Scielo RSS <![CDATA[Revista médica de Chile]]> http://www.scielo.cl/rss.php?pid=0034-988720010011&lang=es vol. 129 num. 11 lang. es <![CDATA[SciELO Logo]]> http://www.scielo.cl/img/en/fbpelogp.gif http://www.scielo.cl <![CDATA[El perfil de seguridad de las estatinas]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001001100001&lng=es&nrm=iso&tlng=es HMG-CoA reductase inhibitors (statins) are the treatment of choice for patients with hypercholesterolaemia. Several large-scale clinical trials have examined the efficacy and tolerability of statins, providing a wealth of information on their safety and adverse effect profile. Adverse hepatic effect is reflected as asymptomatic elevations in serum levels of aminotransaminases. Myopathy, occasionally leading to myoglobulinuria secondary to rhabdomyolysis, is a rare and potentially fatal complication. Cerivastatin, the last statin approved for use in humans, was voluntarily withdrawn from the market by Bayer, because fatal rhabdomyolysis was most frequently reported with cerivastatin than for other approved statins. The concomitant use of statins with drugs that inhibit CYP3A4 (cyclosporin, erythromycin, clarithromycin, itraconazole, and ketoconazole), may result in increased plasma concentrations of HMG-CoA reductase inhibitors leading occasionally to myotoxicity. Fibric acid derivatives can produce myotoxicity, and the association of both types of drugs increases the risk of this adverse event. The reason for the greater association of rhabdomyolysis with cerivastatin than with other statins is unknown. The efficiency of post marketing drug surveillance programs in different countries, was the clue for the awareness of this problem (Rev Méd Chile 2001; 129: 1237-40). <![CDATA[El colágeno de la reestenosis post angioplastia con stent: ¿se origina en la íntima o en la adventicia?]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001001100002&lng=es&nrm=iso&tlng=es Background: Restenosis post stenting is due to the deposit of extracellular matrix, mainly collagen in the neointima. Controversy exists regarding if collagen is generated locally or by immigration from the adventitia. Aim: To study the fibrocellular response after stent implantation in rabbit iliac arteries. To observe, by immunohistochemistry and in situ hybridization, if collagen type I mRNA is expressed in the neointima, in the media or in the adventitia. Material and methods: Thirty eight white rabbits (New Zealand) of 4 kg received an hypercholesterolemic diet during 1 month. After this period, in all but 6 of them, an angioplasty with stent implantation was performed via right carotid artery in both iliac arteries, using a 1:1.3 relationship regarding the reference vessel. Angiograms were performed at day 0, 4, 21, and 40, followed by paraffin fixation of the injured segments, immunohistochemistry for a-actin and in situ hybridization to detect procollagen type I (alpha1R1) mRNA. Results: No hybridization was observed in non injured arteries or at day 0 (n= 6). Expression of a1R1 mRNA was observed in the neointima starting at day 4 after stenting (n= 8). At day 21 (n= 8) hybridization of procollagen type I was not only observed in the neointima, but also in the media, which became equally intense in both areas. At day 40 (n= 6) hybridization was observed similarly in the media and adventitia. Conclusions: In this model, hybridization of procollagen type I started in the neointima, then involved the media and finally the adventitia. This finding might be useful for designing therapies to be delivered locally at the end of an angioplasty to prevent collagen deposition in the neointima (Rev Méd Chile 2001; 129: 1241-7) <![CDATA[Niveles séricos de la molécula CD30 soluble en la infección por el virus de hepatitis B]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001001100003&lng=es&nrm=iso&tlng=es Background: The release of CD30 molecule in the soluble form (sCD30) is considered a feature of Th2 activation and proliferation of the cellular phenotype Th2. Aim: To analyze the immunoregulatory role of sCD30 in the evolution of hepatitis B virus (HBV) infection. Patients and methods: Three study groups were formed: 15 patients with acute infection by HBV who remitted toward the resolution of the infection; 15 patients who evolved to the carrier state and 15 subjects without clinical history of infection by this or other viruses. The determination of serological markers for the HBV was done by the Microparticles Enzymatic Immunoanalysis techniques (MEIA). The method of double antibody by ELISA was used For sCD30 determination. Results: A significant sCD30 increase (p < 0.05) was observed in patients with acute infection, during the acute phase (135.7 ± 36.7). These values decreased to 16.2 ± 2.5 during the convalescent phase. Patients that evolved to the carrier state, did not experience a rise in sCD30 values (40.2 ± 6.7, 38 ± 9.2 and 36.1 ± 8.3 during the acute phase, at 120 and 240 days respectively). The value in the control group was 34.8 ± 6.7. Conclusions: The group that evolved towards remission experienced a higher activation of the Th2 cellular phenotype, promoting humoral immune response. An inactivity of sCD30 values was observed in the group that evolved to the carrier state (Rev Méd Chile 2001; 129: 1248-52). <![CDATA[Factores predictores de riesgo de morbimortalidad en hipertensos esenciales seguidos 25 años]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001001100004&lng=es&nrm=iso&tlng=es Background: Among hypertensive patients, other risk factors for mortality and morbidity, besides blood pressure, must be considered when therapeutic decisions are done. Aim: To assess the incidence and relevance of cardiovascular risk factors in a cohort of patients with essential hypertension. Material and methods: A cohort of 1.072 treated patients with essential hypertension was followed for a period up to 25 years. Four hundred eighty six were men and 586 were women, age ranged from 31 to 70 years. At entry, 56% of subjects did not have any organic complications associated to hypertension (stage I WHO criteria), 30% had mild alterations (Stage II) and 14% had major complications (myocardial infarction, stroke, heart failure or renal failure). Likewise, 43.8% had mild, 14.5%, moderate and 41.7%, severe hypertension. Patients were treated with monotherapy or combined therapy based on diuretics, beta blockers, calcium antagonists and angiotensin converting enzyme inhibitors. Goal of therapy was 140/90 mm Hg. Risk factors associated diseases and complications were registered carefully. Causes of death were obtained from hospital records and death certificates. Mortality was analyzed using life tables (intention to treat method included). Results: Blood pressure dropped significantly during follow up from a mean of 182/110 to 154/92 mm Hg. During follow up, 143 patients died and 429 complications (lethal or non lethal) were recorded. Twenty four percent of patients smoked, 24% reported alcohol intake, 56% had hypercholesterolemia, 11% were obese, 13% had diabetes and 3% had gout. The proportional hazard model showed that the existence of previous complications, the presence of more than 3 risk factors, and age over 60 and mean systolic and diastolic pressure during therapy, were independent and significant risk factors for mortality. Conclusions: The incidence of risk factors among our hypertensive patients is very similar to that of other national or international cohorts (Rev Méd Chile 2001; 129: 1253-61) <![CDATA[Cálculo de la concentración de colesterol de la lipoproteína de baja densidad: análisis de regresión <I> versus</I> fórmula de Friedewald]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001001100005&lng=es&nrm=iso&tlng=es The Friedewald formula is used to estimate cholesterol of low density lipoprotein (LDL) from total cholesterol (CT), cholesterol of high density lipoprotein (HDL) and triglycerides (TG), but there are doubts about its precision. Aim: To compare Friedewald formula and regression analysis for the calculation of LDL cholesterol. Material and methods: One hundred and fifty plasma samples from asymptomatic adults (aged 47.7 ± 13 years, 50.6% male) were analyzed. CT, HDL, LDL and TG were determined by enzymatic methods. Friedewald formula (LDLc=CT-HDL-(TG/5)) and multiple regression analysis were applied to estimate LDL concentration. Results: Mean total cholesterol was 175.3 ± 39.7 mg/dl, HDL cholesterol was 35.57 ± 0.8 mg/dl and TG was 128.4 ± 65.4 mg/dl. Mean values for LDL cholesterol were significantly higher than those estimated by the Friedewald formula (136.4 ± 37.9 mg/dl and 114.1 ± 37.4 mg/dl respectively, p<0.001) with a mean underestimation of 16.4 ± 11.7%. LDL cholesterol values were directly proportional to TG concentration. Multiple regression analysis (LDLr=-14.376 + (age x 0.198) + (CT x 0.949) + (HDL x -0.474) + (TG x -0.064) showed no statistical differences with those obtained by the enzymatic method. Conclusions: These results confirm the underestimation of LDL concentration by the Friedewald formula despite normal range of TG concentration. A multiple regression analysis should be used to estimate LDL concentration with precision (Rev Méd Chile 2001; 129: 1263-70) <![CDATA[Análisis computacional de los ruidos respiratorios en la evaluación de la obstrucción bronquial en niños pequeños que no colaboran con las pruebas espirométricas]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001001100006&lng=es&nrm=iso&tlng=es Background: There are changes in inspiratory breath sound intensity in patients with airway obstruction. Airway narrowing may change sound spectral characteristics. Aim: To define the characteristics of lung sounds at standardized air flow during methacholine challenge and to compare acoustic changes with transcutaneous oxygen tension (PtcO2) during induced airway narrowing. Patients and methods: Forty asthmatic children (20 male) aged 5.2±1 years and 40 normal children (18 male), aged 5.6 ± 1 years were studied. All patients were free of respiratory tract infections one month before the study. A methacholine challenge from 0.06 to 8 mg/ml was performed; the test was ended when a fall in PtcO2 of >20% from baseline was observed or if the final concentration was reached. Subjects breathed through a pneumotachograph aiming at flows of 0.4 to 0.6 l/s. Respiratory sounds were recorded using contact sensors at the suprasternal notch and at the posterior right lower lobe. From average spectra, power at low (100-200 Hz=P1) and high frequencies (400-2000 =P2) was calculated. Frequencies below which 50% (F50) and 99% (SEF90) of the spectral power between 100 and 2000 Hz was contained, were also calculated. Results: In asthmatics, the metacholine concentration at which a 20% fall in PtcO2 was observed, was lower than in normal children (p< 0.05). There was an increase in P1 (p<0.01) and a reduction in P2 (p<0.01) during inspiration, in subjects that experienced a 20% reduction in PtcO2. Also, there was an increase in F50 and SEF99 during inspiration in lung sounds, but not over the trachea. Conclusions: Lung sounds analysis can be useful for the assessment of airway reactivity in asthmatic children (Rev Méd Chile 2001; 129: 1271-8) <![CDATA[Prevalencia de trastornos siquiátricos en hombres y mujeres hospitalizados en un Servicio de Medicina Interna de un hospital de Santiago de Chile]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001001100007&lng=es&nrm=iso&tlng=es Background: Mental disorders may interfere, aggravate or mimic medical conditions. Aim: To study the prevalence of psychiatric disorders among patients hospitalized in a medical ward of a general hospital. Patients and methods: A structured interview for DSM-III, devised for "non patients", was applied to 203 men and 203 women, aged 11 to 90 years old, hospitalized in an internal medicine service of a public hospital. Thirty four psychiatric conditions that can be discriminated with the instrument and others that complied with DSM-III criteria, were investigated. Results: There was a 60% prevalence of mental disorders among men (alcohol dependency in 26%, delirium or dementia in 10.8%, anxiety disorders in 10.4%, major depression in 7.8% and adaptation disorders in 3%). Among women, the prevalence of mental disorders was 65% (major depression in 23.2%, anxiety disorders in 14.3%, adaptation disorders in 8.4%, dementia in 5.6%, delirium in 3% and alcohol dependency in 2.5%). Most conditions were of moderate or mild intensity. Two or more conditions coexisted in 40% of cases. Only in 8% of these subjects, a psychiatric consultation was requested. Conclusions: There is a high frequency of psychiatric disorders among medical patients. These must be adequately diagnosed and treated (Rev Méd Chile 2001; 129: 1279-88) <![CDATA[Derrame pleural y empiema complicado en niños: Evolución y factores pronósticos]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001001100008&lng=es&nrm=iso&tlng=es Background: Complicated pleural empyema has a torpid and longer clinical evolution, requiring in some patients surgical management. The predictive factors for surgical treatment are not well known. Aim: To search for clinical, laboratory or radiological predictors for the requirement of surgical treatment in pediatric patients with empyema. Patients and methods: A retrospective review of the charts of 108 patients hospitalized for pneumonia plus pleural effusion at the Pediatric Service of the Catholic University Hospital between January 1985 and July 2000. Results: Eighty one patients had complete radiological evaluation and pleural fluid biochemical analysis. Forty nine (60%) fulfilled the criteria for empyema and 32 (40%) for an exudate. Thirteen patients with empyema required surgery and 36 were treated medically. The mean age was 3 years (range 9 months-6 years) for the surgically treated and 4 years (range 12 months-14 years) for the non-surgical group. The male/female ratio was 5:1 in the surgical group and 1:1 for the non-surgical group. Pleural fluid cultures were positive in 21 of 79 patients. Streptococcus pneumonia was the most frequently isolated agent. No significant differences were found between groups for the average days of fever prior to the diagnosis or total days of fever, days of hospital stay, pleural fluid pH (6.8 and 7.0 respectively) and glucose (21 and 31 mg/dl respectively). No differences were either observed for pleural fluid risk factors (pH < 7 and glucose <20mgdl), the presence of extensive pleural effusions, pleural loculations or bands on pleural ultrasonography and positive Gram stain or cultures in the pleural fluid. Surgical patients required oxygen for more days than medical patients (7.7 and 5.1 days; p=0.037). Conclusions: This study failed to find predictive clinical, radiological or pleural fluid parameters, for the requirement of surgical treatment of empyema (Rev Méd Chile 2001; 129: 1289-96). <![CDATA[Agentes causantes de infecciones del torrente circulatorio en niños con cáncer, en cinco hospitales de Santiago (1994-1998)]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001001100009&lng=es&nrm=iso&tlng=es Background: Pediatric patients in treatment for cancer can have fatal bacterial infections. Thus, in the presence of fever or other signs infection, antimicrobials have to be prescribed empirically. Aim: To know the causative agents of bacteremia in children with cancer, their changes with time and between different hospitals and their patterns of susceptibility. Material and methods: We reviewed the blood cultores of children with cancer in five hospitals of Santiago, from 1994 at 1998. Results: During the study period, 707 agents were isolated. The most frequently isolated species or genus were coagulase negative Staphylococcus (43%), Staphylococcus aureus (16%), Escherichia coli (9%), Klebsiella spp. (8%), Pseudomonas spp. (5%) and Candida spp. (4%). Coagulase negative Staphylococcus was 55% resistant to meticilin and S. aureus was 44% resistant. Enterobacteriae had 15% resistance to gentamicin and amikacin, 2% to imipenem, 26% to ceftriaxone, 21% to cefotaxim and 20% to ceftazidim. Among non fermenting agents resistance was 6% for imipenem, 9% for amikacin 10% for ciprofloxacin, 19% for ceftazidim and 22% for cefoperazone. The resistance of Streptococcus spp. (non pneumoniae) to penicillin reached 50% and that of Enterococcus spp. was of 33%. Conclusions: Treatment for pediatric patients with cancer must be modified and new guidelines including more active medications for patients at risk for bacteremia, should be devised (Rev Méd Chile 2001; 129: 1297-1304) <![CDATA[Prevalencia del cáncer de próstata en la comuna de Talca, VII región Chile]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001001100010&lng=es&nrm=iso&tlng=es Background: In 1998, there were 1,218 deaths in Chile caused by prostate cancer. This figure results in a death rate of 16.6 per 100,000 males for this disease. Aim: To assess the prevalence of prostate cancer in the Seventh Region of Chile. Material and methods: A probabilistic sample of 327 males aged 40 to 59 years old was studied. In all, a codified questionnaire was applied, a digital rectal examination was performed and a blood sample was drawn to measure prostate specific antigen. All digital rectal examinations were performed by the same observer. Patients with an abnormal rectal examination or prostate specific antigen were subjected to a prostatic biopsy under ultrasound guidance. Results: In 14 subjects, the digital rectal examination was considered abnormal and in seven, prostate specific antigen was over 4 ng/ml. All subjects with elevated prostate specific antigen had an abnormal rectal examination. In three of the 14 subjects, the biopsy showed a well differentiated adenocarcinoma. All three were aged over 50 years old. The resulting calculated prevalence of prostate cancer was 9.2 per 1,000 males (CI 4.2-14.1). Conclusions: the cost effectiveness of screening for early diagnosis of prostate cancer must be calculated, to decide its incorporation in preventive medical examinations (Rev Méd Chile 2001; 129: 1305-10) <![CDATA[Hiperparatiroidismo primario, aislado y de carácter familiar: Caso clínico]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001001100011&lng=es&nrm=iso&tlng=es Familial hyperparathyroidism can be a part of a type 1 or 2 multiple endocrine neoplasia syndrome, can be associated to mandibular fibromas or can appear as an isolated disease. We report a family with 11 members affected by a primary hyperparathyroidism, all with a history of kidney stones and without evidences of other endocrine tumors. Not knowing the familial history of the disease, only one adenoma was resected in four cases and in all, the disease recidivated. Two were operated again, performing a total parathyroidectomy and heterologous autotransplantation of parathyroid tissue in the forearm. The presentation form of primary hyperparathyroidism in this family, is similar to other reported cases. It is more aggressive, is diagnosed at a lower age, has a higher incidence of recurrence and multiglandular involvement than the sporadic disease. (Rev Méd Chile 2001; 129: 1311-4) <![CDATA[Compromiso pulmonar por linfoma no Hodgkin diseminado en un paciente con SIDA]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001001100012&lng=es&nrm=iso&tlng=es Pulmonary involvement due to disseminated non Hodgkin lymphoma (LNH), is an unusual cause of lung disease in AIDS patients. We report a 38 years old male patient, with advanced AIDS, who, in the course of three weeks, developed cough, dyspnea and fever. The chest X ray film showed diffuse thickening of the peribronchovascular connective tissue with possible mediastinal lymph node enlargement. The evolution was unfavorable with hypoxemia, severe anemia, liver damage and elevated levels of lactic dehydrogenase. The presumptive initial diagnoses were Pneumocystis carinii pneumonia, pulmonary tuberculosis with hematogenous dissemination and Kaposi sarcoma. Definitive diagnosis was made through a transbronchial biopsy performed the day before his death. The pathological and inmunohistochemical report demonstrated a highly aggressive lymphoma (lymphoblastic, B precursor). This finding was confirmed by autopsy that revealed multiple organ involvement (Rev Méd Chile 2001; 129: 1315-9). <![CDATA[Isquemia miocárdica reversible en el hipotiroidismo: comunicación de un caso]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001001100013&lng=es&nrm=iso&tlng=es A silent, reversible myocardial ischemia with normal coronary angiography and reversible with thyroid hormone substitution, has been recently described in hypothyroid patients. We report a 49 years old male with an abnormal exercise electrocardiogram detected in a preventive medical examination. He had laboratory evidence of hypothyroidism and a history of two years of asthenia and progressive coarsening of the voice. The Thallium myocardial perfusion study, showed an alteration of coronary flow during exercise in the septum and lower wall of the left ventricle. Thyroid hormone substitution was started and three months later, a coronary angiography was normal. After six months a repeated Thallium perfusion study and exercise electrocardiogram were informed as normal (Rev Méd Chile 2001; 129: 1320-4) <![CDATA[Hipertensión arterial refractaria y uso de drogas anticonvulsivantes: Caso clínico]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001001100014&lng=es&nrm=iso&tlng=es Resistant arterial hypertension is uncommon when there is good compliance to antihypertensive therapy and secondary causes have been ruled out. We report a 41 years old male that suffered hypertensive encephalopathy and received prophylactic anticonvulsant therapy showing progressive raise of arterial pressure levels. Renovascular hypertension, aldosteronism and pheochromocytoma were discarded and, in spite of combined use of antihypertensive drugs, he did not achieve normal blood pressure. When phenytoin was discontinued, blood pressure temporarily normalized. Carbamazepine was started and blood pressure raised again. lt fell when this medication was discontinued. Antiepileptic agents could induce drug metabolizing system and thus reduce the effects of antihypertensive medications. (Rev Méd Chile 2001; 129: 1325-7) <![CDATA[Aplicaciones médicas de los descubrimientos genómicos]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001001100015&lng=es&nrm=iso&tlng=es The discovery of the complete base sequence of human genome unveils several perspectives to understand human diseases and develop new therapies. Human genome contains approximately 39,000 genes of which 26,000 code specific proteins that have been identified. There are approximately 1,500 diseases with identified molecular disturbances. Genes can modify signs and symptoms of common diseases. Thus, there are no pure monogenic diseases. Chronic diseases of adults are complex and dependent on multiple factors. Several genes that predispose to chronic degenerative diseases have been identified. This is revealing the complex nature and the interaction of these ailments with the environment. The discovery of bacterial and viral genomic sequences will allow the manufacturing of new vaccines and specific molecular antimicrobials. The new pharmacogenomics will devise treatments for each subject according to her specific genomic profile. The new applications of genomic technology is creating new paradigms in biomedical research such as functional genomics, proteonomics, epigenetic regulation. Gene diagnosis and therapy will considerably improve the future of medicine (Rev Méd Chile 2001; 129: 1329-33 <![CDATA[Papel del tejido conectivo en la morfología y función de la mucosa intestinal: Su importancia en la patogenia de la enfermedad celíaca]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001001100016&lng=es&nrm=iso&tlng=es The differentiation, architecture and function of the mucosa of the digestive tract is the result of close interactions between the epithelial cells and their underlying connective tissue. This interaction not only plays a role in the normal morphological organization of the intestinal mucosa but also in the organization and maturation of the enterocytes, the development of some of their enzymatic activities, the transport of nutriens and the restitution of the epithelium following denudation of the surface of villi due to loss of enterocytes. It is thought that disturbances of the cells of the connective tissue, especially of the myofibroblasts as well as of some of the above mentioned mechanisms, participate in the pathogenesis of some gastrointestinal diseases, celiac disease among them. This review summarizes some of the knowledge in this area (Rev Méd Chile 2001; 129: 1333-42 <![CDATA[Nuevas tendencias en la regulación de la profesión médica en el contexto de la reforma del sector salud: el caso de México]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001001100017&lng=es&nrm=iso&tlng=es The recent panorama of medical practice regulation in Mexico is exposed. The dynamics of regulation changes is observed in different areas, with particular intensity in the labor market. Changes seem to be moving towards the constitution of a new regulatory model. A full state regulation for the last 50 years, is being substituted by a model where private and professional corporations are increasing their influence through informal mechanisms of regulation. In the constitution of this new model, the presence of a wide variety of actors claiming regulatory authority is notorious. Three of these new actors are analyzed: The National Commission for Medical Arbitrage, managed care models of medical services, and Specialists Certification Councils. The changes that have occurred in the process of regulation and its future transformation have an intimate link with the reform of the Mexican health care system (Rev Méd Chile 2001; 129: 1343-50) <![CDATA[Estrogenoterapia en postmenopausia: ¿qué sabemos hoy?]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001001100018&lng=es&nrm=iso&tlng=es The recent panorama of medical practice regulation in Mexico is exposed. The dynamics of regulation changes is observed in different areas, with particular intensity in the labor market. Changes seem to be moving towards the constitution of a new regulatory model. A full state regulation for the last 50 years, is being substituted by a model where private and professional corporations are increasing their influence through informal mechanisms of regulation. In the constitution of this new model, the presence of a wide variety of actors claiming regulatory authority is notorious. Three of these new actors are analyzed: The National Commission for Medical Arbitrage, managed care models of medical services, and Specialists Certification Councils. The changes that have occurred in the process of regulation and its future transformation have an intimate link with the reform of the Mexican health care system (Rev Méd Chile 2001; 129: 1343-50) <![CDATA[Hipertención arterial mineralocorticoidea]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001001100019&lng=es&nrm=iso&tlng=es The recent panorama of medical practice regulation in Mexico is exposed. The dynamics of regulation changes is observed in different areas, with particular intensity in the labor market. Changes seem to be moving towards the constitution of a new regulatory model. A full state regulation for the last 50 years, is being substituted by a model where private and professional corporations are increasing their influence through informal mechanisms of regulation. In the constitution of this new model, the presence of a wide variety of actors claiming regulatory authority is notorious. Three of these new actors are analyzed: The National Commission for Medical Arbitrage, managed care models of medical services, and Specialists Certification Councils. The changes that have occurred in the process of regulation and its future transformation have an intimate link with the reform of the Mexican health care system (Rev Méd Chile 2001; 129: 1343-50) <link>http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001001100020&lng=es&nrm=iso&tlng=es</link> <description/> </item> <item> <title><![CDATA[<B>¿Tiene algún riesgo cancerígeno el uso del teléfono móvil ("celular")?</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872001001100021&lng=es&nrm=iso&tlng=es The recent panorama of medical practice regulation in Mexico is exposed. The dynamics of regulation changes is observed in different areas, with particular intensity in the labor market. Changes seem to be moving towards the constitution of a new regulatory model. A full state regulation for the last 50 years, is being substituted by a model where private and professional corporations are increasing their influence through informal mechanisms of regulation. In the constitution of this new model, the presence of a wide variety of actors claiming regulatory authority is notorious. Three of these new actors are analyzed: The National Commission for Medical Arbitrage, managed care models of medical services, and Specialists Certification Councils. The changes that have occurred in the process of regulation and its future transformation have an intimate link with the reform of the Mexican health care system (Rev Méd Chile 2001; 129: 1343-50)