Neurological manifestations of neurofibromatosis type 1: our experience.

INTRODUCTION: Neurofibromatosis type 1 (NF1) is a progressive multisystem disorder following an autosomal dominant inheritance pattern that presents with multiple neurological manifestations. METHODS: We reviewed medical histories of patients with NF1 followed up at our hospital's paediatric neurology department from May 1990 to 31 December 2018. We collected data on neurological symptoms. RESULTS: A total of 128 patients with NF1 were identified. Mean age (SD) at NF1 diagnosis was 4.43 (3.38) years (range, 0.5-14.5 years). There was a slight female predominance (53.1%). Macrocephaly (head circumference over 2 SDs above average for age) was present in 37.5% of cases. Attention-deficit/hyperactivity disorder was recorded in 28.9% of patients (37): combined type in 20 patients, predominantly inattentive in 15, and predominantly impulsive/hyperactive in 2. Other manifestations included headache (18.6%), cognitive impairment (7.8%), motor deficit (6.2%), and epilepsy (4.68%). Brain MRI was performed in 85 patients, revealing T2-weighted hyperintensities in the basal ganglia and/or cerebellum in 60 patients (70.5%), Chiari malformation type 1 in 4 cases, and arachnoid cysts in 3. Optic nerve gliomas were identified by MRI in 22 patients (25.8%). Other MRI findings included plexiform neurofibromas (9.3%) and central nervous system gliomas (3.1%). CONCLUSIONS: The neurological manifestations identified in our sample are consistent with those reported in the literature. Effective transfer strategies from paediatric neurology departments and subsequent clinical follow-up by adult neurology departments are needed to prevent loss to follow-up in adulthood.

Manifestaciones neurológicas en neurofibromatosis tipo 1. Nuestra experiencia / Neurological manifestations of neurofibromatosis type 1: our experience

Introducción: La neurofibromatosis tipo 1 (NF1) es un desorden progresivo multisistémico de herencia autosómica dominante que presenta numerosas manifestaciones neurológicas. Métodos: Revisión de historias clínicas de pacientes afectos de NF1 controlados en una Unidad de Neuropediatría de mayo de 1990 a 31 de diciembre de 2018 y sus manifestaciones neurológicas asociadas. Resultados: Se revisaron 128 pacientes afectos de NF1. Edad media al diagnóstico de NF1, 4,43 años ± 3,38 SDS (rango 6 meses-14,5 años) con discreto predominio femenino (53,1%). Se asocia macrocefalia (PC> 2SDS) en el 37,5% de los casos. TDAH en el 28,9% de los casos (37), subtipo combinado 20, inatento 15 casos y predominantemente hiperactivo 2 casos. Otras manifestaciones incluyen; cefalea (18,7%), déficit cognitivo (7,8%), afectación motora (6,2%) y epilepsia (4,68%). Se realizó RM cerebral a 85 pacientes, mostrando 60 (70,5%) hiperseñales en T2 en ganglios basales y/o cerebelo, junto con otras alteraciones como Chiari I (4 casos) y quistes aracnoideos (3 casos). Se identificaron gliomas de nervio óptico en 22 casos (25,8%). Otros hallazgos diagnosticados por RM incluyen neurofibromas plexiformes (9,3%) y otros gliomas localizados en sistema nervioso central (3,1%). Conclusiones: Las manifestaciones neurológicas encontradas concuerdan con lo recogido en la literatura. El seguimiento de estos pacientes se pierde en la edad adulta, siendo necesario establecer adecuadas estrategias de transferencia y posterior seguimiento de pacientes a los servicios de adultos. (AU)

Introduction: Neurofibromatosis type 1 (NF1) is a progressive multisystem disorder following an autosomal dominant inheritance pattern that presents with multiple neurological manifestations. Methods: We reviewed medical histories of patients with NF1 followed up at our hospital's paediatric neurology department from May 1990 to 31 December 2018. We collected data on neurological symptoms. Results: A total of 128 patients with NF1 were identified. Mean age (SD) at NF1 diagnosis was 4.43 (3.38) years (range, 0.5-14.5 years). There was a slight female predominance (53.1%). Macrocephaly (head circumference over 2 SDs above average for age) was present in 37.5% of cases. Attention-deficit/hyperactivity disorder was recorded in 28.9% of patients (37): combined type in 20 patients, predominantly inattentive in 15, and predominantly impulsive/hyperactive in 2. Other manifestations included headache (18.6%), cognitive impairment (7.8%), motor deficit (6.2%), and epilepsy (4.68%). Brain MRI was performed in 85 patients, revealing T2-weighted hyperintensities in the basal ganglia and/or cerebellum in 60 patients (70.5%), Chiari malformation type 1 in 4 cases, and arachnoid cysts in 3. Optic nerve gliomas were identified by MRI in 22 patients (25.8%). Other MRI findings included plexiform neurofibromas (9.3%) and central nervous system gliomas (3.1%). Conclusions: The neurological manifestations identified in our sample are consistent with those reported in the literature. Effective transfer strategies from paediatric neurology departments and subsequent clinical follow-up by adult neurology departments are needed to prevent loss to follow-up in adulthood. (AU)

Neurological manifestations of neurofibromatosis type 1: our experience. / Manifestaciones neurológicas en neurofibromatosis tipo 1. Nuestra experiencia.

INTRODUCTION: Neurofibromatosis type 1 (NF1) is a progressive multisystem disorder following an autosomal dominant inheritance pattern that presents with multiple neurological manifestations. METHODS: We reviewed medical histories of patients with NF1 followed up at our hospital's paediatric neurology department from May 1990 to 31 December 2018. We collected data on neurological symptoms. RESULTS: A total of 128 patients with NF1 were identified. Mean age (SD) at NF1 diagnosis was 4.43 (3.38) years (range, 0.5-14.5 years). There was a slight female predominance (53.1%). Macrocephaly (head circumference over 2 SDs above average for age) was present in 37.5% of cases. Attention-deficit/hyperactivity disorder was recorded in 28.9% of patients (37): combined type in 20 patients, predominantly inattentive in 15, and predominantly impulsive/hyperactive in 2. Other manifestations included headache (18.6%), cognitive impairment (7.8%), motor deficit (6.2%), and epilepsy (4.68%). Brain MRI was performed in 85 patients, revealing T2-weighted hyperintensities in the basal ganglia and/or cerebellum in 60 patients (70.5%), Chiari malformation type 1 in 4 cases, and arachnoid cysts in 3. Optic nerve gliomas were identified by MRI in 22 patients (25.8%). Other MRI findings included plexiform neurofibromas (9.3%) and central nervous system gliomas (3.1%). CONCLUSIONS: The neurological manifestations identified in our sample are consistent with those reported in the literature. Effective transfer strategies from paediatric neurology departments and subsequent clinical follow-up by adult neurology departments are needed to prevent loss to follow-up in adulthood.

[Knowledge and attitudes of health care professionals in advance healthcare directives]. / Conocimientos y actitudes sobre voluntades anticipadas en profesionales sanitarios.

BACKGROUND AND OBJECTIVE: The advanced healthcare directive is a new style of health care relationship, based on the respect of the patients autonomous decisions: as well as a valuable tool that enables a proper management of the decisions made at the end of life. The objective of this study was to explore the knowledge and attitudes of the health care professionals regarding the advance directives, as well as the resources for advanced care planning in a municipality of Madrid during 2016-2017. MATERIAL AND METHODS: A cross-sectional descriptive study was carried out on a population of Health care professionals of Primary and Specialised Care. The knowledge and attitudes questionnaire about the advance directives was used. Sociodemographic and knowledge variables related to resources for the advanced care planning. Statistical-descriptive analysis was performed. RESULTS: A total of 431 professionals were included, with a mean age of 44.55 years (SD: 11.1). As regards knowledge about advance directives, the mean score was 5.08 (SD 2.4), with statistically significant differences being found between professional groups. A small percentage (4.6%) of the professionals had their document of Advance directives ready, and 42% of professionals did not know if they were regulated by the Community of Madrid. Less than half (41.5%) of the professionals knew the palliative resources of their institution. CONCLUSIONS: The health care professional's knowledge about advance directives, as well as the resources for the advanced care planning, show deficiencies at training and information level. Almost half of the professionals did not know if these are regulated in the Community of Madrid. They also believe that it would be useful to plan, and very useful to have the Advance directives document ready.

La Unidad de Oncología e Inmunohematología Pediátricas del Hospital Universitario Miguel Servet en 2015 / Pediatric oncology and immunology unit of the Hospital Universitario Miguel Servet in 2015

La Unidad de Oncología e Inmunohematología Pediatricas del Hospital Universitario Miguel Servet (HUMS) de Zaragoza es la única de referencia en la Cornunidad Autónoma de Aragón para el tratamiento integral y seguimiento de los pacientes pediátricos con cáncer y otras enfermedades hematológicas e inmunológicas graves. Asiste, también, a un número importante de pacientes de otras provincias limítrofes con Aragón, como la Rioja y Soria. Las labores asistencial e investigadora de esta Unidad, que se revisaran a continuación, han evolucionado y se han ampliado de forma continua desde su inauguración, hace mas de 30 años (AU)

Hospital Miguel Servet Pediatric Oncology and Immunohematology Unit, is the only reference center in Aragon for the treatment and follow-up of children with cancer and other severe hematological and immunological diseases. It is also responsible for a significant number of patients from nearby regions to Aragon, such as La Rioja and Soria. Its clinical activity and research work, which will be reviewed next, has improved continuously since its opening, over more than 30 years ago (AU)

Conocimiento, actitud y práctica sobre medidas de odontología preventiva en odontólogos: vi Congreso Paraguayo de Endodoncia, 2011 / Knowledge, attitude and practice on preventive measures in dentistry: vi congress Praguayan of Endodontics, 2011

Objetivo: Describir nivel de conocimiento, actitud y práctica de medidas básicas de prevención en salud oral en odontólogos que asistieron al VI Congreso Paraguayo de Endodoncia en el año 2011.Metodología: Estudio transversal, a través de una encuesta autoaplicada validada que contenía preguntas básicas referentes a Odontología Preventiva. Resultados: Participaron del estudio 173 profesionales, con una mediana de 33 años,62,4% con 1 a 12 años de ejercicio en la profesión y 58,4% procedían de universidades públicas.El 57,8% de los encuestados demostró tener muy buenos niveles de conocimiento,de actitud en el 46,8%y38,2%en práctica.La aplicación de medidas de prevención produjo en el 64,2% de los encuestados satisfacción personal. Respecto a las medidas de control de placa, las técnicas más difundidas fueron:cepillado de Bass 80,4%,método del lazo para el hilo dental 53,8% y el flúor se aplica en el 76,9% en su presentación de enjuagues bucales. Se encontró una fuerte asociación entre el conocimiento y la actitud (OR=4,3;p<0,0001) y entre la actitud y la práctica (OR=2,3;p=0,0162) Conclusión: La práctica de la filosofía preventiva se halla condicionada por la actitud y ésta a su vez depende del conocimiento constituyéndose componentes esenciales para la mejora del estado de salud de una población. Palabras claves: Conocimiento, Odontología Preventiva, Odontólogos.

Objective: To describe the level of knowledge, attitude and practice of basic preventive measures in oral health acquired by dentists who attended the VI Paraguayan Congress of Endodontics in 2011. Methods: Cross-sectional study by a validated self-administered survey containing basic questions regarding to Preventive Dentistry. Results: The study comprised 173 professionals, with an average age of 33 years old, 62.4 % with 1-12 years of practice in the profession and almost 58.4 % were from public universities. Whatsmore, 57.8 % of respondents proved to have very good levels of knowledge, 46.8 % of them proved it in attitude and 38.2 % in practice. The application of preventive measures gave to 64.2% of respondents a personal satisfaction. Concerning plaque control measures, the most widely used techniques were: 80.4 % Bass brushing, 53.8 % in a method to tie dental floss and fluoride applies to 76.9% in its presentation of rinses mouth. Furthermore, it has been found a strong association between attitude and practice (OR = 2.3, p = 0.0162) and between knowledge and attitude (p < 0.0001 OR = 4.3) Conclusion: the practice of prevention philosophy is based on the attitude and this in turn depends on knowledge. Therefore, attitude and knowledge are essential components in order to improve the health status of a population. Keywords: Knowledge, Preventive Dentistry, Dental.

Distribution of nestin protein: immunohistochemical study in enteric plexus of rat duodenum.

The intermediate nestin filament is expressed in neural stem cells, neuroectodermal tumors and various adult tissues under situations that reproduce developmental phases, e.g., physiological renewal of certain cell types, tissue regeneration, and healing or revascularization. In the human gastrointestinal tract, nestin has been reported in glial cells and interstitial cells of Cajal. We examined by immunohistochemistry the appearance and distribution of nestin protein in enteric ganglia of rat duodenum. Through the myenteric and submucosal plexuses, a high number of nestin-positive cells were visualized in this specie. The nestin-positive cells were smaller and more numerous than enteric neurons. They were present both within and around ganglia. The results of this study suggest that the rat enteric glial cells (EGCs) are rich in nestin, a protein usually associated with dividing or migrating cells and the dynamic reorganization of nestin filaments during the cell cycle. EGCs could function as enteric stem cells.

Identification of telocytes in the lamina propria of rat duodenum: transmission electron microscopy.

Recently the new term 'telocytes' has been proposed for cells formerly known as interstitial Cajal-like cells. In fact, telocytes are not really Cajal-like cells, they being different from all other interstitial cells by the presence of telopodes, which are cell-body prolongations, very thin, extremely long with a moniliform aspect. The identification of these cells is based on ultrastructural criteria. The presence of telocytes in others organs was previously documented. We reported for the first time, an ultrastructural study of telocytes in the lamina propria of rat duodenum. Our findings show that typical telocytes are present in the rat duodenum. Telocytes are located in the lamina propria, immediately below mucosal crypts. Telopodes frequently establish close spatial relationships with immune cells, blood vessels and nerve endings. On the basis of their distribution and morphology, we suggest that these cells may be involved in immune response and in our opinion, it may be possible that different locations of telocytes could be associated with different roles.

Características ultraestructurales de células precursoras neurales en intestino de rata / No disponible

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[Contributions of neuroscience to the diagnosis and educational treatment of developmental dyslexia]. / Contribuciones de la neurociencia al diagnóstico y tratamiento educativo de la dislexia del desarrollo.

AIM: To examine the advances made in the fields of cognitive psychology, neuroscience and education and how they have contributed to each other. DEVELOPMENT: The paper offers a review of the current models of dyslexia and analyses the relation between these models and neuroimaging studies and educational intervention. The first model presented here is the 'phonological deficit' model, which is the most widely proven and accepted today. People with dyslexia have difficulty in completing tasks that involve segmenting language at a phonological level. Neuroimaging studies also reveal the existence of atypical brain activation in dyslexics while performing tasks that require phonological processing. Intervention programmes of a phonological nature have proved to be effective on both a behavioural and a neurophysiological level. Given the complexity of the reading process, further research is currently looking into other models. Although the 'temporal processing' deficit model is more controversial and not as widely accepted as the previous model, some reports provide both behavioural and neurophysiological evidence for the existence of differences in the visual and auditory processing of dyslexic and control subjects. Different educational approaches to put this temporal processing deficit to rights have been tested in dyslexic children with successful outcomes. Finally, the present status between neuroscience and education in the area of reading disorders is examined and future implications concerning the different approaches and methods used in current research are analysed. CONCLUSIONS: Although we are still a long way from understanding the causes of reading deficiencies, collaboration between neuroscience, psychology and education does help further our understanding of the psychology of reading, its diagnosis and its intervention.

Contribuciones de la neurociencia al diagnóstico y tratamiento educativo de la dislexia del desarrollo / contributions of neuroscience to the diagnosis and educational treatment of developmental dyslexia

Objetivo. Examinar las contribuciones y el avance entre psicología cognitiva, neurociencia y educación. Desarrollo. Se presenta una revisión de los modelos actuales de dislexia y se analiza la relación de estos modelos con los estudios de neuroimagen y de intervención educativa. El primer modelo presentado es el del ‘déficit fonológico’, que es el más ampliamente demostrado y aceptado en la actualidad. Las personas con dislexia presentan dificultades en tareas que implican segmentación fonológica del lenguaje. Los estudios de neuroimagen muestran, también, una activación cerebral atípica en disléxicos durante tareas que requieren procesamiento fonológico. Los programas de intervención de tipo fonológico han mostrado ser efectivos tanto en relación con la conducta como neurofisiológicamente. Dada la complejidad del proceso lector, se investigan otros modelos en la actualidad. Aunque el modelo del déficit en el ‘procesamiento temporal’ es más controvertido, y no tan ampliamente aceptado, comparado con el modelo anterior, algunos trabajos muestran evidencia tanto conductual como neurofisiológica de que existen diferencias en el procesamiento visual y auditivo entre sujetos disléxicos y controles. Diferentes aproximaciones educativas para remediar este déficit de procesamiento temporal se han probado con éxito en niños disléxicos. Finalmente se examina el estado actual entre neurociencia y educación en el área de las dificultades de lectura y se analizan implicaciones futuras relacionadas con los diferentes enfoques y métodos utilizados en la investigación actual. Conclusiones. A pesar de que todavía queda un largo camino para comprender las causas de los déficit lectores, la colaboración entre la neurociencia, la psicología y la educación contribuye a una mejor comprensión de la psicología de la lectura, de su diagnóstico y de su intervención

Aim. To examine the advances made in the fields of cognitive psychology, neuroscience and education and how they have contributed to each other. Development. The paper offers a review of the current models of dyslexia and analyses the relation between these models and neuroimaging studies and educational intervention. The first model presented here is the ‘phonological deficit’ model, which is the most widely proven and accepted today. People with dyslexia have difficulty in completing tasks that involve segmenting language at a phonological level. Neuroimaging studies also reveal the existence of atypical brain activation in dyslexics while performing tasks that require phonological processing. Intervention programmes of a phonological nature have proved to be effective on both a behavioural and a neurophysiological level. Given the complexity of the reading process, further research is currently looking into other models. Although the ‘temporal processing’ deficit model is more controversial and not as widely accepted as the previous model, some reports provide both behavioural and neurophysiological evidence for the existence of differences in the visual and auditory processing of dyslexic and control subjects. Different educational approaches to put this temporal processing deficit to rights have been tested in dyslexic children with successful outcomes. Finally, the present status between neuroscience and education in the area of reading disorders is examined and future implications concerning the different approaches and methods used in current research are analysed. Conclusions. Although we are still a long way from understanding the causes of reading deficiencies, collaboration between neuroscience, psychology and education does help further our understanding of the psychology of reading, its diagnosis and its intervention

[Anesthesia for cesarean delivery in a woman with congenital aortic stenosis]. / Anestesia para la cesárea a una paciente afecta de estenosis aórtica congénita.

The patient was a 26-year-old primipara diagnosed in the first trimester with aortic stenosis and coarctation of the descending aorta. She had remained stable until the 37th week, when she developed dyspnea, edema in the lower extremities, crepitations, oliguria, hypotension, and mild sinus tachycardia consistent with left ventricular insufficiency. A cesarean was performed under general anesthesia with remifentanil, with good outcomes for mother and infant. Aortic stenosis causes left ventricular hypertrophy that increases the risk of myocardial ischemia and left ventricular insufficiency in combination with the physiological changes that pregnancy produces in the cardiovascular system. An emergency cesarean section in such patients requires preservation of hemodynamic stability, which is difficult to achieve with epidural or subarachnoid techniques. Remifentanil is an alternative to drugs used until now in this context.

Síndrome febril y dolor en sacroilíaca izquierda en una niña de 12 años / Febrile syndrome and pain in the left sacroilium in a 12-year-old-girl

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¿Pubertad precoz mediada por betagonadotropina coriónica humana? / SS-hCG-induced precocious puberty?

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Reintervenciones en cirugía laparoscópica / Reintervention in laparoscopic surgery

Objetivo. Valorar la influencia que puede tener la cirugía abdominal y laparoscópica previa en las reintervenciones por vía laparoscópica, analizando los resultados y las causas de dichas reintervenciones. Pacientes y métodos. Estudio retrospectivo de 4.957 pacientes intervenidos por vía laparoscópica entre octubre de 1991 y octubre de 1999, correspondiendo el mayor número de intervenciones a la cirugía biliar (2.028). En 769 pacientes (15,5 por ciento) existía el antecedente de cirugía abdominal previa, en 43 de los cuales (0,9 por ciento) ésta se había efectuado por laparoscopia. Resultados. El número total de conversiones en todos los pacientes intervenidos fue de 74 (1,49 por ciento). La causa más frecuente de conversión fueron las dificultades técnicas (63,5 por ciento), cifra más elevada que cuando la causa de conversión fue el antecedente de cirugía convencional (27 por ciento). La morbilidad fue superior en los pacientes que presentaban cirugía abdominal previa (3,2 por ciento), frente al 1,3 por ciento en los pacientes que no habían sido intervenidos previamente. La causa de reintervención de la cirugía laparoscópica más frecuente fue el fallo de la cirugía por enfermedad por reflujo gastroesofágico (16,2 por ciento). El tiempo quirúrgico, las complicaciones intraoperatorias y el tiempo de estancia hospitalaria no presenta ninguna diferencia significativa en pacientes con o sin intervención previa, tanto en el grupo de laparotomía como de laparoscopia. Conclusiones. El análisis de los resultados demuestra que las reintervenciones por vía laparoscópica son factibles, independientemente de si existe o no cirugía previa. El número de reintervenciones como consecuencia de la cirugía laparoscópica previa puede reducirse respetando los principios quirúrgicos, admitidos en todo tipo de cirugía (AU)

Mechanisms of cGMP-dependent mesangial-cell relaxation: a role for myosin light-chain phosphatase activation.

Although the cGMP-dependent relaxation of contractile cells seems to depend on the ability of the cyclic nucleotide to interfere with intracellular calcium, this does not appear to be the only mechanism involved. The present experiments were designed to analyse alternative mechanisms, trying to test the hypothesis that cGMP could relax rat mesangial cells by activating myosin light-chain phosphatase (MLC-PP), with the subsequent dephosphorylation of myosin light chain (MLC). The effect of a cGMP analogue, dibutyryl cGMP (dbcGMP), on angiotensin II-(AII) and PMA-induced MLC phosphorylation (MLCP) was tested, in the presence of calyculin A (CA), an inhibitor of MLC-PP. MLCP was measured, after cell labelling with (32)P, by immunoprecipitation. dbcGMP prevented the increased MLCP induced by AII or PMA, and this inhibition was blocked by CA. dbcGMP also increased the MLC dephosphorylation observed in cells incubated with AII and in which MLC kinase and protein kinase C activities were blocked. The AII-elicited increased intracellular calcium concentration was only partially inhibited by dbcGMP. These results suggest that the cGMP-induced mesangial-cell relaxation could be due, at least partially, to the stimulation of MLC-PP.

Progenitor cell subsets and engraftment kinetics in children undergoing autologous peripheral blood stem cell transplantation.

The main objective of the present study was to determine the role of CD34+ cell subsets in the haemopoietic recovery of children undergoing peripheral blood stem cell transplantation. For this purpose, 38 leukaphereses from 33 children with malignancies mobilized with G-CSF were analysed. Using dual-colour flow cytometry, different subpopulations of CD34+ cells were quantified and the number of each reinfused subsets correlated with haemopoietic resurgence. Multivariate analysis showed that the number of CD34+CD38- cells and CD34+CD38+ cells correlated better with time to neutrophil and platelet recovery, respectively, than the total number of CD34+ cells. Threshold values for rapid haemopoietic recovery, determined by the receiver operating characteristic analysis, were found to be 0.5 X 10(6) CD34+CD38- cells for neutrophil engraftment, and 2.0x10(6) CD34+CD38+ cells for platelet recovery. It is suggested that the analysis of CD34+ cell subsets could increase understanding of the repopulation capacity of a given leukapheresis product in peripheral blood stem cell transplantation procedures in children. In particular, this procedure could be extremely useful when low numbers of CD34+ cells are collected.

The role of government in health insurance markets with adverse selection.

This paper analyzes the welfare economics of three arrangements for purchasing health insurance: competitive markets in which consumers are free to choose among options with different levels of coverage and prices; systems with compulsory partial pooling which permit private firms to sell supplementary coverage; and government-run pools that purchase comprehensive coverage at a single price for all consumers. Competitive insurance markets are assumed to face the problem of 'adverse selection'. This refers to a situation in which the insurer cannot observe characteristics of individuals that affect the cost of insurance and that are known to the individuals. Competitive markets with adverse selection are not efficient because low risks cannot purchase comprehensive insurance coverage. However, government-run pools with comprehensive coverage are an inefficient solution to the problem of adverse selection. Compulsory partial coverage may represent an attractive alternative to both competitive markets and comprehensive pools. We discover two situations when government intervention of this type will succeed: when there are not many high risks in the population, and when the risk types are similar. We discuss the implications of these results for health insurance programs in several countries. Our results also have implications for the allocation of public funds for disease-prevention projects. A project targeted at high risks will produce external benefits for low risks, even though they are not directly affected by the program. However, a successful project might eliminate the market for private insurance; in this case the government should consider mandating partial insurance coverage.