Polarization Processes in Nafion Composite Membranes Doped with Rare-Earth Metals.

Dielectric spectroscopy (frequency range f = 100…107 Hz and temperatures T = 293…403 K (accuracy 0.5 K), measuring voltage applied to the sample was 1.0 V) was used to study composite materials based on perfluorosulfonic membranes with inclusions of rare-earth elements, in particular, europium (III) and terbium (III) chlorides. The dispersion of the permittivity and the presence of maxima, corresponding to losses, were revealed, which indicates that relaxation processes of various natures were present. The membrane layers under investigation are characterized by relaxation parameters that correspond to a symmetrical distribution of relaxers over relaxation times. The spectrum of relaxers changed when terbium and europium metal impurities were introduced into the polymer matrix. The investigation of these polymer systems demonstrated a power-law dependence of the specific conductivity on frequency. A decrease in the exponent with increasing temperature indicates the existence of a traditional hopping mechanism for charge transfer. The observed changes in the dielectric permittivity and specific conductivity are due to a change in the nature of polarization processes because of the strong interaction of metal (terbium and europium) ions with the polymer matrix of Nafion.

Low-Frequency Dielectric Relaxation in Structures Based on Macroporous Silicon with Meso-Macroporous Skin-Layer.

The spectra of dielectric relaxation of macroporous silicon with a mesoporous skin layer in the frequency range 1-106 Hz during cooling (up to 293-173 K) and heating (293-333 K) are presented. Macroporous silicon (pore diameter ≈ 2.2-2.7 µm) with a meso-macroporous skin layer was obtained by the method of electrochemical anodic dissolution of monocrystalline silicon in a Unno-Imai cell. A mesoporous skin layer with a thickness of about 100-200 nm in the form of cone-shaped nanostructures with pore diameters near 13-25 nm and sizes of skeletal part about 35-40 nm by ion-electron microscopy was observed. The temperature dependence of the relaxation of the most probable relaxation time is characterized by two linear sections with different slope values; the change in the slope character is observed at T ≈ 250 K. The features of the distribution of relaxation times in meso-macroporous silicon at temperatures of 223, 273, and 293 K are revealed. The Havriliak-Negami approach was used for approximation of the relaxation curves ε″ = f(ν). The existence of a symmetric distribution of relaxers for all temperatures was found (Cole-Cole model). A discussion of results is provided, taking into account the structure of the studied object.

The way forward.

Good public-health decisionmaking is dependent on reliable and timely statistics on births and deaths (including the medical causes of death). All high-income countries, without exception, have national civil registration systems that record these events and generate regular, frequent, and timely vital statistics. By contrast, these statistics are not available in many low-income and lower-middle-income countries, even though it is in such settings that premature mortality is most severe and the need for robust evidence to back decisionmaking most critical. Civil registration also has a range of benefits for individuals in terms of legal status, and the protection of economic, social, and human rights. However, over the past 30 years, the global health and development community has failed to provide the needed technical and financial support to countries to develop civil registration systems. There is no single blueprint for establishing and maintaining such systems and ensuring the availability of sound vital statistics. Each country faces a different set of challenges, and strategies must be tailored accordingly. There are steps that can be taken, however, and we propose an approach that couples the application of methods to generate better vital statistics in the short term with capacity-building for comprehensive civil registration systems in the long run.

A single human leukocyte antigen-antibody test after heart or lung transplantation is predictive of survival.

A single posttransplant test for human leukocyte antigen (HLA) antibodies in heart and lung graft patients was examined for its predictive value for graft survival as part of the 13th and 14th international histocompatibility workshops. We included patients with HLA antibodies who were tested 6 or more months after transplantation. They were followed for 3 to 5 years. Kaplan-Meier survival curves were used to analyze the data. Of the 235 heart transplant patients, 24.7% had HLA antibodies, whereas 13.3% of the 150 lung transplant recipients, tested positive for HLA antibodies. Heart transplant patients with antibodies had a 5-year survival of 42% vs. 58% for those without antibodies (P=0.0065). For lung transplant patients, the 5-year graft survival was 27% for those with antibodies vs. 56% for those without (P<0.0001). These results indicate that for heart and lung transplant patients, a single test after transplantation of HLA antibodies is predictive of graft survival.

The extent of forest in dryland biomes.

Dryland biomes cover two-fifths of Earth's land surface, but their forest area is poorly known. Here, we report an estimate of global forest extent in dryland biomes, based on analyzing more than 210,000 0.5-hectare sample plots through a photo-interpretation approach using large databases of satellite imagery at (i) very high spatial resolution and (ii) very high temporal resolution, which are available through the Google Earth platform. We show that in 2015, 1327 million hectares of drylands had more than 10% tree-cover, and 1079 million hectares comprised forest. Our estimate is 40 to 47% higher than previous estimates, corresponding to 467 million hectares of forest that have never been reported before. This increases current estimates of global forest cover by at least 9%.

Antimicrobial Properties of Biofunctionalized Silver Nanoparticles on Clinical Isolates of Streptococcus mutans and Its Serotypes.

(1) Background: Streptococcus mutans (S. mutans) is the principal pathogen involved in the formation of dental caries. Other systemic diseases have also been associated with specific S. mutans serotypes (c, e, f, and k). Silver nanoparticles (SNP) have been demonstrated to have good antibacterial effects against S. mutans; therefore, limited studies have evaluated the antimicrobial activity of biofunctionalized SNP on S. mutans serotypes. The purpose of this work was to prepare and characterize coated SNP using two different organic components and to evaluate the antimicrobial activity of SNP in clinical isolates of S. mutans strains and serotypes; (2) Methods: SNP with bovine serum albumin (BSA) or chitosan (CS) coatings were prepared and the physical, chemical and microbiological properties of SNP were evaluated; (3) Results: Both types of coated SNP showed antimicrobial activity against S. mutans bacteria and serotypes. Better inhibition was associated with smaller particles and BSA coatings; however, no significant differences were found between the different serotypes, indicating a similar sensitivity to the coated SNP; (4) Conclusion: This study concludes that BSA and CS coated SNP had good antimicrobial activity against S. mutans strains and the four serotypes, and this study suggest the widespread use of SNP as an antimicrobial agent for the inhibition of S. mutans bacteria.

Effects of Side Arm Length and Structure of Para-Substituted Phenyl Derivatives on Their Binding to the Host Cyclobis(paraquat-p-phenylene).

The binding constants with the host cyclobis(paraquat-p-phenylene), 1(4+), have been determined in CH(3)CN by UV-vis spectrophotometry for a series of p-phenylene guests, symmetrically substituted with side arms of varying length and functionality. Semiempirical molecular orbital theory was employed to provide a detailed structural and energetic interpretation of the experimental binding data. In particular, the length of the side arms and the type and position of the heteroatoms on the side arms were systematically varied in order to understand the effects of external interactions on the association constants of the guests with host 1(4+). A large chelate effect involving the ethyleneoxy side arm oxygen atoms and a cooperative effect between the guest aromatic core and the side arms are significant factors which determine the binding with this host. Sequential ethyleneoxy linkages along the side arms markedly increase the binding constant with respect to a compound in which the same number of oxygens along the side arms are separated by longer aliphatic linkages. In addition, a multiplicative rather than additive effect on the binding constant is observed which demonstrates that the oxygen atoms exhibit a strong chelate effect. It was also discovered that while the side arms of these guests contribute most of the driving force for complexation, an aromatic core is necessary for the guest to reside in the cavity of the host. The binding of these guests then is dependent upon cooperation between the arms and the aromatic core. Furthermore, elongation of the central aromatic core with aliphatic side arms containing no heteroatoms leaves the association constant relatively unchanged and replacement of the oxygen atoms with sulfur markedly decreases the observed binding. These effects have been used to rationalize several observations regarding this system in the literature and may serve to improve the design of new supramolecular systems and to better understand the host/guest interaction process.

Producción agroecológica de Stevia rebaudiana Bertoni (variedad criolla) en la Universidad Nacional de Lanús y elaboración de edulcorantes para transferencia a micro escala / Agro-ecological production of Stevia Rebaudiana Bertoni (creole variety) at the National University of Lanús and sweeteners preparation for micro-scale transfer

FUNDAMENTOS: Se desarrolló y evaluó un edulcorante natural, utilizando tecnologías simples, en base a Stevia rebaudiana, reproducibles a escala familiar. MÉTODOS: Se evaluó el cultivo agroecológico de Stevia rebaudiana, con la cual se elaboraron mezclas para infusiones de consumo habitual, las cuales fueron evaluadas sensorialmente. RESULTADOS: El cultivo, cumple objetivos productivos, que permiten la elaboración de mezclas para infusiones de consumo familiar. La prueba de preferencia no mostró diferencias significativas. CONCLUSIONES: La región es apta para el cultivo y producción de Stevia rebaudiana, teniendo un rendimiento adecuado para la aplicación de procedimientos tecnológicos simples para consumo familiar

BACKGROUND: A natural sweetener was developed and evaluated, using simple technologies, based on Stevia rebaudiana, reproducible on a family scale. METHODS: The agroecological culture of Stevia rebaudiana was evaluated, with which mixtures were elaborated for infusions of habitual consumption, which were evaluated sensorially. RESULTS: The crop fulfills productive objectives (20 plants / 4m2), which allow the elaboration of mixtures for family consumption. The preference test showed no significant differences. CONCLUSIONS: The region is suitable for the cultivation and production of Stevia rebaudiana, having an adequate yield for the application of simple technological procedures for family consumption

Creación de un Currículo de Competencias en Cariología para Estudiantes de Pregrado de Odontología en Chile / Development of a Competency-based Curriculum in Cariology for Undergraduate Dental Students in Chile

RESUMEN: Objetivo: Creación de un currículo de competencias mínimas en Cariología, para la formación de los Cirujano-Dentistas egresados de las escuelas de Odontología de Chile. Metodologías: A partir de una reunión de académicos de las Universidades de Talca y de Chile (año 2011), se elaboró una propuesta de currículo inicial, basado en los dominios propuestos por la Unión Europea (Schulte AG y cols). Durante el año 2016, dicha propuesta fue analizada mediante diálogos digitales y grupos de trabajo, con la participación del 96% de las Escuelas de Odontología existentes en el país, que concluyeron en un documento intermedio. Este documento fue analizado, discutido y perfeccionado durante el Taller para el Desarrollo de un Currículo de Competencias Mínimas en Cariología para las Escuelas de Odontología Chilenas (22/Mayo/2017, Talca, organizado por la Universidad de Talca y la Universidad de Chile) con la asistencia de representantes del 96% de las escuelas dentales chilenas, Ministerio de Salud de Chile, Colegio de Cirujano-Dentistas de Chile y con la asesoría de los profesores de Cariología Dres. Margherita Fontana y Carlos González-Cabezas (Universidad de Michigan, Ann Arbor, EEUU). Cada grupo de trabajo revisó el documento y envió nuevos comentarios, los que fueron incorporados en el documento final por una comisión asesora. Resultados: El documento del Currículo en Cariología se organizó en 5 Dominios: 1. Conocimientos base; 2. Determinación de Riesgo, diagnóstico de caries y detección de lesiones de caries; 3. Toma de decisiones y manejo preventivo no operatorio; 4. Toma de decisiones y manejo operatorio y 5. Cariología basada en la evidencia, en la práctica clínica y de salud pública. Se consensuaron las definiciones operacionales, las competencias principales y las sub-competencias para cada uno de los dominios. Las sub-competencias fueron clasificadas en tres niveles: A: Ser competente en; B: Tener conocimientos sobre y C: Estar familiarizado con. El documento final fue enviado a todos los participantes del taller para su aprobación y difusión en cada una de las instituciones involucradas. Conclusiones: Se logró, por medio de consenso, la construcción del Currículo de Competencias mínimas en Cariología para estudiantes de pregrado de Odontología en las universidades chilenas.

ABSTRACT: Objective: Development of a minimum set of competencies in Cariology that every dentist graduated from a Dental School in Chile must have. Methodology: Starting from a meeting of scholars from the Universities of Talca and Chile (year 2011), an initial proposal for a curriculum was developed, based on the domains proposed by the European Cariology Curriculum (Schulte, et al, 2011). During 2016, this proposal was discussed through online dialogues and working groups, with the participation of 95.2% of the Chilean dental schools, which resulted in an intermediate document. This document was analyzed, discussed and refined during the Workshop for the Development of a Curriculum of Minimum Competencies in Cariology for Chilean Dental Schools (May 22, 2017, Talca, organized by the Universities of Talca and Chile) with the attendance of representatives from 95.2% of the Chilean dental schools, the Chilean Ministry of Health, Chilean College od Dentists and with the assistance of the professors of Cariology Margherita Fontana and Carlos González-Cabezas (University of Michigan, Ann Arbor, USA). Each working group revised the document and provided feedback, which was incorporated in the final document by an advisory committee, elected on the day of the workshop, including the authors of the present article. Results: The Cariology Curriculum was organized in 5 Domains: 1. Basic knowledge; 2. Risk assessment, caries diagnosis and caries lesion detection; 3. Decision-making and non-operative preventive treatment; 4. Decision making and operative treatment; and 5. Evidence-based, clinical and public health practice. Operational definitions, main competencies and sub-competencies for each domain were agreed. Sub-competencies were classified into three levels: A: Be competent in; B: Have knowledge about, and C: Be familiar with. The final document was sent to all the participants of the workshop for dissemination in each of the institutions involved. Conclusions: The development of the Competency-based Curriculum in Cariology for undergraduate dental students at Chilean universities was achieved through consensus.

Calidad de vida relacionada con salud oral en mayores de 14 años en la comunidad San Juan bautista, isla Robinson Crusoe, Chile / Quality of life related to oral health in subjects 14 Years or Older, San Juan Bautista community, Robinson Crusoe Island, Chile

El aislamiento geográfico y condiciones medioambientales hacen a la población de Juan Fernández altamente vulnerable, siendo relevante conocer la calidad de vida relacionada con salud oral. Se realizó un estudio transversal en 137 habitantes mayores de 14 años. Se aplicó OHIP-14 para medir calidad de vida relacionada con salud oral previo consentimiento informado. El análisis estadístico fue realizado STATA 12.0. Un 51,8% es población femenina, con una edad media de 42,26 (DE 16,5). Un 91,97%, percibe que la salud oral afecta su calidad de vida, siendo levemente mayor en mujeres. Las molestias psicológicas son una manifestación en 80,29% de los encuestados. Un 75,91% percibe incomodidad por dolor en su boca, 62,77% manifiesta problemas de incapacidad psicológica. Existe mayor impacto en la calidad de vida relacionada con salud oral a medida que aumenta la edad. Por cada año de vida, el valor del OHIP-14 aumenta 0,07 (IC:95% 0,04­0,1). Los resultados obtenidos sugieren la necesidad de generar políticas públicas que consideren la salud oral desde una perspectiva integral, con énfasis en poblaciones altamente vulnerables considerando la mejora en la calidad de vida como un resultado a esperar

Geographic isolation and environmental conditions make the population of Robinson Crusoe Island, in the Juan Fernández archipielago highly vulnerable. It is therefore relevant to know the quality of life related to oral health (QOLRTO). In this report a cross sectional study in 137 inhabitants over 14 years of age was carried out. OHIP-14 was applied to measure QOLRTO, after informed consent was obtained. Statistical analysis was made in STATA 12.0. The population is 51.8% female, mean age 42.26 (SD 16.5) being similar in both sexes. Of the subjects studied, 91.97% perceived that oral health affects their quality of life, being slightly higher in women. Psychological distress was a manifestation in 80.29% of subjects, while 75.91% perceived discomfort and mouth pain, and 62.77% reported psychological disability issues. There is a greater impact of oral health issues with increasing age. For each year of life, the value of the OHIP-14 increased 0.07 (CI 95%, 0.04 to 0.1). The results suggest that public health policies that include a comprehensive oral health perspective, with emphasis on highly vulnerable populations should be considered

Impacto en la salud y el medio ambiente por exposición a plaguicidas e implementación de buenas prácticas agrícolas en el cultivo de tomate, Colombia, 2011 / Impact on health and environment of exposure to pesticides and implementation of best agricultural practices in tomato production, Colombia, 2011

Objetivo: describir los posibles efectos adversos en salud y medio ambiente por el uso de plaguicidas en zonas productoras de Colombia e implementar las buenas prácticas agrícolas (BPA) en el cultivo de tomate. Material y método: se realizó un estudio descriptivo en el municipio de La Merced-Caldas con tres fases: una de diagnóstico, donde se seleccionaron 132 trabajadores del sector agrícola y se recolectaron muestras biológicas y ambientales. Una segunda fase de intervención en la cual se incluyeron 5 parcelas, en estas se implementaron las (BPA) y una fase de evaluación de estas parcelas. Se llevó a cabo análisis simple de las variables y se exploraron posibles asociaciones. Resultados: el tiempo de exposición a plaguicidas en promedio fue de nueve años. Con mayor frecuencia el sistema nervioso central (95,5 por ciento) fue el más afectado; seguido por órganos de los sentidos (46,2 por ciento); sistema digestivo (33,3 por ciento ); piel (21,2 por ciento) y otros (19,7 por ciento). Se encontraron niveles de organoclorados en el 97,0 por ciento (128), inhibición de la enzima acetilcolinesterasa en el 34,1 por ciento (45) de los participantes y ningún nivel del metabolito etilentiourea. En las muestras ambientales se hallaron niveles de organofosforados en tomate y suelo. En el agua y lodo se detectaron niveles de organoclorados. La producción de tomate, mostró una diferencia estadísticamente significativa entre las parcelas con BPA y las tradicionales (p=0,020). Conclusiones: se evidenciaron los riesgos por uso de plaguicidas y la necesidad de fortalecer la vigilancia sobre los potenciales efectos para la salud que pueden producir los plaguicidas y mediante el empleo de las BPA.

Objective: Describe the possible adverse effects on population health and environment due to pesticide use in agricultural zones in Colombia, and implement the best agricultural practices (BAP) in tomato production. Materials and methods: A descript intoxicative study was carried out in the municipality of Merced-Caldas, consisting in three phases: a diagnostic phase, in which environmental and biological samples were collected, using a sample of 132 agricultural workers. In a second phase, BAP were implemented, and in the third phase, the results were evaluated. A univariate analysis was completed and posible associations were explored. Results: Average length of exposure to pesticides was 9 years. The central nervous system was the most affected (95.5 percent), followed by sensory organs (46.2 percent ), the digestive system (33.3 percent ), skin (21.2 percent) and others (19.7 percent). Organoclorides were found in 97.0 percent (128), inhibition of acetylcholinesterase enzyme was found in 43.1 percent (45); no metabolite ethylenethiourea was found. In the environmental samples, presence of organophosphates was found in tomatoes and soil. In water and mud samples, organochlorides were found. There was a statistically significant difference between BPA farms and traditional farms. (p=0,020). Conclusions: Risks due to pesticide use were demonstrated, and the need to strengthen vigilance on the potential effects of pesticide use.

Impact of immunosuppression on HLA-antibody formation.

1. The prevalence of HLAabs was 25% in the entire population, with a similar distribution for class I and class II. 2. For kidney transplant recipients the prevalence of HLAabs was 25.7 % and the prevalence of de novo HLAabs was 19.8 % in patients without preformed antibodies. 3. Patients with less than 5 years from transplant to blood sampling had lesser HLAabs. The WS were on 2002 and 2004, and then those patients were transplanted after 1997 when TAC was routinely used in some centers. 4. In patients transplanted after 1992, the prevalence of HLAabs was lower and it is consistent with the incorporation of the new IS drugs (TAC was introduced around 1994). 5. For kidney transplantation, the use of cyclosporine plus rapamune had the strongest protector effect for the presence of HLAabs, followed by tacrolimus and cyclosporine group. 6. This protective effect is diminished in patients with female gender, history of previous transplant, and pre-transplant positive PRA. 7. For kidney transplantation, the presence of HLAabs was associated with a higher rate of graft loss (P < 0.0001, HR = 2.26, 95% CI 2.11 - 3.36) but not with patient survival. 8. Patients with liver transplantation showed the lowest prevalence of HLAabs with only 9.6 % and similar distribution for both classes. The presence of HLAabs was not associated with patient or graft survival in Liver Transplantation. 9. For heart and lung transplantation, a posttransplant positive test for HLAabs was associated with worse graft survival, similar to kidney transplantation, with a HR = 3.05 and 3.87 respectively.

Reduction in neonatal mortality in Chile between 1990 and 2000.

OBJECTIVE: Our objective with this article was to describe the declining trend in neonatal mortality in Chile between 1990 and 2000 and examine potential causal factors. METHODS: Descriptive analysis of data that were provided by the Chilean Ministry of Health on all approximately 2,900,000 births occurred in Chile between 1990 and 2000. Total neonatal mortality rates (<28 days), and birth weight-specific and gestational age-specific mortality rates from 1990 to 2000 were analyzed by year. Public health interventions that were implemented during the 1990s were reviewed to assess their potential influence on the observed trends in neonatal mortality. RESULTS: The neonatal mortality rate between 1990 and 2000 decreased from 8.3 to 5.7 per 1000 live births. This decline was not associated with decreases in the proportion of low birth weight and preterm infants but rather with declines in birth weight-specific and gestational age-specific mortality rates. Examination of the trends in birth weight-specific and gestational age-specific mortality rates showed that a marked proportional decrease in mortality rates was achieved among infants who weighed <1500 g and were delivered before 32 weeks. It is plausible, both biologically and temporally, that the observed trends in the reduction in birth weight-specific and gestational age-specific mortality rates are associated with the introduction of specific sector-wide interventions that aim to improve newborn care in very preterm and low birth weight infants. CONCLUSIONS: Important reductions in newborn mortality in developing countries are possible with the implementation of effective neonatal care interventions.

[Maternal obesity and reproductive risk]. / Obesidad materna y riesgo reproductivo.

BACKGROUND: The prevalence of obesity in school children and pregnant women, a known risk factor of the reproductive cycle, has increased significantly over the last few years. AIM: To analyze the association between maternal obesity and the outcome of pregnancy and newborn health. To quantify the attributable population risk of obesity in relation to negative events of pregnancy. MATERIAL AND METHODS: A prospective study in 883 pregnant women of 6 public health centers in Santiago. Weight, height, arm circumference, skinfold thicknesses, body mass index (BMI) and fat mass were determined in each trimester. Maternal socio demographic history, smoking habits, incidence of diseases during pregnancy, labor and newborn characteristics were analyzed. Logistic regressions of multiple factors were used to determine nutritional and non-nutritional variables associated to negative events, to determine the population attributable risk of each variable that the model retained. RESULTS: Controlling the effect of other variables, a BMI > or = 30 or initial body fat mass > or = 35% determined a greater risk for assisted labor with an odds ratio (OR) of 1.9 (95% confidence interval (CI) 1.3-2.9), gestational diabetes with an OR of 6.4 (95% CI 2.1-19.6), hypertension with an OR of 7.8 (95% CI 3.0-20.4), late fetal mortality with an OR of 3.4 (95% CI 1.2-10.0), p < 0.001. The risk was mostly associated with the initial maternal nutritional status and in a lesser degree, with the weight gained during pregnancy. CONCLUSIONS: Maternal obesity is an important risk factor during pregnancy. The prenatal control obesity could reduce approximately 10% of the cesarean sections and late fetal deaths and half of the hypertension and gestational diabetes cases.

[A national birth weight distribution curve according to gestational age in Chile from 1993 to 2000]. / Curva nacional de distribución de peso al nacer según edad gestacional. Chile, 1993 a 2000.

BACKGROUND: The World Health Organization recently defined the criteria for constructing birth weight curves using population based data. AIM: To construct a national curve of weight, size and ponderal index at birth for Chile, following the criteria suggested by the World Health Organization (WHO) expert committee report from 1995. MATERIAL AND METHODS: A national database from the Chilean Istitute for Statistics was used. All alive singleton deliveries during tbe period from 1993 to 2000 were included. A birth weight curve for the total population as well as for size and ponderal index at birth was construted, including percentile distribution, mean and standard deviation of values for gestational age. Stratification by sex was performed. RESULTS: A total of 2,049,446 singleton deliveries were analyzed. The 10 percentiles (raw data) for birth weight throughout gestation from 22 to 42 weeks were: 470, 520, 560, 630, 660, 749, 810, 926, 1,031, 1,160, 1,320, 1,480, 1,680, 1,920, 2,190, 2,500, 2, 750, 2,910, 3,010, 3,080 and 3,090 g, respectively. CONCLUSIONS: A national birth weight for Chilean population (a predominant Hispanic population) was constructed. There are not differences between this curve and the standard proposed by WHO (population from California, USA) suggesting that under comparable perinatal indices, ethnicity is not a relevant factor deterimining birth weight.

Breast-feeding and the nutritional status of nursing children in Chile

The work reported here sought to describe the feeding patterns of Chilean children up to 18 month old and their relation to nutritional status. To this end, a survey was conducted in 1993 of 9 330 Chilean children under 18 month old who were receiving care through the Natinonal Health Service System-which provides care for 75 per cent of all children under age 6. The children, whose mothers or caretakers were interviewed, constituted 94 per cent of a sample selected at random from 102 of the 320 urban health clinics located throughout the country. The interview served to identify the type of feeding (exclusive breast-feeding, breast-feeding plus bottle-feeding, breast-feeding plus solid food, exclusive bottle-feeding, or bottle-feeding plus solid food) and to determine the nutritional status of the participants in terms of standards used by United States National Center for Health Stadistics and the World Health Organization. Children were deemed at risk of malnutrition if they have z scores on the weight-for-age distribution between 1.0 and 2.0 standard deviations below the US/WHO standard and as actually malnourished if they have z scores of over 2.0 standard deviations below the standard. The survey found exclusive breast-feeding prevalences of 86.5 per cent, 66.7 per cent, and 25.3 per cent among infants 1, 3, and 6 months old. Some 12.1 per cent of the participants were found to have a weight-for-age deficiency, 30.7 per cent exhibited a height-for-age deficiency, and 35.7 per cent were found to be overweight. The prevalence of weight-for-age and height-for-age deficiencies were found to be considerably higher among bottle-fed children than among breast-fed children. In general, the results demostrated the benefits of exclusive breast-feeding through the first 6 months of live, the need to complement exclusive breast-feeding with solid food after that time, and the superior nutritional status of breast-fed children within the age groups studied

Lactancia natural y estado nutricional del lactante chileno / Breast-feeding and the nutritional status of Chilean infants

El objetivo de este trabajo fue describir la situación alimentaria de menores de 18 meses y su relación con el estado nutricional. Para ello, en 1993 se llevó a cabo un estudio de prevalencia con niños atendidos por el Sistema Nacional de Servicios de Salud de Chile. El sistema público de salud chileno atiende a 75 por ciento de los menores de 6 años y, especialmente, a niños cuyas familias se sitúan en los quintiles más bajos de la distribución de ingresos del país. En el estudio participaron 9330 niños menores de 18 meses, que se seleccionaron al azar de 102 de los 320 consultorios urbanos de todo el país. Se determinó la alimentación del día anterior al de la entrevista (lactancia materna exclusiva,lactancia materna más alimentos sólidos, fórmula exclusiva, fórmula más sólidos) y el estado nutricional de los participantes en relación con los estándares del National Center for Health Statistics de los Estados Unidos de América y de la OMS. Se consideró en riesgo de desnutrición a los niños con valores z de la distribución de peso según la edad entre - 1,0 y 2,0 desviaciones estándar, y como desnutridos, a aquellos con valores z menores de 2 desviaciones estándar. Las prevalencias de lactancia materna exclusiva al primero, tercero u sexto mes de vida fueron, respectivamente, 86,5, 66,7 y 25,3 por ciento. El 12,1 por ciento de los participantes presentaban deficiencia de peso según la edad, 30,7 por ciento, de talla según la edad, y 35,7 por ciento, soprepeso. La deficiencia de peso según la edad de los niños alimentados con leche artificial fue de 1,2 a 5 veces más elevada que la de los que recibían leche materna. Asimismo, se observo el efecto protector de la lactancia materna sobre la talla. Los resultados obtenidos constatan los beneficios de la lactancia materna exclusiva hasta los 6 meses de edad, la necesidad de complementarla con alimentos sólidos desde esa edad, y su efecto protector sobre el estado nutricional de los niños de todas las edades estudiadas

Cálculo gigante en el espacio balanoprepucial en un paciente pediátrico / Giant calculus in the balanoprepucial space in a child

Introducción. La presencia de un cálculo gigante en el espacio balanoprepucial es una entidad sumamente rara en pediatría. El paciente que se presenta es el tercer caso reportado en la literatura médica mundial en cualquier edad y el segundo en pediatría. Objetivo: difusión del caso, del procedimiento diagnóstico y tratamiento del mismo.Caso clínico. Masculino de 7 años de edad, con vejiga neurogénica y tumoración peneana de un año de evolución. A la exploración física el pene presentaba características normales en el tercio proximal, en el tercio distal se encontraba una tumoración de consistencia pétrea de 4 x 5 cm. En la cirugía se encontró: un cálculo gigante en el espacio balanoprepucial, de superficie rugosa, espiculada, color amarillo grisáceo, que ocupaba la totalidad del espacio balanoprepucial. Conclusión. En la formación del cálculo intervienen factores como: incontinencia urinaria, presencia de bacterias, obstrucción distal en el prepucio, cristales de oxalato de calcio en la orina, asociados a falta de higiene y atención médica inadecuada.

Utilización de injertos autólogos de mucosa oral en la reconstrucción de la uaretra masculina en pediatría / Reconstruction of male urethra with oral mucosa graft in a group of children

Introducción. La reconstrucción de la uretra masculina es requerida para anomalías congénitas y adquiridas. Los procedimientos para la corrección de estos problemas son muy variados, siendo más utilizados para los casos complejos los injertos de mucosa oral y vesical. Material y métodos. Se revisó la experiencia del Servicio de Urología del Hospital Infantil de México Federico Gómez del año 1983 a 1999, de todos los casos tratados con injertos de mucosa oral, con un estudio observacional, descriptivo, retrospectivo y longitudinal, evaluando diagnóstico, edad, tipo de lesión, resultados y complicaciones. Resultados. Se revisaron 524 expedientes. La edad promedio de los pacientes fue de 12 años. El injerto se aplicó a 9 casos, siendo 1.7 por ciento de las plastias de uretra. El diagnóstico de estos casos fue de hipospadias, 7 relacionados a problemas de diferenciación sexual y 2 hipospadias simples. En 45 por ciento se aplicó el injerto en forma de tubo y 55 por ciento como parche. Los resultados fueron buenos en 77.7 por ciento y 22.2 por ciento regulares. En la actualidad 100 por ciento de los casos tienen buenos resultados funcionales y estéticos. Conclusión. Se sugiere a los injertos de mucosa oral como una buena alternativa en casos seleccionados para reconstrucción uretral.