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Biomedical subjects

L Myers

Publications and source records attributed to L Myers.

At least 37 records · Page 2Linked to original sources
PubMed2001

Challenges and opportunities for speech and language therapists in secondary schools.

Language and communication difficulties experienced by secondary school students are outlined. The challenges that the secondary school environment presents for both children and speech and language therapy services are discussed. Two case studies illustrate how speech and language therapists (SLTs) working for the Newham Education Authority Language and Communication Support Service support students in their secondary schools.

Adolescent↗
PubMed2001

An outbreak of viral gastro-enteritis at a charity function.

One hundred and thirty-eight people of 431 who attended a charity function fell ill with gastro-enteritis mainly between 12 and 72 hours later. Three people were ill at the event, and a further three became ill within two hours of the event. A cohort study undertaken using a postal questionnaire showed that illness was statistically associated with having eaten cream, mints, or profiteroles. The duration of illness ranged from two to 120 hours, with a median of 48 hours. Twenty-three of the cases sent a stool sample to the laboratory. Six of these were taken to the laboratory within three days of the onset of illness and examined for bacteria before being sent for virological examination by electron microscopy (EM) and polymerase chain reaction (PCR). All six were positive for small round structured virus (SRSV) on PCR, and negative on EM. The illness was likely to have been transmitted both by foodborne transmission and person to person spread at the event.

Cohort Studies↗
PubMed2001

Patellar resurfacing in total knee arthroplasty. A prospective, randomized, double-blind study with five to seven years of follow-up.

BACKGROUND: Whether to resurface the patella during a primary total knee arthroplasty performed for the treatment of degenerative osteoarthritis remains a controversial issue. Parameters that have been suggested as being useful in guiding this decision include patient height and weight, the presence of anterior knee pain preoperatively, and the grade of chondromalacia encountered intraoperatively. The purpose of this study was to determine whether these parameters were predictive of the clinical result following total knee arthroplasty with or without patellar resurfacing. METHODS: Eighty-six patients (118 knees) undergoing primary total knee arthroplasty for the treatment of osteoarthritis were enrolled in a prospective, randomized, double-blind study. All patients received the same posterior-cruciate-sparing total knee prosthetic components. Patients were randomized to treatment with or without resurfacing of the patella. Evaluations consisted of the determination of a Knee Society clinical score, the completion of a patient satisfaction questionnaire, specific questions relating to patellofemoral symptoms, and radiographs. Sixty-seven patients (ninety-three knees) were followed for a minimum of five years (range, sixty to eighty-four months; average, 70.5 months). RESULTS: With the numbers available, there was no significant difference between the groups treated with and without resurfacing with regard to the overall Knee Society score or the pain and function subscores. Obesity, the degree of patellar chondromalacia, and the presence of preoperative anterior knee pain did not predict postoperative clinical scores or the presence of postoperative anterior knee pain. CONCLUSIONS: The occurrence of anterior knee pain could not be predicted with any clinical or radiographic parameter studied. On the basis of these results, it seems likely that postoperative anterior knee pain is related either to the component design or to the details of the surgical technique, such as component rotation, rather than to whether or not the patella is resurfaced.

Arthroplasty, Replacement, Knee↗
PubMed2000

Subunit interactions in yeast transcription/repair factor TFIIH. Requirement for Tfb3 subunit in nucleotide excision repair.

A yeast strain harboring a temperature-sensitive allele of TFB3 (tfb3(ts)), the 38-kDa subunit of the RNA polymerase II transcription/nucleotide excision repair factor TFIIH, was found to be sensitive to ultraviolet (UV) radiation and defective for nucleotide excision repair in vitro. Interestingly, tfb3(ts) failed to grow on medium containing caffeine. A comprehensive pairwise two-hybrid analysis between yeast TFIIH subunits identified novel interactions between Rad3 and Tfb3, Tfb4 and Ssl1, as well as Ssl2 and Tfb2. These interactions have facilitated a more complete model of the structure of TFIIH and the nucleotide excision repairosome.

Adenosine Triphosphatases↗
PubMed2000

Upregulation of myogenin by N-cadherin adhesion in three-dimensional cultures of skeletal myogenic BHK cells.

Cells of the baby hamster kidney (BHK) line express the skeletal muscle determining transcription factor MyoD but fail to differentiate. Unlike most skeletal myogenic cells, which express multiple members of the cadherin family of cell-cell adhesion proteins, the BHK cells lack a robust cadherin adhesion system. We previously published that forced expression of N- (or E)-cadherin in BHK cells increases the level of endogenous catenins, mediates strong cell-cell adhesion, and enhances differentiation of BHK cells induced to differentiate by placing them in three-dimensional (3-D) culture (Redfield et al. [1997] J. Cell. Biol. 138:1323-1331). This report demonstrates that N-cadherin adhesion upregulates the protein level of nuclear myogenin in cells induced to differentiate by 3-D culture. Myogenin is a transcription factor required for differentiation of skeletal muscle. It was not detected in monolayer culture, whether the cells expressed N-cadherin or not, nor was it upregulated in 3-D cultures of cells lacking N-cadherin. The activity of two myogenin-chloramphenicol acetyltransferase (CAT) reporter constructs containing 3.7 or 1.1 kb upstream regulatory region of the mouse myogenin gene was increased significantly in N-cadherin-expressing cells induced to differentiate by 3-D culture. Our observations indicate that N-cadherin adhesion stimulates skeletal myogenesis by upregulating myogenin.

Animals↗
PubMed2000

Optimization of multiple-isocenter treatment planning for linac-based stereotactic radiosurgery.

OBJECTIVE: Computer-assisted treatment planning for linac-based radiosurgery is still an open research problem, especially for multiple-isocenter procedures, primarily due to its high complexity and computational requirements. This paper focuses on the optimization of multiple-isocenter treatment planning for linac systems, and addresses several important issues associated with multiple isocenters, such as dose conformality, homogeneity, and optimization of isocenter position and dose. METHODS: The key idea behind our approach is that the desired dose distribution can be decomposed into a number of fundamental components. In the current paper, an analytical form, the so-called Ellipsoidal Dose Distribution Estimation (EDDE) model, represents each component. We establish ways (arc configurations) to achieve such ellipsoidal doses of arbitrary position, orientation, and size. Since the EDDE model is described by relatively few parameters, it allows very quick estimation of the dose distribution corresponding to a particular isocenter and thus makes the optimization of isocenter position very efficient. It is further used in a framework for optimal treatment planning, in which a number of ellipsoidal dose distributions, each corresponding to a different isocenter, are optimally placed to cover the target while sparing healthy tissue. RESULTS: The general ellipsoidal dose distribution of linac-based radiosurgery is summarized as a mathematical model with the aid of supporting experiments. Comparisons between the EDDE-optimized and clinically implemented plans are made, revealing the superior performance of the former. In addition, a dramatic reduction in planning time is achieved using the EDDE model. CONCLUSION: The proposed EDDE model is a useful and effective dose model in multiple-isocenter treatment planning for linac-based radiosurgery.

Brain Neoplasms↗
PubMed2000

Risk variables of insulin resistance syndrome in African-American and Caucasian young adults with microalbuminuria: the Bogalusa Heart Study.

Microalbuminuria is a strong predictor of cardiovascular disease. Previous studies are inconsistent regarding the relationship between microalbuminuria and insulin resistance syndrome. Therefore, we examined this relationship in 1031 young adults (61% Caucasian, 39% African-American) aged 19 to 32 years. Individuals with either urinary albumin to creatinine ratio at or above the 90th percentile (age, race, and gender specific) or urinary albumin level at or above 30 mg/L were considered as having slightly elevated albumin excretion (microalbuminuria). The multiple risk variables of insulin resistant syndrome measured include body mass index, waist circumference, blood pressure (BP), triglycerides, high-density lipoprotein (HDL) cholesterol, glucose, insulin, insulin resistance index (calculated from a homeostasis model assessment equation), and uric acid. After controlling for age and gender, African-Americans with microalbuminuria by either measure had higher mean systolic (P < .001) and diastolic (P < .05) BP, prevalence of hypertension (P < .05), and, contrary to expectations, HDL cholesterol (P < .05) than those without this condition. On the other hand, Caucasians showed no such associations. In African-Americans, the above differences in BP levels persisted when hypertensive subjects were excluded. None of the other risk variables displayed any relation to microalbuminuria in both races. These results suggest that microalbuminuria is not necessarily an intrinsic component of the insulin resistance syndrome, at least in the young adult age. Furthermore, the observed association between hypertension and microalbuminuria among young African-Americans may reflect early evidence of renal dysfunction due to the burden of elevated BP in this group.

Adult↗
PubMed2000

Breakfast consumption with and without vitamin-mineral supplement use favorably impacts daily nutrient intake of ninth-grade students.

PURPOSE: To assess the contribution of breakfast consumption (with and without dietary supplement intake) on total daily nutrient intake of ninth-grade students. METHODS: Twenty-four-hour recall of dietary intake was collected from a random sample of 711 ninth-grade students attending 12 Archdiocesan high schools in New Orleans, Louisiana. Analysis of variance techniques, Pearson's Chi-square statistic, and Breznahn-Shapiro method with Scheffé probabilities were used to analyze nutrient intake data, dietary adequacy, and nonorthogonal comparisons, respectively. RESULTS: Nineteen percent of 15-year-olds skipped breakfast, with more females skipping breakfast than males (23% vs. 14%, respectively). Thirty-six percent of nonwhite females versus 20% white females skipped breakfast. Eleven percent of subjects took some type of dietary supplement, most commonly a multivitamin and mineral supplement. Among those who ate breakfast, average energy intake from breakfast was 437 kcal. Percentage of total daily energy intake was higher from fats and lower from carbohydrates for adolescents who skipped breakfast, compared with adolescents who consumed breakfast. The percentage of subjects consuming at least two-thirds of the Recommended Dietary Allowance was significantly lower among adolescents skipping breakfast than those consuming breakfast. CONCLUSION: Regardless of supplement use, breakfast consumption makes an important nutritional contribution to total daily intake of ninth-grade students. Encouraging breakfast consumption and healthful breakfast choices is an important step toward improving the nutritional quality of diets of this age group.

Adolescent↗
PubMed2000

Patients' perception of pain after total hip arthroplasty.

A study was undertaken to determine the frequency with which patients had pain that they attributed to their hip after total hip arthroplasty. Pain drawings were used to allow patients to localize the area of their symptoms, and the degree of pain was quantified with visual analog scales. Complete clinical and radiographic data were collected on all patients so that the occurrence of pain could be correlated with a number of parameters previously reported to affect the incidence of pain, including age, sex, activity level, length of follow-up, stem size, bone type (Dorr index), and type of stem fixation (proximally coated, fully coated, or cemented). Results indicated that type of stem fixation was the only parameter statistically correlated with a higher incidence of thigh pain. Patients with proximally coated stems were more than twice as likely to complain of pain than patients with fully coated or cemented hips (P < .01). Although the incidence of thigh pain was significantly higher with proximally coated stems, the severity was not, averaging 3.0 to 3.5 out of 10 on visual analog scale in all 3 groups. The results indicate that patients perceived pain as originating in the hip in a high percentage of cases, particularly when proximally coated stems were used.

Adult↗
PubMed2000

The effect of modest monetary incentives on follow-up rates in sexually transmitted disease studies.

The purpose of the study was to determine if follow-up rates in sexually transmitted disease (STD) research could be improved by offering modest monetary incentives. Women aged 14-34, infected with Chlamydia trachomatis, and enrolled in either of 2 studies between May 1995 and January 1999 were included. Beginning in March 1996 participants were offered a $20 incentive to return to both the one- and four-month follow-up visits. Data were analysed using polychotomous logistic regression. Of 962 women followed, the majority (74.7%) received monetary incentives and 66% returned for at least one visit. Women who received the incentive were more likely (OR 1.9, CI 1.2-2.9) to return for either one or both of their follow-up visits after adjusting for interviewer and the months of work experience of that interviewer. Age and method of birth control were not associated with return rates. The study provides evidence that modest monetary incentives can improve follow-up rates.

Adolescent↗
PubMed2000

Impact of dietary fat and fiber intake on nutrient intake of adolescents.

OBJECTIVE: To evaluate the impact of fat and fiber intake on energy and nutrient intake of 15-year-old adolescents. STUDY DESIGN: Twenty-four-hour dietary recalls were collected on a random sample of 15-year-olds. Subjects were then categorized into groups based on fat and fiber intake, with 319 students meeting criteria for 1 of 4 dietary intake quadrants: low fat, low fiber; low fat, high fiber; high fat, low fiber; and high fat, high fiber. Students with medium fat or fiber intakes were excluded from the study. Low-fat and high-fat intake were defined as <30% and >40% of total energy intake, respectively. Low- and high-fiber intake were defined as <15 g/day and >20 g/day, respectively. RESULTS: Low-fat and high-fiber intake had a minimal impact on energy intake and did not adversely affect nutrient intake. High-fiber intake was associated with greater likelihood of adequate intake of vitamins A, B6, B12, and C; niacin; thiamin; riboflavin; folacin; magnesium; iron; zinc; phosphorus; and calcium. High-fat intake was associated with greater likelihood of adequate vitamin B12 intake. Significant differences in fat and fiber intake distributions were found for ethnic background and gender, with more non-white than white students in the high-fat groups and more males than females in the high-fiber groups. CONCLUSIONS: A low-fat and high-fiber diet meeting current nutrition recommendations does not adversely affect energy or nutrient intake, increases nutrient density of the diet, and increases the likelihood of adequate intake for several key nutrients.

Adolescent↗
PubMed1999

Plasma homocysteine distribution and its association with parental history of coronary artery disease in black and white children: the Bogalusa Heart Study.

BACKGROUND: Elevated homocysteine is associated with increased risk for coronary artery disease (CAD) in adults, but its distribution in children is not well documented. We examined the distribution of homocysteine in children and its relation to parental history of CAD. METHODS AND RESULTS: A subsample of 1137 children (53% white, 47% black) aged 5 to 17 years in 1992 to 1994 examined in the Bogalusa Heart Study (n=3135), including all with a positive parental history of CAD (n=154), had plasma homocysteine levels measured. Homocysteine correlated positively with age (r=0.16, P=0.001). No race or sex differences in homocysteine levels were observed; geometric mean (GM) levels were 5.8 micromol/L (95% CI, 5.6 to 6.1) among white males, 5.8 micromol/L (95% CI, 5.5 to 6.0) among white females, 5.6 micromol/L (95% CI, 5.4 to 5.8) among black males, and 5.6 micromol/L (95% CI, 5.4 to 5.9) among black females. Children with a positive parental history of CAD had a significantly greater age-adjusted GM homocysteine level (GM, 6.7 micromol/L; 95% CI, 6.4 to 7.1) than those without a positive history (GM, 5.6 micromol/L; 95% CI, 5.4 to 5.7); this relation was observed in each race-sex group. CONCLUSIONS: Higher homocysteine levels were observed among children with a positive family history of CAD. Additional studies should elucidate the contribution of genetic, dietary, and other factors to homocysteine levels in children.

Adolescent↗
PubMed1999

Temporal association between obesity and hyperinsulinemia in children, adolescents, and young adults: the Bogalusa Heart Study.

Obesity is generally associated with hyperinsulinemia. However, whether obesity precedes or follows hyperinsulinemia is not clear. The present study examined the temporal nature of the association between obesity and hyperinsulinemia in a biracial (black-white) community-based population enrolled in the Bogalusa Heart Study. Three longitudinal cohorts of children (n = 427; baseline age, 5 to 7 years), adolescents (n = 674; baseline age, 12 to 14 years), and young adults (n = 396; baseline age, 20 to 24 years) were selected retrospectively, with a follow-up period of approximately 3 years. In general, longitudinal changes in the mean body mass index (kilograms per meter squared), an indicator of adiposity, and fasting insulin level did not parallel each other. In a bivariate analysis, baseline insulin levels correlated significantly with the follow-up body mass index in adolescents and adults, but not in children. On the other hand, the baseline body mass index correlated significantly with follow-up insulin levels in all cases. Logistic regression analysis showed that the proportion of subjects who developed obesity (body mass index > 75th percentile, specific for age, race, gender, and survey year) at follow-up study increased significantly across baseline quintiles (specific for age, race, gender, and survey year) of insulin only among adolescents, irrespective of race and gender. This relationship disappeared after adjusting for the baseline body mass index. By contrast, a significant positive trend between baseline quintiles of the body mass index and incidence of hyperinsulinemia (> 75th percentile) at follow-up study was noted among all age groups independent of race, gender, and baseline insulin levels. Further, in a multiple stepwise regression model, the best predictor of the follow-up insulin level was the baseline body mass index in children and adults and the baseline insulin in adolescents. The baseline body mass index was the best predictor of the follow-up body mass index in all three age groups. These results, by showing the temporal nature of the relation between obesity and hyperinsulinemia beginning in childhood, support the role of obesity in the development of hyperinsulinemia.

Adolescent↗
PubMed1999

Knowledge, attitudes, and practices related to fruit and vegetable consumption of high school students.

PURPOSE: To assess the level of nutrition knowledge, attitudes and practices related to fruit and vegetable consumption of high school students attending participating parochial schools in the New Orleans area. METHODS: The baseline data reported in this study, "Gimme 5: A Fresh Nutrition Concept for Students," represents one of the nine National Cancer Institute-funded projects from the national "5-A-Day for Better Health Program" initiated in 1991. A survey containing 22 nutrition-related items about fruit and vegetables was used to assess knowledge in 2213 students. RESULTS: On average, adolescents reported 39% correct knowledge scores. A significant ethnic effect (p < .001) was noted, with White adolescents scoring higher than African American adolescents. Significant ethnic differences in the frequency of fruit and vegetable consumption were also observed, with African-American adolescents reporting a lower mean consumption (2.17 servings) than white adolescents (2.69 servings). Consumption by Hispanic youth (2.48 servings) was similar to those in the "other" ethnic category (2.55 servings). Girls reported being more confident in their ability to eat five servings of fruits and vegetables per day than did boys (p < .05). CONCLUSIONS: Although the knowledge and consumption levels of adolescents with regard to fruits and vegetables were low, their attitudes toward learning about healthier eating practices were favorable.

Adolescent↗
PubMed1999

Disclosure of HIV status to sexual partners: predictors and temporal patterns.

BACKGROUND AND OBJECTIVES: Failure to disclose human immunodeficiency virus (HIV) infection to sexual partners interferes with risk reduction. GOAL OF THIS STUDY: The purpose of this study was to identify factors associated with disclosure and failure to disclose HIV infection to sexual partners and to describe condom use with nondisclosure. STUDY DESIGN: A longitudinal survey study of HIV seropositive persons recruited at a public STD clinic. RESULTS: Approximately 76% of the study population (n = 147) reported disclosing their HIV status to their last sex partner at baseline. Predictors of disclosure included consistent condom use and being in a monogamous relationship. Twenty-two percent of those who disclosed at baseline reported nondisclosure during follow-up. Approximately 23% reported not using a condom with a person to whom their status was not disclosed. CONCLUSIONS: These results suggest that ongoing partner notification may be necessary to increase disclosure of HIV status to sex partners over time.

Adult↗
PubMed1999

Remote infrared signage evaluation for transit stations and intersections.

Opportunities for education and employment depend upon effective and independent travel. For mainstream society, this is accomplished to a large extent by printed signs. People who are print disabled, visually impaired, or totally blind are at a disadvantage because they do not have access to signage. Remote infrared signage, such as the Talking Signs (TS) system, provides a solution to this need by labeling the environment for distant viewing. The system uses a transmitting "sign" and a hand-held receiver to tell people about their surroundings. In a seamless infrared signage environment, a visually impaired traveler could: walk safely across an intersection to an ATM or fare machine, from fare machine to bus stop, from bus stop to bus; from bus to building, from building to elevator, from elevator to office, from office to restroom, and so forth. This paper focuses on two problems that are among the most challenging and dangerous faced by blind travelers: negotiating complex transit stations and controlled intersections. We report on human factors studies of TS in these critical tasks, examining such issues as how much training is needed to use the system, its impact on performance and safety, benefits for different population subgroups and user opinions of its value. Results indicate that blind people can quickly and easily learn to use remote infrared signage effectively, and that its use improves travel safety, efficiency, and independence.

Adolescent↗
PubMed1998

Impact of breakfast consumption on nutritional adequacy of the diets of young adults in Bogalusa, Louisiana: ethnic and gender contrasts.

OBJECTIVE: To evaluate the impact of breakfast consumption patterns on the nutritional adequacy of diets of young adults and determine possible ethnic and gender differences. DESIGN AND SETTING: Cross-sectional survey of young adults in Bogalusa, La. SUBJECTS: Twenty-four-hour dietary recalls were collected from October 1988 through October 1991 on 504 young adults (mean age=23 years, 58% women, 70% white). STATISTICS: Analysis of variance and logistic regression techniques were used to investigate the relationship of breakfast consumption, ethnicity, and gender on dietary adequacy. The P values are from an analysis of variance model that adjusted for gender and ethnicity. RESULTS: Thirty-seven percent of young adults skipped breakfast. Of those who ate breakfast, 75% ate at home, 10% ate a fast-food breakfast, and 15% reported other sources. Mean energy intake from breakfast was 485 kcal; men consumed more energy than women (P<.001), and blacks consumed more energy than whites (P<.01). The breakfast meal provided an average of 13% of energy from protein, 55% from carbohydrate, 14% from sucrose, 34% from fat, and 12% from saturated fat. Whites consumed a breakfast higher in carbohydrate and sucrose than blacks, who consumed a breakfast higher in fat and saturated fat. Variations in breakfast foods consumed explained the racial differences in the nutrient composition of the breakfast meal. Young adults who skipped breakfast had lower total daily intakes of energy (P<.0001), protein per 1,000 kcal (P<.05), and saturated fat per 1,000 kcal (P<.01) than those who consumed breakfast. For all vitamins and minerals studied, a higher percentage of young adults who skipped breakfast did not meet two thirds of the Recommended Dietary Allowance than those who consumed a breakfast. APPLICATIONS: Encouraging consumption of breakfast, along with selection of more healthful breakfast food choices or snacks that are culturally appropriate, may be important strategies for improving the nutritional quality of young adults' diets.

Adult↗