Biomedical subjects

D F Tate

Publications and source records attributed to D F Tate.

7 recordsLinked to original sources

PubMed2006

Obesity is associated with memory deficits in young and middle-aged adults.

Recent findings suggest obesity is associated with reduced memory performance in older adults. The present study examined whether similar deficits also exist in younger adults and the degree to which the relationship between body mass index (BMI) and memory varies as a function of age. Prior to inclusion, participants were rigorously screened and excluded for medical conditions known to impact cognitive functioning, including neurological disorders, head injury, cardiovascular disease, and diabetes. A total of 486 healthy adults completed a verbal list-learning task. Participants were categorized into normal weight, overweight, and obese groups based on their BMI. Performance on learning, delayed recall, and recognition performance were compared across BMI groups. Results showed obese individuals had poorer memory performance when comparing persons across the adult lifespan (age 21-82 yr), but also when examining only younger and middle-aged adults (age 21-50 yr). Regression analyses found no evidence of an interaction between BMI and age on any memory variable, suggesting the relationship between BMI and memory does not vary with age. These findings provide further support for an independent relationship between obesity and reduced memory performance and suggest these effects are not limited to older adults. Further research is needed to identify etiological factors.

Adult↗

PubMed2004

Relationship between changes in food group variety, dietary intake, and weight during obesity treatment.

BACKGROUND: Experimental studies show diets with greater variety in energy-dense foods increase consumption and body weight. Reducing variety in energy-dense food groups may decrease energy and dietary fat intake, promoting weight loss. OBJECTIVE: This study examined changes in food group variety during obesity treatment and the relation between changes in food group variety, dietary intake, and weight. DESIGN: Overweight men and women (n=202) were randomly assigned to one of two standard behavioral treatments with varying exercise prescriptions (exercise level of 4186 kJ/week (1000 kcal/week) or 10465 kJ/week (2500 kcal/week)), but received the same diet. Complete measures were obtained from 122 participants, of which 70 (58%) were female, with a mean body mass index of 31.3 kg/m(2) (s.d.=2.5). MEASUREMENTS: Food group variety and diet composition were assessed at 0, 6, and 18 months from food-frequency questionnaires. Food group variety was calculated as percent of foods consumed on a weekly basis within a food group, irrespective of servings consumed. RESULTS: Participants reported increased variety (P</=0.001) in low-fat breads (LFB) and vegetables, and decreased variety (P</=0.001) in high-fat foods (HFF), and fats, oils, and sweets (FOS) over the course of the 18-month study. From 0 to 6 months, decreased HFF and FOS variety was associated with reduced energy and percent dietary fat intake, and decreased HFF variety was related to weight loss. From 6 to 18 months, decreased HFF variety and increased LFB variety was associated with reduced percent dietary fat consumed and weight loss. CONCLUSION: Changing variety in specific food groups may help in adopting and sustaining a diet low in energy and fat, producing better weight loss and weight loss maintenance.

Adult↗

PubMed2001

Using Internet technology to deliver a behavioral weight loss program.

CONTEXT: Rapid increases in access to the Internet have made it a viable mode for public health intervention. No controlled studies have evaluated this resource for weight loss. OBJECTIVE: To determine whether a structured Internet behavioral weight loss program produces greater initial weight loss and changes in waist circumference than a weight loss education Web site. DESIGN: Randomized, controlled trial conducted from April to December 1999. SETTING AND PARTICIPANTS: Ninety-one healthy, overweight adult hospital employees aged 18 to 60 years with a body mass index of 25 to 36 kg/m(2). Analyses were performed for the 65 who had complete follow-up data. INTERVENTIONS: Participants were randomly assigned to a 6-month weight loss program of either Internet education (education; n = 32 with complete data) or Internet behavior therapy (behavior therapy; n = 33 with complete data). All participants were given 1 face-to-face group weight loss session and access to a Web site with organized links to Internet weight loss resources. Participants in the behavior therapy group received additional behavioral procedures, including a sequence of 24 weekly behavioral lessons via e-mail, weekly online submission of self-monitoring diaries with individualized therapist feedback via e-mail, and an online bulletin board. MAIN OUTCOME MEASURES: Body weight and waist circumference, measured at 0, 3, and 6 months, compared the 2 intervention groups. RESULTS: Repeated-measures analyses showed that the behavior therapy group lost more weight than the education group (P =.005). The behavior therapy group lost a mean (SD) of 4.0 (2.8) kg by 3 months and 4.1 (4.5) kg by 6 months. Weight loss in the education group was 1.7 (2.7) kg at 3 months and 1.6 (3.3) kg by 6 months. More participants in the behavior therapy than education group achieved the 5% weight loss goal (45% vs 22%; P =.05) by 6 months. Changes in waist circumference were also greater in the behavior therapy group than in the education group at both 3 months (P =.001) and 6 months (P =.005). CONCLUSIONS: Participants who were given a structured behavioral treatment program with weekly contact and individualized feedback had better weight loss compared with those given links to educational Web sites. Thus, the Internet and e-mail appear to be viable methods for delivery of structured behavioral weight loss programs.

Adult↗

PubMed2001

Brain volume, intracranial volume, and dementia.

RATIONALE AND OBJECTIVES: Using a large magnetic resonance (MR) imaging data set (n = 532), we investigated the utility of total intracranial volume (TICV) as a correction factor for head size variability when assessing total brain volume (TBV) and the subcortical volumes of the temporal horn of the lateral ventricular system and the hippocampus. METHODS: A uniform tissue segmentation procedure (analyze) was used to calculate volumes. Total brain volume was compared with TICV in 357 control subjects and 175 patients with various dementing and neuropsychiatric disorders (mixed dementia/neuropsychiatric group). These MR-based TBV/TICV relationships were compared with actual postmortem (n = 87) values obtained from a study of neurologically healthy subjects at the time of death. Comparisons were also made in which temporal horn and hippocampal volumes were corrected by TICV and TBV. Lastly, the ability of corrected TBV and temporal horn and hippocampal volumes to distinguish subjects in the mixed dementia/neuropsychiatric group from controls was examined by logistic regression. RESULTS: In the control sample, brain volume averaged 9% of TICV, regardless of age. In contrast, TBV in the mixed dementia/neuropsychiatric subjects showed, on average, a 22% reduction compared with TICV. By plotting TBV/TICV curves, highly significant but different regression lines emerged, wherein a reduction in brain volume in conditions of mixed dementia/neuropsychiatric disorder showed a distinct separation from the norm. The TBV/TICV regression line generated from MR imaging in controls did not differ from the postmortem TBV/TICV regression line. Logistic regression showed a 96% correct classification of mixed dementia/neuropsychiatric subjects from controls by using the TBV/TICV ratio. This technique has the advantage that each subject serves as his or her own control. CONCLUSIONS: In cases of dementia and neuropsychiatric disorder in persons 65 and older, TBV corrected by TICV readily differentiated this clinical population from controls. This technique is easy and simple to use and has various clinical applications. For temporal horn and hippocampal volume, corrections with TBV rather than TICV may provide more clinically meaningful corrections.

Aged↗

PubMed1976

Isolation and identification of two learning-induced brain peptides.

Goldfish were trained either to avoid the blue compartment of a tank and swim into the green compartment or, conversely, to avoid green and prefer blue. Preliminary experiments indicated that acquisition of the avoidance behavior was associated with the presence in the brain of two peptides, one found in blue avoiding (BA), another in green avoiding (GA) fish. With the help of behavioral bioassays, the peptides were isolated and purified, and their structure was determined by ultrasmicroanalytical techniques. The sequence of the BA peptide, pglu-ile-gly-ala-val-phe-pro-leu-lys-tyr-gly-ser-lys-OH was reproduced by synthesis. Sequential analysis of the GA peptide gave two alternative structures, NAc-lys-gly-gln-ile-ala-val-phe-pro-leu-lys-tyr-gly-ser-OH or NAc-lys-gly-ala-val-gln-ile-phe-pro-lys-tyr-gly-ser-OH, both of which are being synthetized to be compared with the natural compound. Overlapping sequences between the BA and GA peptides suggest the existence of a family of peptides associated with behavior based on color discrimination.

Amino Acid Sequence↗

PubMedDate not supplied

Who reports receiving advice to lose weight? Results from a multistate survey.

BACKGROUND: Overweight and obesity are increasingly prevalent in the United States. The prevalence of health care provider advice to lose weight is not clear. METHODS: We examined the percentage of individuals who reported being advised to lose weight by a health care practitioner in the past year by population subgroup. Participants were individuals in the 10 states participating in the 1996 Behavioral Risk Factor Surveillance System, which assessed advice to lose weight, hypertension awareness, and cholesterol awareness. RESULTS: The prevalence of reporting advice to lose weight was most strongly associated with body mass index (BMI) (calculated as weight in kilograms divided by the square of height in meters) and weight-related comorbidities. In individuals with a BMI of 25 to 27, only 5.6% of those with no comorbidities and 13.6% of those with comorbidities received advice. These rates were increased to 32.4% and 47.3%, respectively, in those with a BMI greater than 30. Middle-aged individuals, those with more education, and those living in the northeast were also more likely to receive advice. Receiving advice to maintain weight was reported by only 2. 5% of respondents. Receiving advice to lose weight was strongly associated with trying to lose weight, especially in those with a BMI of 25 to 27, where 77.5% who received advice reported trying to lose weight vs 33.4% of those who did not receive advice. CONCLUSIONS: Advice to lose weight is uncommon and is given primarily to those who are already obese, are middle-aged, and have comorbidities. Practitioners may be missing important opportunities to counsel mildly overweight individuals to lose weight or to maintain their weight and thereby prevent comorbidities.

Adolescent↗

PubMedDate not supplied

Fornix and hippocampal atrophy in traumatic brain injury.

This study compared a fornix cross-sectional-area measurement and hippocampal volume in 86 traumatic brain injury (TBI) subjects with 46 normal controls. The TBI group showed a significant reduction in fornix area and hippocampal volume. It was also shown that initial injury severity was related to the degree of atrophy in both structures. Although fornix size and hippocampal volume correlated, such a modest correlation between these two structures suggests differential and potentially independent mechanisms of injury. The General Memory Index score from the Wechsler Memory Scale-Revised was shown to be significantly correlated with hippocampal volume following TBI.

Adolescent↗