Determinación de Valores de Armonía del Perfil Facial en la Población Chilena / Determination of harmony values of the facial profile in the Chilean population

El realizar un tratamiento ortodóntico sólo en base a referencias de tejidos duros, puede llevar a resultados estéticos desfavorables, debido a la gran variabilidad que existe en los tejidos blandos que los recubren. Arnett et al. (1999) presentaron un análisis basado en los tejidos blandos y determinó normas que definen un rostro armónico. Sin embargo, éstas normas se obtuvieron de pacientes norteamericanos y puede que no reflejen los conceptos estéticos de nuestra población. El objetivo del presente trabajo fue determinar valores de armonía facial para la población chilena, utilizando el análisis cefalométrico de tejidos blandos presentado por Arnett et al., y compararlos con los valores previamente establecidos para la población caucásica. Se analizaron 200 fotografías y se clasificaron los perfiles en balanceados y no balanceados según el criterio de un grupo de especialistas. Posteriormente se analizaron las telerradiografías correspondientes a los perfiles clasificados, con el análisis cefalométrico de tejidos blandos. Los valores de las diferentes variables fueron analiza dos separadamente por sexo, clase esqueletal y biotipo facial, y se determinaron las diferencias entre las variables presentadas por Arnett et al. y las obtenidas en el presente estudio. Para ello se utilizaron pruebas de significancia estadística como el test t y otros no paramétricos. Sólo se encontró diferencias significativas en dos variables respecto de las normas sugeridas por Arnett et al., correspondientes a un menor espesor del labio inferior en ambos sexos, y una mayor prominencia del pómulo en mujeres chilenas, por lo que consideramos que los valores de armonía de Arnett et al., pueden ser también aplicados como parámetro estético para la población chilena.

Performing an orthodontic treatment based only on hard tissue references can lead to unfavorable aesthetic results due to the great variability that exists in soft tissues that cover them. In 1999, W.Arnett, presented an analysis based on soft tissues and determined norms that define a harmonious face. However, these standards that were obtained from North Americans and Chilean aesthetic concepts could be different. The aim of the study was to determine the values of facial harmony for the Chilean population, using the cephalometric analysis of soft tissues presented by Arnett, and compare them with the values previously established for the Caucasian population. In this study 200 photographs were analyzed, and the profiles were classified in balanced and unbalanced according to the criteria of a group of specialists. Subsequently, teleradiographs corresponding to the classified profiles were analyzed, with the cephalometric analysis of soft tissues. The values of the different variables were analyzed separately by sex, skeletal class and facial biotype, and the differences between the variables presented by Arnett et al., and those obtained in the present study. For this purpose, statistical significance tests such as the t test and other non- parametric tests were used. There were only significant differences in two variables: inferior lip variables in both sexes, and a greater prominence of the cheekbone in Chilean women, therefore we consider that the values of harmony of Arnett, can also be applied as an aesthetic parameter for the Chilean population.

Antiepileptogenic repair of excitatory and inhibitory synaptic connectivity after neocortical trauma.

The "final common path" to epileptogenesis induced by cortical trauma and disease processes ultimately depends on changes in relative weights of excitatory and inhibitory synaptic activities in neuronal networks. Results of two experiments summarized here provide proof in principle that prophylaxis of posttraumatic epileptogenesis can result when antiepileptogenic treatments are focused on basic underlying synaptic mechanisms. (1) Brief gabapentin treatment after injury limits new excitatory synapse formation by preventing binding of thrombospondins to α2δ-1 receptors, resulting in long-lasting effects that limit aberrant excitatory connectivity and decrease epileptogenesis. (2) Fast-spiking (FS) interneurons are structurally and functionally abnormal in the partial cortical isolation and other models of epileptogenesis. Brain-derived neurotrophic factor (BDNF) supports growth and maintenance of GABAergic neurons during brain development, leading to the hypothesis that it might favorably affect injured interneurons. Partial activation of BDNF TrkB receptors with a small molecule reverses structural abnormalities in FS interneuronal terminals, increases the frequency of mIPSCs, and increases probability of GABA release. These changes are associated with significantly reduced spontaneous and evoked epileptiform bursts in vitro and increased threshold for pentylenetetrazole-induced seizures in vivo. Each of these treatments offers a potential promising approach to prophylaxis of injury-induced cortical epileptogenesis.

SECOND LATIN AMERICAN INTERCOMPARISON ON INTERNAL DOSE ASSESSMENT.

Internal dosimetry intercomparisons are essential for the verification of applied models and the consistency of results'. To that aim, the First Regional Intercomparison was organised in 2005, and that results led to the Second Regional Intercomparison Exercise in 2013, which was organised in the frame of the RLA 9/066 and coordinated by Autoridad Regulatoria Nuclear of Argentina. Four simulated cases covering intakes of (131)I, (137)Cs and Tritium were proposed. Ninteen centres from thirteen different countries participated in this exercise. This paper analyses the participants' results in this second exercise in order to test their skills and acquired knowledge, particularly in the application of the IDEAS Guidelines. It is important to highlight the increased number of countries that participated in this exercise compared with the first one and, furthermore, the improvement in the overall performance. The impact of the International Atomic Energy Agency (IAEA) Projects since 2003 has led to a significant enhancement of internal dosimetry capabilities that strengthen the radiation protection of workers.

Randomized controlled trial of prophylactic rectal stimulation and enemas on stooling patterns in extremely low birth weight infants.

OBJECTIVE: We hypothesized that rectal stimulation and small volume enemas would accelerate normalization of stooling patterns in extremely low birth weight infants. STUDY DESIGN: In a randomized controlled trial, infants with a gestational age 28 weeks received one of the following: twice daily rectal stimulation and/or enemas until two stools were passed daily, without enemas or stimulation, for three consecutive days. Intervention only occurred when symptoms, abdominal distension and no defecation, occurred in the previous 24 h. Enema administration occurred if abdominal distension persisted without defecation occurring after rectal stimulation. Multivariable linear regression was used to determine the contribution of a patent ductus arteriosus (PDA) on normalization of stooling patterns and feeding tolerance. RESULT: Rectal stimulation and/or small volume enemas did not accelerate the median (quartile range) time normalization of stooling patterns, 13 (11-20) days in control group and 16 (12-25.5) days in intervention group. A higher frequency of PDA occurred in the intervention than the non-intervention group. Infants with a persistent PDA had a longer duration of parenteral nutrition, worse feeding tolerance and more days to achieve normal stooling patterns. In multivariable regression analysis, a PDA, not repeated rectal stimulation and/or enemas, was significantly related to stooling and feeding tolerance. CONCLUSION: Twice daily administration of rectal stimulation and/or enemas did not normalize stooling patterns (fecal frequency). A PDA is an important determinant of acquisition of normal stooling patterns and feeding tolerance of very immature newborns.

Temporal and topographic alterations in expression of the alpha3 isoform of Na+, K(+)-ATPase in the rat freeze lesion model of microgyria and epileptogenesis.

Na(+),K(+)-ATPase contributes to the asymmetrical distribution of sodium and potassium ions across the plasma membrane and to maintenance of the membrane potential in many types of cells. Alterations in this protein may play a significant role in many human neurological disorders, including epilepsy. We studied expression of the alpha3 isoform of Na(+),K(+)-ATPase in the freeze lesion (FL) microgyrus model of developmental epileptogenesis to test the hypothesis that it is downregulated following neonatal cortical injury. FL and sham-operated rat brains were examined at postnatal day (P)7, P10, P14, P21-28 and P50-60 after placement of a transcranial freeze lesion at P0 or P1. Immunohistochemistry and in situ hybridization were used to assess the expression of the alpha3 isoform of Na(+),K(+)-ATPase (termed alpha3, or alpha3 subunit below) in neuropil and the perisomatic areas of pyramidal cells and parvalbumin-containing interneurons. There was a significant decrease (P<0.05) in alpha3 subunit immunoreactivity (IR) in the neuropil of FL cortical layer V of the P14 and P21-28 groups that extended up to 360 mum from the border of the microgyrus, an area that typically exhibits evoked epileptiform activity. Alpha-3 was decreased in the perisomatic area of pyramidal but not parvalbumin-containing cells in P21-28 FL animals. A reduction in alpha3 mRNA was observed in the neuropil of FL cortical layer V up to 1610 mum from the microgyral edge. The developmental time course for expression of the alpha3 subunit between P7 and P60 was examined in naive rat cortices and results showed that there was a significant increase in alpha3 IR between P7 and P10. The significant decreases in Na(+),K(+)-ATPase in the paramicrogyral cortex may contribute to epileptogenesis.

Nuclear Regulatory Authority low energy germanium detection system: performance for the uranium individual monitoring.

The lung counter facility of the Nuclear Regulatory Authority (ARN) is presented. A calibration was carried out using the Lawrence Livermore National Laboratory (LLNL) phantom. This phantom is provided with a pair of lungs and lymph nodes containing uranium homogeneously distributed and a set of four overlay plates covering a chest wall thickness (CWT) ranging from 1.638 to 3.871 cm. Individual organ calibration factors were acquired for 235U photopeaks energies and for each effective chest thickness. Using these factors, a collection of theoretical fitting curves were found. A counting efficiency formulae and a curve for simultaneously active lymph nodes and lung was obtained and checked through measures. Background measurements of the chamber with and without volunteer persons were performed in order to obtain the detection limits (DL) of the system. As this task involves the knowledge of the volunteers CWTs, these magnitudes were determined through formulae selected from the literature taking into account the detection system characteristics. The deviation in the CWT assigned to an individual, generated by applying different equations, produces variations up to 33% in the estimations of the incorporated activity and DL. An analysis of the changes in efficiencies as consequences of the detectors locations and CWT was also performed. This reveals that the DL of the camera (detectors, shield and blank phantom) is between 2.7 and 6.4 Bq of 235U, which implies 4.9 and 11.5 mg lung burden of natural uranium. An estimation of the minimum detectable intake performed with the DL considering blank persons shows that a system with the characteristics described is only adequate for non-routine individual monitoring.

Health care costs and financial consequences of epidemiological changes in chronic diseases in Latin America: evidence from Mexico.

OBJECTIVE: To determine the costs of health services and the financial consequences of changes in the epidemiological profile of chronic diseases in Latin America. STUDY DESIGN: We conducted longitudinal analyses of costs and of the economic impact of the epidemiological transition in healthcare services for diabetes and hypertension in the Mexican health system. The study population included both the insured and uninsured populations. METHODS: The cost-evaluation method was based on the instrumentation and consensus techniques. To estimate the epidemiological changes and financial consequences for 2004-2006, six models were constructed according to the Box-Jenkins technique, using confidence intervals of 95% and the Box-Pierce test. FINDINGS: Costs ranged from US$613 to US$887 for diabetes, and from US$485 to US$622 for hypertension. Regarding epidemiological changes for 2004 compared with 2006, an increase is expected in both cases, although results predict a greater increase for diabetes, 10-15% in all three institutions (P<0.05). Comparing the financial consequences of health services required by insured and uninsured populations, the greater increase (17%) will be for the insured population (P<0.05). The financial requirements for both diseases will amount to 9.5% of the total budget for the uninsured population and 13.5% for the insured population. CONCLUSIONS: If the risk factors and the different healthcare models remain as they are at present, the economic impact of expected epidemiological changes on the social security system will be particularly strong. Another relevant financial factor is the appearance of internal competition in the use and allocation of financial resources among the main providers in the health services; this factor becomes even more complicated within each provider. In effect, within each institution, hypertension and diabetes programmes must compete for resources with other programmes for chronic and infectious diseases.

La salud oral en la dentición primaria: (yIII) Estudio sobre los traumatismos dentales, las patologías orales y los problemas en el manejo de la conducta en la consulta dental en una muestra de 441 niños de Vigo / Oral health in temporary dentition: (and III) Research about dental traumatisms, oral pathologies and problems with handling of behaviour in a 441 child sample from Vigo

El propósito de este estudio dividido en tres partes, es valorar la salud oral en los niños de Vigo con dentición primaria. En esta tercera y última parte, se estudian las prevalencias de los daños por traumatismos dentales, de las patologías orales y de los problemas en el manejo de la conducta de estos niños en la consulta dental. MUESTRA: 441 niños entre los 14 y 92 meses de edad (edad media 59,6 meses), todos ellos presentan al inicio del estudio dentición primaria. RESULTADOS: el 18,82 por ciento de la muestra presenta algún tipo de lesión como consecuencia de traumatismos dentales. Del total de patologías, la patología infecciosa secundaria a la caries dental representa el 40,7 por ciento y la exfoliación tardía del diente temporal constituye el 39,8 por ciento. Se encuentra una prevalencia de problemas de manejo de la conducta en el 11,3 por ciento de los niños. CONCLUSION: Los traumatismos dentales se dan fundamentalmente en los incisivos centrales superiores, la consecuencia más común es el cambio de color del diente. Aproximadamente 1 de cada 10 niños presenta una infección oral como consecuencia de la caries dental. Parece que los niños con conductas de evitación y problemas en el manejo de la conducta con el dentista presentan una salud oral peor (AU)

The purpose of this three-part research is to evaluate the oral health of children from Vigo with temporary dentition. In this third and last part, prevalences of damages because of dental traumatisms, of oral pathologies and of problems with handling of behaviour of those children at the dental c1inic are studied. Sample: 441 children, aged between fourteen and ninety-two months (average age: 59.6 months), all of them with milk teeth at the beginning of the research. Results: The 18,82 percent of the sample show some kind of injury as a consequence of dental traumatisms. The infectious secundary pathology to dental caries represents the 40,7 per cent of the total of pathologies, and belated missing of temporary tooth represents the 38,9 per cent. The prevalence of problems with handling of behaviour of children is 11,3%. Conclusion: Dental traumatisms happen mainly in central higher incisors, the most frequent consequence is the change of the color of the tooth. Approximately, one of each ten children shows an oral infection as a consequence of dental caries. It seems that children with avoiding behaviours and problems with handling of behaviour show a worse oral health (AU)

[Trends on generation and reproduction of knowledge about economic evaluation and health]. / Tendencias en la generación y reproducción del conocimiento sobre evaluación económica y salud.

This paper identifies the trends and recent progress in the generation and reproduction of knowledge on health economic evaluation. Analysis is organized along nine public health action fields, namely: health determinants and predictors, economic value of health, healthcare demand, healthcare supply, microeconomic evaluation of healthcare, healthcare market balance, evaluation of policy instruments, general evaluation of the health system, and healthcare planning, regulation and supervision. Each action field is defined to place the reader in the proper setting and level of analysis. In addition, thematic research topics developed in each action field are proposed and discussed. The generation and reproduction of knowledge on the different action fields was based on the review of the bibliographic databases MEDLINE and LILACS for the 1992-2000 period. Results lead to the conclusion that development and application of economic evaluation of healthcare has been uneven across different countries and that there is a growing increase of applications starting in 1994, the year of initiation of healthcare reform in Latin America.

Financing indicators for health care decentralization in Latin America: information and suggestions for health planning.

This article presents the results from an evaluative longitudinal study with before-after design. The main objective was to determine the effects of health care decentralization on changes in health financing. Taking into account feasibility, political and technical criteria, three Latin American countries were selected as study populations: Mexico, Nicaragua and Peru. The methodology had two main phases. In the first phase, the study referred to secondary sources of data and documents to obtain information about the following variables: type of decentralization implemented, source of finance, funds of financing, providers, final use of resources and mechanisms for resource allocation. In the second phase, the study referred to primary data collected in a survey of key personnel from the health sectors of each country. Taking into account the changes implemented in the three countries, as well as the strengths and weaknesses of each country in financing and decentralization, a rule for decision-making is proposed that attempts to identify the main financial changes implemented in each country and the basic indicators that can be used in future years to direct the planning, assessment, adjustment and correction of health financing and decentralization.

Health financing changes in the context of health care decentralization: the case of three Latin American countries.

OBJECTIVE: The results of an evaluative longitudinal study, which identified the effects of health care decentralization on health financing in Mexico, Nicaragua and Peru are presented in this article. METHODS: The methodology had two main phases. In the first, secondary sources of data and documents were analyzed with the following variables: type of decentralization implemented, source of financing, funds for financing, providers, final use of resources, mechanisms for resource allocation. In the second phase, primary data were collected by a survey of key personnel in the health sector. RESULTS: Results of the comparative analysis are presented, showing the changes implemented in the three countries, as well as the strengths and weaknesses of each country in matters of financing and decentralization. CONCLUSIONS: The main financing changes implemented and quantitative trends with respect to the five financing indicators are presented as a methodological tool to implement corrections and adjustments in health financing.

Postlesional epilepsy: the ultimate brain plasticity.

Lesions that occur either during fetal development or after postnatal brain trauma often result in seizures that are difficult to treat. We used two animal models to examine epileptogenic mechanisms associated with lesions that occur either during cortical development or in young adults. Results from these experiments suggest that there are three general ways that injury may induce hyperexcitability. Direct injury to cortical pyramidal neurons causes changes in membrane ion channels that make these cells more responsive to excitatory inputs, including increases in input resistance and a reduction in calcium-activated potassium conductances that regulate the rate of action potential discharge. The connectivity of cortical circuits is also altered after injury, as shown by axonal sprouting within pyramidal cell intracortical arbors. Enhanced excitatory connections may increase recurrent excitatory loops within the epileptogenic zone. Hyperinnervation attributable to reorganization of thalamocortical, callosal, and intracortical circuitry, and failure to prune immature connections, may be prominent when lesions affect the developing neocortex. Finally, focal injury can produce widespread changes in gamma-aminobutyric acid and glutamate receptors, particularly in the developing brain. All of these factors may contribute to epileptogenesis.

Chronic focal neocortical epileptogenesis: does disinhibition play a role?

Several lines of evidence have suggested that decreases in postsynaptic inhibition may have a role in epileptogenesis in cortical structures. However, other studies have suggested that GABAergic inhibition is spared, or even augmented in some forms of post-lesional epilepsy. In the studies described here, inhibitory events were recorded in two models of post-lesional chronic epileptogenesis. (i) As previously reported (D.A. Prince and G.-F. Tseng. J. Neurophysiol. 69: 1276-1291. 1993), epileptiform activity develops in slices from partially isolated rat neocortical islands 2-3 weeks after the initial in vivo lesion. In this model of post-traumatic epilepsy, large amplitude polyphasic inhibitory postsynaptic currents (IPSCs) in layer V pyramidal neurons are associated with each interictal epileptiform field potential. The frequency of spontaneous IPSCs as well as miniature IPSCs was significantly increased in neocortical slices from the epileptogenic chronically injured cortex versus controls. Immunocytochemical reactions for parvalbumin and calbindin, calcium binding proteins present in subgroups of GABAergic neurons, showed an increased staining of both neuropil and somata within the epileptogenic tissue. Immunoreactivity for glutamic acid decarboxylase (GAD) and GABA also appeared to be increased in the neuropil. (ii) Cortical microgyri resembling human malformations were produced by freeze lesions made transcranially in P0 rat cortex (K.M. Jacobs, M.J. Gutnick, and D.A. Prince. Cereb. Cortex, 6: 514-523. 1996). The boundary between the four-layered microgyrus and surrounding cortex become epileptogenic within about 2 weeks, as judged by evoked extracellular field potentials and cellular activities. Epileptogenesis in the surrounding cortex is not altered when the microgyrus itself is isolated by transcortical cuts. Patch-clamp recordings from layer V neurons in the epileptogenic zone showed that spontaneous IPSCs are larger and more dependent on glutamatergic synapses than in control neurons. The amplitudes of polysynaptic IPSCs evoked by threshold stimulation were also larger than in control cells. Although evaluation of inhibitory events in these models is still incomplete, results to date suggest that GABAergic inhibition may be enhanced in epileptogenic areas associated with chronic cortical injury. Sprouting of axonal arborizations of pyramidal cells onto interneurons, upregulation of GABAergic neurons, and perhaps sprouting of inhibitory axons that make increased numbers of contacts onto pyramidal cells may all contribute to the increased inhibitory drive. Results in these models do not support the disinhibitory hypothesis of chronic epileptogenesis.

Axonal sprouting in layer V pyramidal neurons of chronically injured cerebral cortex.

We performed experiments to determine whether axonal sprouting occurs in neurons of chronic neocortical epileptogenic lesions. Partially isolated somatosensory cortical islands with intact pial blood supply were prepared in mature rats. Neocortical slices from these lesions, studied 6-39 d later, generated spontaneous and/or evoked epileptiform field potentials (Prince and Tseng, 1993) during which neurons displayed prolonged polyphasic excitatory and inhibitory synaptic potentials/currents. Single electrophysiologically characterized layer V pyramidal neurons in control and epileptogenic slices were filled with biocytin using sharp and patch-electrode techniques, their axonal arbors reconstructed and compared quantitatively. Neurons in injured cortex had a 56% increase in total axonal length, a 64% increase in the number of axonal collaterals and more than a doubling (115% increase) of the number of axonal swellings. The presumed boutons were smaller and more closely spaced than those of control cells. In some neurons the main descending axon had hypertrophic segments from which branches arose. These highly significant changes were most marked in the perisomatic region of layer V. The axonal sprouting was associated with a decrease in somatic area but no significant change in dendritic arbors. Results suggest that a significant degree of axonal reorganization takes place in the chronically injured cortex where it might be an adaptive mechanism for recovery of function after injury, or might be maladaptive and play an important role in the generation of epileptiform events by increasing the numbers and density of synaptic contacts between neurons.

Double-labelling with rhodamine beads and biocytin: a technique for studying corticospinal and other projection neurons in vitro.

Corticospinal neurons retrogradely labelled with rhodamine-labelled latex microspheres (RLMs) in vivo were studied intracellularly in a slice preparation up to 13 months later with electrodes containing biocytin. The physiological properties of these double-labelled corticospinal neurons were indistinguishable from those of comparable neurons which were impaled with biocytin-containing electrodes without prior RLM-labelling, and neurons studied with potassium acetate-filled electrodes in similar areas. Thus, neither labelling with RLMs nor injection of biocytin affected neuronal properties. This important advantage of RLMs makes them suitable for prelabelling projection neurons in vivo for subsequent studies that take advantage of the versatility of a brain slice preparation. In addition to its lack of effects on neuronal properties, intracellular labelling with biocytin also provides high-quality morphological details ideal for anatomical analysis. The compatibility of retrograde labelling with RLMs and intracellular staining with biocytin make this a useful combined technique for tracking electrophysiological and anatomical changes in identified projection neurons over time.

Mossy fiber synaptic reorganization in the epileptic human temporal lobe.

The distribution of the mossy fiber synaptic terminals was examined using the Timm histochemical method in surgically excised hippocampus and dentate gyrus from patients who underwent lobectomy of the anterior part of the temporal lobe for refractory partial complex epilepsy. The dentate gyrus of epileptic patients demonstrated intense Timm granules and abundant mossy fiber synaptic terminals in the supragranular region and the inner molecular layer. In contrast, the dentate gyrus of presenescent nonepileptic primates demonstrated no Timm granules in the supragranular region. In nonepileptic senescent primates, occasional very sparse supragranular Timm granules were results are morphological evidence of mossy fiber synaptic reorganization in the temporal lobe of epileptic humans, and suggest the intriguing possibility that mossy fiber sprouting and synaptic reorganization induced by repeated partial complex seizures may play a role in human epilepsy.

Acidic fibroblast growth factor stimulates adrenal chromaffin cells to proliferate and to extend neurites, but is not a long-term survival factor.

Acidic fibroblast growth factor (aFGF) is a heparin-binding polypeptide that is a mitogen for endothelial cells and glial cells, as well as a differentiation factor for PC12 cells and certain neurons. We show here that aFGF is as potent as nerve growth factor (NGF) in stimulating both neuritic outgrowth and proliferation in adrenal chromaffin cells from young rats, but it fails to support long-term survival. Heparin strongly potentiates aFGF-dependent neuritic outgrowth but not aFGF-dependent proliferation. As is the case with NGF, phorbol myristate acetate depresses aFGF-induced cell division and increases the outgrowth of neurites. On the other hand, dexamethasone antagonizes neuritic outgrowth elicited by both NGF and aFGF but inhibits only proliferation induced by NGF. The effects of basic FGF (bFGF) are similar but not identical to those of aFGF. Thus the regulatory pathways controlled by aFGF, bFGF, and NGF are partially distinct.