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Resumen INTRODUCCIÓN : La radiación ultravioleta solar puede resultar perjudicial para la salud y provocar desde quemaduras hasta enfermedades como el cáncer, por ello, el cuidado frente a la alta radiación solar es importante. OBJETIVOS : El objetivo general del presente estudio fue determinar si existe asociación entre los conocimientos y las prácticas sobre foto protecciónen los bañistas peruanos. MATERIALES Y MÉTODOS : Se realizó un estudio trasversal analítico con 380 bañistas peruanos en ocho playas de Lima. Los participantes respondieron un cuestionario donde se recopiló información de los conocimientos y las prácticas de foto protección. Los conocimientos se categorizaron en altos y bajos, y las prácticas en adecuadas e inadecuadas. Para el análisis se empleó la prueba de Chi cuadrado de Pearson y el modelo de regresión de Poisson ajustado por la edad, sexo, nivel educativo y estado civil. RESULTADOS : Se encontró que la práctica de protección adecuada más frecuente fue el uso de foto protector(63%) y la menos frecuente fue el uso adecuado de manga larga y pantalón largo (9,7%). También se evidenció una relación entre los conocimientos altos y tres prácticas fundamentales: uso de foto protector, sombrilla y lentes de sol. CONCLUSIONES : En la muestra de bañistas peruanos, los participantes reportaronde manera general prácticas de foto proteccióndeficientes; además, el poseer conocimientos acerca de la protección solar no aseguró una práctica adecuada de todas las medidas de foto protección.

Abstract INTRODUCTION : Ultraviolet rays can have damaging health effects and cause from sunburn all the way up to diseases such as cancer. Thus, precautionary measures against intense solar radiation are important. OBJECTIVES: The overall objective of this study was to determine whether there is an association between photoprotection knowledge and practices in Peruvianbeach-goers. MATERIALS AND METHODS : An analytical cross-sectional study comparing survey and observational data obtained from 380 Peruvians at eight beaches in Lima was conducted. The participants answered a questionnaire where knowledge was categorized into high and low, and reported practices were dichotomized as appropriate and inappropriate. For variable analysis, Chi square test of Pearson and Poisson regression model adjusted for age, sex, education level and marital status were used. RESULTS : It was found that the most common reported appropriate practice of photoprotection was the use of sunscreen (63%) and the least frequent was the appropriate use of a long sleeve t-shirt and long pants (9.7%). It was also evident that there is a significant relationship between high knowledge and three core practices, including use of sunscreen, beach umbrellas and sunglasses. CONCLUSIONS : In this sample of Peruvian beach-goers, participants generally reported poor photoprotection practices; furthermore, knowledge about sun protection did not assure the practice of all photoprotection measures.

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El desarrollo de lesiones de mancha blanca (WSLs) es un riesgo significativo asociado con el tratamiento de ortodoncia cuando la higiene oral es deficiente. Aparatos de ortodoncia fijos transforman los procedimientos de higiene oral convencionales más difíciles y aumentan el número de sitios de retención de placa. Si bien los valores de prevalencia son variados, los datos son suficientes para considerar la desmineralización como un problema importante, haciendo de la prevención durante el tratamiento uno de los mayores desafíos clínicos. El propósito de este trabajo es realizar una revisión actualizada de la literatura disponible respecto a la etiología, prevención y tratamiento de manchas blancas asociadas al tratamiento de ortodoncia con aparatología fija (AU)

The development of white spot lesions (WSLS) is a significant risk associated with orthodontic treatment when oral hygiene is poor. Fixed orthodontic appliances transform procedures of conventional oral hygiene more difficult and increase the number of sites plaque retention. While prevalence values vary, the data are sufficient to consider the demineralization as an important problem, making prevention during treatment one of the major clinical challenges. The purpose of this paper is review to date the available literature regarding the etiology, prevention and treatment of white spots associated with orthodontic treatment with dental braces (AU)

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Prior studies have implicated an involvement of the Msx1 homeobox gene in cleft palate in mice and its homolog in humans (called MSX1 in the HOX7 gene, located on chromosome 4). In this study we present evidence of a sex-dependent association between MSX1 and non-syndromic cleft lip/palate (NSCLP) in the Chilean population. The sample included 73 NSCLP cases, 37 from multiplex families (Mx), 36 from simplex families (Sx), and 87 controls. Polymerase chain reaction amplification of the MSX1 intragenic microsatellite (CA)n-sequence shows significant (p = 0.035) differences in the allele frequencies between NSCLP-Mx males and control males. These differences are mainly due to frequency differences in allele *2 (173 base pairs) among cases (21.9%) and controls (13.2%). When the NSCLP cases are subdivided by sex and positive family history (Mx versus Sx), the Mx males (27.8%) as well as the total NSCLP-Mx cases (25.7%) showed significantly higher frequencies of allele *2, compared to controls (11.4% and 13.2%, respectively). Analysis of the genotype data indicates that the relative risk for NSCLP is greater for persons carrying allele *2 (i.e., odds ratio [OR] larger than 1), reaching significance for all Mx cases (OR = 2.67; 95% confidence interval [CI], 1.10 to 6.52) and even more pronounced for Mx males (OR = 3.33; 95% CI, 1.08 to 10.32). Taken together, these findings support the hypothesis that the genetic variation at the MSX1 locus is a predisposing gene involved in sex-dependent susceptibility to clefting and that it also differentiates simplex from multiplex families.

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BACKGROUND: The presence of major genes in the susceptibility of non syndromic cleft lip with or without cleft palate (CL/P) in Chile has been postulated, considering the high prevalence and familial aggregation of this condition. AIM: To study the familial recurrence of CL/P in Chile. PATIENTS AND METHODS: The recurrence risk of CL/P was studied in 217 extended pedigrees where 33 (15.2%) were multiplex (21 male and 12 female propositi). These multiplex extended pedigrees (with more than one affected individual) represented 75 nuclear pedigrees, constituted by 840 males and 803 females and are the basic information of this study. RESULTS: A significantly higher frequency of affected males (4.15%) than affected females (2.27%) was observed, independent of the difference in number of propositi by sex. Even though no differences were observed between families where both parents were unaffected, compared to those with only one affected parent, a higher proportion of affected descendants was found when the affected propositi was the mother. In multiplex families, the recurrence risk, according to the genetic proximity to the proband, was 10.1, 3.6 and 3.3% respectively for first, second and third degree relatives. The figures were 1.5, 0.5 and 0.4% respectively, when adjusted to the 217 extended pedigrees. Considering that the risk for the general population in Chile is approximately 0.16%, it is 10.3, 3.2 and 2.6 times higher among affected families. CONCLUSIONS: The high heritability of CL/P and the risk encountered for the Chilean population supports the hypothesis of major genes involved in its susceptibility.

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Race and ethnicity influence the form of the human craniofacial complex in varying ways. The aim of the present investigation was to quantify the effects of ethnicity (mestizos, Aymara, non-Aymara), age (adolescents and adults), and sex on the form (size and shape) of the hard palate in normal Native American individuals. From the dental casts of 51 individuals with a complete permanent dentition, the x, y, and z coordinates of several standardized palatal landmarks were obtained with a computerized 3-dimensional digitizer. Palatal landmarks were used to derive a mathematical equation for palatal shape in the frontal and sagittal planes. Palatal width and length, frontal and sagittal heights, sagittal slope, and deviation of the raphe from the midline were also calculated. In the Aymara subjects, there was no effect of sex on palatal size, but there was an effect on palatal shape independent of size, especially with respect to male growth. Indeed, female palates apparently did not change their shape between adolescence and adulthood, while male palates increased their posterior "height." Overall, the 3 ethnic groups appeared to possess similar palatal size, with small significant differences. In the adult individuals, ethnicity did not seem to influence palatal shape. In contrast, adolescent males showed differences: non-Aymara subjects had the "highest" palatal shape, Aymara the "lowest," and mestizos an intermediate position. In conclusion, ethnicity does not seem to be a factor of major variability of human hard palate morphology, at least in the present 3 northern Chilean groups, as already found for dental arch shape. Age probably has a larger effect, particularly in the posterior part of the palate, where the eruption of the second and third molars between adolescence and young adulthood may play a role. A further development of the present investigation may involve larger samples of individuals from different ethnic groups.

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Race and ethnicity variably influence the form of the human craniofacial complex. In the present study, the effects of ethnicity and sex on the global size of normal adult dental arches were analyzed. The dental arches of 47 northern Chilean mestizos (25 men, 22 women) and 95 northern Italian Caucasians (50 men, 45 women) were cast in stone. All subjects had a complete dentition in both arches. In all models the coordinates of dental cusp tips were digitized using an image analyzer. The center of gravity of each tooth was computed and arches were interpolated using a polynomial model (y = ax + bx2 + cx3 + dx4). In all arches, the intercanine, intermolar, and mid-intercanine to mid-intermolar distances were computed from the dental centers of gravity. These arch distances were entered in a linear discriminant function analysis. The polynomial model accurately interpolated data points in all instances, and most of the dental arch form was determined by the first and second degree coefficients. On average, Italian Caucasian arches were smaller than Chilean mestizo arches. Male mean distances were larger than female distances regardless of ethnic group or arch. The linear discriminant analysis performed between male and female arches within ethnic groups was significant only for both Italian Caucasian arches, but the percentage errors for the classification of a new individual were very high (about 30%). Conversely, Italian Caucasian arches could always be discriminated from Chilean mestizo arches of the same sex with a much smaller error.

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BACKGROUND: Nonsyndromic cleft lip with or without cleft palate (NSCLP) is a common craniofacial developmental defect. Association studies have suggested that a clefting locus is located on chromosome 6p at or near two possible loci, Factor 13A (FI3A) in the region 6p 25-24 and HLA at 6p 21.3. AIM: To test the hypothesis on the possible presence of a major gene on chromosome 6p associated with NSCLP. PATIENTS AND METHODS: We carried out an association study on a sample of unrelated NSCLP patients from multiplex (Mx) and simplex (Sx) families, of their unaffected relatives and in control individuals. DNA was analyzed with three PCR markers close to the putative NSCLP locus, dinucleotide repeats at loci D6S89, D6S109 and D6S105. PCR products were resolved by PAGE and visualized by silver staining. Statistical analysis was performed by means of chi 2 log ratio. RESULTS: Significant differences were observed when comparing the allele frequency distribution of D6S89 in patients with NSCLP and controls and in patients with NSCLP-Mx and controls. No significant differences were observed for patients with NSCLP-Sx. D6S109 and D6S105 showed no significant differences in any of the comparisons. CONCLUSIONS: Our results support the hypothesis that a NSCLP locus maps on 6p23 very close to D6S89. Results for D6S109 and D6S105 do not show a clear association. Differences observed between NSCLP-MX and Sx families seem to represent different etiologic entities. The results of the present study, plus those already published for candidate loci, TGFA and MSX1, support the hypothesis that several interacting major genes participate in the etiology of NSCLP.

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BACKGROUND: Nonsyndromic cleft lip with or without cleft palate (NSCLP) is a common craniofacial defect. Association studies have suggested that a clefting locus is located on chromosome 4q at or near two microsatellite markers D4S175 and D4S192. AIM: To test the hypothesis on the possible presence of a clefting locus on chromosome 4q. MATERIAL AND METHODS: We carried out an association study on a sample of unrelated NSCLP patients, of their unaffected relatives and in controls. Both probands and relatives were further analyzed depending if they originated from simplex or multiplex families. DNA was analyzed with two PCR markers close to the putative NSCLP locus, dinucleotide repeats D4S175 and D4S192. PCR products were resolved by PAGE and visualized by silver staining. Statistical analysis was performed by means of chi 2 log ratio. RESULTS: Significant differences between NSCLP and controls were observed when comparing the allele frequency distribution of D4S192 both in the total sample as well as in NSCLP-multiplex and simplex cases. No significant differences for D4S175 were observed in any of the comparisons. Unaffected relatives showed significant differences with controls both for D4S175 and D4S192. CONCLUSIONS: Our results support the hypothesis that a NSCLP locus maps on chromosome 4q close to the microsatellite marker D4S192. No differences were observed between NSCLP multiplex and simplex cases versus controls, implying that they do not represent different etiologic entities. The results of the present and previous studies in the same group of patients support the hypothesis that several major interacting genes participate in the etiology of NSCLP.

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BACKGROUND: Recent studies in mice have demonstrated that the Msx-1 homebox gene is implicated in cleft palate. Thus, it has been suggested that its human homologue, MSX1 (HOX-7), located in chromosome 4 could be involved in the etiology of non syndromic cleft lip palate. AIM: To study the linkage between non syndromic cleft palate and variations of MSX1 gene. PATIENTS AND METHODS: Seventy three patients with non syndromic cleft lip palate (34 simplex and 37 multiplex), 127 unaffected relatives of the cases (61 relatives of simplex cases and 66 relatives of multiplex cases) and 77 controls were studied. DNA was extracted from leukocytes and the intragenic microsatellite sequence was amplified by PCR. RESULTS: A polymorphism of four alleles was observed, 1 (175 bp), 2 (173 bp), 3 (171 bp) and 4 (169 bp). Alleles 2 and 4 showed a joint variation in males with multiplex cleft lip palate and in their respective unaffected male relatives, that was significant when compared with male controls. Instead, the joint variation of alleles 1 and 4 of unaffected female relatives had significant differences with female controls. Females with multiplex cleft lip palate differed from female controls only in allele 1. CONCLUSIONS: These results support the hypothesis of a genetic heterogeneity in the etiology of non syndromic cleft lip palate.

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Nonsyndromic cleft lip with or without cleft palate (CL/P) has an incidence of 1.5 per 1,000 live births in Chile, with 1.7 per 1,000 in males and 1.3 per 1,000 in females, which is nearly the same as the level found in Asian populations. The high rate of occurrence of CL/P in Chile is probably due to the presence of Amerindian genes in Chilean populations. Using the computer program PAP, a complex segregation analysis of CL/P was conducted for 67 multigeneration pedigrees from Chile, each ascertained from one affected proband. These pedigrees yielded 162 affected individuals and over 898 family members who were included in the analysis. The most parsimonious model of transmission indicated the presence of an autosomal dominant gene with reduced (20-25%) penetrance.

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Two RFLPs at the TGFA locus were studied in 39 unrelated Chilean (Caucasoid-Mongoloid) patients with non-syndromic cleft lip/palate [CL(P)] and 51 control individuals. A highly significant association between BamHI A2 allele and CL(P) was detected (chi 2 = 6.00; P = 0.014), while no association was found between TaqI RFLPs and clefting. No significant differences were found when comparing genotypes by type of cleft and a positive or negative family history of clefting. Our results seem to support rather definitively the association between TGFA and clefting but do not support the hypothesis that TGFA is a major causal gene of CL(P).

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The aim of this study was to identify possible candidate genes for the susceptibility to cleft palate. We studied hyaluronic and glycoprotein levels with morphometric and histochemical techniques, in palatine processes of 13 and 14 days old mouse embryos of strains A/Sn and C/57 BL, that are respectively susceptible and resistant to glucocorticoid and non steroid anti-inflammatory drug induced cleft palate. At 13 days, in palatine processes of the resistant strain and when these are still vertical, there was a significantly higher amount of extracellular matrix, constituted principally by hyaluronic acid. These differences disappeared at 14 days, when the processes became horizontal. The basal membrane of the medial palatine epithelium of the susceptible strain, showed interruptions due to a lower amount of glycoproteins. It is concluded that the observed differences in the amount and quality of these molecules, are a consequence of genetic differences that could determine the susceptibility to cleft palate.

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A large earthquake (8-9 on the Richter scale) and a series of aftershocks took place on 2 March 1985 in Santiago, Chile. The characteristics of over 22,000 births registered in three public hospitals in the same year were reviewed. A significant increase in the rate of facial clefts was found; 2.01 per 1000 births in contrast to 1.6 per 1000 births in previous years. The increase was greater in those born in September: 3.8 per 1000 births. This increase in clefting could be related to the effects of stress in mothers induced by the earthquake, and to test this hypothesis 13.5-day-old embryos from two inbred mouse strains, A/Sn and C57BL/10, were subjected to a similar stress using a vibrator cage to imitate the main shock and the first five replicas of the earthquake. The same intensity and duration of shock as in the original earthquake were applied. The results were 19.8% cleft palates in stressed A/Sn mice and no clefting in C57BL/10. This was highly significant in A/Sn mice (chi 2 = 19.9; P < 0.001) but not in C57BL/10. No clefting was found in controls in both strains. A surprising finding was the proportion of resorbed embryos in the stressed groups, which increased from 8.3 to 49.3% in A/Sn and from 5.8 to 48.3% in C57BL/10. It is known that A/Sn mice are genetically sensitive to cleft palate induction by cortisone, while C57BL/10 are not. These findings in mice support the stress hypothesis for the increase in cleft palate observed in humans. The increase in resorbed embryos in both strains also suggests an effect on stress.

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The most generally accepted model for cleft lip/palate not associated to specific syndromes has been the one that postulates multifactorial inheritance with a threshold. Recent studies using complex analytical techniques have suggested the existence of a major gene with decreased penetrance in its etiology. Some authors have postulated that only a fraction of all cases of non-syndromic CL (P) would be explained by a single major gene. Other cases may be due to different genes, to environmental agents or to the interaction between them. The present study tests the monogenic inheritance model for CL (P) using segregation analysis in a sample of 211 extended pedigrees collected through CL (P) affected probands. The hypotheses of an autosomic recessive gene was analyzed in 151 sibships (size 2 or more) using "Apert's" method, "maximum likelihood method", "singles method" and "sib's, method" (single incomplete ascertainment). Results obtained do not support the hypotheses of autosomal recessive inheritance. Instead, the hypothesis of an autosomal dominant mode of inheritance with low penetrance is not rejected when analyzing the proportion of normal and affected progeny in certain types of matings in a subsample of 30 extended pedigrees with two or more affected individuals.

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In recent studies we have demonstrated that the model that better explains the genetic etiology of non syndromic cleft lip/palate (CL/P) in the Chilean population is one that postulates the existence of a major dominant autosomic locus with low penetrance, without discarding the possible influence of polygenes. Similar conclusions have been communicated by others authors in different populations. Thus, investigations have been initiated to seek possible associations between candidate genes and restriction length polymorphisms (RFLP's), specifically between Transforming Growth Factor Alpha (TGFA) gene RFLP's and CL/P, in caucasian populations. Results thus far obtained have been inconclusive. Therefore, the aim of this work was to study this association in the Chilean population, that is ethnically different. The gene and phenotype frequencies of the TGFA gene BamH1 polymorphism in CL/P probands (n = 21) and controls (n = 16) were determined. No significant differences were detected in the frequencies of the A1 and A2 alleles of the TGFA gene between probands and controls. These results do not support an association between the cleft palate phenotype and TGFA RFLP.

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Investigación que muestra la magnitud de una serie de problemas sanitarios relacionados con la venta ambulatoria de comidas en la ciudad de Lima. Destaca y analiza las deficientes condiciones higiénicas de los puestos de venta y sus alrededores; las precarias condiciones de conservación e higiene de los utensilios y vajillas; los escasos o prácticamente nulos servicios de saneamiento básico; la escasa capacitación que en higiene de alimentos reciben los ambulantes; la baja calidad de los víveres que se emplean en la preparación de las comidas; y el consumo de platos que por su naturaleza constituyen medios ideales para la transmisión de enfermedades infecciosas y parasitarias. Propone soluciones a esta problemática

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The present study investigates the effects of several nonsteroidal anti-inflammatory drugs on mouse palatal fusion in vivo and in vitro. Five different nonsteroidal anti-inflammatory agents were injected into pregnant mice of the AKR-strain on day 13.5 of gestation. Paired palatal processes from 13.5- and 14.5-day-old mouse embryos were organ-cultured for 72 hours in control and anti-inflammatory drug-containing media. Each experimental group of animals and explants received one of the following drugs: naproxen, sulindac, indomethacin, diclofenac, and mefenamic acid. Drug treatment induced different frequencies of cleft palate in the offspring. The most teratogenic drug was sulindac, and indomethacin was almost ineffective. In vitro each drug prevented fusion of the palatine processes in treated explants, and the degree of inhibition was dependent on the stage of development at the time of explanation. In both the in vivo and in vitro experiments, the drugs prevented medial epithelial cell breakdown that normally occurs in the medial secondary palatal epithelium. The results obtained in the present study suggest that prostaglandins may play an important role in normal differentiation of the developing palatine region.

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We studied the effect of nonsteroid antiinflammatory (Indomethacin, R), in the palate fusion of rat embryos from different strains with variable susceptibility and also the influence of glucocorticoids. Indomethacin inhibits the fusion of the palate process with variable rate depending of the rat strain. In reciprocal inbred we observed that the effect is greater in embryo from susceptible females than from resistant females. This demonstrates that there are a maternal influence in the induction of cleft palate due to Indomethacin.

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Susceptibility to glucocorticoid-induced cleft palate in mice has been related to the H-2 histocompatibility complex on chromosome 17. Indomethacin administered in vitro to palatal processes from 13.5-day-old mouse embryos inhibited palatal fusion. Strains with the A background and the H-2a haplotype had significantly higher rates of inhibition than their partners with the H-2b haplotype. The inhibition was prevented in both strains by the addition to the media of prostaglandin E2, but this corrective effect was greater in the A strain with the H-2a haplotype. Thus, blockade of palatal fusion involves prostaglandins, suggesting a similar genetic and biochemical pathway for the different susceptibilities to cleft palate induced by both indomethacin and glucocorticoids.

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