[Myopia and Myopic Astigmatism in school-children]. / Miopía y Astigmatismo miópico en escolares.

INTRODUCTION: Worldwide, there is an epidemic increase in myopia. In children, the evidence points to a lack of ex posure to natural light. In Chile, the population situation of myopia in children is unknown. Objec tive: To estimate the tendency of myopia and myopic astigmatism in 1st- and 6th-grade students from the public education system in Chile. SUBJECTS AND METHOD: Ecological study based on diagnostic confirmations of the JUNAEB Medical Services Program, between 2012 and 2018. Annual country prevalence of myopia and astigmatism was estimated by region and sex. The screening evaluation included visual acuity using Snellen Eye Abbreviated chart, red reflex, Hirschberg test, Titmus test, Cover test, ocular motility, and anterior segment examination. Chi2 and logistic regression were used to assess differences and linear regression to estimate average annual change. RESULTS: Between 2012 and 2018, myopia and myopic astigmatism had a heterogeneous geographical presentation. Myopia and myopic astigmatism ≥ 3 dioptres increased by an annual average of 0.11% (R2 0.67) and 1.21% (R2 0.90), respectively, in 1st-grade children and by 0.2% (R2 0.65) and 8.7% (R2 0.79), respectively, in 6th-grade children. Myopia < 3 dioptres decreased by 0.13% annual average (R2 0.45) in 1st-grade children and myopic astigmatism < 3 dioptres by 0.5% (R2 0.53) in 6th-grade children. High myopic astigmatism affected men more than women and myopia < 3 dioptres affected more 6th-grade females. DISCUSSION: In schoolchildren of the public education system, myopia and myopic astigmatism > 3 dioptres tend to increase. The protective effect of natural light against myopia has been demonstrated in longitudinal and experimental studies. This evidence is to be considered in promoting children's time spent outdoors.

W.A. Mozart ¿murió de una carditis reumática? / W.A. Mozart, died of a rheumatic carditis?

Wolfgang Amadeus Mozart murió en Viena el 5 de diciembre de 1791, dos meses antes de cumplir 36 años. Sus restos fueron sepultados con otros cadáveres. El certificado de defunción consignó como causa de muerte "Fiebre miliar," sin mayores precisiones. Se ha postulado como causa de muerte un envenenamiento, pero no existen evidencias para precisar la naturaleza de su enfermedad, lo que ha dado origen a diversas hipótesis diagnósticas. Por los testimonios disponibles, es razonable postular una carditis por fiebre reumática aguda como causa de muerte.

Wolfgang Amadeus Mozart died in Vienna on December 5, 1791, two months before his 36th birthday. His remains were buried with other bodies. The death certificate stated as a cause of death "Miliary fever," without further clarification. Poisoning has been postulated as a cause of death, but there is no evidence to specify the nature of his illness, which has given rise to various diagnostic hypotheses. From the available testimonies, it is reasonable to postulate acute rheumatic fever carditis as a cause of death.

Estatinas y riesgo de diabetes / Use of statins and the risk of new onset diabetes mellitus

Se ha descrito relación entre el uso de estatinas y aparición de nueva diabetes. Se revisa advertencia de la FDA, así como análisis de estudios y meta análisis, que permiten deducir una acción de las estatinas que favorece el desarrollo de nueva diabetes. Las precauciones del uso de estatinas se deben orientar a pacientes con factores de riesgo de diabetes en prevención primaria cardiovascular. Se expresa la necesidad de estudios prospectivos con objetivos primarios específicos, para mayor precisión de información y adopción de recomendaciones basadas en alto nivel de evidencias.

Relationship between statin use and appearance of new diabetes has been described. We review the FDA warning and analysis of studies and meta-analysis, which point to an action of statins which favors the development of new diabetes. Precautions of statin use should guide patients with risk factors for diabetes in primary cardiovascular prevention. It expresses the need for prospective studies with specific primary objectives, for accuracy of information and making recommendations based on high-level evidence.

[Academic performance of medical students: a predictable result?]. / Desempeño académico de los estudiantes de medicina: un resultado predecible?

BACKGROUND: Traditionally, medical schools demand their students a high dedication in time, responsibility and integrity. AIM: To assess the predictive capacity of several specific variables, on the academic performance of medical students. MATERIAL AND METHODS: All students who entered during 1984-1995 period were studied. The academic performance was assessed using two indices: an overall evaluation of successfulness as determined by the approval rate in different courses and grade-point average obtained during the first three years at the Medical School. The variables used to predict academic performance were year of enrollment, high school grades, university admission test scores, biomedical and demographic characteristics. All these were measured at the time when the student was enrolled. RESULTS: Eight hundred and eight students were studied at the end of the third year. The most important predictive variables selected for both performance indices were: high school grades, admission biology test scores, place were high school studies were done, and previous university studies. In addition verbal and mathematics admission academic performance tests scores were selected for grade-point average index. Although, the overall admission score and high school academic performance were significantly associated with the two outcomes, they were not selected in the final models. CONCLUSIONS: The best predictors of an optimal academic performance in these medical students were high school grades, admission biology test scores, residing in Metropolitan Santiago and previous university studies.

[Number of physicians in Chile: current and prospective estimate, and an international comparison]. / Número de médicos en Chile: estimaciones, proyecciones y comparación internacional.

BACKGROUND: In the last decades, the number of Universities with medical schools has increased dramatically in our country. AIM: To introduce a conceptual model to estimate the number of physicians that are incorporated to the profession in Chile every year as well as the cumulative number of active physicians in specific time frame. To provide information about the number of available physicians in the country and compare it with the international context. MATERIAL AND METHODS: This model includes information about the number of students that are admitted in all medical schools of the country, the dropout rate, the number of immigrant physicians from other countries, and the cumulative number of active physicians in the previous period. RESULTS: There is an increased number of new medical students starting in 1994 that will produce, starting in 2001, a significant increased in the number of new physicians graduated from Chilean Universities. Meanwhile the increased number of new physicians in recent years is mainly explained by a significant increase in immigrant physicians. The number of active physicians estimated by the year 2000 is 18,549 and this number will be 25,704 by the year 2007. With these estimated numbers, we introduce a qualitative model that allowed us to compare the current number of active physicians in Chile with other countries, especially those with a comparable degree of development. This model uses first The Human Development Index and later the per capita income of different countries adjusted by purchasing power in USA. According to these calculations, Chile has a lower number of physicians than similar countries, and this difference will persist, even after the significant increase in the new physicians expected for the new future. CONCLUSIONS: Chile continues to have a lower number of physicians than countries with similar human development indices (Rev Méd Chile 2000; 128: 1167-76).

[Gastric cancer and cerebrovascular diseases. A natural history with common elements? Analysis of the salt theory in Chile (1955-1994)]. / Cáncer gástrico y enfermedad cerebrovascular. Una historia natural con elementos comunes? Análisis de la teoría de la sal en Chile (1955-1994).

BACKGROUND: In the last forty years, a sustained reduction in the gastric cancer and cerebrovascular disease mortality has been recorded. Joossens has postulated that sodium intake has an influence in the natural history of both diseases. AIM: To analyze the mortality caused by both diseases in Chile. MATERIAL AND METHODS: The mortality of people aged 35 to 64 years old, due to gastric cancer and cerebrovascular diseases in the period 1955-1994, was analyzed. An analysis according to regions, using temporal series and correlation techniques was performed. RESULTS: In the studied period, the mortality due to gastric cancer decreased by 71.6% in men and by 79.5% in women. Mortality due to cerebrovascular diseases decreased by 56.9% in men and by 63.9% in women. There was a correlation coefficient of +0.91 between the mortality due to both diseases. Cerebrovascular disease mortality appears as a predictor of gastric cancer mortality in temporal series analysis. CONCLUSIONS: Joossens theories are supported by the present data. Prospective studies should be designed to confirm the hypothesis.

[Mortality due to traffic accidents in Chile, 1994: an epidemiological approach]. / Mortalidad por accidentes de tránsito en Chile, 1994: una aproximación epidemiológica.

BACKGROUND: Traffic accidents are one of the most important public health problems in the world and produce social, work and human resources losses. AIM: To perform an epidemiological description of traffic accidents occurred in Chile during 1994. MATERIAL AND METHODS: Data were obtained from death certificates in which the cause of death was a traffic accident. All death certificates obtained by the National Institute of Statistics during 1994 were used. Social, demographic and seasonal variables were recorded. RESULTS: During 1994, there were 1679 deaths due to traffic accidents (81% male), with a rate of 19.6 per 100,000 inhabitants. Gender specific risks were 19.62 and 4.48 for men and women, respectively. Mean age at the moment of death was 39 years old. Fifty three percent of deceased people were single, 42% married and 5% widowers. Ten percent had no formal education, 48% had basic education, 23% college education and 6.5% university education. Seventy seven percent of fatalities occurred in urban areas. The risk of death by traffic accidents was 7.02 per 100,000 inhabitants in the metropolitan region. CONCLUSIONS: The information obtained in the present study may help to generate preventive strategies to control deaths caused by traffic accidents.

Increased sensitivity and accumulation of estradiol in the rat oviduct during early pregnancy.

We have previously reported that a single injection of estradiol-17 beta (E2) given on day 3 of pregnancy (P3) is far more effective for accelerating oviductal transport in the rat, than treatment given on day 1 (P1). In order to quantify this change, dose-response curves were established for six different doses of E2 (range 0.031 to 1.00 micrograms per animal) given on P1, P2 or P3. In addition, a possible mechanism was explored by comparing the plasmatic and oviductal levels of E2 between 30 and 180 min following treatment with E2 on P1 or P3. As the interval from ovulation to treatment was increased, the transport of a larger number of embryos was accelerated and a smaller dose was required. The minimal effective dose decreased 30-fold from P1 to P3, the oviducts accumulated 20% to 90% more E2 on P3 than on P1, tissue levels were 6- to 48-fold higher than plasma levels and the latter did not differ between P1 and P3. It is concluded that the oviduct exhibits increased sensitivity and responsiveness to E2 on P3 and this is associated with greater accumulation of the hormone in the organ, not attributable to higher E2 plasma levels.

Increased sensitivity and accumulation os estradiol in the rat oviduct during early pregnancy

We have previously reported that a single injection of estradiol-17 beta (E2) given on day 3 of pregnancy (P3) is far more effective for accelerating oviductal transport in the rat, than treatment given on day 1 (P1). In order to quantify this change, dose-response curves were established for six different doses of E2 (range 0.031 to 1.00 micrograms per animal) given on P1, P2 or P3. In addition, a possible mechanism was explored by comparing the plasmatic and oviductal levelsof E2 between 30 and 180 min following treatment with E2 on P1 or P3. As the interval from ovulation to treatment was increased, the transport of a larger number of embryos was accelerated and a smaller dose was required. The minimal effective dose decreased 30-fold from P1 to P3, the oviducts accumulated 20 percent to 90 percent more E2 on P3 than on P1, tissuelevels were 6- to 48-fold higher than plasma levels and the latter did not differ between P1 and P3. It is concluded that the oviduct exhibits increased sensitivity and responsiveness to E2 on P3 and this isassociated with greater accumulation of the hormone in the organ, not attributable to higher E2 plasma levels

Importance of uterine expulsion of embryos in the interceptive mechanism of postcoital oestradiol in rats.

This study compares the interceptive effectiveness of 1 microgram oestradiol given as a single s.c. injection at 0900 or 1700 hours on Day 1, 2, 3, or 4 of pregnancy in rats. Increasing the interval from ovulation to treatment accelerated the oviducal transport of a larger number of embryos, the majority of which were lost from the genital tract. However, after treatment at 1700 hours on Day 3 the majority of accelerated embryos were retained in the uterus. The number of implanted embryos on Day 14 was equal to the number of eggs remaining in the tract 24 h after treatment. As a consequence, the highest interceptive effectiveness was obtained with treatment given at 1700 hours on Day 2 and at 0900 hours on Day 3 of pregnancy. Accelerated oviducal transport and uterine expulsion of embryos begin to dissociate after Day 2 of pregnancy in the rat. This explains why the most effective treatments to accelerate oviducal transport are not always the most effective to reduce the number of implantations. These data emphasize the importance of retentive and expulsive properties of the uterus for fertility and infertility.

Manifestaciones electrocardiográficas precoces del infarto agudo del miocardio / Early electrocardiographic manifestations of acute myocardial infarction

Se estudió prospectivamente los casos de infarto Agudo al Miocardio (IAM) ingresados al Hospital Dr. Gustavo Fricke de Viña del Mar, entre febrero y mayo de 1991, con el objetivo de evaluar el rendimiento de la electrocardiografía en el diagnóstico del IAM e investigar las características precoces electrocardiográficas que permitan un diagnóstico de esta patología. Se obtuvo un total de 20 pacientes con un diagnóstico final de IAM, los cuales ingresaron a un protocolo con variables generales y estudio específico de tres trazados electrocardiográficos, investigando la presencia de los criterios predictores de IAM. El diagnóstico inicial se confirmó en un 85% y el 15% restante correspondió a Angina Inestable que resultó ser IAM. Los criterios predictores estuvieron presentes en un 95%, siendo el más frecuente el de supradesnivel de ST (80%). El infradesnivel de ST aparece en menor frecuencia y más inespecífico. La onda Q patológica es infrecuente y siempre asociada al supradesnivel de ST. Se destaca el valor que pueda tener una onda T alta muy precoz, que tiende a disminuir en los siguientes controles. Finalmente se concluyó, que la clínica y el primer electrocardiograma son suficientes en la mayoría de los casos para efectuar un diagnóstico precoz de esta patología