Search PubMed⌕ Search

Biomedical subjects

C A Taylor

Publications and source records attributed to C A Taylor.

At least 19 recordsLinked to original sources
PubMed2003

Snacking patterns influence energy and nutrient intakes but not body mass index.

OBJECTIVE: To study dietary intake and body mass index (BMI) patterns among US adults, stratified by snacking patterns. DESIGN: The 1994-1996 Continuing Survey of Food Intakes by Individuals (CSFII) provided the study sample. Snacking episodes were defined as a 'food and/or beverage break', and subjects were classified as morning, afternoon, evening, multiple or never snackers. SUBJECTS/SETTING: Our study included data from 1756 men and 1511 women who provided two nonconsecutive, multiple-pass 24-h dietary recalls. STATISTICAL ANALYSES: Mean values of each subject's two 24-h recalls were used for analyses, and data were analysed using the Statistical Package for the Social Sciences (SPSS) for Windows and SUDAAN. RESULTS: Compared with women, men were more likely to be evening, multiple or never snackers. Male multiple snackers had significantly higher energy intakes than did afternoon and never snackers, whereas female multiple snackers had higher energy intakes than did morning, evening and never snackers. At the same time, male and female multiple snackers had more prudent energy-adjusted intakes of protein, cholesterol, calcium and sodium. Coffee, cola, milk, ice cream and fruits were among the most frequently consumed snacks by men and women. The BMI did not differ significantly across snacker categories. CONCLUSIONS: These data indicate that snacking patterns have some effects on energy and nutrient intakes but not on BMI. Snack food choices remain a concern, especially beverages, including those that are sweetened. Vegetables and fruits as snacks should be encouraged.

Adult↗
PubMed2002

Segregation analysis of Parkinson disease revealing evidence for a major causative gene.

The role of genetics in Parkinson disease (PD) continues to be an area of considerable interest and controversy. We collected information involving the nuclear families of 948 consecutively ascertained PD index cases from the University of Virginia (UVA) Health System, the University of Medicine and Dentistry of New Jersey-Robert Wood Johnson (RWJ) School of Medicine, and Boston University (BU) School of Medicine. We performed a segregation analysis to assess evidence for the presence of a Mendelian pattern of familial transmission. The proportion of male (60.4%) and female (39.6%) cases, the mean age of onset (57.7 years), and the proportion of affected fathers (4.7%), mothers (6.6%), brothers (2.9%), and sisters (3.2%) were similar across the three sites. While most of the index cases were male, modestly more of the reported affected relatives were female. These analyses support the presence of a rare major Mendelian gene for PD in both the age-of-onset and susceptibility model. The age-of-onset model provides evidence for a gene that influences age-dependent penetrance of PD, influencing age of onset rather than susceptibility. We also found evidence for a Mendelian gene influencing susceptibility to the disease. It is not evident whether these two analyses are modeling the same gene or different genes with different effects on PD. The finding of significant genes influencing penetrance for PD raises the question of whether these may interact with environmental factors or other genes to increase the risk for PD. Such gene environment interactions, involving reduced penetrance in PD, may explain the low concordance rates among monozygotic twins for this disease.

Age of Onset↗
PubMed2002

The nature of newspaper coverage of homicide.

OBJECTIVES: Previous research has shown that some homicides are more likely than others to receive newspaper coverage (for example, homicides by strangers). The present investigation examined whether, once the decision has been made to report on a homicide, the nature of the coverage (that is, how much visibility is given to a story, what information is included, and how a story is written) differs according to two key variables, victim ethnicity, and victim-suspect relationship. SETTING: Los Angeles, California (USA). METHODS: Homicide articles from the 1990-94 issues of the Los Angeles Times were stratified according to the predictors of interest (victim ethnicity and victim-suspect relationship) and a sample was drawn. Data that characterized two primary aspects of newspaper coverage, prominence and story framing (including background information, story focus, use of opinions, story tone, and "hook" or leading introductory lines) were abstracted from the articles. Descriptive statistics and cross tabulations were generated. Multivariate analyses were conducted to examine the predictive value of victim ethnicity and victim-suspect relationship on the nature of the newspaper coverage. RESULTS: Newspaper coverage of homicide was generally factual, episodic, and unemotional in tone. Victim-suspect relationship, but not victim ethnicity, was related to how a story was covered, particularly the story frame. Homicides by intimates were covered consistently differently from other types of homicides; these stories were less likely to be opinion dominated, be emotional, and begin with a "hook". CONCLUSION: Victim-suspect relationship was related to the nature of coverage of homicides in a large, metropolitan newspaper. Given the agenda setting and issue framing functions of the news media, these findings have implications for the manner in which the public and policy makers perceive homicides and, consequently, for the support afforded to various types of solutions for addressing and preventing violence.

Bibliometrics↗
PubMed2000

Expression and functional characterization of a Drosophila neuropeptide precursor with homology to mammalian preprotachykinin A.

Peptides structurally related to mammalian tachykinins have recently been isolated from the brain and intestine of several insect species, where they are believed to function as both neuromodulators and hormones. Further evidence for the signaling role of insect tachykinin-related peptides was provided by the cloning and characterization of cDNAs for two tachykinin receptors from Drosophila melanogaster. However, no endogenous ligand has been isolated for the Drosophila tachykinin receptors to date. Analysis of the Drosophila genome allowed us to identify a putative tachykinin-related peptide prohormone (prepro-DTK) gene. A 1.5-kilobase pair cDNA amplified from a Drosophila head cDNA library contained an 870-base pair open reading frame, which encodes five novel Drosophila tachykinin-related peptides (called DTK peptides) with conserved C-terminal FXGXR-amide motifs common to other insect tachykinin-related peptides. The tachykinin-related peptide prohormone gene (Dtk) is both expressed and post-translationally processed in larval and adult midgut endocrine cells and in the central nervous system, with midgut expression starting at stage 17 of embryogenesis. The predicted Drosophila tachykinin peptides have potent stimulatory effects on the contractions of insect gut. These data provide additional evidence for the conservation of both the structure and function of the tachykinin peptides in the brain and gut during the course of evolution.

Animals↗
PubMed2000

Simulation-based medical planning for cardiovascular disease: visualization system foundations.

A technique for visualizing computational models along with volumetric imaging data in a real-time, interactive, simulation-based medical planning system for cardiovascular disease treatment is described. This technique involves an ordered rendering of faceted geometry and volumetric image data. We have developed a software system based on this image-fusion technique that is capable of capturing and representing the inherent anatomic constraints of an individual patient. Such constraints must be represented accurately in a medical planning system to ensure the validity of a potential procedure. A hypothetical clinical scenario is described for which vascular treatment plans were constructed pre-operatively without reference to the physical anatomic structure. These models were later embedded into patient-specific diagnostic MRA scans to establish the anatomic context for physiologic observations.

Algorithms↗
PubMed2000

Increased cellularity of tumor-encased native vessels in prostate carcinoma is a marker for tumor progression.

Changes in the native vasculature of the prostate gland associated with prostate adenocarcinoma have not been well characterized. Eighty-nine whole mounts of entirely submitted radical prostatectomies were reviewed. Thirty prostates with a minimum of five native arteries surrounded by carcinoma with corresponding control arteries were found and included in this study. The number of nuclei in the media of native arteries was recorded per 0.138 mm2 using a 40x objective. The number of nuclei in vessels embedded in carcinoma (n = 204) was increased when compared with controls (26.37 versus 20.58 mean nuclei per 0.138 mm2; P < .001). Pathologic Stage T3 carcinomas contained vessels that were more cellular than stage T2 (P < .001). Vessels embedded in Gleason Grade 4 showed more cellularity than arteries embedded in Gleason Grade 3 (P < .002). Increased media cellularity of native prostate vessels encased in carcinoma is a histologic feature of higher grade/stage prostate carcinoma and provides positive indicator of advanced prostate cancer.

Adenocarcinoma↗
PubMed2000

Low intakes of vegetables and fruits, especially citrus fruits, lead to inadequate vitamin C intakes among adults.

OBJECTIVE: To determine vitamin C intakes among adults and to identify differences in dietary intake associated with vitamin C consumption. DESIGN: This cross-sectional study compared vitamin C intake, nutrient intake, and food group choices of adults with low (<30 mg/d), marginal (30-60 mg/d), and desirable (>60 mg/d) vitamin C intakes. SUBJECTS: Data from 2472 men and 2334 women aged 25-75 y were obtained from the 1994-1996 Continuing Survey of Food Intakes by Individuals (CSFII). RESULTS: Overall, 18% of the sample had low vitamin C intakes, 24% had marginal intakes, and 58% had desirable intakes. In addition to consuming less vitamin C, adults with low vitamin C intakes consumed significantly less (P</=0.001) energy-adjusted (ie nutrient/1000 kcal) folate, fiber, beta-carotene, and vitamin B6, and significantly more (P<0.001) fat. Compared to adults with low intakes, adults with desirable vitamin C intakes consumed significantly more (P</=0.001) high-vitamin C fruit juice and low-vitamin C vegetables, while consuming significantly less (P</=0.009) soft drinks, coffee/tea and alcoholic beverages. On average, adults with desirable vitamin C intakes consumed more than five daily servings of vegetables and fruits, of which more than one was citrus. Adults with low and marginal vitamin C intakes consumed less than one-fifth of a serving of citrus. CONCLUSIONS: A considerable number of adults under-consume vitamin C and total vegetables and fruits. Nutritionists should continue to promote five to nine daily servings of vegetables and fruits, at least one of which should be rich in vitamin C.

Adult↗
PubMed2000

Effect of insulin and heparin on glucose-induced vascular damage in cell culture.

BACKGROUND: Clinical trials have shown that tight glycemic control reduces the risk of diabetic microvascular complications, namely retinopathy, nephropathy, and neuropathy. The mechanism of these microvascular complications is not yet fully elucidated. The present study describes the effect of different concentrations of glucose on vascular endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) in cell culture. Our objective was to shed some light through this biological study on the mechanism and prevention of diabetic microvascular complications. METHODS: ECs and VSMCs were treated with 5 mmol/L (90 mg/dL) or 30 mmol/L (540 mg/dL) D-glucose or D-glucose plus insulin or D-glucose plus insulin and heparin in culture. ECs were studied with light microscopy (LM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) for surface changes. The cultured ECs were treated with vimentin antibodies and VSMCs with actin antibodies for immunoflourescence microscopy (IFM) study. Endothelin-1 (ET-1) assay was done on ECs culture medium using enzyme-linked immunosorbent assay (ELISA). RESULTS: LM, SEM, and TEM of ECs treated with a physiological concentration (90 mg/dL) of D-glucose appeared the same as control. However, LM and SEM of ECs treated with a high concentration of D-glucose (540 mg/dL) showed pronounced intercellular gaps. This finding was further confirmed by TEM study. These gaps were minimally or not at all discernible when insulin, heparin, or a combination of both was added to the culture medium. IFM showed increased vimentin expression with a high concentration of D-glucose. Vimentin expression was attenuated with the addition of insulin or heparin in the medium and more markedly with combined insulin and heparin. Significant correlations were obtained between glucose levels, vimentin expression, and ET-1 levels. The higher the glucose level, the higher is the ET-1 production and the greater vimentin expression in ECs. Cultured VSMCs treated with a high concentration of D-glucose showed enhanced actin expression. Actin expression was blunted with the addition of insulin or heparin in the culture medium. CONCLUSIONS: These biological findings indicate the salutary effect of insulin or insulin and heparin in the mitigation of vascular disorganization caused by a high concentration of D-glucose.

Cell Line↗
PubMed2000

More Americans are eating "5 a day" but intakes of dark green and cruciferous vegetables remain low.

Epidemiological investigations repeatedly show that the regular consumption of dark green and cruciferous vegetables, tomatoes and citrus fruits in particular is related to reduced cancer risk. We used the 1994-1996 Continuing Survey of Food Intakes by Individuals to examine the types of fruits and vegetables consumed by Americans. The analytic sample population, which consisted of 4806 men and women (25-75 y old) who completed two nonconsecutive 24-h recalls, consumed 3.6 +/- 2.3 servings of vegetables and 1.6 +/- 2.0 servings of fruit daily. Iceberg lettuce, tomatoes, French fried potatoes, bananas and orange juice were the most commonly consumed fruits and vegetables, accounting for nearly 30% of all fruits and vegetables consumed. The most popular items, lettuce and tomatoes, were consumed by 39-42% of the sample population during the reporting period. Fewer respondents (16-24%) consumed French fried potatoes, bananas or orange juice. Only 3% of the sample consumed broccoli during the reporting period. White potato consumption averaged 1.1 servings daily, with French fried potatoes representing 0.4 serving. Tomato product consumption averaged 0.5 serving daily, dark green vegetable consumption averaged 0.2 serving daily and citrus, berries or melon consumption amounted to nearly 0.8 serving daily. These data indicate that Americans are consuming more fruits and vegetables but that dark green and cruciferous vegetable intake is low.

Adult↗
PubMed1999

Environmental, medical, and family history risk factors for Parkinson's disease: a New England-based case control study.

Controversy persists about the etiology of Parkinson's disease (PD). Pesticides, herbicides, well-water consumption, head injury, and a family history of PD have been reported as risk factors for PD. The purpose of this study was to (1) investigate the impact of environmental factors on PD risk (2) estimate the chronology, frequency, and duration of those exposures associated with PD; and (3) investigate the effects of family history on PD risk. One-hundred and forty PD cases were recruited from Boston University Medical Center. The control group was composed of 147 friends and in-laws of PD patients. Environmental, medical, and family history data were obtained by structured interview from each participant for events recalled prior to PD onset for cases, or corresponding censoring age for controls (mean age = 56 years of age for each group). A traditional stratified analysis, adjusting for birth cohort and sex, was employed. Four factors were associated with increased risk for PD: (1) head injury (OR=6.23, confidence interval [CI]: 2.58-15.07); (2) family history of PD (OR=6.08, CI: 2.35-15. 58); (3) family history of tremor (OR=3.97, CI: 1.17-13.50); and (4) history of depression (OR=3.01, CI: 1.32-6.88). A mean latency of 36. 5 (SE=2.81) years passed between the age of first reported head injury and PD onset. A mean latency of 22 (SE=2.66) years passed between the onset of the first reported symptoms of depression and onset of PD. Years of education, smoking, and well-water intake were inversely associated with PD risk. PD was not associated with exposure to pesticides or herbicides. These findings support the role of both environmental and genetic factors in the etiology in PD. The results are consistent with a multifactorial model. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 88:742-749, 1999.

Adult↗
PubMed1999

Dose-response hapatotoxicity of the peroxisome proliferator, perfluorodecanoic acid and the relationship to phospholipid metabolism in rats.

Perfluorodecanoic acid (PFDA) is a potent peroxisome proliferator that causes hepatotoxicity but lacks tumor-promoting activity in rats. We previously showed that a single dose of PFDA at 50 mg/kg (approximately LD50) causes an elevation in liver phosphocholine (PCho) and other effects related to phospholipid metabolism. In this study, we examined metabolic effects in the dose range 2-50 mg/kg in rats. At doses < or =20 mg/kg, PFDA is significantly less hepatotoxic than the LD50 as manifested by electron microscopy and measurements of daily food consumption and body weight. At 50 mg/kg rat serum tumor necrosis factor (TNF)-alpha concentration was increased 8-fold, while at 15 mg/kg there was no apparent increase in this cytokine. This lower dose, however, induces metabolic effects similar to those seen at the LD50. Liver fatty acyl-CoA oxidase activity showed a dose-dependent increase from 5-25 mg/kg PFDA. Treatments at 15 and 50 mg/kg caused a significant increase in liver phosphatidylcholine (28 and 66%) and phosphatidylethanolamine (31 and 74%). Both doses caused a significant increase in liver PCho but did not affect liver ATP levels, as manifested in 31P nuclear magnetic resonance (NMR) spectra from rat livers in vivo. These data suggest that the increase in liver [PCho] observed following PFDA exposure in rats represents a specific metabolic response, rather than a broad-range hepatotoxic effect.

Acyl-CoA Oxidase↗
PubMed1999

Predictive medicine: computational techniques in therapeutic decision-making.

The current paradigm for surgery planning for the treatment of cardiovascular disease relies exclusively on diagnostic imaging data to define the present state of the patient, empirical data to evaluate the efficacy of prior treatments for similar patients, and the judgement of the surgeon to decide on a preferred treatment. The individual variability and inherent complexity of human biological systems is such that diagnostic imaging and empirical data alone are insufficient to predict the outcome of a given treatment for an individual patient. We propose a new paradigm of predictive medicine in which the physician utilizes computational tools to construct and evaluate a combined anatomic/physiologic model to predict the outcome of alternative treatment plans for an individual patient. The predictive medicine paradigm is implemented in a software system developed for Simulation-Based Medical Planning. This system provides an integrated set of tools to test hypotheses regarding the effect of alternate treatment plans on blood flow in the cardiovascular system of an individual patient. It combines an Internet-based user interface developed using Java and VRML, image segmentation, geometric solid modeling, automatic finite element mesh generation, computational fluid dynamics, and scientific visualization techniques. This system is applied to the evaluation of alternate, patient-specific treatments for a case of lower extremity occlusive cardiovascular disease.

Arterial Occlusive Diseases↗
PubMed1999

Absence of effect of seven functional mutations in the CYP2D6 gene in Parkinson's disease.

The reduction or loss of cytochrome P450 enzyme activity as a result of mutations in the CYP2D6 gene has been suggested as a risk factor for Parkinson's disease (PD). Conflicting results among reported studies of the prevalence of mutations among patients with PD suggested a more comprehensive genotyping and an analysis of the interactions with other suspected risk factors and family history. We determined the frequency of seven CYP2D6 mutations among 109 patients with PD and 110 control subjects. Family history of PD, age of onset, exposure to pesticides or herbicides, and well-water consumption were obtained for all cases. There was no significant difference in frequency between patients with PD and control subjects for any mutant allele and no significant association with family history, onset age, or environmental exposures. We sought to increase the power of our study by combining reports from the literature, choosing allele frequencies as the most informative measure. Although we found variability in reported allele frequencies for control subjects that made a meta-analysis problematic, summing all reports demonstrated no difference in CYP2D6 mutation frequency between patients with PD and control subjects. This comprehensive study of CYP2D6 mutations demonstrates that other genes or shared environmental exposures account for the familial risk of PD.

Age of Onset↗
PubMed1999

Pharmacokinetics of intraperitoneal epoetin alfa in patients on peritoneal dialysis using an 8-hour "dry dwell" dosing technique.

Pharmacokinetic studies of intraperitoneal (IP) epoetin alfa administered to continuous ambulatory peritoneal dialysis (CAPD) patients have shown low bioavailability, primarily attributable to the dilutional effect of coadministered dialysate. However, bioavailability is improved by instilling the dose into a dry peritoneum. The current study was designed to determine whether absorption after administration into a dry peritoneum is improved by extending the dry dosing period from 4 to 8 hours. The pharmacokinetics of a single 100-unit/kg IP epoetin alfa dose were studied in 8 noninfected CAPD patients. The dose was instilled into a dry peritoneum via the peritoneal catheter and allowed to dwell for 8 hours. CAPD was then resumed. Blood samples were collected for 96 hours after the dose. A 14-hour effluent dialysate sample was collected to determine epoetin alfa recovery. Enzyme immunoassay was used for epoetin alfa analysis of serum and effluent. Standard pharmacokinetic methods were employed for analysis of the serum concentration time data. The extent of epoetin alfa absorption was significantly greater than previously reported for a 4-hour dry dwell. The mean (+/-SD) dose-normalized area-under-the-curve (nlAUC(0-infinity)) using the 8-hour dry dwell dosing technique was 6,331 +/- 2,536 mIU. h/mL. This is significantly greater than the value of 2,589 +/- 1,450 mIU. h/mL (two-sided P value = 0.002) from a previous study in which patients received the same 100-unit/kg dose using a 4-hour dry dwell. The absorption of epoetin alfa administered by the intraperitoneal route is improved by extending the time the dose resides in a dry peritoneum.

Adolescent↗
PubMed1999

Effect of exercise on hemodynamic conditions in the abdominal aorta.

PURPOSE: The beneficial effect of exercise in the retardation of the progression of cardiovascular disease is hypothesized to be caused, at least in part, by the elimination of adverse hemodynamic conditions, including flow recirculation and low wall shear stress. In vitro and in vivo investigations have provided qualitative and limited quantitative information on flow patterns in the abdominal aorta and on the effect of exercise on the elimination of adverse hemodynamic conditions. We used computational fluid mechanics methods to examine the effects of simulated exercise on hemodynamic conditions in an idealized model of the human abdominal aorta. METHODS: A three-dimensional computer model of a healthy human abdominal aorta was created to simulate pulsatile aortic blood flow under conditions of rest and graded exercise. Flow velocity patterns and wall shear stress were computed in the lesion-prone infrarenal aorta, and the effects of exercise were determined. RESULTS: A recirculation zone was observed to form along the posterior wall of the aorta immediately distal to the renal vessels under resting conditions. Low time-averaged wall shear stress was present in this location, along the posterior wall opposite the superior mesenteric artery and along the anterior wall between the superior and inferior mesenteric arteries. Shear stress temporal oscillations, as measured with an oscillatory shear index, were elevated in these regions. Under simulated light exercise conditions, a region of low wall shear stress and high oscillatory shear index remained along the posterior wall immediately distal to the renal arteries. Under simulated moderate exercise conditions, all the regions of low wall shear stress and high oscillatory shear index were eliminated. CONCLUSION: This numeric investigation provided detailed quantitative data on the effect of exercise on hemodynamic conditions in the abdominal aorta. Our results indicated that moderate levels of lower limb exercise are necessary to eliminate the flow reversal and regions of low wall shear stress in the abdominal aorta that exist under resting conditions. The lack of flow reversal and increased wall shear stress during exercise suggest a mechanism by which exercise may promote arterial health, namely with the elimination of adverse hemodynamic conditions.

Aorta, Abdominal↗
PubMed1999

Intakes of vitamin C, vegetables and fruits: which schoolchildren are at risk?

OBJECTIVE: The purpose of this study was to determine vitamin C intakes among American schoolchildren. We investigated the leading sources of vitamin C in children's diets, the leading vegetables and fruits consumed by children and differences in dietary intake associated with vitamin C consumption. METHODS: Data from 1,350 7- to 12-year-old and 908 13- to 18-year-old schoolchildren were obtained from the 1994-1996 Continuing Survey of Food Intakes by Individuals (CSFII). The children were stratified by age and gender and then split into three vitamin C consumption groups based upon two 24-hour recalls: low (0 to 30.0 mg), marginal (30.1 to 59.9 mg), and desirable (>60.0 mg). Data were analyzed by tabulation and by ANOVA followed by post hoc Scheffe's test. Outcome measures included food groups and energy-adjusted intakes of micro- and macronutrients. RESULTS: Among the 7- to 12-year-olds, 12% of boys and 13% of girls had mean vitamin C intakes that were less than 30 mg/day, and, among 13- to 18-year-olds, 14% of boys and 20% of girls had low vitamin C intakes. In addition to consuming significantly more vitamin C, children with desirable vitamin C intakes also consumed significantly more (p <0.001) energy-adjusted folate and vitamin B6; children with low vitamin C intakes tended to have significantly greater (p <0.001) energy-adjusted intakes of fat and saturated fat. Children with desirable vitamin C intakes consumed significantly more (p <0.006) high-vitamin C fruit juice, low-vitamin C vegetables and whole milk. Children with low vitamin C intakes on average consumed two daily servings of vegetables and fruits, of which less than 1/5 of a serving was citrus, while children with desirable vitamin C intakes consumed an average of one daily serving of citrus. CONCLUSIONS: A considerable number of children drastically under-consumed vitamin C and total vegetables and fruits. Overall, children with desirable vitamin C intakes had healthier diets, including more milk and vegetables, than did their peers with low vitamin C intakes. Health care professionals should continue to promote at least five daily servings of vegetables and fruits and should advise parents that at least one of these should be rich in vitamin C.

Adolescent↗