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Biomedical subjects

S A Henderson

Publications and source records attributed to S A Henderson.

At least 19 recordsLinked to original sources
PubMed2005

Total ankle replacement. Early experiences with STAR prosthesis.

Early designs of Total Ankle Replacement (TAR) had a high failure rate. More recent experience with the 3-piece, meniscal bearing, total ankle replacement has been more promising. We report a review of the early results of our first 22 prostheses in 20 patients undergoing Scandinavian Total Ankle Replacement (STAR) in Northern Ireland. There was a mean follow-up time of 26 months. Seventeen patients are pain-free at the ankle joint during normal daily activities. Two of the early cases have required revision surgery due to technical errors. Other complications have included malleolar fractures, poor wound healing and postoperative stiffness. These early results show high levels of patient satisfaction, and we are encouraged to continue with total ankle arthroplasty. There is a steep initial learning curve and use of TAR should be restricted to foot and ankle surgeons.

Adult↗
PubMed2001

Genetic taste markers and food preferences.

Sensitivity to the bitter taste of 6-n-propylthiouracil (PROP) is an inherited trait. Although some people find PROP to be extremely bitter, others cannot distinguish PROP solutions from plain water. In a series of studies, greater PROP sensitivity was linked with lower acceptability of other bitter compounds and with lower reported liking for some bitter foods. Women, identified as "super-tasters" of PROP, had lower acceptance scores for grapefruit juice, green tea, Brussels sprouts, and some soy products. Many of these foods contain bitter phytochemicals with reputed cancer-protective activity. These include flavonoids in citrus fruit, polyphenols in green tea and red wine, glucosinolates in cruciferous vegetables, and isoflavones in soy products. Consumer acceptance of these plant-based foods may depend critically on inherited taste factors. This review examines the role of genetic taste markers in determining taste preferences and food choices.

Anticarcinogenic Agents↗
PubMed2000

Impaired contractile performance of cultured rabbit ventricular myocytes after adenoviral gene transfer of Na(+)-Ca(2+) exchanger.

Na(+)-Ca(2+) exchanger (NCX) gene expression is increased in the failing human heart. We investigated the hypothesis that upregulation of NCX can induce depressed contractile performance. Overexpression of NCX was achieved in isolated rabbit ventricular myocytes through adenoviral gene transfer (Ad-NCX). After 48 hours, immunoblots revealed a virus dose-dependent increase in NCX protein. Adenoviral beta-galactosidase transfection served as a control. The fractional shortening (FS) of electrically stimulated myocytes was analyzed. At 60 min(-1), FS was depressed by 15.6% in the Ad-NCX group (n=143) versus the control group (n=163, P:<0.05). Analysis of the shortening-frequency relationship showed a steady increase in FS in the control myocytes (n=26) from 0.027+/-0.002 at 30 min(-1) to 0. 037+/-0.002 at 120 min(-1) (P:<0.05 versus 30 min(-1)) and to 0. 040+/-0.002 at 180 min(-1) (P:<0.05 versus 30 min(-1)). Frequency potentiation of shortening was blunted in NCX-transfected myocytes (n=27). The FS was 0.024+/-0.002 at 30 min(-1), 0.029+/-0.002 at 120 min(-1) (P:<0.05 versus 30 min(-1), P:<0.05 versus control), and 0. 026+/-0.002 at 180 min(-1) (NS versus 30 min(-1), P:<0.05 versus control). Caffeine contractures, which indicate sarcoplasmic reticulum Ca(2+) load, were significantly reduced at 120 min(-1) in NCX-transfected cells. An analysis of postrest behavior showed a decay of FS with longer rest intervals in control cells. Rest decay was significantly higher in the Ad-NCX group; after 120 seconds of rest, FS was 78+/-4% in control and 65+/-3% in the Ad-NCX group (P:<0.05) relative to steady-state FS before rest (100%). In conclusion, the overexpression of NCX in rabbit cardiomyocytes results in the depression of contractile function. This supports the hypothesis that upregulation of NCX can result in systolic myocardial failure.

Adenoviridae↗
PubMed2000

Genetic taste markers and preferences for vegetables and fruit of female breast care patients.

OBJECTIVE: To explore links between genetic responsiveness to the bitter taste of 6-n-propylthiouracil (PROP) and self-reported preferences for vegetables and fruit of female breast care patients. METHODS: PROP tasting was defined by detection thresholds and by perceived bitterness and hedonic ratings for PROP solutions. Nontasters, medium tasters, and supertasters were identified by their PROP thresholds and by the ratio of perceived bitterness of PROP to the perceived saltiness of sodium chloride solutions. Subjects rated preferences for vegetables and fruit using 9-point category scales. SUBJECTS/SETTING: A clinical sample of 170 patients with newly diagnosed breast cancer and 156 cancer-free control subjects were recruited from the University of Michigan Breast Care Center. STATISTICAL ANALYSES: Principal components factor analysis, one-way analyses of variance, and Pearson correlations and chi 2 tests were used to analyze taste and food preference data. RESULTS: Genetic responsiveness to PROP was associated with lower acceptance of cruciferous and selected green and raw vegetables (P < .05). Women who reported disliking such foods were medium tasters or supertasters of PROP. Preference ratings for fruit were unrelated to PROP taster status. APPLICATIONS/CONCLUSIONS: Women who are PROP tasters may be less likely to comply with dietary strategies for cancer prevention that emphasize consumption of cruciferous vegetables and bitter salad greens. Alternatively, PROP-sensitive women may seek to reduce bitter taste by adding fat, sugar, or salt.

Breast Neoplasms↗
PubMed2000

Both food preferences and food frequency scores predict fat intakes of women with breast cancer.

OBJECTIVE: To determine whether self-reported frequencies of food use were linked to self-reported preferences for the same foods. The hypothesis was that both food frequencies and food preferences can predict nutrient intakes. RESPONDENTS: Participants were adult women patients (n = 339), recruited through the University of Michigan Breast Care Center. The sample included both persons with breast cancer and persons who were cancer-free. DESIGN: All women completed a 98-item food frequency questionnaire and rated preferences for many of the same foods using a 9-point category scale. Percent energy from fat and saturated fat, and intakes of dietary fiber and vitamin C were estimated from analyses of 4-day food records. STATISTICAL ANALYSES: Pearson correlations coefficients were used for data analysis. RESULTS: Dislike was a strong predictor of nonuse. In contrast, the more preferred foods were also reported as more frequently consumed. Significant correlations between preference and frequency scores were obtained for virtually all item pairs. Median Pearson correlation coefficient was 0.30 (range 0.04 to 0.56). Correlations improved when foods were aggregated into the chief dietary sources of fat, saturated fat, and vitamin C. Food frequencies and food preferences showed the same strength of association with percent energy from fat and saturated fat (r = 0.20 to 0.25). Food frequencies showed a stronger association with vitamin C intakes than did preferences for vegetables and fruit. APPLICATIONS: Food preferences may provide a potential alternative to the food frequency approach.

Adult↗
PubMed2000

Young women's food preferences and taste responsiveness to 6-n-propylthiouracil (PROP).

This study examined links between taste responsiveness to 6-n-propylthiouracil (PROP), a heritable trait, and sensory responses to six common foods. Sixty-three young women subjects were divided into PROP tasters (n = 25) and nontasters (n = 25), based on their responses to PROP-impregnated filter paper and mean bitterness intensity ratings for seven PROP solutions. Thirteen subjects were excluded as unclassifiable. The 50 subjects sampled Brussels sprouts, broccoli, spinach, black coffee, soy milk, and soybean tofu. Sensory ratings for bitter intensity; pleasantness of taste, odor, and texture, and overall food acceptability scores were obtained using nine-point category scales. All subjects completed a food-preference checklist and a modified food-frequency questionnaire. PROP tasters rated Brussels sprouts as more bitter than did nontasters (p<0.05). Subjects who perceived the foods as more bitter also rated them as less pleasant and less acceptable. Taste preferences and food preferences were linked. Self-reported food preferences and self-reported frequencies of consumption for the same foods were also linked. Taste factors and food preferences may impact dietary choices and the frequency of food consumption.

Adult↗
PubMed1999

Taste and food preferences as predictors of dietary practices in young women.

OBJECTIVE: To investigate links between taste responses, self-reported food preferences and selected dietary outcomes in young women. METHODS: Subjects were 159 women, with a mean age of 27.0 years. Taste responses were measured using aqueous solutions of 6-n-propylthiouracil (PROP) and sucrose. All subjects completed a 171-item food preference checklist, using nine-point category scales. Food preference data were reduced using principal components factor analyses, with the internal consistency of factor-based subscales established using Cronbach's alpha. Dietary intakes, available for a subset of 87 women, were based on 3 days of food records. Estimated intakes of carbohydrate, fibre and beta-carotene were the key dietary outcome variables. RESULTS: Genetically-mediated sensitivity to the bitter taste of PROP was associated with reduced preferences for Brussels sprouts, cabbage, spinach and coffee beverages. Higher preferences for sucrose in water were associated with increased preferences for sweet desserts. Food preferences, in turn, were associated with measures of current diet. Reduced acceptability of vegetables and fruits was associated with lower estimated intakes of carbohydrate, fibre and beta-carotene. CONCLUSIONS: Taste responses to sucrose and PROP were predictive of some food preferences. Food preferences, in turn, were associated with food consumption patterns. Given that taste responsiveness to PROP is an inherited trait, there may be further links between genetic taste markers, eating habits and the selection of healthful diets.

Adult↗
PubMed1999

Age and food preferences influence dietary intakes of breast care patients.

Identifying major influences on food choice is an important component of nutrition intervention research. Sensitivity to the bitter taste of 6-n-propylthiouracil (PROP) and self-reported preferences for meats, fats, vegetables, and fruit were examined in 329 female breast care patients. Intakes of fat, saturated fat, fiber, folate, and vitamin C, established using 4-day food diaries, were the chief health outcome variables. The strongest predictor of food preferences was age. Preferences were linked to food intakes. Older women consumed less energy and saturated fat and more dietary fiber and vitamin C than did younger women. Age-related decline in taste sensitivity to PROP was associated with increased liking for bitter cruciferous vegetables. Age-associated changes in food preferences and eating habits have implications for the dietary approach to cancer prevention and control.

Adult↗
PubMed1998

Sensory responses to 6-n-propylthiouracil (PROP) or sucrose solutions and food preferences in young women.

Genetic sensitivity to the bitter taste of 6-n-propylthiouracil (PROP) has been linked with a greater number of food aversions and reported rejection of some bitter foods. Healthy young women (n = 121) were divided into nontasters, tasters and supertasters of PROP according to their PROP detection thresholds and the ratio of intensity ratings of PROP versus NaCl solutions. Hedonic response profiles to sucrose solutions distinguished between likers and dislikers of sweet. All subjects completed a 171-item food preference checklist. Food preference data were reduced by factor analyses, subscales of which were tested for reliability using Cronbach's alpha. Greater PROP sensitivity was associated with lower acceptance of coffee, cruciferous vegetables, tart citrus fruit, dark breads, and selected fats. In contrast, liking for sucrose solutions was linked to liking for sugar in tea and coffee, but not to any special pattern of food acceptance. Strategies aimed at increasing the consumption of grains, vegetables, and fruit should consider the role of inherited taste makers and their potential impact on dietary habits.

Adult↗
PubMed1998

Tyrosine kinase and c-Jun NH2-terminal kinase mediate hypertrophic responses to prostaglandin F2alpha in cultured neonatal rat ventricular myocytes.

Myocardial infarction results in focal areas of ischemia, hypoxia, necrosis, and decreased contractile function. To compensate for loss of contractile function, remaining viable myocytes undergo hypertrophic growth. Prostaglandin F2alpha (PGF2alpha), which is released from cells of the myocardium during periods of stress such as hypoxia or ischemia/reperfusion, has recently been shown to stimulate hypertrophic growth in neonatal rat ventricular myocytes. In the present study, we determine which growth-related intracellular pathways are required for PGF2alpha to induce morphological and genetic features characteristic of the hypertrophic phenotype. In cardiomyocytes, PGF2alpha increases the hydrolysis of inositol phosphates and induces the translocation of protein kinase C epsilon to the myocyte membrane, consistent with PGF2alpha receptor coupling to Gq. PGF2alpha also activates the extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase pathways. Surprisingly, studies using pharmacological inhibitors and transfection of dominant-interfering proteins demonstrate that PGF2alpha-induced myocyte hypertrophy occurs independent of either PKC, p38, or ERK pathways. Additional studies demonstrate that PGF2alpha stimulates protein tyrosine phosphorylation and activates c-Jun NH2-terminal kinase and suggest that these pathways mediate hypertrophic growth in response to PGF2alpha.

Animals↗
PubMed1998

Genetic sensitivity to 6-n-propylthiouracil and sensory responses to sugar and fat mixtures.

This study tested the hypothesis that genetic sensitivity to 6-n-propylthiouracil (PROP) is associated with greater sensitivity to sugar and fat in foods. Subjects were 118 young women from different ethnic backgrounds, mean age 26.9 years and mean body mass index (BMI) 23.4. The women were classified as nontasters (n = 39), medium tasters (n = 48), or supertasters (n = 31) of PROP. Nontasters of PROP had thresholds of 1.8 x 10(-4) mol/L PROP or greater, whereas tasters had thresholds below 1.0 x 10(-4) mol/L PROP. PROP tasters were divided into medium tasters and supertasters, based on the ratio of intensity ratings of suprathreshold PROP solutions relative to NaCl solutions. Supertasters were defined as those with PROP/NaCl ratios of 1.90 or more. The pattern of sensory responses to sweetened dairy products of varying sugar and fat contents closely replicated data obtained in other studies. Genetic sensitivity to PROP was not associated with enhanced perception or altered hedonic response profiles for this range of 15 sugar/fat mixtures. Separating subjects into "likers" and "dislikers" of sweetened dairy products failed to reveal significant links to PROP taster status in this all-female sample.

Adult↗
PubMed1997

The fat-sucrose seesaw in relation to age and dietary variety of French adults.

Guidelines for a healthy diet often recommend limiting dietary sugars and fats. Some researchers have called these aims mutually incompatible, suggesting that fat and sugar intakes, when expressed as percent dietary energy, are inversely linked. Others have argued that sugar, more specifically sucrose, acts as a vehicle for dietary fat and serves to suppress the overall quality of the diet. This study examined the relationship between age, sucrose and fat intakes, body mass index (BMI), and measures of dietary diversity and variety in a community-based sample of 837 French adults. Consistent with other studies, high consumption of added sucrose (in g/day or g/1000 kcal per day) was associated with higher consumption of energy and fat and lower consumption of vegetables and fruit. However, eating patterns were strongly influenced by age. High-sucrose consumers were significantly younger and had lower BMI values than did low-sucrose consumers, who were both older and had higher BMIs. High-sucrose diets had minimal effect on the diet diversity score and were associated with more varied diets, as evidenced by a higher dietary variety score.

Adolescent↗
PubMed1997

The Dietary Variety Score: assessing diet quality in healthy young and older adults.

OBJECTIVE: To develop a new dietary variety score (DVS) and link it to other measures of diet quality, including a modified diet quality index (DQI). SUBJECTS: The subjects were 24 healthy young (ages 20 to 30 years) and 24 healthy older (ages 60 to 75 years) adults, including 24 men and 24 women. Their dietary intake assessments were based on one 24-hour food recall interview and 14 consecutive days of food records. DESIGN AND MEASURES: Energy and nutrient intakes were estimated using Nutritionist IV software. DVS was based on the cumulative number of different foods consumed over the 15-day period. DQI was a 5-point scale based on conformity with the key US dietary recommendations. Full score was awarded for diets deriving 30% or less of energy from fat, 10% or less of energy from saturated fat, more than 50% of energy from carbohydrate, and containing less than 300 mg cholesterol and 2,400 mg sodium per day. Analytic measures included analyses of variance, correlation analyses, and chi 2 tests. RESULTS: Older subjects consumed more varied diets than did young subjects. Higher DVS values were linked positively to vitamin C intakes and negatively to the consumption of salt, sugar, and saturated fat. However, a high DVS was not linked to a high score on the DQI in this subject sample. DISCUSSION/CONCLUSIONS: Few studies have addressed the issue of how many different foods constitute a varied diet. The present classification scheme offers a new way of assessing dietary variety at the individual or group level. Measures of dietary variety may represent an additional facet of diet quality and their relationship to selected health outcomes should be examined further.

Adult↗
PubMed1997

Nontasters, tasters, and supertasters of 6-n-propylthiouracil (PROP) and hedonic response to sweet.

Genetic sensitivity to 6-n-propylthiouracil (PROP) has been reported to predict hedonic response to sweet taste in both women and men. This study was based on a sample of 159 women of different ethnic backgrounds, mean age 27.0 years, and mean body mass index (BMI) 23.2. The women were classified as nontasters (n = 43), regular tasters (n = 70), or supertasters (n = 46) of PROP on the basis of their PROP detection thresholds and the scaling of 5 suprathreshold solutions of PROP and NaCl. Nontasters had thresholds > 1.8 x 10(-4) mol/L PROP and PROP/NaCl ratios < 1.60. Supertasters had thresholds < 3.2 x 10(-5) mol/L PROP and PROP/NaCl ratios > 1.60. Genetic sensitivity to PROP failed to predict sweetness intensity ratings or hedonic response profiles for sucrose solutions. Separating subjects into sucrose "likers" and "dislikers" failed to reveal any significant links to PROP nontaster, taster, or supertaster status in this all-female sample.

Adult↗