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Biomedical subjects

B Shannon

Publications and source records attributed to B Shannon.

At least 19 recordsLinked to original sources
PubMed2002

A polymorphism in the methylenetetrahydrofolate reductase gene predisposes to colorectal cancers with microsatellite instability.

BACKGROUND: The enzyme methylenetetrahydrofolate reductase (MTHFR) catalyses the formation of folate intermediates that are vital to methylation reactions. A polymorphic variant (TT) has been linked to reduced levels of plasma folate, aberrant DNA methylation in leucocytes, and increased risk of colorectal cancer (CRC) under conditions of low folate intake. The cystathionine beta-synthase (CBS) enzyme reduces homocysteine levels and thus may protect against CRC. The CBS gene has a variant, 844ins68, that has been linked with increased activity. These variants may be involved in the development of the subgroup of CRC displaying aberrant DNA methylation and frequently associated with microsatellite instability (MSI). AIM: To investigate the frequencies of the TT and 844ins68 genotypes in CRC patients with MSI+ tumours compared with those with MSI- tumours and a control population. SUBJECTS: Patients with CRC (n=501) and healthy control subjects (n=1207) were studied. CRC cases were classified as MSI+ (n=75) or MSI- (n=426) based on deletions within the BAT-26 mononucleotide repeat. METHODS: Subjects were genotyped for MTHFR using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and PCR-restriction fragment length polymorphism (PCR-RFLP) techniques, and for CBS using PCR. RESULTS: The MTHFR TT genotype was more frequent in older CRC patients (>or=70 y) compared with equivalent aged controls (p=0.03), was associated with a significantly later age of diagnosis in patients with proximal colon tumours (p=0.02), and was almost twice as frequent in MSI+ than in MSI- tumours (p=0.05). Compared with normal controls, the 844ins68 variant of CBS was less frequent in patients with proximal tumours (p=0.02). CONCLUSIONS: The TT genotype of MTHFR is associated with an increased risk of CRC in older populations, possibly due to age related disturbances in folate metabolism. The TT genotype appears to predispose to CRC that is MSI+. This may reflect the involvement of aberrant DNA methylation frequently associated with MSI+. The 844ins68 CBS polymorphism may protect against proximal tumours.

Adult↗
PubMed2000

Responses of older adults to theory-based nutrition newsletters.

OBJECTIVE: To evaluate the effect of a theory-based newsletter on knowledge, attitude, and behavior change in older adults. DESIGN: Pretest-posttest, random assignment, and treatment-control design with 2 treatment groups: 1 that received newsletters only and 1 that received newsletters with follow-up telephone interviews. Control group completed pretest-posttest surveys only. SUBJECTS/SETTING: Four hundred eighty men and women, aged 60 to 74 years, were recruited to participate in a home-based educational intervention using a patient list generated from a rural tertiary care hospital database, Geisinger Medical Center in Danville, Pa. INTERVENTION: Five nutrition newsletters designed using the nutrition communication model and adult learning theory principles were mailed biweekly. Telephone interviews followed each of the 5 newsletters 10 to 14 days after distribution. OUTCOME MEASURES: Nutrition knowledge and interest, food behavior related to dietary fat, and stages of change for dietary fat and fiber. STATISTICAL ANALYSES PERFORMED: Analysis of covariance was used to determine group differences in posttest outcome measures using pretest as covariate. RESULTS: In addition to achieving higher scores than the control group, the treatment groups were significantly different from each other in correct and perceived nutrition knowledge at posttest. Those in the treatment group receiving telephone calls scored higher (mean change = 19.0% for correct and 20.3% for perceived) than those who received the newsletters only (mean change = 12.5% for correct and 14.3% for perceived; P < .05). Treatment groups also rated their interest in nutrition higher than the control group did; there was no between-treatment difference. Treatment groups performed significantly better than the control group for dietary fiber stage of change (P < .05). Those receiving only newsletters scored significantly better than the control for the "avoid fat" food behavior (P < .05). APPLICATIONS/CONCLUSIONS: This study provides an example of the incorporation of a theoretical model in development and evaluation of newsletters. Home-delivered nutrition newsletters based on this model can communicate health and nutrition information to older adults. Consumers today have more opportunities than ever before to access nutrition information quickly and inexpensively. Newsletters can help dietetics professionals filter and limit what consumers must process, saving clients time and improving the accuracy of information obtained. Dietetics professionals in both clinical and community practice are uniquely positioned to provide highly focused and understandable information to consumers via a newsletter format.

Aged↗
PubMed2000

Diet quality of young children who received nutrition education promoting lower dietary fat.

OBJECTIVE: : To evaluate the impact of nutrition education promoting lower dietary fat on the overall diet quality in children using a multidimensional index that measures nutrient and food intakes in relation to US dietary recommendations. DESIGN: : Prospective cohort study with two intervention and two control groups. Children with elevated low density lipoprotein (LDL) cholesterol were randomized to one of two intervention groups or an at-risk control group. The intervention children received either the parent-child autotutorial (PCAT) programme, a 10-week home-based self-instruction nutrition education programme, or nutrition counselling from a registered dietitian. Children with non-elevated plasma cholesterol formed the not-at-risk control group. Dietary and blood data were collected at baseline and at 3 months. SETTING: : Paediatric practices in suburbs north of Philadelphia, PA. SUBJECTS: : Two hundred and twenty-seven 4-10-year-old children with elevated LDL cholesterol between the 80th and 98th percentiles, and 76 age- and gender-matched children with non-elevated plasma cholesterol, were studied. RESULTS: : Children who received PCAT or counselling significantly improved their overall diet quality (-0.6 and -0.4 change in diet quality index (DQI) scores) compared with at-risk control children. Children who received either form of nutrition education were more likely to meet the recommendations for three components of the DQI (total fat, saturated fat, sodium) (OR >1.7), but did not improve their intakes of three components of the DQI (vegetables and fruits, complex carbohydrates, calcium) at 3 months. CONCLUSIONS: : Nutrition education promoting lower dietary fat improved children's overall diet quality. However, several dietary behaviours important for long-term health remained unchanged.

Analysis of Variance↗
PubMed1999

Hypermethylation of the MYF-3 gene in colorectal cancers: associations with pathological features and with microsatellite instability.

Myf-3 is the human homologue of the murine Myo-D1 gene involved in muscle-cell differentiation. Using Southern blot analysis, we examined methylation of Myf-3 in histologically normal colonic mucosae, adenomas and carcinomas from a large series of patients with primary colorectal cancer. Hypermethylation of this gene in comparison with normal mucosa was observed in 88% of adenomas and in 99% of carcinomas. The pattern of Myf-3 methylation was similar in different areas of the same tumour, suggesting that methylation imbalances occur before the bulk of clonal-cell expansion. Significantly increased levels of Myf-3 methylation were observed in tumours which were more invasive, located in the proximal colon or from older patients. Patients whose tumours had extensive methylation showed a trend for shortened survival, though this was probably related to their being more invasive. Extensive methylation was significantly more frequent in tumours with microsatellite instability. Further work is required to determine whether the hypermethylation of Myf-3 observed in colorectal cancers is a specific alteration with functional significance or whether it reflects non-specific methylation imbalances occurring early during tumorigenesis.

Adenoma↗
PubMed1997

Superantigen-based immunotherapy: a phase I trial of PNU-214565, a monoclonal antibody-staphylococcal enterotoxin A recombinant fusion protein, in advanced pancreatic and colorectal cancer.

PURPOSE: To establish the maximum-tolerated dose (MTD) and define the toxicities of a single-dose infusion of PNU-214565, a recombinant Escherichia coli-derived fusion protein of Staphylococcal enterotoxin A (SEA) and the Fab-fragment of the C242 monoclonal antibody in patients with advanced colorectal and pancreatic carcinomas. To investigate the capability of PNU-214565 to induce a superantigen (SAg) response resulting in cytokine production and tumor regression. PATIENTS AND METHODS: Twenty-one patients (age range, 39 to 76 years; median, 64; 12 men, nine women; 18 colorectal, three pancreatic cancers) were treated with a single 3-hour infusion of PNU-214565, with doses ranging from 0.01 to 1.5 ng/kg. All patients had prior chemotherapy and a good performance status Eastern Cooperative Oncology Group [ECOG] performance status [PS] = 0 [n = 10]; PS = 1 [n = 11]), 10 had prior radiation, and 18 had prior surgery. RESULTS: Fever and hypotension were the most common toxicities. Fever of any grade occurred in 16 of 21 patients (76%): four of 21 (19%) with grade 2 and two of 21 (9.5%) with grade 3. Hypotension of any grade occurred in 13 of 21 (62%): four of 21 with grade 2 and one of 21 (5%) with grade 3. Interleukin-2 (IL-2) and tumor necrosis factor alpha (TNF alpha) induction correlated with toxicity. In the two patients with grade 3 fever, peak IL-2 and TNF alpha levels were 2.9 IU/mL and 165 pg/mL, and 8.3 IU/mL and 245 pg/mL, respectively. Transient, > or = 50% decreases in circulating monocytes were observed in 17 of 21 patients as early as 0.5 hours (median time, 2 hours) from the start of infusion. Decreases (mean 33%) in circulating lymphocytes were observed in seven of 21 patients. All three patients with grade 3 toxicity were treated at the 0.5-ng/kg dose. The significance of baseline anti-SEA, human antimouse antibody (HAMA), CA242-soluble antigen levels, and T-cell receptor variable beta region (TCR V beta) subsets and histocompatibility leukocyte antigen-DR (HLA-DR) genotypes was assessed as possible predictors of toxicity. All toxicities were transient and easily managed. No grade 3 toxicity occurred at the higher dose levels. CONCLUSION: PNU-214565, a SAg-based tumor targeted therapy, is safe when given as a single 3-hour infusion at doses up to 1.5 ng/kg. The MTD for a single dose was not determined. The safety of a repeated dose schedule is currently under investigation, beginning with doses determined to be safe in this trial.

Adult↗
PubMed1996

Change in nutrient intakes, number of servings, and contributions of total fat from food groups in 4- to 10-year-old children enrolled in a nutrition education study.

OBJECTIVE: To determine change in nutrient intakes, number of servings, and contributions of total fat from food groups in children who lowered their dietary fat intake. DESIGN: A research and demonstration study designed to lower plasma low-density lipoprotein cholesterol level. There were four study groups: two intervention and two control groups. All children had hypercholesterolemia except for those in one control group. There 24-hour dietary recalls were collected on randomly assigned days over a 2-week period at baseline and 3 months after the intervention. SUBJECTS: Three hundred three 4-to 10-year old children from suburbs north of Philadelphia, Pa. INTERVENTIONS: One intervention involved a home-based, parent-child autotutorial program (PCAT group) with audiotaped stories and print materials for the children and their families; the other intervention involved one face-to-face counseling session with a registered dietitian (counseling group). OUTCOME MEASURES: Change in mean nutrient intakes compared with the Recommended Dietary Allowance (RDA); change in number of servings and mean grams of total fat contributed from 10 different food groups. STATISTICAL ANALYSES PERFORMED: Analyses of variance and chi 3 analyses. RESULTS: Children in every study group had mean intakes of all nutrients (except vitamin D) greater than 67% of the RDA 3 months after the baseline measurement. Several food groups (ie, meats, dairy products, fats/oils, and desserts) provided less total fat to the diets of children who reduced their dietary lipid intake after 3 months (i.e., PCAT and counseling groups). These children also reduced the mean number of servings selected from these food groups. Within these same food groups, some children consumed fewer servings of higher fat foods and more servings of lower fat foods. APPLICATIONS/CONCLUSIONS: Children who lowered their dietary fat intake after intervention reported both quantitative and qualitative changes in food choices from several food groups. These choices did not significantly reduce their nutrient intakes.

Aging↗
PubMed1992

The status of school-based nutrition education at the state agency level.

The status of school-based nutrition education at the state agency level was examined. Telephone interviews with agencies in all 50 states revealed that nine states mandated nutrition be taught and another 21 included nutrition as a required topic in mandated subjects, frequently health. The other states had initiatives to promote school-based nutrition education but it was not required. Published requirements for teacher certification in elementary education, home economics, and health education seldom (two to three states) specified nutrition as a requirement. However, follow-up investigations revealed many states indirectly promote nutrition preparation for home economics and health education teachers through guidelines for approval of college programs in these areas. An inventory of nutrition education curricular materials revealed they were most frequently directed to grades K-6 and focused mainly on general foods and nutrition or that related to health. Given the links that emerged between health and nutrition, incorporating nutrition into health education may help promote school-based nutrition education.

Certification↗
PubMed1991

A dietary education program for hypercholesterolemic children and their parents.

A parent-child autotutorial dietary education program for 4- to 10-year-old, hypercholesterolemic children and their families was developed and pilot tested. The 10-lesson program, designed for weekly use at home, uses a "talking-book" approach (audiotapes with accompanying picture booklet) for the child. Parents are provided with information on ways to make recommended dietary changes, along with hands-on activities to do with the children. To help match the instructional approach to the wide developmental range within the children's age span, materials are divided into three program levels that use different story characters and concept presentations. During program development, evaluation by two children (and their parents) for each of the program levels guided the design and refinement of the lessons. A pilot test among 22 hypercholesterolemic children (whose treatment was limited to diet modification) revealed that children within the 4- to 10-year age range liked the "talking-book" approach and identified positively with the story characters. Parents indicated that their materials were clear and helpful. Between the baseline and 3-month follow-up visits, the children exhibited a significant increase in knowledge of heart healthy foods, a decrease in total fat consumption that approached significance, and a significant decrease in plasma low-density-lipoprotein cholesterol values.

Adult↗
PubMed1991

Inaccuracies in self-reported weights and heights of a sample of sixth-grade children.

We collected self-reported weights and heights of 806 sixth-graders in Pennsylvania and compared these values with measures of the children obtained by trained personnel who used standard clinical scales and rigid stadiometers. Approximately 10% of the children either were unable to specify a value for weight, height, or both or reported values of a magnitude indicating that they could not quantitatively conceptualize these measurements. Of the remaining 90%, both boys and girls tended to underreport their weight. Underreporting weight was more pronounced among girls than among boys; for both sexes, the degree of underreporting was much greater among taller, heavier children than among shorter, lighter children. Deviation between self-reported and measured height was substantial for many individuals, but there was no consistent trend toward underreporting or overreporting. These findings indicate that children's self-reported weight data may have a systematic bias, particularly if a large proportion of the sample is over-weight; height data may have considerable random error. We, therefore, conclude that self-reported weights and heights of children may be subject to errors that could confound results if used in clinical or research efforts.

Bias↗
PubMed1989

Psychosocial determinants of compliance in adolescents with iron deficiency.

The relationship between selected psychosocial variables and compliance was studied in 71 adolescents prescribed medication for iron deficiency. The mean compliance rate in the study group was 67%. Home pill counts were highly correlated with the other methods of measuring compliance, ie, change in serum ferritin level and urinary assay for tracer riboflavin. Statistically significant predictors of compliance included adverse side effects, initial estimate by the adolescent as to his probable level of compliance, and frequency of family reminders to take the medication. There was no significant correlation between self-esteem, locus of control, or most variables of the Health Belief Model and the level of patient compliance. Our findings suggest that home pill counts are an accurate method of assessing compliance and that instituting family reminders may be helpful in those adolescents who are potentially non-compliant.

Adolescent↗
PubMed1989

Examination of specific nutrition/health behaviors using a social cognitive model.

Nutrition intervention programs are not always successful. In some cases, an insufficient understanding of the interrelationships among factors influencing health behaviors may be responsible for the failures. This study used social cognitive theory, a framework for studying behaviors, to structure the relationships between measurable factors important to the frequency of health-oriented food consumption. We developed a model that incorporated factors for social environment, reinforcement, commitment, behavior modeling, knowledge, and attitude relative to the frequency of consumption of four beverages (whole milk, low-fat/skin milk, regular soda, and diet soda). Four-hundred fifty-seven middle-aged adults (mean age, 47 years; 58% female) and 709 college students (mean age, 21 years; 50% female) responded to a written questionnaire designed as a self-report on frequency of consumption and measures for 10 social cognitive variables. For all four beverages, the model explained 35% or more of the variance in frequency of consumption, thus confirming its predictive power. We used the statistical approach known as path analysis to examine the relationships within the model. The analysis demonstrated that factors influencing the consumption varied between the two age groups (e.g., nutrition knowledge was related to attitude in adult soda-drinking models but not in student soda-drinking models) and between forms of the beverages (e.g., for student models, nutrition knowledge was related to taste enjoyment for low-fat/skim milk but not for whole milk).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

A nutrition curriculum for health education: its effect on students' knowledge, attitude, and behavior.

The objective of the study was to determine the effect of nutrition instruction, using the curriculum guides, Nutrition In A Changing World, A Curriculum for Junior High Health, and A Curriculum for Senior High Health, on improving the nutrition knowledge, selected food/nutrition attitudes, and dietary behavior of students enrolled in secondary level health courses. Three groups of students were utilized including one experimental and two control groups at each level (junior high and senior high). The experimental group was pretested, taught the nutrition curriculum, and posttested. One control group was posttested only to measure the effect of the pretest on posttest performance. A second control group was pretested and posttested. Neither control group received nutrition instruction until after the study was completed. The three instruments used to collect data were a nutrition knowledge test, a food/nutrition attitude instrument, and a food frequency form. The results indicate that, at all grade levels, the experimental group had significantly improved knowledge scores. Little change in attitude scale scores was noted in grades seven and eight, while ninth grade experimental students scored significantly higher on the posttest for all attitude scales. Little improvement was seen in the posttest food frequency scores.

Adolescent↗