Nuclear medicine technologists and unauthorized self-injections.

An Office of Investigation (OI) investigation by the U.S. Nuclear Regulatory Commission (NRC) determined that, on three separate occasions over the past 10 years, technologists in one licensed nuclear medicine program were injected with radiopharmaceuticals without Authorized User knowledge or approval. The most recent instance, the one that precipitated the investigation, was discovered by the licensee and self-reported to the NRC; the other two instances were discovered during the OI investigation and came as a complete surprise to the licensee. In a mediated Alternative Dispute Resolution (ADR) involving the licensee, a professional, independent mediator and representatives of the NRC, an agreement was worked out whereby the licensee would admit to the violations and work with the NRC to inform other licensees that this is not an acceptable practice and that there are additional precautions that licensees can and should take to assure that such violations do not happen on their watch.

Modifiable determinants of bone status in young women.

The purpose of this study was to evaluate the contributions of exercise, fitness, body composition, and calcium intake during adolescence to peak bone mineral density and bone structural measurements in young women. University Hospital and 75 healthy, white females in the longitudinal Penn State Young Women's Health Study were included. Body composition, total body, and hip bone mineral density (BMD) were measured by dual-energy X-ray absorptiometry (DXA), exercise scores by sports-exercise questionnaire during ages 12-18 years, and estimated aerobic capacity by bike ergometry. Section modulus values (a measurement of bending strength) cross-sectional area (CSA), subperiosteal width, and cortical thickness were calculated from DXA scan data for the femoral neck and femoral shaft. Calcium intakes were calculated from 39 days of prospective food records collected at 13 timepoints between ages 12 and 20 years; supplemental calcium intakes were included. Section moduli at the femoral neck and shaft were correlated significantly with lean body mass, sports-exercise scores (R(2) = 0.07-0.19, p < 0.05), and aerobic capacity (R(2) = 0.06-0.57, p < 0.05). Sports-exercise scores correlated with BMD at the femoral neck and shaft. Average total daily calcium intake at age 12-20 years ranged from 486 to 1958 mg/day and was not significantly associated with total or regional peak BMD or bone structure measures at 20 years of age. It was shown that achievable levels of exercise and fitness have a favorable effect on BMD and section modulus of the femoral neck and femoral shaft in young adult women, whereas daily calcium intake of >500 mg in female adolescents appears to have little, if any effect.

Oral contraceptive use by teenage women does not affect peak bone mass: a longitudinal study.

OBJECTIVE: To determine the effect of oral contraceptive pill (OCP) use during adolescence on peak bone mass. DESIGN: Longitudinal observational study. SETTING: Academic clinical research center. PATIENT(S): Sixty-two non-Hispanic, white females in The Penn State Young Women's Health Study, who were studied for 8 years during ages 12-20. INTERVENTION(S): There were 28 OCP users, who used OCPs for a minimum of 6 months and were still using at age 20, and 34 nonusers who had never used OCPs. MAIN OUTCOME MEASURE(S): Total body bone, dedicated hip bone, and body composition measurements were made by dual-energy roentgenogram absorptiometry. RESULT(S): The OCP users and nonusers did not differ at entry in anthropometric, body composition, or total body bone measurements. By age 20, the average duration of OCP use by the user group was 22 months. At age 20, the groups remained indistinguishable in anthropometric, body composition, total body, and hip bone measures, and in age of menarche and sports exercise scores. CONCLUSION(S): Oral contraceptive pill use by healthy, white, teenage females does not affect acquisition of peak bone mass.

PIP: This longitudinal observational study determined the effect of oral contraceptive (OC) use during adolescence on peak bone mass (PBM). The sample comprised 62 non-Hispanic, White females in The Penn State Young Women's Health Study, who were studied for 8 years between the ages of 12 and 20. There were 28 OC users who used OCs for a minimum of 6 months and were still using them at age 20, and 34 nonusers who had never used the regimen. Total body bone, dedicated hipbone, and body composition measurements were made by dual-energy roentgenogram absorptiometry. There was no difference between OC users and nonusers in the anthropometric, body composition, or total body bone measurements. By age 20, the average duration of OC use by the user group was 22 months. At this age, the groups remained indistinguishable in anthropometric, body composition, total body, and hipbone measurements, and in age of menarche and sports exercise scores. These findings suggest that OC use by healthy, White, teenage females does not affect acquisition of PBM.

Adult female hip bone density reflects teenage sports-exercise patterns but not teenage calcium intake.

OBJECTIVE: To examine how cumulative teenage sports histories and time-averaged teenage calcium intake are related to total body bone mineral gain between ages 12 and 18 years and to proximal femur bone mineral density (BMD) at age 18 years. Design. Longitudinal. Setting. University Hospital and local suburban community in Central Pennsylvania. STUDY PARTICIPANTS: Eighty-one white females in the ongoing Penn State Young Women's Health Study. OUTCOME MEASURES: Total body and proximal femur (hip) bone measurements by dual energy radiograph absorptiometry; nutrient intakes, including calcium, from 33 days of prospective food records collected at regular intervals between ages 12 and 18 years; and self-reported sports-exercise scores between ages 12 and 18 years. RESULTS: Cumulative sports-exercise scores between ages 12 and 18 years were associated with hip BMD at age 18 years (r = .42) but were not related to total body bone mineral gain. Time-averaged daily calcium intake, which ranged from 500 to 1500 mg/day in this cohort was not associated with hip BMD at age 18 years, or with total body bone mineral gain at age 12 through 18 years. CONCLUSIONS: The amount of physical activity that distinguishes a primarily sedentary teenager from one who engages in some form of exercise on a nearly daily basis is related to a significant increase in peak hip BMD.

Bone status among postmenopausal women with different habitual caffeine intakes: a longitudinal investigation.

OBJECTIVE: Caffeine consumption has been proposed as a risk factor for bone loss in postmenopausal women. Past epidemiologic studies on caffeine and bone have been confounded by covariates including cigarette and alcohol use, differing levels of physical activity and hormone replacement therapy. The purpose of the study was to use a longitudinal design to determine the relationship between habitual dietary caffeine intake and postmenopausal bone status. METHODS: Data were collected at two time points separated by two years; 138 women with little or no exposure to tobacco or to drugs known to affect bone status were seen at Visit 1, and 112 returned for Visit 2. Ninety-two of these subjects had received no drugs known to affect bone status over the two-year interval and were kept in the sample. Nutrient and caffeine intake were assessed from three-day diet records. Bone measurements were made by dual energy x-ray absorptiometry (DXA). RESULTS: Correlation analyses indicated no association between dietary caffeine intake and total body or femoral neck bone density or bone mass. Similarly, no associations were found between caffeine consumption and longitudinal changes in total body or femoral neck bone measurements. These results held true both with and without statistical adjustment for calcium intake. CONCLUSIONS: This study does not support the idea that caffeine is a risk factor for bone loss in healthy postmenopausal women.

Dietary caffeine intake is not correlated with adolescent bone gain.

OBJECTIVE: This study was conducted to determine whether dietary caffeine consumed by American white females between ages 12 to 18 affects total body bone mineral gain during ages 12 to 18 or affects hip bone density measured at age 18. METHODS: The Penn State Young Women's Health Study is a longitudinal investigation of bone, endocrine and cardiovascular health in non-Hispanic, white, teenage women. Nutrient and food group intakes were obtained by averaging over 6 years of prospective diet records. The cohort, as of age 18, (n = 81) was separated into three subgroups according to mean daily caffeine intake averaged across ages 12 to 18. Group I (n = 37) consumed less than 25 mg caffeine per day; Group II (n = 33) consumed 25 to 50 mg caffeine per day; and Group III (n = 11) consumed greater than 50 mg caffeine per day. The group mean daily caffeine intakes (SD) were Group I = 14 (6) mg/day; Group II = 35 (7) mg/day; Group III = 77 (27) mg/day. Total body bone gain and hip bone density were determined by dual energy x-ray absorptiometry (DXA). RESULTS: There were no significant differences among the three caffeine intake groups for total body bone mineral gain during the ages 12 to 18 or of hip bone density at age 18. The low caffeine intake group consumed more milk (and therefore more calcium) and more fruit per day than did the other two groups. Group III, the highest caffeine intake group, consumed more sugar per day than did the other two groups. The observed differences in nutrient and food intakes among the three groups were not associated with any differences in anthropometric measurements or bone gain among the three groups. CONCLUSION: These findings indicate that dietary caffeine intake at levels presently consumed by American white, teenage women is not correlated with adolescent total bone mineral gain or hip bone density at age 18.

Body composition development of adolescent white females: the Penn State Young Women's Health Study.

OBJECTIVE: To obtain simultaneous and longitudinal measures of height, weight, total body bone mineral content, total body bone mineral density, percentage of body fat, lean body mass, and body mass index in healthy white females between the ages of 11 and 18 years. DESIGN: A longitudinal, observational study. SETTING: University medical center in a small city. STUDY PARTICIPANTS: At initiation in 1990, 112 premenarchal, healthy girls were enrolled. Results presented in this report are based on measurements made on the 82 participants who remained in the study in 1996 and for whom we had comprehensive measurements. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Dual-energy x-ray absorptiometry was used to obtain measurements of total body bone mineral content, total body bone mineral density, percentage of body fat, and lean body mass every 6 months for the first 4 years of the study and yearly thereafter. RESULTS: The mean age for peak velocity and peak accumulation for each measurement was as follows: height, 11 1/2 and 17 1/2 years, respectively; weight, 11 1/2 and 17 1/2 years; body mass index, 11 1/2 and 17 1/2 years; percentage of body fat, 11 1/2 and 13 1/2 years; lean body mass, 12 and 17 1/2 years; total body bone mineral content, 13 1/2 and 17 1/2 years; and total body bone mineral density, 13 1/2 and 17 1/2 years. CONCLUSIONS: Among a healthy population of white females, the age of peak velocities for height, weight, body fat, and lean body mass occur at 11 1/2 to 12 years. Thus, peak soft-tissue velocities precede hard-tissue velocities by about 2 years, with peak accumulation of all tissue components being reached, on average, by age 17 1/2 years.

Radiation dose from DXA scanning to reproductive tissues of females.

The objective of this study was to use an anatomically arrayed whole-body phantom to measure radiation exposure to the ovaries and uterus during standard dual-energy Xray absorptiometry (DXA) scanning. DXA instrument manufacturers' published entrance skin exposure is about 3 mR (0.77 microC/kg), which is equivalent to the radiation exposure received during a transcontinental plane trip. Nonetheless, since DXA scanning is used more frequently with very young females, the need for pregnancy testing has become an issue that requires attention and formulation of research guidelines. We attached thermoluminescent dosimeters (TLDs) to anatomically arrayed balloon models for ovaries and the uterus, and placed these in the appropriate sites within a small human skeleton along with appropriate amounts of aqueous and fat soft tissue equivalents. Whole-body scanning with a Hologic QDR-2000W was performed 10 times with the pencil beam mode and, using separate TLD detectors, 10 times with the fan beam mode. Overall, the average exposures at skin entrance were 0.89 mR (0.23 microC/kg) with doses for the ovaries of 0.52 mrad (5.2 microgy) and 0.59 mrad (5.9 microgy) for the uterus. These doses are equivalent to 2 d of ambient background radiation in central Pennsylvania or 1 h of flying at 39,000 ft. Although different DXA models by Hologic and DXA instruments by other manufacturers will have different radiation outputs, we believe that these low radiation levels do not require pregnancy testing or questioning of whether the scan subject might be pregnant.

Dietary caffeine intake and bone status of postmenopausal women.

Dietary caffeine intake has been suggested as a risk factor for bone loss in postmenopausal women. We measured the bone density of both hips and the total body in 138 healthy, postmenopausal women aged 55-70 y who had either never used hormone replacement therapy (HRT) or had used HRT for < 1 y. In this cross-sectional study, participants were stratified according to their reported current and long-time caffeinated beverage use into one of three groups: low [0-2 cups (180 mL, or 6 oz per cup) caffeinated coffee per day], moderate (3-4 cups caffeinated coffee per day), or high (> or = 5 cups caffeinated coffee per day). Caffeine intake was measured from diet records and by gas chromatography of each subject's brewed, caffeinated beverages. No association between caffeine intake and any bone measurement was observed. The anthropometric and nutrient intakes of the three groups were similar. Compared with caffeine intake based on chemical analysis of brewed beverages, 3-d prospective food records and computer-assisted analysis overestimated caffeine intake by nearly two-thirds. In conclusion, the habitual dietary caffeine intake of this cohort of 138 postmenopausal women ranged from 0-1400 mg/d and was not associated with total body or hip bone mineral density measurements. This study does not support the notion that caffeine is a risk factor for bone loss in healthy postmenopausal women.

Quantitative aspiration during sleep in normal subjects.

STUDY OBJECTIVE: To determine the within-subject variability and to estimate the quantity of occult aspiration of nasopharyngeal secretions during sleep in normal humans. DESIGN: Prospective duplicate full-night sleep studies. SETTING: Pulmonary sleep laboratory, university hospital. PARTICIPANTS: Ten normal male volunteers aged 22 to 55 years. INTERVENTIONS: Two full-night polysomnographic recordings with infusion of 2 mL/h radioactive 99mTc tracer into the nasopharynx through a small catheter during EEG-documented sleep. Standard lung scans were conducted immediately following final awakening. Aspiration was defined as the presence of radioactivity in the pulmonary parenchyma on two separate views. RESULTS: A mean sleep efficiency of 85.7 +/- 2.6% was found with no difference between the two study nights. A total of 5 of the 10 subjects studied had tracer evident in the pulmonary parenchyma following final awakening. Three had the tracer apparent following the first-night study and four had tracer apparent following the second-night study. Thus, two subjects aspirated on both nights. Comparing the subjects who aspirated with those who did not, no significant difference could be found for age, time spent in bed, sleep efficiency, apnea-hypopnea index, arousal plus awakening index, or percent of sleep time spent in a supine position. The quantities of tracer aspirated were on the order of magnitude of 0.01 to 0.2 mL. CONCLUSIONS: Aspiration measured by this technique occurs commonly in healthy young men during sleep, is unrelated to sleep quality, and is variable within subjects studied on more than one occasion. The quantity aspirated is of an order of magnitude likely to contain bacterial organisms in physiologically significant quantities.

Technetium-99m-MAG3 scintigraphy in acute renal failure after transplantation: a marker of viability and prognosis.

UNLABELLED: This study assessed 99mTc-mercaptoacetyltriglycine (MAG3) for determination of renal transplant prognosis for recovery in patients with early postoperative dysfunction. The postulate tested was that good tracer extraction may imply high likelihood of recovery, while poor extraction may confer a poor prognosis. METHODS: A 2-min image acquired 1 min after MAG3 administration, named a cortical uptake phase (CUP) image, was visually analyzed according to standardized semiquantitative guidelines. Interpretation was expressed in tubular injury severity scores (TISS) that ranged from 1 (a normally functioning renal transplant) to 6 (a photopenic defect in place of renal transplant). RESULTS: The study analyzed 64 patients (35 men, 29 women, age 45.9 +/- 14 yr). All five patients with TISS of 6 or 5 lost the transplant. Only 1 of 10 patients with TISS of 4 lost the transplant. All patients with TISS of less than 4 recovered renal transplant function. CONCLUSION: This study suggests that MAG3 scan (the CUP image specifically) is an accurate prognosticator in patients with early postoperative renal transplant dysfunction. Reproduction of these results in a larger population and other institutions is necessary before clinical implementation of this methodology.

The effect of calcium supplementation and Tanner stage on bone density, content and area in teenage women.

One hundred and twelve Caucasian girls, 11.9 +/- 0.5 years of age at entry, were randomized into a 24-month, double-masked, placebo-controlled trial to determine the effect of calcium supplementation on bone mineral content, bone area and bone density. Supplementation was 500 mg calcium as calcium citrate malate (CCM) per day. Controls received placebo pills, and compliance of both groups averaged 72%. Bone mineral content, bone mineral area and bone mineral density of the lumbar spine and total body were measured by dual energy X-ray absorptiometry (DXA). Calcium intake from dietary sources averaged 983 mg/day for the entire study group. The supplemented group received, on average, an additional 360 mg calcium/day from CCM. At baseline and after 24 months, the two groups did not differ with respect to anthropometric measurements, urinary reproductive hormone levels or any measurement of pubertal progression. The supplemented group had greater increases of total body bone measures: content 39.9% versus 35.7% (p = 0.01), area 24.2% versus 22.5% (p = 0.15) and density 12.2% versus 10.1% (p = 0.005). Region-of-interest analyses showed that the supplemented group had greater gains compared with the control group for bone mineral density, content and area. In particular, in the lumbar spine and pelvis, the gains made by the supplemented group were 12%-24% greater than the increases made by the control group. Bone acquisition rates in the two study groups were further compared by subdividing the groups into those with below- or above-median values for Tanner score and dietary calcium intake. In subjects with below-median Tanner scores, bone acquisition was not affected by calcium supplementation or dietary calcium level. However, the calcium supplemented subjects with above-median Tanner had higher bone acquisition rates than the placebo group with above-median Tanner scores. Relative to the placebo group, the supplemented group had increased yearly gains of bone content, area and density which represented about 1.5% of adult female values. Such increases, if held to adult skeletal maturity, could provide protection against future risk of osteoporotic fractures.