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D R Parker

Publications and source records attributed to D R Parker.

At least 37 records · Page 2Linked to original sources
PubMed1997

Comparison of urine dipsticks with quantitative methods for microalbuminuria.

We describe a new dip- and read dipstick that detects urine albumin at concentrations of 10 mg/l and above and urine creatinine at concentrations of 300 mg/l and above. The albumin assay is based on a high-affinity, dye-binding technique while the creatinine assay is based on the peroxidase-like activity of copper creatinine complexes. With these two-test dipsticks, urines from normal adults supplemented with albumin and creatinine were correctly identified to within +/- 15% of the expected value for both analytes; the between-day coefficients of variation ranged from 7.1% to 16.1%. We tested 275 patients' unmodified urines by the Bayer and Boehringer Mannheim Micral-Test albumin dipsticks and for albumin with the Beckman Array on the same specimens. We also analyzed 42 selected urines from the group of 275 for albumin by another quantitative immunochemical method and by electrophoresis plus a total protein method to estimate the albumin concentration. The quantitative immunochemical methods appear to underestimate the urine albumin concentrations; in these 42 urines measured as negative, i.e., < ca. 16-20 mg/l, by one of the quantitative method but positive by the Bayer dipstick, 33 of these were positive by the electrophoresis/total protein assay combination. The Bayer albumin dipstick correctly identified urines as having < 16 mg/l or > or = 16 mg/l at an 80% rate. At a cutoff of 20 mg/l, the rate increased to 87%. We also determined the urinary albumin/creatinine ratios on the 275 patients using the Bayer two-pad dipstick and found agreement 84% of the time with the same ratio obtained from a quantitative immunochemical method for albumin and a rate-Jaffe method for creatinine; an albumin/creatinine ratio (mg/g) of 30 was used as the discrimination point. Albumin stability studies performed on the Beckman Array patients with six fresh urines showed small but consistent decreases at -20 degrees C but not at 4 degrees C after one month of storage. The albumin in contrived urines, as estimated by electrophoreses/total protein and by the dipsticks did not change at these storage conditions. Boric acid at 1 g/l as a urine preservative had no effect on the measurement of albumin by any of the methods described here nor of the assay of creatinine. Other urinary proteins present at abnormal excretion rates did not interfere with the Bayer albumin dipstick. Abnormal concentrations of bilirubin, citrate, creatine, ascorbic acid, albumin, hemoglobin and myoglobin in urine did not interfere with the creatinine dipstick measurements. The first four of the above did not affect the Bayer dipstick results for albumin.

Adult↗
PubMed1996

Self-reported alcohol intake using two different question formats in southeastern New England.

BACKGROUND: Quantitative measures of alcohol intake are not always available in population studies. METHOD: The authors evaluated whether a question on alcohol intake embedded within a general health survey could be used as a surrogate marker for alcohol intake. We compared alcohol intake assessed with a food frequency questionnaire (FFQ) with alcohol intake assessed with a simple dichotomous survey question in a population-based sample. RESULTS: The study population consisted of 755 men and 1164 women from two communities in southeastern New England in the USA. There was strong agreement between the two alcohol questions for the classification of nondrinkers (98.1%). When participants were classified according to the quantity of alcohol consumed on the FFQ, the ability of the simple question to identify drinkers improved in a dose-response fashion. The Kappa statistic was 0.08 (P < 0.001), 0.38 (P < 0.001), and 0.81 (P < 0.001) for low, medium, and high consumers of alcohol, respectively. CONCLUSIONS: These results suggest that the survey alcohol question provides a useful qualitative measure of categorizing nondrinkers and identifying drinkers who consume more than one drink per day. In population studies where quantitative measures of alcohol intake may not be available a survey alcohol question may prove useful when alcohol intake is likely to confound results, and adjustment of the data is needed.

Adult↗
PubMed1996

High-density-lipoprotein cholesterol and types of alcoholic beverages consumed among men and women.

OBJECTIVES: Differences by sex in the relationship between high-density-lipoprotein (HDL) cholesterol and consumption of alcoholic beverages were examined in 1516 individuals. METHODS: Questionnaires and blood-sample data from cross-sectional surveys were analyzed. RESULTS: Both beer and liquor were independently associated with increased HDL cholesterol in the total group, in men, and in women after covariates were controlled for. Wine was associated with a significant increase in HDL cholesterol in women only. CONCLUSIONS: Among women and men, amount may be more important than type of alcoholic beverage consumed. The independent effect of wine on HDL cholesterol among men remains unclear since few men in this population consumed wine exclusively or in large quantities.

Adolescent↗
PubMed1995

Osteopenia in Crohn's disease.

A 16 year old boy presented soon after diagnosis of Crohn's disease with diffuse osteopenia of the lumbar spine with collapse of three vertebral bodies and grossly reduced bone mineral density noted on dual energy x ray absorptiometry scan. Treatment of the underlying Crohn's disease and induction of puberty resulted in marked improvement in bone mineralisation.

Absorptiometry, Photon↗
PubMed1995

Nutrition and health practices of diabetic and nondiabetic men and women from two southeastern New England communities.

Diabetes occurs in at least 13 million persons in the United States and is a major cause of morbidity and premature mortality. Diet is the cornerstone of diabetes management, and the purpose of this investigation was to examine dietary intakes and health practices among diabetic and nondiabetic individuals from a recently surveyed population-based sample from two communities in southeastern New England. Data were collected during cross-sectional home health surveys conducted in random population samples of two New England communities during 1987-1988, 1989-1990, and 1992-1993. A food frequency questionnaire was completed by 1,897 of 2,077 eligible respondents who made up our study sample. Statistical analyses suggest that diabetic individuals do not appear to be adhering to measures known to improve metabolic control (i.e., weight reduction and physical activity). Furthermore, both diabetic and nondiabetic individuals alike should be targeted for educational programs aimed at improving dietary intakes which lead to a reduction in consumption of total and saturated fatty acid.

Adolescent↗
PubMed1995

Postprandial mesenteric blood flow in humans: relationship to endogenous gastrointestinal hormone secretion and energy content of food.

OBJECTIVE: To examine the relationship between postprandial superior mesenteric arterial blood flow (SMABF) and endogenous gastrointestinal hormone secretion after liquid meals of varying energy content. METHODS: Six healthy volunteers received four isovolumetric meals of differing energy content. SMABF was measured before and for 120 min after feeding using duplex ultrasound; plasma levels of gastrointestinal hormones and noradrenaline were measured. RESULTS: Results are given as means +/- SEM. Postprandial SMABF increased after each meal; the peak mean percentage increment occurred at 28 +/- 8 min, varying from 106 +/- 26% (P < 0.05) with the 800 kj meal to 240 +/- 62% (P < 0.05) with the 4800 kj meal. The rise was sustained and correlated with energy content (r = 0.969; P = 0.031). The subjects' pulse rate increased after each meal and the increment appeared to be related to meal size (r = 0.990; P = 0.008). Blood pressure did not change. The postprandial concentration of N-terminal neurotensin peaked between 30 and 120 min. The mean peak concentration increased from a baseline value of 30.9 +/- 3.5 ng/l by 19.3 ng/l after 800 kj, 31 ng/l after 1600 kj, 38 ng/l after 2400 kj and 64.3 ng/l after the 4800 kj meal (all differences P < 0.05). The rise was sustained and correlated with energy content (r = 0.967; P = 0.033). Plasma noradrenaline concentration also increased significantly after each meal and was related to energy content (r = 0.90; P = 0.036). Plasma insulin concentration showed a similar postprandial response but had no relationship to energy content. Gastrin concentration increased transiently but changes in the concentration of glucagon, vasoactive intestinal polypeptide and neurokinin A were not significant. CONCLUSIONS: The results indicate a relationship between meal energy content, postprandial SMABF and pulse rate increments. Postprandial increases in N-terminal neurotensin and noradrenaline concentration were also related to energy content and may indicate a role for these hormones in the control of SMABF after feeding.

Adult↗
PubMed1993

Relationship of dietary saturated fatty acids and body habitus to serum insulin concentrations: the Normative Aging Study.

The purpose of this study was to examine the relationship of body mass index, abdomen-hip ratio, and dietary intake to fasting and postprandial insulin concentrations among 652 men aged 43-85 y, followed in the Normative Aging Study. Log-transformed fasting insulin was significantly associated with body mass index, abdomen-hip ratio, total fat energy, and saturated fatty acid energy, with correlation coefficients ranging from 0.14 for total fat to 0.45 for body mass index. When multivariate models were used, body mass index, abdomen-hip ratio, and saturated fatty acid intake were statistically significant independent predictors of both fasting and postprandial insulin concentrations, after age, cigarette smoking, and physical activity were adjusted for. If saturated fatty acids as a percentage of total energy were to decrease from 14% to 8%, there would be an 18% decrease in fasting insulin and a 25% decrease in postprandial insulin. These data suggest that overall adiposity, abdominal obesity, and a diet high in saturated fatty acids are independent predictors for both fasting and postprandial insulin concentrations.

Adipose Tissue↗
PubMed1992

Relationship of catecholamine excretion to body size, obesity, and nutrient intake in middle-aged and elderly men.

Catecholamine release from sympathetic nerves and the adrenal medulla is influenced by diet under controlled research conditions. To test whether diet affects catecholamine excretion in free-living men, the urinary content of dopamine (DA), epinephrine (Epi), or norepinephrine (NE) was measured in 24-h collections provided by 572 participants of the Normative Aging Study of the Veterans Administration. Average daily intakes of energy and macronutrients were assessed by means of a semiquantitative food frequency questionnaire and sodium intake by quantitation of sodium excretion. Catecholamine excretion was also examined in relation to anthropometric variables. Because DA and Epi excretion were inversely related to age, all subsequent analyses included adjustments for age. Although DA and NE were positively related to measures of body size and fatness, Epi was negatively related to body fatness. Excretion rates of all three catecholamines were directly related to total energy intake and inversely related to energy-adjusted CHO consumption.

Adult↗
PubMed1992

Operationally defined apoplastic and symplastic aluminum fractions in root tips of aluminum-intoxicated wheat.

Knowledge of the mechanistic basis of differential aluminum (Al) tolerance depends, in part, on an improved ability to quantify Al located in the apoplastic and symplastic compartments of the root apex. Using root tips excised from seedlings of an Al-tolerant wheat cultivar (Triticum aestivum L. cv Yecora Rojo) grown in Al solutions for 2 d, we established an operationally defined apoplastic Al fraction determined with six sequential 30-min washes using 5 mm CaCl(2) (pH 4.3). Soluble symplastic Al was eluted by freezing root tips to rupture cell membranes and performing four additional 30-min CaCl(2) washes, and a residual fraction was determined via digestion of root tips with HNO(3). The three fractions were then determined in Yecora Rojo and a sensitive wheat cultivar (Tyler) grown at 18, 55, or 140 mum total solution Al (Al(T)). When grown at equal Al(T), Tyler contained more Al than Yecora Rojo in all fractions, but both total Al and fractional distribution were similar in the two cultivars grown at Al(T) levels effecting a 50% reduction in root growth. Residual Al was consistently 50 to 70% of the total, and its location was elucidated by staining root tips with the fluorophore morin and examining them using fluorescence and confocal laser scanning microscopy. Wall-associated Al was only observed in tips prior to any washing, and the residual fraction was manifested as distinct staining of the cytoplasm and nucleus but not of the apoplastic space. Accordingly, the residual fraction was allocated to the symplastic compartment for both cultivars, and recalculated apoplastic Al was consistently approximately 30 to 40% of the total. Distributions of Al in the two cultivars did not support a symplastic detoxification hypothesis, but the role of cytoplasmic exclusion remains unsettled.

Journal Article↗
PubMed1992

Fatal haematemesis due to benign retrosternal goitre.

The development of a goitre in the retrosternal space may result in many different symptoms due to local compression. We describe a case in which such a goitre resulted in full-thickness ulceration of the oesophagus, which presented as a fatal haematemesis. We believe that such a complication has not been previously reported.

Aged↗
PubMed1991

Pulmonary Kaposi sarcoma in patients with AIDS: scintigraphic diagnosis with sequential thallium and gallium scanning.

Pulmonary Kaposi sarcoma associated with acquired immunodeficiency syndrome (AIDS) is difficult to diagnose because the clinical presentations and radiographic findings are nonspecific. The authors report three proved cases of AIDS-associated pulmonary Kaposi sarcoma diagnosed with sequential thallium and gallium scans. These scans demonstrated abnormal increase of pulmonary thallium uptake, whereas the gallium uptake was negative. In the authors' experience and in reports in the radiology literature, infected areas of the chest are generally thallium-negative on the delayed (3-hour) scans but are gallium-avid, whereas lymphomas are both thallium- and gallium-avid. The authors conclude that sequential thallium and gallium scans can be used to help diagnose pulmonary Kaposi sarcoma and distinguish it from other common AIDS-associated chest complications such as lymphoma and infections.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Relation of obesity and diet to sympathetic nervous system activity.

The hypothesis that dietary intake and obesity stimulate the sympathetic nervous system was investigated in a cross-sectional study of 572 men aged 43-85 years from the Normative Aging Study. Habitus was represented by body mass index, as a measure of overall adiposity, and by the ratio of abdomen-to-hip circumference (abdomen/hip ratio), as a measure of centripetal fat distribution. Sympathetic activity was assessed by measurement of 24-hour urinary norepinephrine excretion. Increased body mass index and total caloric intake were independently associated with increased 24-hour urinary norepinephrine excretion (p = 0.0001 and p = 0.0055, respectively). In addition, mean urinary norepinephrine excretion was higher in subjects classified as either hyperglycemic (serum fasting glucose greater than or equal to 113 mg/dl) and hyperinsulinemic (serum fasting insulin greater than or equal to 19 microIU/ml) (p = 0.0023) or in subjects classified as either hyperglycemic or hyperinsulinemic (p = 0.0063) than the mean urinary norepinephrine excretion in normal subjects. These relations were demonstrated to be independent of age, smoking status, and physical activity. Our results are consistent with the hypothesis that insulin mediates sympathetic stimulation in response to dietary intake and increases sympathetic nervous system activity in the obese.

Adipose Tissue↗