Clinical, microbiological, and immunological markers of gingival and periodontal disease induction and progression

The potential impact of periodontal disease, a suspected risk factor for systemic diseases, presents challenges for health promotion and disease prevention strategies. This study examined clinical, microbiological, and immunological factors in a disease model to identify potential biomarkers that may be useful in predicting the onset and severity of both inflammatory and destructive periodontal disease. This project used an historical cohort design based on data obtained from 47 adult, female nonhuman primates followed over a 6-year period for 5 unique projects where the ligature-induced model of periodontitis was utilized. Standardization of protocols for sample collection allowed for comparison over time. Bleeding and pocket depth measures were selected as the dependent variables of relevance to humans based upon the literature and historical observations. Exposure variables included supragingival plaque, attachment level, total bacteria, black-pigmented bacteria, Gram-negative and Gram-positive bacteria, total IgG and IgA in crevicular fluid, specific IgG antibody in both crevicular fluid and serum, and IgG antibody to four select pathogenic microorganisms. Three approaches were used to analyze the data from this study. The first approach tested for differences in the means of the response variables within the group and among longitudinal observations within the group at each time point. The second approach examined the relationship among the clinical, microbiological, and immunological variables using correlation coefficients and stratified analyses. Multivariable models using GEE for repeated measures were produced as a predictive description of the induction and progression of gingivitis and periodontal disease. The multivariable models for bleeding (gingivitis) include supragingival plaque, total bacteria and total IgG while the second also contains supragingival plaque, Gram-positive bacteria, and total IgG. Two multivariable models emerged for periodontal disease. One multivariable model contains plaque, total bacteria, total IgG and attachment level. The second model includes black-pigmented bacteria, total bacteria, antibody to Campylobacter rectus, and attachment level. Utilization of the nonhuman primate model to prospectively examine causal hypotheses can provide a focus for human research on the mechanisms of progression from health to gingivitis to periodontitis. Ultimately, causal theories can guide strategies to prevent disease initiation and reduce disease severity. ^

The effectiveness of a promotora-led intervention for Mexican Americans with type 2 diabetes

Purpose. The purpose of this randomized control repeated measures trial was to determine the effectiveness of a self-management intervention led by community lay workers called promotoras on the health outcomes of Mexican Americans with type 2 diabetes living in a major city on the Texas - Mexico border. The specific aims of this study, in relation to the intervention group participants, were to: (1) decrease the glycosylated hemoglobin (A1c) blood levels at the six-month assessment, (2) increase diabetes knowledge at the three and six-month assessments, and (3) strengthen the participants' beliefs in their ability to manage diabetes at the three and six-month assessments.^ Methods. One hundred and fifty Mexican American participants were recruited at a Catholic faith-based clinic and randomized into an intervention group and a usual-care control group. Personal characteristics, acculturation and baseline A1c, diabetes knowledge and diabetes health beliefs were measured. The six-month, two-phase intervention was culturally specific and it was delivered entirely by promotoras. Phase One of the intervention consisted of sixteen hours of participative group education and bi-weekly telephone contact follow-up. Phase Two consisted of bi-weekly follow-up using inspirational faith-based health behavior change postcards. The A1c levels, diabetes knowledge and diabetes health beliefs were measured at baseline, and three and six months post-baseline. The mean changes between the groups were analyzed using analysis of covariance. ^ Results. The 80% female sample, with a mean age of 58 years, demonstrated very low: acculturation, income, education, health insurance coverage, and strong Catholicism. No significant changes were noted at the three-month assessment, but the mean change of the A1c levels (F (1, 148 = 10.28, p < .001) and the diabetes knowledge scores (F (1, 148 = 9.0, p < .002) of the intervention group improved significantly at six months, adjusting for health insurance coverage. The diabetes health belief scores decreased in both groups.^ Conclusions. This study demonstrated that an intervention led by promotoras could result in decreased A1c levels and increased diabetes knowledge in spite of the very low acculturation, educational level and insurance coverage of the intervention group participants. Clinical implications and recommendations for future research are suggested. ^

Ambulatory blood pressure and physical activity in heart failure

Background. Ambulatory blood pressure (ABP) measurement is a means of monitoring cardiac function in a noninvasive way, but little is known about ABP in heart failure (HF) patients. Blood pressure (BP) declines during sleep as protection from consistent BP load, a phenomenon termed "dipping." The aims of this study were (1) to compare BP dipping and physical activity between two groups of HF patients with different functional statuses and (2) to determine whether the strength of the association between ambulatory BP and PA is different between these two different functional statuses of HF. ^ Methods. This observational study used repeated measures of ABP and PA over a 24-hour period to investigate the profiles of BP and PA in community-based individuals with HF. ABP was measured every 30 minutes by using a SpaceLabs 90207, and a Basic Motionlogger actigraph was used to measure PA minute by minute. Fifty-six participants completed both BP and physical activity for a 24-hour monitoring period. Functional status was based on New York Heart Association (NYHA) ratings. There were 27 patients with no limitation of PA (NYHA class I HF) and 29 with some limitation of PA but no discomfort at rest (NYHA class II or III HF). The sample consisted of 26 men and 30 women, aged 45 to 91 years (66.96 ± 12.35). ^ Results. Patients with NYHA class I HF had significantly greater dipping percent than those with NYHA class II/III HF after controlling their left ventricular ejection fraction (LVEF). In a mixed model analysis (PROC MIXED, SAS Institute, v 9.1), PA was significantly related to ambulatory systolic and diastolic BP and mean arterial pressure. The strength of the association between PA and ABP readings was not significantly different for the two groups of patients. ^ Conclusions. These preliminary findings demonstrate differences between NYHA class I and class II/III of HF in BP dipping status and ABP but not PA. Longitudinal research is recommended to improve understanding of the influence of disease progression on changes in 24-hour physical activity and BP profiles of this patient population. ^ Key Words. Ambulatory Blood Pressure; Blood Pressure Dipping; Heart Failure; Physical Activity. ^

Determining appropriate measurement methods for etiological research of computing-related musculoskeletal symptoms and disorders

Two studies among college students were conducted to evaluate appropriate measurement methods for etiological research on computing-related upper extremity musculoskeletal disorders (UEMSDs). ^ A cross-sectional study among 100 graduate students evaluated the utility of symptoms surveys (a VAS scale and 5-point Likert scale) compared with two UEMSD clinical classification systems (Gerr and Moore protocols). The two symptom measures were highly concordant (Lin's rho = 0.54; Spearman's r = 0.72); the two clinical protocols were moderately concordant (Cohen's kappa = 0.50). Sensitivity and specificity, endorsed by Youden's J statistic, did not reveal much agreement between the symptoms surveys and clinical examinations. It cannot be concluded self-report symptoms surveys can be used as surrogate for clinical examinations. ^ A pilot repeated measures study conducted among 30 undergraduate students evaluated computing exposure measurement methods. Key findings are: temporal variations in symptoms, the odds of experiencing symptoms increased with every hour of computer use (adjOR = 1.1, p < .10) and every stretch break taken (adjOR = 1.3, p < .10). When measuring posture using the Computer Use Checklist, a positive association with symptoms was observed (adjOR = 1.3, p < 0.10), while measuring posture using a modified Rapid Upper Limb Assessment produced unexpected and inconsistent associations. The findings were inconclusive in identifying an appropriate posture assessment or superior conceptualization of computer use exposure. ^ A cross-sectional study of 166 graduate students evaluated the comparability of graduate students to College Computing & Health surveys administered to undergraduate students. Fifty-five percent reported computing-related pain and functional limitations. Years of computer use in graduate school and number of years in school where weekly computer use was ≥ 10 hours were associated with pain within an hour of computing in logistic regression analyses. The findings are consistent with current literature on both undergraduate and graduate students. ^

Determinants of CD4 cell count decline after treatment interruption

Patients who had started HAART (Highly Active Anti-Retroviral Treatment) under previous aggressive DHHS guidelines (1997) underwent a life-long continuous HAART that was associated with many short term as well as long term complications. Many interventions attempted to reduce those complications including intermittent treatment also called pulse therapy. Many studies were done to study the determinants of rate of fall in CD4 count after interruption as this data would help guide treatment interruptions. The data set used here was a part of a cohort study taking place at the Johns Hopkins AIDS service since January 1984, in which the data were collected both prospectively and retrospectively. The patients in this data set consisted of 47 patients receiving via pulse therapy with the aim of reducing the long-term complications. ^ The aim of this project was to study the impact of virologic and immunologic factors on the rate of CD4 loss after treatment interruption. The exposure variables under investigation included CD4 cell count and viral load at treatment initiation. The rates of change of CD4 cell count after treatment interruption was estimated from observed data using advanced longitudinal data analysis methods (i.e., linear mixed model). Using random effects accounted for repeated measures of CD4 per person after treatment interruption. The regression coefficient estimates from the model was then used to produce subject specific rates of CD4 change accounting for group trends in change. The exposure variables of interest were age, race, and gender, CD4 cell counts and HIV RNA levels at HAART initiation. ^ The rate of fall of CD4 count did not depend on CD4 cell count or viral load at initiation of treatment. Thus these factors may not be used to determine who can have a chance of successful treatment interruption. CD4 and viral load were again studied by t-tests and ANOVA test after grouping based on medians and quartiles to see any difference in means of rate of CD4 fall after interruption. There was no significant difference between the groups suggesting that there was no association between rate of fall of CD4 after treatment interruption and above mentioned exposure variables. ^

The role of workplace absence as an organizational mechanism in predicting employee alcohol and drug disorders

Background. EAP programs for airline pilots in companies with a well developed recovery management program are known to reduce pilot absenteeism following treatment. Given the costs and safety consequences to society, it is important to identify pilots who may be experiencing an AOD disorder to get them into treatment. ^ Hypotheses. This study investigated the predictive power of workplace absenteeism in identifying alcohol or drug disorders (AOD). The first hypothesis was that higher absenteeism in a 12-month period is associated with higher risk that an employee is experiencing AOD. The second hypothesis was that AOD treatment would reduce subsequent absence rates and the costs of replacing pilots on missed flights. ^ Methods. A case control design using eight years (time period) of monthly archival absence data (53,000 pay records) was conducted with a sample of (N = 76) employees having an AOD diagnosis (cases) matched 1:4 with (N = 304) non-diagnosed employees (controls) of the same profession and company (male commercial airline pilots). Cases and controls were matched on the variables age, rank and date of hire. Absence rate was defined as sick time hours used over the sum of the minimum guarantee pay hours annualized using the months the pilot worked for the year. Conditional logistic regression was used to determine if absence predicts employees experiencing an AOD disorder, starting 3 years prior to the cases receiving the AOD diagnosis. A repeated measures ANOVA, t tests and rate ratios (with 95% confidence intervals) were conducted to determine differences between cases and controls in absence usage for 3 years pre and 5 years post treatment. Mean replacement costs were calculated for sick leave usage 3 years pre and 5 years post treatment to estimate the cost of sick leave from the perspective of the company. ^ Results. Sick leave, as measured by absence rate, predicted the risk of being diagnosed with an AOD disorder (OR 1.10, 95% CI = 1.06, 1.15) during the 12 months prior to receiving the diagnosis. Mean absence rates for diagnosed employees increased over the three years before treatment, particularly in the year before treatment, whereas the controls’ did not (three years, x = 6.80 vs. 5.52; two years, x = 7.81 vs. 6.30, and one year, x = 11.00cases vs. 5.51controls. In the first year post treatment compared to the year prior to treatment, rate ratios indicated a significant (60%) post treatment reduction in absence rates (OR = 0.40, CI = 0.28, 0.57). Absence rates for cases remained lower than controls for the first three years after completion of treatment. Upon discharge from the FAA and company’s three year AOD monitoring program, case’s absence rates increased slightly during the fourth year (controls, x = 0.09, SD = 0.14, cases, x = 0.12, SD = 0.21). However, the following year, their mean absence rates were again below those of the controls (controls, x = 0.08, SD = 0.12, cases, x¯ = 0.06, SD = 0.07). Significant reductions in costs associated with replacing pilots calling in sick, were found to be 60% less, between the year of diagnosis for the cases and the first year after returning to work. A reduction in replacement costs continued over the next two years for the treated employees. ^ Conclusions. This research demonstrates the potential for workplace absences as an active organizational surveillance mechanism to assist managers and supervisors in identifying employees who may be experiencing or at risk of experiencing an alcohol/drug disorder. Currently, many workplaces use only performance problems and ignore the employee’s absence record. A referral to an EAP or alcohol/drug evaluation based on the employee’s absence/sick leave record as incorporated into company policy can provide another useful indicator that may also carry less stigma, thus reducing barriers to seeking help. This research also confirms two conclusions heretofore based only on cross-sectional studies: (1) higher absence rates are associated with employees experiencing an AOD disorder; (2) treatment is associated with lower costs for replacing absent pilots. Due to the uniqueness of the employee population studied (commercial airline pilots) and the organizational documentation of absence, the generalizability of this study to other professions and occupations should be considered limited. ^ Transition to Practice. The odds ratios for the relationship between absence rates and an AOD diagnosis are precise; the OR for year of diagnosis indicates the likelihood of being diagnosed increases 10% for every hour change in sick leave taken. In practice, however, a pilot uses approximately 20 hours of sick leave for one trip, because the replacement will have to be paid the guaranteed minimum of 20 hour. Thus, the rate based on hourly changes is precise but not practical. ^ To provide the organization with practical recommendations the yearly mean absence rates were used. A pilot flies on average, 90 hours a month, 1080 annually. Cases used almost twice the mean rate of sick time the year prior to diagnosis (T-1) compared to controls (cases, x = .11, controls, x = .06). Cases are expected to use on average 119 hours annually (total annual hours*mean annual absence rate), while controls will use 60 hours. The cases’ 60 hours could translate to 3 trips of 20 hours each. Management could use a standard of 80 hours or more of sick time claimed in a year as the threshold for unacceptable absence, a 25% increase over the controls (a cost to the company of approximately of $4000). At the 80-hour mark, the Chief Pilot would be able to call the pilot in for a routine check as to the nature of the pilot’s excessive absence. This management action would be based on a company standard, rather than a behavioral or performance issue. Using absence data in this fashion would make it an active surveillance mechanism. ^

Obesity during pregnancy on vagal tone, hemoglobin A1c, oxygenation, and perinatal outcomes

Purpose: To examine the effect of obesity and gestational weight gain on heart rate variability (HRV), oxygenation (HbO 2 and SpO2), hemoglobin A1c (HbA1c) and the frequency of pregnancy complications in obese (O) and non-obese (NO) women.^ Design: The study was an observational comparison study with a repeated measures design. ^ Setting: The setting was a low risk prenatal, university clinic located in a large southeastern metropolitan city. ^ Sample: The sample consisted of a volunteer group of 41 pregnant women who were observed at the three time points of 20, 28, and 36 weeks gestation. ^ Analysis: Analysis included general linear modeling with repeated measures to test for group differences with changes over time on vagal response, HbA1c, and oxygenation. Odds ratios were computed to compare the frequency of birth outcomes. ^ Findings: The interaction effect of time between O and NO women on HbO2 was significant. The mean HP, RSA, and HbO2 changed significantly over time within the NO women. The mean HbA 1c increased significantly over time within the O women. Women with excess gestational weight gain had significantly lower heart period than women with weight gain within the IOM recommendations. Obese women were more likely to have Group B streptococcal infections, gestational hypertension, give birth by cesarean or instrument assistance, and have at least one postnatal event. ^ Conclusions: Monitoring HRV, oxygenation, and HbA1c using minimally invasive measures may permit early identification of alterations in autonomic response. Implementation of interventions to promote vagal tone may help to reduce risks for adverse perinatal outcomes related to obesity. Future studies should examine the effect of obesity on the vagal response and perinatal outcomes. ^

Identfying predictors of St. Louis encephalitis activity in Houston Texas

Generalized linear Poisson and logistic regression models were utilized to examine the relationship between temperature and precipitation and cases of Saint Louis encephalitis virus spread in the Houston metropolitan area. The models were investigated with and without repeated measures, with a first order autoregressive (AR1) correlation structure used for the repeated measures model. The two types of Poisson regression models, with and without correlation structure, showed that a unit increase in temperature measured in degrees Fahrenheit increases the occurrence of the virus 1.7 times and a unit increase in precipitation measured in inches increases the occurrence of the virus 1.5 times. Logistic regression did not show these covariates to be significant as predictors for encephalitis activity in Houston for either correlation structure. This discrepancy for the logistic model could be attributed to the small data set.^ Keywords: Saint Louis Encephalitis; Generalized Linear Model; Poisson; Logistic; First Order Autoregressive; Temperature; Precipitation. ^

The role of cardiorespiratory fitness and weight status on 24-hr ambulatory blood pressure among adolescents

BACKGROUND: This observational research study investigated the association of cardiorespiratory fitness and weight status with repeated measures of 24-hr ambulatory blood pressure (24-hr ABP). Little is known about these associations and few data exist examining the interaction between cardiorespiratory fitness and weight status and the contributions of each on 24-hr ABP in youth. ^ METHODS: This research study used secondary analysis data from the "Adolescent Blood Pressure and Anger: Ethnic Differences" study. This current study sample included 374 African-American, Anglo-American, and Mexican-American adolescents 11-16 years of age. Mixed-effects models were used for testing the relationship between weight status and cardiorespiratory fitness and repeated measures of ambulatory blood pressure over 24 hours (24-hr ABP). Weight status was categorized into "normal weight" (BMI<85th percentile), "overweight" (85th≤BMI<95th), and "obese" (BMI≥95th). Cardiorespiratory fitness, determined by heart rate recovery (HRR), was defined as the difference between heart rate at peak exercise and heart rate at two minutes post-exercise, as measured by a height-adjusted step test and stratified into two groups: low and high fitness, using a median split. Ambulatory blood pressure (ABP) was monitored for a 24-hr period on a school day using the Spacelabs ambulatory monitor (Model 90207). Blood pressure and heart rate were recorded at 30 minute intervals throughout the day of recording and at 60 minute intervals during sleep. ^ RESULTS: No significant associations were found between weight status and mean 24-hr systolic blood pressure (SBP) or mean arterial pressure (MAP). A significant and inverse association between weight status and mean 24-hr diastolic blood pressure (DBP) was revealed. Cardiorespiratory fitness was significantly and inversely associated with mean 24-hr ABP. High fitness adolescents had significantly lower mean 24-hr SPB, DBP, and MAP measurements than low fitness adolescents. Compared to low fitness adolescents, high fitness adolescents had 1.90 mmHg, 1.16 mmHg, and 1.68 mmHg lower mean 24-hr SBP, DBP, and MAP, respectively. Additionally, high fitness appeared to afford protection from higher mean 24-hr SBP and MAP, irrespective of weight status. Among normal weight adolescents, low fitness resulted in higher mean 24-hr SBP and MAP, compared to their fit counterparts. Among adolescents categorized as high fitness, increasing weight status did not appear to result in higher mean 24-hr SBP or MAP. Cardiorespiratory fitness, rather than weight status, appeared to be a more dominant predictor of mean 24-hr SBP and MAP. ^ CONCLUSIONS: To our knowledge, this research is the first study to investigate the independent and combined contributions of cardiorespiratory fitness and weight status on 24-hr ABP, all objectively measured. The results of this study may potentially guide and inform future research. It appears that early cardiovascular disease (CVD) prevention should focus on improving cardiorespiratory fitness levels among all adolescents, particularly those adolescents least fit, regardless of their weight status, while obesity prevention efforts continue.^

Health outcomes, quality improvement and cost-effectiveness of the Community Diabetes Education (CoDE) program: Results of a randomized controlled trial

The objectives of this dissertation were to evaluate health outcomes, quality improvement measures, and the long-term cost-effectiveness and impact on diabetes-related microvascular and macrovascular complications of a community health worker-led culturally tailored diabetes education and management intervention provided to uninsured Mexican Americans in an urban faith-based clinic. A prospective, randomized controlled repeated measures design was employed to compare the intervention effects between: (1) an intervention group (n=90) that participated in the Community Diabetes Education (CoDE) program along with usual medical care; and (2) a wait-listed comparison group (n=90) that received only usual medical care. Changes in hemoglobin A1c (HbA1c) and secondary outcomes (lipid status, blood pressure and body mass index) were assessed using linear mixed-models and an intention-to-treat approach. The CoDE group experienced greater reduction in HbA1c (-1.6%, p<.001) than the control group (-.9%, p<.001) over the 12 month study period. After adjusting for group-by-time interaction, antidiabetic medication use at baseline, changes made to the antidiabetic regime over the study period, duration of diabetes and baseline HbA1c, a statistically significant intervention effect on HbA1c (-.7%, p=.02) was observed for CoDE participants. Process and outcome quality measures were evaluated using multiple mixed-effects logistic regression models. Assessment of quality indicators revealed that the CoDE intervention group was significantly more likely to have received a dilated retinal examination than the control group, and 53% achieved a HbA1c below 7% compared with 38% of control group subjects. Long-term cost-effectiveness and impact on diabetes-related health outcomes were estimated through simulation modeling using the rigorously validated Archimedes Model. Over a 20 year time horizon, CoDE participants were forecasted to have less proliferative diabetic retinopathy, fewer foot ulcers, and reduced numbers of foot amputations than control group subjects who received usual medical care. An incremental cost-effectiveness ratio of $355 per quality-adjusted life-year gained was estimated for CoDE intervention participants over the same time period. The results from the three areas of program evaluation: impact on short-term health outcomes, quantification of improvement in quality of diabetes care, and projection of long-term cost-effectiveness and impact on diabetes-related health outcomes provide evidence that a community health worker can be a valuable resource to reduce diabetes disparities for uninsured Mexican Americans. This evidence supports formal integration of community health workers as members of the diabetes care team.^

Impacto de un programa de alfabetización temprana en niños de sectores urbano marginales

Este trabajo tiene como objetivos contribuir al conocimiento del proceso de alfabetización temprana en español en niños de sectores sociales desfavorecidos, y analizar los resultados de la implementación de un programa destinado al desarrollo de habilidades y conocimientos relativos a la lectura y la escritura inicial. El tipo de intervención propuesta, surge del programa ECOS , ya probado en español, pero no replicado suficientemente en niños de edades preescolares. Se ha estudiado el impacto de la aplicación de dicho programa, destinado a niños de 4, 5 y 6 años de edad, pertenecientes a sectores en desventaja socio económica, que concurrían a jardines de infantes de la Provincia de Buenos Aires (Argentina). Esta tesis se enmarca en los modelos de investigación proporcionados desde la Psicología Cognitiva y la corriente sociocultural, y sustenta la hipótesis de que el presente programa incrementa, en mayor medida que la curricula escolar las habilidades de conciencia fonológica, el reconocimiento y escritura de palabras y textos, así como también las habilidades de comprensión y producción oral de textos narrativos, en el corto y mediano plazo. Su originalidad reside en la especificidad del programa seleccionado y en haber considerado de manera conjunta la evaluación de su impacto, a través de un seguimiento longitudinal, que permitió no sólo verificar la persistencia de sus efectos a mediano plazo, sino también las relaciones que guardan entre sí las variables evaluadas, el poder predictivo de unas sobre otras, el momento en el que se produce el impacto y sobre cuáles de las variables y el tamaño de ese impacto. La investigación se realizó comparando el desempeño de dos grupos de niños uno experimental en el cual se aplicó dicho programa y uno control. Al inicio de la investigación los niños fueron homologados en cuanto al estrato social de procedencia (identificado por el nivel educacional y ocupacional de los padres), a las características de los establecimientos educativos a los que concurrían y a la de los contextos alfabetizadores hogareños así como respecto de sus conocimientos y habilidades iniciales. Las variables a ser consideradas en la evaluación de los desempeños fueron las siguientes: habilidades de conciencia fonológica, conocimientos sobre material impreso y sobre el sistema de escritura, lectura y escritura de palabras de diferente longitud y complejidad, lectura de pseudopalabras, lectura y escritura de textos y comprensión y renarración oral de textos narrativos. Los niños fueron evaluados en cuatro oportunidades diferentes, comparándose los desempeños de ambos grupos en el transcurso de dos años y medio: Se aplicó un modelo de medidas repetidas y se calculó el estadístico Effect Size para todas las variables al finalizar la intervención y mediano plazo. Las conclusiones extraídas de esta investigación ponen en evidencia el impacto positivo del programa de intervención. A mediano plazo se verifica una diferencia promedio de alrededor del 30 entre los niños de ambos grupos, en los porcentajes de aciertos en las pruebas que evalúan las habilidades de conciencia fonológica, lectura y escritura de palabras y comprensión de textos

Impacto de un programa de alfabetización temprana en niños de sectores urbano marginales

Este trabajo tiene como objetivos contribuir al conocimiento del proceso de alfabetización temprana en español en niños de sectores sociales desfavorecidos, y analizar los resultados de la implementación de un programa destinado al desarrollo de habilidades y conocimientos relativos a la lectura y la escritura inicial. El tipo de intervención propuesta, surge del programa ECOS , ya probado en español, pero no replicado suficientemente en niños de edades preescolares. Se ha estudiado el impacto de la aplicación de dicho programa, destinado a niños de 4, 5 y 6 años de edad, pertenecientes a sectores en desventaja socio económica, que concurrían a jardines de infantes de la Provincia de Buenos Aires (Argentina). Esta tesis se enmarca en los modelos de investigación proporcionados desde la Psicología Cognitiva y la corriente sociocultural, y sustenta la hipótesis de que el presente programa incrementa, en mayor medida que la curricula escolar las habilidades de conciencia fonológica, el reconocimiento y escritura de palabras y textos, así como también las habilidades de comprensión y producción oral de textos narrativos, en el corto y mediano plazo. Su originalidad reside en la especificidad del programa seleccionado y en haber considerado de manera conjunta la evaluación de su impacto, a través de un seguimiento longitudinal, que permitió no sólo verificar la persistencia de sus efectos a mediano plazo, sino también las relaciones que guardan entre sí las variables evaluadas, el poder predictivo de unas sobre otras, el momento en el que se produce el impacto y sobre cuáles de las variables y el tamaño de ese impacto. La investigación se realizó comparando el desempeño de dos grupos de niños uno experimental en el cual se aplicó dicho programa y uno control. Al inicio de la investigación los niños fueron homologados en cuanto al estrato social de procedencia (identificado por el nivel educacional y ocupacional de los padres), a las características de los establecimientos educativos a los que concurrían y a la de los contextos alfabetizadores hogareños así como respecto de sus conocimientos y habilidades iniciales. Las variables a ser consideradas en la evaluación de los desempeños fueron las siguientes: habilidades de conciencia fonológica, conocimientos sobre material impreso y sobre el sistema de escritura, lectura y escritura de palabras de diferente longitud y complejidad, lectura de pseudopalabras, lectura y escritura de textos y comprensión y renarración oral de textos narrativos. Los niños fueron evaluados en cuatro oportunidades diferentes, comparándose los desempeños de ambos grupos en el transcurso de dos años y medio: Se aplicó un modelo de medidas repetidas y se calculó el estadístico Effect Size para todas las variables al finalizar la intervención y mediano plazo. Las conclusiones extraídas de esta investigación ponen en evidencia el impacto positivo del programa de intervención. A mediano plazo se verifica una diferencia promedio de alrededor del 30 entre los niños de ambos grupos, en los porcentajes de aciertos en las pruebas que evalúan las habilidades de conciencia fonológica, lectura y escritura de palabras y comprensión de textos

Impacto de un programa de alfabetización temprana en niños de sectores urbano marginales

Este trabajo tiene como objetivos contribuir al conocimiento del proceso de alfabetización temprana en español en niños de sectores sociales desfavorecidos, y analizar los resultados de la implementación de un programa destinado al desarrollo de habilidades y conocimientos relativos a la lectura y la escritura inicial. El tipo de intervención propuesta, surge del programa ECOS , ya probado en español, pero no replicado suficientemente en niños de edades preescolares. Se ha estudiado el impacto de la aplicación de dicho programa, destinado a niños de 4, 5 y 6 años de edad, pertenecientes a sectores en desventaja socio económica, que concurrían a jardines de infantes de la Provincia de Buenos Aires (Argentina). Esta tesis se enmarca en los modelos de investigación proporcionados desde la Psicología Cognitiva y la corriente sociocultural, y sustenta la hipótesis de que el presente programa incrementa, en mayor medida que la curricula escolar las habilidades de conciencia fonológica, el reconocimiento y escritura de palabras y textos, así como también las habilidades de comprensión y producción oral de textos narrativos, en el corto y mediano plazo. Su originalidad reside en la especificidad del programa seleccionado y en haber considerado de manera conjunta la evaluación de su impacto, a través de un seguimiento longitudinal, que permitió no sólo verificar la persistencia de sus efectos a mediano plazo, sino también las relaciones que guardan entre sí las variables evaluadas, el poder predictivo de unas sobre otras, el momento en el que se produce el impacto y sobre cuáles de las variables y el tamaño de ese impacto. La investigación se realizó comparando el desempeño de dos grupos de niños uno experimental en el cual se aplicó dicho programa y uno control. Al inicio de la investigación los niños fueron homologados en cuanto al estrato social de procedencia (identificado por el nivel educacional y ocupacional de los padres), a las características de los establecimientos educativos a los que concurrían y a la de los contextos alfabetizadores hogareños así como respecto de sus conocimientos y habilidades iniciales. Las variables a ser consideradas en la evaluación de los desempeños fueron las siguientes: habilidades de conciencia fonológica, conocimientos sobre material impreso y sobre el sistema de escritura, lectura y escritura de palabras de diferente longitud y complejidad, lectura de pseudopalabras, lectura y escritura de textos y comprensión y renarración oral de textos narrativos. Los niños fueron evaluados en cuatro oportunidades diferentes, comparándose los desempeños de ambos grupos en el transcurso de dos años y medio: Se aplicó un modelo de medidas repetidas y se calculó el estadístico Effect Size para todas las variables al finalizar la intervención y mediano plazo. Las conclusiones extraídas de esta investigación ponen en evidencia el impacto positivo del programa de intervención. A mediano plazo se verifica una diferencia promedio de alrededor del 30 entre los niños de ambos grupos, en los porcentajes de aciertos en las pruebas que evalúan las habilidades de conciencia fonológica, lectura y escritura de palabras y comprensión de textos

Bone metabolic and hormonal characteristics of Australian Antarctic expeditioners

Summary: Serum 25(OH)D levels decline without sunlight exposure. We studied 120 expeditioners to Antarctica to determine the skeletal and hormonal responses to sunlight deprivation. With emerging vitamin D insufficiency, serum calcium decreased, PTH increased, and bone loss at the proximal femur was observed. Baseline serum 25(OH)D levels >100 nmol/L prevented vitamin D insufficiency. Introduction: Vitamin D stores deplete without adequate sunlight exposure unless supplementation is provided. We studied 120 healthy adults who spent a year in Antarctica as a model for sunlight deprivation to define the timing and magnitude of the skeletal and hormonal responses to emerging vitamin D insufficiency. Methods: Fasting blood samples were assessed at baseline, 6 and 12 months for serum 25-hydroxyvitamin D (25(OH)D), osteocalcin (OC), bone formation (P1NP) and resorption (CTx), PTH and calcium. Lumbar spine and proximal femur BMD was measured using DXA. Differences over time were determined using repeated measures ANOVA. Percent changes were expressed as (Delta value/(value A +value B)/2)x100. Relationships between outcome measures were determined using Spearman's correlations. Results: Vitamin D insufficiency (<50 nmol/L) was observed in 85% of expeditioners by 6 months when serum calcium decreased and PTH increased (p<0.01). By 12 months, OC increased by 7.4±3.0% (p<0.05), and BMD decreased by 1.0±2.0% at the total proximal femur (p<0.05). For those with vitamin D sufficiency at baseline (>50 nmol/L), sunlight deprivation produced vitamin D insufficiency within 4 months unless baseline values were >100 nmol/L. Conclusion: Supplementation may be necessary for expeditioners with limited access to UV light.

Influence of the vitreomacular interface on the efficacy of intravitreal therapy for uveitis-associated cystoid macular oedema.

PURPOSE To evaluate the effect of the vitreomacular interface (VMI) on treatment efficacy of intravitreal therapy in uveitic cystoid macular oedema (CME). METHODS Retrospective analysis of CME resolution, CME recurrence rate and monthly course of central retinal thickness (CRT), retinal volume (RV) and best corrected visual acuity (BCVA) after intravitreal injection with respect to the VMI configuration on spectral-domain OCT using chi-squared test and repeated measures anova adjusted for confounding covariates epiretinal membrane, administered drug and subretinal fluid. RESULTS Fifty-nine eyes of 53 patients (mean age: 47.4 ± 16.9 years) were included. VMI status had no effect on complete CME resolution rate (p = 0.16, corrected p-value: 0.32), time until resolution (p = 0.09, corrected p-value: 0.27) or CME relapse rate (p = 0.29, corrected p-value: 0.29). Change over time did not differ among the VMI configuration groups for BVCA (p = 0.82) and RV (p = 0.18), but CRT decrease was greater and faster in the posterior vitreous detachment (PVD) group compared to the posterior vitreous attachment (PVA) and vitreous macular adhesion (VMA) groups (p = 0.04). Also, the percentage of patients experiencing a ≥ 20% CRT thickness decrease after intravitreal injection was greater in the PVD group (83%) compared to the VMA (64%) and the PVA (16%) group (p = 0.027), however, not after correction for multiple testing (corrected p-value: 0.11). CONCLUSION The VMI configuration seems to be a factor contributing to treatment efficacy in uveitic CME in terms of CRT decrease, although BCVA outcome did not differ according to VMI status.