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Biomedical subjects

B Munoz

Publications and source records attributed to B Munoz.

At least 19 recordsLinked to original sources
PubMed2001

Hormone replacement therapy and lens opacities: the Salisbury Eye Evaluation project.

BACKGROUND: Data suggest a possible protective effect against lens opacity with use of hormone replacement therapy (HRT). However, no agreement exists on which opacity type is affected, and more exploration of the additional role of endogenous estrogen exposure is warranted. OBJECTIVE: To determine whether HRT and the prevalence of different lens opacity types are associated after controlling for endogenous estrogen exposure. DESIGN AND SETTING: Salisbury Eye Evaluation population-based prevalence survey of residents in an eastern US city. PARTICIPANTS: One thousand two hundred thirty-nine women aged 65 through 84 years. MAIN OUTCOME MEASURES: Nuclear, cortical, and posterior subcapsular opacity. RESULTS: We found a protective association between nuclear opacity and current (odds ratio [OR], 0.5; 95% confidence interval [CI], 0.3-0.7) and recent (OR, 0.4; 95% CI, 0.3-0.7) HRT use. Increasing number of births in younger women was also protective (test of trend, P =.05). Past HRT use protected against nuclear opacity only in women who had never been pregnant (OR, 0.2; 95% CI, 0.1-0.7). Past (OR, 0.2; 95% CI, 0.1-0.7) and current (OR, 0.3; 95% CI, 0.1-0.9) HRT use were associated with a lower prevalence of posterior subcapsular opacity. CONCLUSION: A protective association between the use of HRT and nuclear and posterior subcapsular opacities is reported, which should be confirmed in prospective studies.

Aged↗
PubMed2001

The prevalence of glaucoma in a population-based study of Hispanic subjects: Proyecto VER.

OBJECTIVE: To determine the prevalence of glaucoma in a population-based sample of Hispanic adults older than 40 years. METHODS: Using 1990 census data for Arizona, groups of persons living in sections of the city in Nogales and Tucson were randomly selected with a probability proportional to the Hispanic population older than 40 years. We tried to recruit all eligible adults in homes with 1 self-described Hispanic adult. Detailed ocular examinations at a local clinic included visual acuity testing, applanation tonometry, gonioscopy, an optic disc evaluation, and a threshold visual field test. Open-angle glaucoma (OAG) was defined using a proposed international system for prevalence surveys, including threshold visual field defect and optic disc damage. Angle-closure glaucoma was defined as bilateral appositional angle closure, combined with optic nerve damage (judged by field and disc as for OAG). RESULTS: Examinations were conducted in 72% (4774/6658) of eligible persons, with a 1.97% prevalence (95% confidence interval, 1.58%-2.36%) of OAG (94 persons). The age-specific OAG prevalence increased nonlinearly from 0.50% in those aged 41 to 49 years to 12.63% in those 80 years and older. Angle-closure glaucoma was detected in 5 persons (0.10%). Sex, blood pressure, and cigarette smoking were not significant OAG risk factors. Only 36 (38%) of the 94 persons with OAG were aware of their OAG before the study. Screening results with an intraocular pressure higher than 22 mm Hg (in the eye with a higher pressure) would miss 80% of the OAG cases. CONCLUSIONS: The prevalence of OAG in Hispanic persons was intermediate between reported values for white and black persons. The prevalence increased more quickly with increasing age than in other ethnic groups. Glaucoma was the leading cause of bilateral blindness.

Adult↗
PubMed2001

Psychometric properties of the 25-item NEI-VFQ in a Hispanic population: Proyecto VER.

PURPOSE: To assess the psychometric properties of the NEI-VFQ-25 in a population-based study of older Hispanic persons living in the United States, explore other demographic factors that affect participant response, and observe the comparability of the Spanish and English versions of the instrument. METHODS: A sample of randomly selected block groups in Tucson and Nogales, Arizona, were selected for study. Participants were interviewed at home; a majority of the interviews were conducted in Spanish. The home interview included questions from the NEI-VFQ-25 and HHANES: Presenting acuity was done using ETDRS methodology, followed by a standardized eye examination by an ophthalmologist. The authors analyzed the internal consistency of the NEI-VFQ-25 responses using Cronbach's alpha coefficient and the construct validity by assessing the relationship between presenting acuity and scale scores, adjusting for age and gender. A second model was also explored to determine whether other demographic variables affected scale scores; differences in reporting between the Spanish and English versions was observed in this model, used in a subset of the population that minimized interviewer effect. RESULTS: Of the 4774 participants in the study, 99.7% had completed questionnaires, not completed by proxy. The highest nonresponse rate occurred in the Driving scale, with 25% of participants not driving for reasons other than problems with vision. Internal consistency was high, with Cronbach alpha ranging between 0.65 and 0.86 for scales with multiple items. Adjusting for age and gender, those with presenting acuity worse than 20/40 scored significantly lower than those with presenting acuity 20/40 or better, for all scales. The demographic variables with the most consistent association across the NEI-VFQ-25 scales were presenting acuity, income, and gender. No significant differences in reporting were found between the Spanish and English versions of the questionnaire in the subset of the population. CONCLUSIONS: In this study of Hispanic people age 40 years or older, the NEI-VFQ-25 was sensitive to presenting acuity and other demographic variables, such as age, gender, and income. The findings from this psychometric analysis provide evidence of the reliability and validity of some of the scales in the 25-item NEI-VFQ when used among people with a range of visual acuity level, providing other explanatory variables are also considered.

Activities of Daily Living↗
PubMed2000

Resin activation capture technology: libraries from stabilized acyl-pyridinium on solid support.

REsin Activation/Capture APproach or REACAP Technology, a novel approach to the synthesis of compound libraries, capitalizes on the formation and retention of a resin-bound reactive intermediate, which can be subsequently transformed into a stable, covalently attached molecule. Any unreacted "reactive intermediate" is quenched and removed from the resin upon work-up, leaving only the desired product on the solid support. In contrast to more traditional solid-supported chemistry that must address issues such as resin-loading, capping of unreactive functionalized moieties, and reaction yields, REACAP offers an attractive alternative with the focus more on the purity of the released products and less on yield. In an endeavor to generate truly non-peptide leads, we describe herein the synthesis of N-acyl-2-substituted-dihydro-4-pyridones, dihydro-4-pyridones, 4-ketopiperidines, tetrahydropyridines, and 2-acyl-3,7,8-substituted-5-oxo-2-azabicyclo[2.2.2]octane and triaza analogs using REACAP Technology.

Databases as Topic↗
PubMed1999

Determination of risk factor associations with questionnaire outcomes: a methods case study.

Increasingly in biomedical studies, health status is inferred through a series of questionnaire item responses. Challenges for analyzing associations between such responses and risk factors include multiplicity-many indicators must be combined to derive summary statements about health status, and measurement error-persons' self-report fluctuates due to causes other than substantive health changes. In order to deal with these challenges, the authors propose a strategy which comprises three methods: 1) score the item responses, then regress the score on predictors; 2) regress each item response on predictors, accounting for within-person associations; and 3) summarize and analyze the item responses jointly, using a latent variable model. The authors develop modeling and diagnostic procedures for method 3. They then show how the three-method analytic strategy can be used to solve the problem of determining which aspects of vision are associated with self-reported functioning in activities that require seeing at a distance. They demonstrate that methods 2 and 3 illuminate basic findings from method 1 by adding specificity, describing patterns as well as severities of health impairments, and identifying isolated items that relate to risk factors differentially than others. They conclude that the three-method strategy specifies how risk factors determine questionnaire-based health outcomes substantially better than any of the methods in isolation.

Activities of Daily Living↗
PubMed1999

Characteristics of discrepancies between self-reported visual function and measured reading speed. Salisbury Eye Evaluation Project Team.

PURPOSE: Visual impairment is a risk factor for morbidity in the elderly and is often screened for by self-report. This study evaluates whether there are subsets for whom there is a discrepancy between self-reported and measured function. METHODS: The prevalence of a discrepancy between self-reported difficulty reading a newspaper and measured reading speed was determined in 2520 community-based men and women, aged 65 to 84 years, and the discrepant group characterized by polychotomous regression. RESULTS: Of subjects who reported minimal difficulty reading a newspaper, 10.8% (227/2107) read newsprint-sized text (0.21 degrees) more slowly than 80 words/min, a level previously shown to be necessary for sustained reading. Poor visual acuity, presence of psychiatric symptoms, and less satisfaction with vision were associated with being in the group that read slowly and reported difficulty with reading. Better cognition, better visual acuity, more years of education, white race, and fewer psychiatric symptoms were associated with being in the group that read more quickly and reported minimal difficulty. When reading the text size at which subjects read their fastest, only 2.6% of those with minimal difficulty remained discrepant. These individuals were more likely to have less education, be male, be African American, and have poorer cognitive status than those who did not remain discrepant. CONCLUSIONS: A subset of the elderly population have a substantial discrepancy between self-reported reading difficulty and measured reading speed. In some, this discrepancy may be based on underlying expectations and experiences, and in others it may represent a transition from no visual impairment to visual impairment.

Aged↗
PubMed1999

Digital image capture and automated analysis of posterior capsular opacification.

PURPOSE: To develop and validate a digital imaging and analysis technique for assessing the extent of posterior capsular opacification after cataract surgery. METHODS: Retroillumination images of the posterior capsule were obtained by using a digital camera mounted on a slit lamp. The images were analyzed using an available image analysis software program. The image acquisition and analysis techniques were tested for face validity, reproducibility, and the ability to detect progression of capsular opacity over time. RESULTS: Digital retroillumination images were obtained without patient discomfort. Automated analysis of images correlated well with clinical grading both at slit lamp examination and when looking at the images themselves (Spearman's correlation coefficient >0.7). Analysis of images taken at different times showed high reproducibility (intraclass correlation >0.9), and the system was able to identify progression of capsular opacity over a 2-year period with a mean increase of 15.8% in progressors versus an increase of 0.6% in nonprogressors (P < 0.05). CONCLUSIONS: Digital retroillumination images of the posterior capsule can be obtained reliably, and automated analyses correlate well with clinical assessment. The system presented here uses commercially available instruments and software, and it is practical for use in longitudinal studies of posterior capsule opacification. It is reliable, easy to use, and can detect small changes in the percentage area covered by posterior capsule opacification over time.

Cataract↗
PubMed1999

Self-reported assessment of visual function in a population-based study: the SEE project. Salisbury Eye Evaluation.

PURPOSE: To report on the usefulness of the Activities of Daily Vision Scale (ADVS) questionnaire for assessing visual functioning, a population-based sample of elderly Americans. METHODS: The ADVS questionnaire was administered to a population-based sample of 2520 community-dwelling individuals 65 to 84 years of age in Salisbury, MD. Items and subscales were evaluated for internal consistency, item discrimination, and content validity. Published subscale groupings and item associations in our population were compared for coherence using correlation, factor, and cluster analyses. Whole-sample and race- and gender-specific analyses were conducted. External validity was explored by regressing ADVS scores on standard psychophysical vision measures. RESULTS: ADVS scores were skewed to high visual functioning levels; approximately 60% of the population had function scores of 95 or better (of a possible 100). The overall, night driving, and near vision scales were internally consistent and had strong item-subscale associations; the day driving and glare subscales were not acceptable regarding these properties. The far vision subscale was acceptably scalable but only weakly differentiated from the other subscales. Overall, night driving, near vision, and far vision scores were all statistically and independently associated with multiple psychophysical vision measures. Findings were consistent across race and gender subgroups. CONCLUSIONS: As assessed by the ADVS, reported visual functioning is high in our representative older population. The overall scale and selected subscales effectively distinguish persons along a spectrum of ability. They correlate with measures of visual impairment in a reasonable way and thus hold promise for risk factor investigations. The published day driving and glare subscales should be examined for relevance and consistency before being applied in population-based settings. Methods specific to population-based settings should be investigated for their ability to better elicit additional visual function dimensions and early visual disability.

Activities of Daily Living↗
PubMed1998

Prevalence of symptoms of dry mouth and their relationship to saliva production in community dwelling elderly: the SEE project. Salisbury Eye Evaluation.

OBJECTIVE: To estimate the prevalence of dry mouth symptoms and their correlation with saliva production in a population based sample of elderly people in the United States. METHODS: Two dry mouth questions were administered to and a modified Saxon test was performed in participants in a population based prevalence survey conducted among 2520 noninstitutionalized community dwelling residents of Salisbury, Maryland, aged 65-84 years. RESULTS: Seventeen percent reported having either dryness of mouth or waking at night feeling dryness in the mouth and needing to drink fluids often or all the time; 10.7% noted the former and 11.5% the latter. The prevalence of dry mouth symptoms increased with increasing age, was greater in women than men, and was greater in whites than blacks. The mean (SD) amount of saliva production was 2.38 (1.00) g/min; mean saliva production decreased with increasing age and was lower in women than men; no difference was noted by race. Persons with dry mouth symptom either often or all the time had significantly lower salivary production, even after adjustment for age and sex. CONCLUSION: Symptoms of dry mouth are common in the community dwelling elderly population, especially in white women, and correlate with decreased salivary production.

Age Factors↗
PubMed1997

Incidence estimates of late stages of trachoma among women in a hyperendemic area of central Tanzania.

The purpose of this study is to estimate 5-year incidences of conjunctival scarring and trichiasis, and 10-year incidence of corneal opacities due to trachoma, using prevalence data from a population sample of 6038 women living in a trachoma-hyperendemic area of central Tanzania. Previous surveys have documented the age-specific prevalence of scarring, trichiasis, and corneal opacities in women in hyperendemic areas. Using the age-stratified prevalences of these different clinical signs, corresponding incidence rates were estimated. Transition rates from one sign to the next were also obtained by restricting the risk group to only women with a specific trachoma sign. Thus, the 5-year incidence of trichiasis among women with conjunctival scarring, and the 10-year incidence of corneal opacities among women with trichiasis were estimated. Incidences of all the signs markedly increased with age. For scarring, 5-year incidence rates increased from 3.1% in the 15-19 age category to 14.3% for women between 55 and 59 years. The 5-year incidence of trichiasis ranged from 0.3% in the 15-19 age category to 7.5% in the age group 55-59. Corneal opacities due to trachoma were highest in the age group 45-54; the 10-year incidence increased to 2.8%. The 5-year incidence of trichiasis among only women with scars increased from 3.2% in the 15-19 age group to 15.1% in women in the 55-59 age group. Once trichiasis is present, almost one-third of the women below 35 and more than 40% of the women older than 45 will develop corneal opacities in a 10-year interval. These estimates are important in understanding the dynamics of progression of trachoma from conjunctival scarring to the potentially blinding signs of trichiasis and corneal opacities. They provide important information for planning adequate services in areas where trachoma is endemic and surgery for trichiasis is a key factor to avoid blindness from trachoma. They also provide clues to the pathogenesis that may be useful in the development of new methods of control.

Adolescent↗
PubMed1997

Assessing functional status: correlation between performance on tasks conducted in a clinic setting and performance on the same task conducted at home. The Salisbury Eye Evaluation Project Team.

BACKGROUND: Many studies of functional status in elderly people use performance-based measures. There is an underlying assumption that these measures reflect, at least for some tasks, functional abilities in everyday tasks carried out at home. The purpose of this study was to determine the correlation between tasks carried out in the clinic and at home, and the role of visual impairment in performance at either setting. METHODS: We compared the performance of 97 participants in the Salisbury Eye Evaluation (SEE) project at the clinic and at home on eight different tasks: semitandem stand, functional reach, stair climb and descend, inserting a plug, looking up and dialing a telephone number, and reading. RESULTS: The correlations were good for all tasks, with coefficients ranging from .52 to .86. Those with visual impairment were slightly more likely to perform better at home compared to the clinic, although the differences were statistically significant only for the reading task. The most important predictor of performance on any task in the home was performance on the task at the clinic, even after adjusting for age, race, sex, education, and visual impairment. Educational level and visual impairment were consistent predictors of performance in the home for most tests. CONCLUSIONS: We conclude that performances on standardized tasks in the clinic setting do correlate with similar tasks performed in the home, although the relationship is complicated in the presence of visual impairment.

Aged↗
PubMed1997

Function and visual impairment in a population-based study of older adults. The SEE project. Salisbury Eye Evaluation.

PURPOSE: The Salisbury Eye Evaluation (SEE) project investigates the impact of vision on functional status in a population-based sample of elderly persons. The prevalence of self-reports of functional status and the association with visual acuity loss are described. METHODS: A random sample of men and women 65 to 84 years of age from Salisbury, Maryland were recruited for home interviews and clinic examinations. Of the eligible sample, 78% responded to the home questionnaire and 65% responded to the questionnaire and the clinic examination. Binocular visual acuity of each person was measured using ETDRS charts and protocols. Questions were asked concerning activities of daily living, instrumental activities of daily living, physical function, social interaction, and activities of daily vision. Analyses of the association of presenting visual acuity worse than 20/40 with the measures of function were carried out and adjusted for age, race, and sex. RESULTS: All measures of functional status showed a decline with age; women and blacks were more likely to report difficulties. The age-adjusted proportions of those with visual impairment were not significantly different between men and women (7.2% versus 6.7%; P = 0.60). Black persons had almost twice the rate (10.4%) of white persons (5.6%; P < 0.001). Age, race, gender, and visual impairment were all significantly related to declines in functional status in multivariate models. CONCLUSIONS: Data on functional status in the project population were similar to national data and confirmed higher rates of disability in women and blacks. Binocular visual acuity worse than 20/40 appeared to have an impact on all the self-report measures of functional status. Further analyses on the interaction of vision with other comorbid conditions on function status clearly are indicated.

Activities of Daily Living↗
PubMed1996

Potential force of infection of human rabies transmitted by vampire bats in the Amazonian region of Brazil.

Human rabies transmitted by bats has acquired greater epidemiologic relevance in various Latin American countries, just when cases transmitted by dogs have decreased. Concern has been heightened by reports of increased rates of bats biting humans in villages in the Amazonian region of Brazil. The aim of the present work was to estimate the potential force of infection (per capita rate at which susceptible individuals acquire infection) of human rabies transmitted by the common vampire bat if the rabies virus were to be introduced to a colony of bats close to a village with a high rate of human bites. The potential force of infection could be then used to anticipate the size of a rabies outbreak in control programs. We present an estimator of potential incidence, adapted from models for malaria. To obtain some of the parameters for the equation, a cross-sectional survey was conducted in Mina Nova, a village of gold prospectors in the Amazonian region of Brazil with high rates of bates biting humans. Bats were captured near dwellings and sent to The Rabies Diagnostic Laboratory at the Center for Control of Zoonoses (Sao Paulo, Brazil) to be examined. To estimate the force of infection, a hypothetical rabies outbreak among bats was simulated using the actual data obtained in the study area. Of 129 people interviewed, 23.33% had been attacked by a vampire bat during the year prior to the study, with an average of 2.8 bites per attacked person. Males (29.41%) were attacked more often than females (11.36%); also, adults (29.35%) were attacked more often than children (8.33%). None of the 12 bats captured in Mina Nova tested positive for rabies, but the force of infection for a hypothetical outbreak was estimated to be 0.0096 per person per year. This risk represents 0.96 cases per 100 area residents, giving an incidence of 1.54 cases of bat-transmitted human rabies per year in the village of Mina Nova (160 inhabitants). The estimated risk is comparable with what has been observed in similar Brazilian villages.

Adult↗
PubMed1995

Five-year incidence and disappearance of drusen and retinal pigment epithelial abnormalities. Waterman study.

PURPOSE: To obtain 5-year longitudinal data on age-related macular degeneration (AMD) that might be useful for disease prognosis, public health planning, and clinical trial development. PATIENTS AND METHODS: Baseline (1985) and 5-year follow-up (1990) fundus photographs of 483 watermen over 30 years of age who participated in a cohort study conducted on the eastern shore of Maryland were graded independently in a reliable, standardized fashion. Eyes in which AMD appeared or disappeared also were graded in a side-by-side fashion. RESULTS: Development of definite choroidal neovascularization and/or disciform scarring occurred in one of 50 participants over 70 years of age, specifically one of 15 participants over 70 years of age with AMD-3 (defined as large or confluent drusen focal hyperpigmentation of the retinal pigment epithelium [RPE], and/or nongeographic atrophy of the RPE). Appearance of large drusen, focal hyperpigmentation, or AMD-3 was age related, occurring in 5%, 1%, and 7%, respectively, of participants aged 50 to 59 years; 17%, 3%, and 14%, respectively, of participants aged 60 to 69 years; and 17%, 9%, and 26%, respectively, of participants aged 70 years or more. Disappearance of large drusen, hyperpigmentation, or AMD-3 occurred in 16 (34%) of 47 participants, 11 (58%) of 19 participants, and 17 (28%) of 61 participants, respectively, who had each feature photographically present in 1985. Among the 47 eyes identified in which AMD-3 developed by independent gradings, 38 cases of AMD-3 (81%) were confirmed on side-by-side grading. Among the 16 eyes identified as having AMD-3 that disappeared, nine disappearances (56%) were confirmed. Borderline differences in appearance of pigment, drusen size, drusen location, or photographic quality may have accounted for disappearance in seven cases (44%). CONCLUSIONS: Prospective studies on the nonneovascular features of AMD (including large drusen and abnormalities of the RPE) must account for the appearance and disappearance of these features and support the idea that side-by-side gradings can complement independent gradings identifying appearance or disappearance of features of AMD.

Adult↗
PubMed1995

Potent and selective inhibitors of leukotriene A4 hydrolase: effects on purified enzyme and human polymorphonuclear leukocytes.

Leukotriene (LT) A4 hydrolase (EC 3.3.2.6) is a bifunctional zinc metalloenzyme that catalyzes the hydrolysis of the unstable epoxide intermediate LTA4 into the proinflammatory substance LTB4 and also exhibits an amidase/peptidase activity toward synthetic substrates. Based on proposed reaction mechanisms for other zinc hydrolases, we have synthesized inhibitors of LTA4 hydrolase and evaluated their effects on the formation of LTB4 from LTA4 using both purified enzyme and intact polymorphonuclear leukocytes. The two most effective inhibitors, an alpha-keto-beta-amino ester (compound IV) and a thioamine (compound VIII), exhibited IC50 values of 1.9 +/- 0.9 and 0.19 +/- 0.12 microM (mean +/- SD, n = 4), respectively. Compounds IV and VIII were also potent inhibitors of LTB4 biosynthesis in ionophore stimulated polymorphonuclear leukocytes with IC50 < 200 nM. At higher concentrations, the biosynthesis of 5-hydroxy-eicosatetraenoic acid was also inhibited with IC50 approximately 10 microM for both substances. In contrast, leukocyte 15-lipoxygenase and platelet LTC4 synthase activity were not inhibited by these substances at the highest concentrations tested, 50 and 10 microM, respectively. Compounds IV and VIII thus exhibit selectivity among enzyme activities in the arachidonic acid cascade. In conclusion, we describe two compounds that are among the most potent and selective inhibitors of LTA4 hydrolase and LTB4 biosynthesis by intact polymorphonuclear leukocytes, described thus far.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1994

Predicting surgical compliance in a cohort of women with trichiasis.

Trichiasis/Entropion are the severe consequences of chronic trachoma during early life. Blindness and vision loss is preventable with timely lid surgery to correct trichiasis. In a trachoma hyperendemic region of Central Tanzania, a two year follow-up survey was conducted among 205 women with trichiasis to determine the proportion who had had surgery and the barriers to having surgery. Only 18% of the women had undergone surgery by the 2 year follow-up. Those who had surgery tended to report more eye problems at baseline and have more corneal opacities at baseline. Barriers preventing women from going to surgery were costs, problem of children left at home alone, and difficulties in identifying someone to accompany them to the health center. Over 2/3 of those who had surgery reported a significant decrease in pain, improvement of vision, and improved ability to carry out activities of daily life. Ways to improve compliance with recommendations for trichiasis surgery need to be developed.

Adolescent↗
PubMed1994

Alpha-ketoamide Phe-Pro isostere as a new core structure for the inhibition of HIV protease.

Studies on the inhibition of HIV-1 protease utilizing a core isostere with replacement of the scissle bond for an alpha-amino-ketone have resulted in the development of an alpha-keto-amide isosteric replacement of the Phe-Pro scissle amide bond. The simple dipeptide isostere was shown to be a promising new core structure for the development of the enzyme inhibitors. The Ki of this core structure was determined to be 6 microM, compared to 230 microM and > 50 microM for the corresponding phosphinic acid and hydroxyethylamine isosteres.

Amides↗