Scielo RSS <![CDATA[Revista médica de Chile]]> vol. 127 num. 11 lang. es <![CDATA[SciELO Logo]]> <![CDATA[Ética Médica y Medicina Molecular: dos nuevas Secciones en la Revista Médica de Chile]]> Revista Médica de Chile has incorporated "Medical Ethics" as an independent Section since the October 1998 issue, aiming to give more relevance to articles dealing with merging biomedical and clinical ethical issues. Since July 1999, a new Section labelled "Molecular Medicine" publishes special articles devoted to review the impact of those novel techniques in genetic and molecular biology that are being progressively incorporated into medical research and clinical practice. <![CDATA[Epidemiología molecular del virus de inmunodeficiencia humana tipo 1 en Santiago, Chile]]> Background: Most of the studies of HIV-1 infection in South America have been limited to Brazil and little is known about the viral variants that are causing disease elsewhere in the continent. Aim: To determine the characteristics of the viral variants present in Chile as well as patterns of viral transmission. Material and methods: Viral sequences were obtained from 21 HIV-1 infected people from Santiago, Chile who were infected either via sexual contact or intravenous drug use. Cloned sequences obtained from both the third variable and conserved regions of the envelope as well as the viral protease were evaluated. Results: We found only clade B subtype viruses in Santiago. An evaluation of the envelope gene revealed no evidence that the sequences were monophyletic by risk group. A number of the protease sequences were predicted to encode amino acid substitutions commonly found during selection for protease inhibitor resistance. Conclusions: The HIV-1 strains studied in Chile, belong to the subtype B. There is no molecular evidence of separate introductions of the virus into the different risk groups. A number of substitutions in the protease gene that may confer resistance to protease inhibitors were found in patients with no previous exposure to this class of drugs. <![CDATA[Efecto inmunosupresor in vitro de las lipoproteínas de baja densidad]]> Background: Immune cells participate in the formation of atheromatous plate, however little is known about the effects of native or oxidatively modified lipoproteins on these cells. Aim: To study the effects of lipoproteins on in vitro mononuclear cell proliferation. Material and methods: Peripheral blood mononuclear cells were obtained from 10 patients with type 2 diabetes mellitus (aged 52 ± 9 years old with a disease duration of 8.2 ± 5.7 years and a mean glycosilated hemoglobin of 9.3 ± 2.2%) and 10 non diabetic healthy controls (aged 50.3 ± 7.1 years old). These were stimulated with phytohemagglutinin (PHA) alone or in the presence of native LDLS, malondialdehyde modified LDLs or glycated LDLs. Proliferation was measured as 3H-thymidine incorporation and expressed as Stimulation Index (SI). Results: SI of patients and healthy subjects, after PHA stimulation were similar: (57.5 ± 29.8 and 61.1 ± 23.5) respectively LDLs did not induce proliferation in neither group. Native LDLs produced a 98% inhibition of PHA induced proliferation. Malondialdehyde modified and glycated LDLs caused a 50% inhibition. The suppressive effect was maintained when lipoproteins were incorporated to culture media 60 min prior or after PHA stimulation. Conclusions: Lipoproteins inhibit in vitro PHA induced peripheral blood mononuclear cell proliferation both in diabetic and in non diabetic subjects. <![CDATA[Dependencia de nicotina:: seguimiento a un año plazo de pacientes tratados con terapia grupal más reemplazo de nicotina]]> Background: Smoking is the main single avoidable cause of death in our country. Little research in the treatment of such disorder has been made. Aim: To report the results of a prospective follow up for one year of outpatients from our "Smoker’s Clinic" at the Department of Psychiatry of the Catholic University. Patients and methods: One hundred twenty seven patients (84 male, aged 21 to 70 years old), with DSM-IV criteria for nicotine dependence, were included in a total of 18 groups. Each group received an intensive treatment program of 10 sessions with cognitive-behavioral relapse prevention techniques and nicotine replacement. Patients with active psychiatric diseases were not included in the program. Results: Eighty seven percent of subjects were abstinent at the first month and 50% were still abstinent after twelve months of follow up. We did not find differences in gender, age, previous psychiatric disease, number of cigarettes and breath carbon monoxide level between abstinent and non abstinent patients after 12 months of follow up. Conclusion: This intensive nicotine dependence treatment in seriously dependent patients, proved to be successful, regardless of the previous psychiatric history. <![CDATA[Hallazgos clínicos, endoscópicos y magnitud del reflujo de contenido gástrico y duodenal en pacientes con metaplasia intestinal cardial y esófago de Barrett corto, comparados con controles]]> Background: The diagnosis of patients with short segments of intestinal metaplasia in the distal esophagus, has increased in recent years. Aim: To assess the clinical, pathological and functional features of patients with esophageal intestinal metaplasia. Patients and methods: A prospective study was performed in 95 control subjects, 115 patients with cardial intestinal metaplasia and 89 patients with short Barret esophagus with intestinal metaplasia. All had clinical and endoscopic assessments, esophageal manometry and determination of 24 h esophageal exposure to acid and duodenal content. Results: Control patients were younger and, in this group, the pathological findings in the mucosa distal to the squamous-columnar change, showed a preponderance of fundic over cardial mucosa. In patients with intestinal metaplasia and short Barret esophagus, there was only cardial mucosa, that is the place where intestinal metaplasia implants. Low grade dysplasia was only seen in the presence of intestinal metaplasia. Gastroesophageal sphincter pressure decreased and gastric and duodenal reflux increased along with increases in the extension of intestinal metaplasia. Conclusions: These findings confirm the need to obtain multiple biopsies from the squamous-columnar mucosal junction in all patients with gastroesophageal reflux symptoms, for the detection of early pathological changes of Barret esophagus and eventual dysplasia. <![CDATA[Violencia doméstica y sexualidad]]> Background: Women’s reproductive health is closely related to the conditions in which intercourse is carried out with the sexual partner. Physical and emotional abuse is expressed as loss of bonds, reduction in self esteem and deterioration in interpersonal relationships. Aim: To assess the effects of domestic violence on pregnant women attitudes towards sexual relations with their partners, and to critically analyze the dependence of these variables on biosociodemographic factors, socioeconomic status and family functioning. Material and methods: Sixty three pregnant women with a domestic violence background (index group) and 43 women without such background (control group) were subjected to a structured survey including questions about biosociodemographic variables, socioeconomic status, family relations, couple interactions and questions about attitudes towards sexual relations. Results: Domestic violence was caused by the woman’s partner or ex partner in 73% of cases. A greater family dysfunction and disturbance in the couple’s relation was observed in the index group (p< 0,05). Association tests and multiple correspondence analysis did not show a clear correspondence between variables related to a woman’s attitude towards sex relations and the risk of domestic violence. Conclusions: This quantitative methodology was unable to identify the reasons, interpretations and meanings that women with a background of violence, give to features associated with their sexuality. <![CDATA[Síndrome de respuesta inflamatoria sistémica severa: ¿Es comparable a la sepsis severa?]]> Background: In 1992, a consensus conference defined the terms systemic inflammatory response syndrome (SIRS), sepsis, severe sepsis and septic shock. Since then, numerous reports have validated the prognostic usefulness of these operative definitions. Aim: To evaluate if sepsis severity criteria, as defined by the Consensus Conference, can be applied to noninfectious SIRS. Patients and methods: Five hundred eighteen patients admitted to 5 intensive care units (ICU) from 4 hospitals were prospectively evaluated during a 3 months period. Patients that met at least one severity criteria were included. SIRS etiology, organ dysfunction and evolution were recorded in each patient. Results: One hundred two patients were included: 79 with sepsis (group I) and 23 with noninfectious SIRS (group II). ICU and hospital mortality were comparable (43 and 48% in sepsis compared to 43 and 51% in non infectious SIRS). The most common sources of sepsis were pneumonia and peritonitis. Group II patients had a wide variety of diseases. ICU stay, APACHE score and number of organs with dysfunction were not different among groups. Only the incidence of renal dysfunction was higher in the septic group. Conclusions: The Consensus sepsis severity criteria can be applied to noninfectious SIRS, defining a population subset with similar high mortality and organ dysfunction incidence, although with greatly heterogeneous etiologies. <![CDATA[Tratamiento conservador del carcinoma ductal in situ de la mama]]> Background: Since the widespread use of mammography, the incidence of ductal carcinoma in situ of the breast has increased. Until few years ago the standard treatment was mastectomy, however from the analysis of conservative treatment trials for invasive carcinoma, it was evident that ductal carcinoma in situ could also be treated conservatively. This was confirmed later by randomized trials. Aim: to analyze the experience of our Institution with conservative treatment of ductal carcinoma in situ of the breast. Patients and methods: A search through the data base of our Institution found 69 patients treated with lumpectomy and radiotherapy between the years 1976 and 1997. Results: Twenty three of 69 patients (33%) were diagnosed because of a palpable mass. Eleven of twelve were diagnosed prior to 1990 and 12 of 57 after 1990. With a median follow-up of 48 months local control and overall survival is 97%. None of the patients underwent mastectomy. Conclusions: Conservative treatment of ductal carcinoma in situ of the breast is a reasonable alternative, mainly if we realize that with increasing frequency-the diagnosis is made through mammography and with non-palpable lesions. The results reported in this study are similar to those reported by other centers. <![CDATA[Manejo multidisciplinario de tumores hepáticos malignos en el niño: una experiencia nacional reciente]]> Background: Malignant hepatic tumors (Mht) are rare in children. Among them hepatoblastoma (HB) is the most common. Aim: To report the results of the multidisciplinary management in 6 consecutive children: five HB and one metastatic Wilms tumor (MWT). Patients and methods: The mean age of patients was 42 months. All HB patients had elevated serum alfafetoprotein (median 150,000 ng/ml). All patients received preoperative chemotherapy: HB patients received carboplatin/doxorrubicin alternating with cisplatin, and the MWT patient, vincristine alone. Surgery included two formal right and two formal left hepatectomies, one extensive central resection with partial left segmentectomy, and one lateral segmentectomy. Extracorporeal circulation was used in the child with atrial involvement. All patients received postoperative chemotherapy. Results: All tumors had variable regresion on preoperative chemotherapy. Complete resection with negative margins was achieved in all patients. The degree of tumor necrosis on histology ranged from 60% to 90%. Alfafetoprotein levels fell to under 10 ng/ml in all HB cases, one to three months after surgery. All patients survive free of disease at a median follow up of 19 months. Conclusion: A multidisciplinary approach including the well timed used of chemotherapy and surgery is highly effective in the management of pediatric malignant tumors. <![CDATA[Brote de histoplasmosis aguda en viajeros chilenos a la selva ecuatoriana: un ejemplo de Medicina Geográfica]]> Eight Chilean teenagers traveled to Ecuador in January 1999, where they were bitten by mosquitoes, had contact with parakeets and lodged in poorly hygienic places; 6/8 visited for 5-10 minutes the interior of a bat cave. About a week later these 6 began with headache, myalgia and fever that lasted 2-3 weeks. 5/6 had dry cough with no respiratory distress. The index case was seen in the 2nd week of symptoms. A chest x-ray showed multiple nodular infiltrates as in the other five. Two had histoplasma serology, one was negative and the other positive at a low titer; histoplasmine skin test showed induration of 17-27 mm in all six. An acute histoplasmosis with massive exposure was diagnosed and treated with itraconazole for 3 weeks. All became asymptomatic and chest x-rays returned to normal. Histoplasmosis (non existent endogenously in Chile) is, among other geographic and tropical diseases, a risk for Chilean travelers. Awareness of this in the general population and development of expertise in these diseases by local health care providers is required. <![CDATA[Esclerosis tuberosa sangrante.: Caso clínico en un paciente Testigo de Jehová]]> We report a 26 years old male with a tuberous sclerosis with multiple and bilateral kidney cysts and angiomyolipomas. The patient presented to the emergency room with a severe abdominal pain and anemia, secondary to a bleeding angiomyolipoma. The patient rejected blood transfusions due to his religious beliefs. A selective angiography was performed confirming diagnosis and the lesion artery was selectively embolized, stopping the bleeding immediately. The patient had a satisfactory evolution thereafter. This is a rare lesion and the fact that the patient was a Jehovah witness that rejected blood transfusions, required an innovative medical approach. <![CDATA[Estenosis segmentaria de intestino delgado luego de trombosis de vena mesentérica superior.: Caso clínico]]> We report a 24 years old female with a Superior Mesenteric and Portal Vein Thrombosis due to an Antithrombin III factor deficiency, associated to oral contraceptive use and smoking. She presented with severe abdominal pain and the diagnosis was reached after surgery with a CT scan. The patient was treated with intravenous heparin and oral anticoagulation, with a good clinical and Doppler endosonographic response. One month after the onset, she developed an intestinal occlusion caused by two concentric jejunal stenoses, measuring 2 and 0.7 cm in length and demonstrated with a barium jejunogram. A 35 cm intestinal resection was done and the patient recovered uneventfully. The pathological study showed granulation tissue on both stenotic zones with an ulcer near to the distal stricture, that reached the internal muscularis propria, with subserosal fibrosis. The development of segmental stenosis is a rare complication superior mesenteric vein thrombosis, that must be bore in mind. <![CDATA[Aseguramiento de la calidad profesional.: Un nuevo marco ético para el ejercicio de la medicina]]> Accreditation of physicians and medical education programs are progressively standing as well established procedures in most related institutions and countries, worldwide. Yet, an ample and consistent review of this issue is still required for a more complete knowledge and universal acceptance. Quality health care is a goal of the profession and a demanding requirement of society. Reaching high standards in medicine is a major responsibility of the medical schools and of the pertinence and appropriateness of the programs. This is a useful and sound frame for the model that is being developed in Chile, to better regulate and improve both medical education and practice. The bioethics implications that merge from this perspective are underlined to give the accreditation system a deep moral relevance as are expression of people’s wills and expectations on medical professional services. <![CDATA[Aspectos que afectan el análisis de contenido de ADN por citometría de flujo]]> DNA ploidy and cell cycle analysis by flow cytometry is used to obtain additional information about the diagnosis and prognosis of different types of cancer. However, there are several disagreements among authors about the tissue source (fresh-frozen or paraffin embedded), cellular dissociation methods (mechanical, enzymatic or other), use of different dyes, lasers, analysis software with different mathematical models and interpretation of results. A discussion about the different aspects that affect the study of DNA ploidy and cell cycle and a consensus in publications is mandatory. A strict control of analysis processes and data interpretation is also necessary. <![CDATA[Medicina basada en evidencias: ¿Una estrategia que acerca o aleja de la Medicina Interna?]]> In the last years, evidence based medicine has been considered a main factor for the diagnostic and therapeutic decisions in medical practice. However, one must consider the complexity of human beings and the difficulties in the interpretation of some results obtained in randomized prospective trials that support this theory. Therefore the importance of clinical experience, rational and logical medical thinking and facing patients as individuals must prevail at the moment of complex medical decisions. <![CDATA[Recomendaciones para el uso del Sildenafil en pacientes cardiópatas]]> In the last years, evidence based medicine has been considered a main factor for the diagnostic and therapeutic decisions in medical practice. However, one must consider the complexity of human beings and the difficulties in the interpretation of some results obtained in randomized prospective trials that support this theory. Therefore the importance of clinical experience, rational and logical medical thinking and facing patients as individuals must prevail at the moment of complex medical decisions.