de acuerdo al grado de desarrollo puberal alcanzado</B>]]> Background: Body mass index (BMI) is the recommended parameter to assess the nutritional status of subjects aged less than 20 years. However, during puberty the correlation between BMI and fat mass decreases notably. Therefore, the use of BMI for the diagnosis of obesity during puberty may be misleading. Aim: To evaluate the variations of the BMI during puberty according to chronological and biological ages. Material and methods: Descriptive cross sectional study in school age children of elementary and high schools (4,531 males and 5,326 females) representing all socioeconomic strata of 4 regions of Chile. BMI was calculated from weight and height measurements (W/H²) and pubertal development was evaluated according to Tanner stages. The sample selected to evaluate the variations of BMI according to chronological age and pubertal stages consisted in 3,913 females aged 8-14 years and 2,494 males aged 10-16 years. Analyses of variance (F test) and Tukey HSD test were used to compare mean BMI according to chronological and biological ages. Results: The age of onset of puberty (Tanner Stages IB2 and G2) varied greatly, from 8 to 14 years in females and 10 to 16 years in males. Mean BMI in a specific stage of pubertal development did not show significant differences according to age in both sexes. However, there were significant differences (p <0.05) in mean BMI when comparing children of the same chronological age but in different Tanner stages. Per each stage of Tanner development, BMI increased 1.0 or more points among females and 0.6 points among males. Conclusions: During puberty, BMI is associated to biological and not chronological age <![CDATA[<B>Inactivación del gen CDKN2A (p16) en cáncer de la vesícula biliar</B>]]> Background: The CDKN2A gene encodes a cyclin dependent kinase inhibitor, p16, which promotes cell cycle arrest. Methylation of the promoter region trans-criptionally inactivates the gene. Aim: To study the relationship between methylation status of the prometer region of p16 gene, the immunohistochemical expression of p16 and clinical and morphological features of gallbladder carcinoma. Material and methods: We analyzed the methylation status of the promoter region of the CDKN2A gene in gallbladder adenocarcinomas using methylation specific PCR (MSP). We also used microsatellite markers near the CDKN2A gene to detect allelic imbalance (AI) and examined the tumors by immunohistochemistry (IHC) for p16 expression. Results: Of 38 gallbladder adenocarcinomas analyzed by IHC, 11 cases (29%) were negative for p16 protein. Nine (24%) had methylation of the promoter region of the CDKN2A gene. Twenty nine cases were negative for methylation, but four (14%) of these 29 exhibited AI at one or more of the microsatellite markers. CDKN2A promoter methylation was not associated with microsatellite instability (MSI-H). Conclusions: The inactivation of CDKN2A by methylation and/or deletion might play an important role in gallbladder carcinogenesis <![CDATA[<B>Mielopatía por déficit de vitamina B12</B>: <B>caracterización clínica de 11 casos </B>]]> Background: Subacute combined degeneration is a clinical manifestation of vitamin B12 deficiency, that we observe with unusual frequency. Aim: To report a series of eleven patients with subacute combined degeneration. Patients and methods: Retrospective analysis of 11 patients hospitalized in a public hospital in Santiago, between March 2001 and February 2003. All had a myelopathy of more than three weeks of evolution with serum vitamin B12 levels of less than 200 pg/ml. Results: A risk factor was identified in 10 cases and the most common was an age over 60 years old. The main presenting symptom was the presence of paresthesias. On admission, sphincter dysfunction, posterior column and pyramidal syndromes coexisted in nine patients. A level of sensitive deficit was detected in six. Ten patients had macrocytosis and eight were anemic. Serum vitamin B12 was measured in ten and in nine, it was below 200 pg/ml. The mean lapse between onset of symptoms and treatment was eight months. All received intramuscular vitamin B12 in doses on 1,000 to 10,000 IU/day. Sphincter dysfunction and propioception were the first symptoms to improve. Conclusions: Subacute combined degeneration must be suspected in patients older than 60 years with a subacute myelopathic syndrome and low serum vitamin B12 levels <![CDATA[<B>Autopercepción del estado nutricional en adultos de Santiago</B>]]> Background: The prevalence of obesity is growing in Chile. The personal perception about the own nutritional status is associated to the risk of obesity. Aim: To analyze the personal perception about their nutritional status among adults living in Santiago and to compare it to the objective diagnosis obtained according to Chilean Health Ministry norms. Material and methods: The body image was explored in 735 people between the ages of 20 and 90. The weight and height were obtained under standard conditions, and the body mass index (BMI) was calculated (kg/m²) and classified according to the criteria of the Health Ministry. The concordance and Kappa index between both criteria in function of age, gender, nutritional status and height were analyzed. The model that best explained the weight subestimation was determined with multivariate logistic regressions. Results: Fifty two percent of subjects classified correctly their nutritional status, 30% subestimated, and 18% overstimated the nutritional status (Kappa 0.27). The multivariate analysis showed greater subestimation in obese (OR 5.8 95% IC 4.2-7.9), in men (OR 4.5 95% IC 2.7-7.3), people younger than 60 years old (OR 2.0 95% IC 1.3-3.1) and people of small stature (OR 3.1 95% IC 1.9-4.9). Conclusions: Half of the studied subjects had an inadequate perception of the body image. Educative campaigns are needed to reinforce the concept of adequate weight. This may contribute to promote health and reduce the risk of obesity <![CDATA[<B>Candidiasis esofágica en pacientes inmunocompetentes: Estudio clínico e inmunológico</B>]]> Background: Esophageal candidiasis is associated with conditions that cause an immune depression. It is a defining disease for AIDS, is observed in poorly controlled diabetics, in patients with renal or hepatic failure, in patients with cancer and in subjects using medications causing immunosuppression or broad spectrum antimicrobials. Aim: To report the features of 10 immunocompetent patients with esophageal candidiasis. Patients and methods: Six males and four females aged between 48 and 82 years, without conditions associated with immunosuppression, in whom an esophageal candidiasis was found on an upper gastrointestinal endoscopy. Delayed skin hypersensitivity to eight antigens, Iymphocyte subpopulations, yeast phagocytosis and neutrophil chemotaxis were measured. Results: Six patients had a low CD4 Iymphocyte count and seven had a low CD8 count. Seven patients were anergic on skin hypersensitivity challenge. Yeast phagocytosis was abnormal in one patient and neutrophil chemotaxis was abnormal in two. Humoral immunity was normal in all subjects. All patients were treated with oral fluconazole in doses of 150 mg/day for 14 days, with complete resolution of candidiasis in all. Conclusions: Patients with esophageal candidiasis, have frequent alterations of cellular immunity, that must be diagnosed and treated <![CDATA[<B>Estado nutricional y resistencia aeróbica en escolares de educación básica</B>: <B>línea base de un Proyecto de Promoción de la Salud </B>]]> Background: The Chilean Ministry of Health has developed a health promotion program called «Vida Chile», whose aim is to target risk factors for chronic diseases. To achieve this, school-based initiatives in nutrition and physical activity have been implemented. The evaluation of these initiatives includes a baseline assessment of these two variables. Aim: Baseline assessment of the nutritional status and aerobic capacity of elementary school children (1st to 8th grade). Material and methods: Children from seven public schools were studied. Weight, height, triceps skinfold thickness and waist circumference were measured. To test the aerobic capacity, the 20-m Shuttle Run Test (Navette) was utilized. Results: The assessment included 4,271 children, mean age was 10.2 years. The percentile of body mass index, as compared to the CDC 2000 Reference was 67.8±26.7 and 68±26.7 for boys and girls, respectively. The prevalence of obesity among children from 6 to 8 years, was 20.3 and 17.7% for boys and girls, respectively. Approximately 30% of males and 15% of females with normal weight had a good aerobic resistance, compared to 15 and 4% of their overweight counterparts. Aerobic capacity decreased with increasing age. Conclusions: There is a high prevalence of obesity and a deficient level of aerobic capacity among children attending public schools in Chile <![CDATA[<B>Linfoma intravascular tratado con anticuerpos monoclonales anti CD20</B>: <B>Descripción de un caso clínico </B>]]> We report a 78 year old male with prostatism, that was subjected to a prostate biopsy. The pathological study showed a microvascular lymphocytic infiltration. Four months later, the patients presentd with reduced alertness, cough, dyspnea, fever and elevation of lactic dehydrogenase and erythrocyte sedimentation rate. Chest and abdominal CAT scans, bone marrow aspirate, protein electrophoresis and prostate specific antigen were normal. A re-evaluation of prostate biopsy showed an intravascular lymphoid infiltration, positive for CD45 and CD20, compatible with the diagnosis of intravascular lymphoma. Chemotherapy was started, but it was not tolerated by the patient and the response was partial. Therefore, treatment with monoclonal antibodies anti CD20 (Rituximab) was started. The tumor had a complete and prolonged (24 months) remission after the treatment <![CDATA[<B>Meningoencefalitis post estapedotomía</B>: <B>Análisis de un caso clínico </B>]]> Bacterial meningitis of otological origin is caused by the pass of bacteria from a suppurated otitis to the central nervous system. Patients subjected to otological surgery have a higher risk of contracting it. We report a 30 years old female with a history of non progressive long lasting hear loss in the left ear, that suffered two episodes of bacterial meningitis after being subjected to a stapedotomy. Temporal CAT scan revealed a malformation of the inner ear. An exploratory tympanostomy showed a perilymphatic fistula that was repaired <![CDATA[<B>Trastornos del ánimo, psicofármacos y tiroides </B>]]> For more than 40 years thyroid hormones and mood disorders have been associated. Some psychiatric symptoms are produced by thyroid illnesses and there is a frequent association of thyroid dysfunction with mood disorders. Therefore, routine thyroid function assessment in patients with mood disorders and the treatment of sub-clinical thyroid dysfunctions is recommended. The usefulness of adding thyroid hormones to antidepressive treatment in euthyroid patients to obtain a potentiation effect has been probed repeatedly. The most common strategy is potentiation with T3, but high doses of T4 have been also used in patients with resistant depression. Thyroid hormones exert their action in the central nervous system through a variety of mechanisms: modulation of gene expression of several groups of proteins, some of them with known physiopathological implications in mood disorders and the influence over serotonin and noradrenergic neurotransmission, known to be one of the modes of action of antidepressants. Finally, it is also important to stress the complex relationship between psychiatric drugs, deiodinases and thyroid hormones, that can potentially help to understand the mechanisms of action of these drugs <![CDATA[<B>Causas de la crisis de la profesión médica en Chile </B>]]> There is a growing dissatisfaction among physicians towards their professional practice. This article tries to identify causes of this dissatisfaction and to explain the fears that physicians experience during their practice. The authors pose the hypothesis that physicians have non resolved internal problems with the application of technological advances and that medical practice has not changed along with the dramatic social changes that have occurred in the last decades. Medical organizations work in a confusing environment. Considering the main characteristics of medical work, the causes of difficulties and the reasons to explain the slowness of physicians to identify the problems and react, are analyzed. Finally some solutions are proposed to overcome this crisis <![CDATA[<B>Acerca de la comunicación médico-paciente desde una perspectiva histórica y antropológica </B>]]> This paper attempts to perform a historical anthropological analysis of the factors that currently either favor or obstruct the doctor-patient relationship. For this purpose, the main works of reference are the sociologist Gilles Lipovetsky and the Spanish author Pedro Laín Entralgo. The former, identified with the concept of Postmodernity and individual Hedonism, is crucial in understanding what are the main determinants in the most recent developments affecting the doctor-patient relationship. Since the technological revolution, advances in science have surpassed all imagination, information technology has worked its way into all types of relationship, and thus medical practice has been particularly affected. On the other hand, the work of Laín Entralgo enables us to perform a review of the history of the doctor-patient relationship in the Western world, which affords a more accurate view of the origins and evolution of the current situation <![CDATA[<B>Isaac y josé Horwitz en la psiquiatría chilena </B>]]> During the XXth century, neuropsychiatrists Isaac and José Horwitz worked in the Asylum, the current Psychiatric Institute Dr José Horwitz. While Isaac dedicated part of his time to teach in Medical and Nursing Schools, his brother José preferred clinical work on mental health. Both chaired consecutively the Service A of the old Hospital and José occupied in his last year the Director's position. After a scholarship in Mental Health in Baltimore, José developed, in conjunction with other outstanding colleagues, the first investigations on psychiatric morbidity in Chile, promoted the use of work therapy for individuals with chronic mental diseases, and helped to improve and plan projects for the prevention and treatment of alcoholism