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M W Plankey

Publications and source records attributed to M W Plankey.

12 recordsLinked to original sources
PubMed1999

Delta-9-tetrahydrocannabinol delays the gastric emptying of solid food in humans: a double-blind, randomized study.

BACKGROUND: Delta-9-tetrahydrocannabinol (THC), the active constituent of marijuana, is an effective agent in the prevention of chemotherapy-induced nausea and vomiting. AIM: To determine the effect of THC on gastric emptying of a radiolabelled solid food in humans. METHODS: Thirteen healthy volunteers underwent gastric emptying studies after receiving THC and placebo in a randomized double-blind fashion on 2 separate days. THC, at a dose of 10 mg/m2 of body surface area, or placebo were administered. RESULTS: Gastric emptying after THC was slower than placebo in all subjects. Mean percentage of isotope remaining in the stomach was significantly greater than after placebo from 30 min (85.5 +/- 4.3% vs. 94.2 +/- 1. 4% placebo and THC, respectively, P < 0.05) to 120 min (45.6 +/- 7. 2% vs. 73.9 +/- 7.1% placebo and THC, respectively, P < 0.001) after the test meal. No correlation was found between plasma THC levels and the delay in gastric emptying. CONCLUSIONS: THC at a dose used for preventing chemotherapy-induced nausea and vomiting significantly delays gastric emptying of solid food in humans. Therefore, the anti-emetic property of THC may be mediated through the central nervous system.

Adult↗
PubMed1998

The body mass index-mortality relationship in white and African American women.

OBJECTIVE: To examine the association of body mass index to all-cause and cardiovascular disease (CVD) mortality in white and African American women. RESEARCH METHODS AND PROCEDURES: Women who were members of the American Cancer Society Prevention Study I were examined in 1959 to 1960 and then followed 12 years for vital status. Data for this analysis were from 8,142 black and 100,000 white women. Body mass index (BMI) was calculated from reported height and weight. Associations were examined using Cox proportional hazards modeling with some analyses stratified by smoking (current or never) and educational status (less than complete high school or high school graduate). RESULTS: There was a significant interaction between ethnicity and BMI for both all-cause (p<0.05) and CVD mortality (p<0.001). BMI (as a continuous variable) was associated with all-cause mortality in white women in all four groups defined by smoking and education. In black women with less than a high school education, there were no significant associations between BMI mortality. For high school-educated black women, there was a significant association between BMI and all-cause mortality. Among never smoking women with at least a high school education, models using the lowest BMI as the reference indicated a 40% higher risk of all-cause mortality at a BMI of 35.9 in black women vs. 27.3 in white women. DISCUSSION: The impact of BMI on mortality was modified by educational level in black women; however, BMI was a less potent risk factor in black women than in white women in the same category of educational status.

Adult↗
PubMed1997

Prediction equations do not eliminate systematic error in self-reported body mass index.

Epidemiological studies of the risks of obesity often use body mass index (BMI) calculated from self-reported height and weight. The purpose of this study was to examine the pattern of reporting error associated with self-reported values of BMI and to evaluate the extent to which linear regression models predict measured BMI from self-reported data and whether these models could compensate for this reporting error. We examined measured and self-reported weight and height on 5079 adults aged 30 years to 64 years from the second National Health and Nutrition Examination Survey. Measured and self-reported BMI (kg/m2) was calculated, and multiple linear regression techniques were used to predict measured BMI from self-reported BMI. The error in self-reported BMI (self-reported BMI minus measured BMI) was not constant but varied systematically with BMI. The correlation between measured BMI and the error in self-reported BMI was -0.37 for men and -0.38 for women. The pattern of reporting error was only weakly associated with self-reported BMI, with the correlation being 0.05 for men and -0.001 for women. Error in predicted BMI (predicted BMI minus measured BMI) also varied systematically with measured BMI, but less consistently with self-reported BMI. More complex models only slightly improved the ability to predict measured BMI compared with self-reported BMI alone. None of the equations were able to eliminate the systematic reporting error in determining measured BMI values from self-reported data. The characteristic pattern of error associated with self-reported BMI is difficult or impossible to correct by the use of linear regression models.

Adult↗
PubMed1995

Patient compliance in mobile screening mammography.

RATIONALE AND OBJECTIVES: We assessed the follow-up behavior of women who had abnormal results of screening mammograms taken on a mobile van. METHODS: A retrospective cohort study was conducted between 1988 and 1991 of all women served by a mobile mammography van in rural North Carolina. Compliance with radiologist recommendations for follow-up was assessed through review of patient records and mail surveys of patients with incomplete records. RESULTS: Compliance was 44% for negative or benign mammograms, 57% for indeterminate mammograms, and 62% for probably malignant or malignant mammograms. Women who had a previous mammogram or had a malignant finding were more likely to comply with follow-up recommendations (p < .0001) than women with normal or benign results and no history of mammography. Compliers and noncompliers did not differ with respect to family history of breast cancer or personal history of breast discomfort. CONCLUSION: Compliance with recommendations in this setting was lower than expected. This may be because rural women using mobile van mammography have limited access to the resources needed for appropriate follow-up. Further research is needed to examine explanations for poor compliance in this setting.

Adult↗
PubMed1994

Black women have smaller abdominal girths than white women of the same relative weight.

Anthropometric measurements were compared in 312 white and 242 black women (mean age 54) who were participants in the Charleston Heart Study. Body mass index (BMI) was greater in black women (27.8 kg/m2) than in white women (24.7 kg/m2) as were body circumferences. However, when the girth measurements were adjusted for BMI, some racial differences were reversed. Age, smoking and BMI-adjusted abdominal girth was smaller in the black women than in the white women (88.9 cm vs 92.2 cm). The ratio of abdomen to midarm circumference was larger in white women than black women (3.24 vs 3.09), and could be interpreted to indicate a less central fat pattern in the black women. This conclusion should be viewed with caution since circumference measurements, though often used in epidemiologic research, do not differentiate between subcutaneous fat and visceral fat.

Abdomen↗
PubMed1991

A 20-minute breath test for helicobacter pylori.

In this study, we evaluated a simplified rapid 14C-urea breath test for the diagnosis of Helicobacter pylori. Fasting patients undergoing initial assessment for H. pylori drank 5 microCi of 14C-urea in 20 ml of water. Breath was collected at intervals for 30 min. Samples were counted in a beta-counter, and the results were expressed as counts per minute (cpm). In the same week, patients underwent endoscopy, and a blinded investigator examined biopsy samples of gastric mucosa by culture and histology for H. pylori. There were 49 H. pylori-negative (HP-) and 104 H. pylori-positive (HP+) patients in the study. HP+ patients expired a mean of 4398 cpm (SD 2468) per mmol CO2 in a sample taken 20 min after ingestion of the isotope. In contrast, HP--patients expired only 340 cpm (SD 196). If the mean +3 SD of HP- patients was used as a cutoff value, the 20-minute sample gave a sensitivity of 97% and a specificity of 100% for detecting H. pylori. The radiation exposure from this test is less than 1% of that received from an upper gastrointestinal series, and the short collection time makes it both convenient and cost effective.

Biopsy↗
PubMed1991

A noninvasive scintigraphic assessment of the colonic transit of nondigestible solids in man.

A noninvasive, scintigraphic technique for quantifying large intestinal transit time that provides low radiation doses was developed. The scintigraphic large intestinal transit (SLIT) method uses a total of 100 microCi of 111In encapsulated in ten 2-cm nondigestible capsules, which are ingested after a 6-hr fast. Two hundred fifty microcuries of 99mTc-sulfur colloid were given to outline the gastrointestinal tract. Images were acquired at 4-hr intervals until all capsules were excreted. Normal volunteers (n = 10) consumed a standardized diet 2 days prior and during imaging. Segmental transit times were measured in the following: ascending, transverse, descending, recto-sigmoid colons; hepatic and splenic flexures. The radiation absorbed dose to the large intestine for the SLIT technique is less than half of that associated with other radiographic methods of colonic transit time measurement.

Adult↗
PubMed1989

Detection of esophageal motor disorders by radionuclide transit studies. A reappraisal.

Radionuclide measurement of esophageal transit has been proposed as a screening test for esophageal motor dysfunction. In this study we evaluated the radionuclide esophageal transit test in 49 consecutive patients undergoing esophageal manometry for esophageal motor disorders. Esophageal transit was assessed using a 10-ml water bolus labeled with 250 microCi technetium-99m sulfur colloid. In preliminary studies in 14 healthy controls, mean transit time was 9.6 +/- 2.1 (SD) sec. Prolonged transit (greater than 15 sec) was observed in two of 28 swallow sequences in the control subjects. Transit times were prolonged in all patients with achalasia or diffuse esophageal spasm, and in five of seven patients with nonspecific abnormalities of peristaltic progression. The test was abnormal in only three of seven patients with high-amplitude peristalsis (nutcracker esophagus) and in none of three patients with hypertensive lower esophageal sphincter. Additionally, prolonged transit was seen in two of 18 patients with normal manometry. We conclude that the radionuclide transit test using a liquid bolus successfully identifies motor disorders characterized by defective peristaltic progression but not disorders in which peristalsis is intact. A major limiting factor appears to be the small number of swallow sequences tested. The test may not, therefore, be accurate enough to consider adopting as a sensitive and noninvasive screening test in the evaluation of patients with suspected esophageal motor disorders.

Adult↗
PubMed1983

Gold-195m for serial first pass radionuclide angiocardiography during upright exercise in patients with coronary artery disease.

Sequential first pass radionuclide angiocardiography can be performed in rapid succession using gold-195m because of its low radiation dose and short half-life (30.5 seconds). In 25 patients with known or suspected coronary artery disease, first pass studies with gold-195m were obtained using a computerized multicrystal gamma camera at rest (n = 29), at the end of each 3 minute stage of exercise (n = 25) and immediately after exercise (n = 23). In 13 patients, assessment of left ventricular function during exercise with gold-195m was combined with thallium-201 stress scintigraphy. Left ventricular ejection fraction at rest assessed with technetium-99m and gold-195m correlated well (r = 0.93). In addition, repeat left ventricular ejection fractions at rest with gold-195m correlated closely (r = 0.96). Comparing peak exercise left ventricular ejection fraction with ejection fraction at rest, abnormal left ventricular reserve was found in 20 of 25 patients. Various abnormal patterns of left ventricular ejection fraction response were noted, showing the diagnostic potential of serial exercise angiocardiography. Thallium-201 myocardial images, obtained on a single crystal gamma camera after multiple gold-195m injections, were all of good diagnostic quality and were abnormal in 10 of 13 patients. Thus, multiple high count rate first pass studies can be obtained with gold-195m during and after exercise, allowing serial study of physiologic changes in left ventricular function during exercise. Thallium-201 myocardial imaging can be performed using the same exercise test, providing direct comparison of myocardial function and perfusion.

Adult↗