Consumption of fructose-sweetened beverages for 10 weeks reduces net fat oxidation and energy expenditure in overweight/obese men and women.

BACKGROUND/OBJECTIVES: The results of short-term studies in humans suggest that, compared with glucose, acute consumption of fructose leads to increased postprandial energy expenditure and carbohydrate oxidation and decreased postprandial fat oxidation. The objective of this study was to determine the potential effects of increased fructose consumption compared with isocaloric glucose consumption on substrate utilization and energy expenditure following sustained consumption and under energy-balanced conditions. SUBJECTS/METHODS: As part of a parallel arm study, overweight/obese male and female subjects, 40-72 years, consumed glucose- or fructose-sweetened beverages providing 25% of energy requirements for 10 weeks. Energy expenditure and substrate utilization were assessed using indirect calorimetry at baseline and during the 10th week of intervention. RESULTS: Consumption of fructose, but not glucose, led to significant decreases of net postprandial fat oxidation and significant increases of net postprandial carbohydrate oxidation (P<0.0001 for both). Resting energy expenditure (REE) decreased significantly from baseline values in subjects consuming fructose (P=0.031) but not in those consuming glucose. CONCLUSIONS: Increased consumption of fructose for 10 weeks leads to marked changes of postprandial substrate utilization including a significant reduction of net fat oxidation. In addition, we report that REE is reduced compared with baseline values in subjects consuming fructose-sweetened beverages for 10 weeks.

Normal organ volume assessment from abdominal CT.

We determined the normal distribution of abdominal organ volumes measured from abdominal computed tomographic (CT) images. A total of 149 adult abdominal CT studies were selected, and 711 organs (388 from males, 323 from females) were outlined by hand on each CT image by using a computer. More than 18000 organ outlines were traced. The organs studied included left and right kidneys, left and right adrenals, spleen, pancreas, and liver, and the first lumbar vertebrae was also evaluated. Using the known pixel size and section thickness, organ volumes were computed. Organ volumes were corrected for height and weight for each sex. The normal and cumulative normal distributions for each organ studied were computed, demonstrating the range of organ volumes for each sex that exist in the normal adult population. Organ volumes ranged from a mean of 4.4 mL (female left adrenal) to 1710 mL (male liver). Mean organ volumes were 64.4, 156.5, 179.8, and 1411 mL for the female pancreas, kidneys, spleen, and liver, respectively. Corresponding male volumes were 87.4, 193.1, 238.4, and 1710 mL, respectively. Tabular data are provided that indicate the relative size for each organ volume in terms of the cumulative probability distribution. Normative data are provided to allow physicians to estimate where in the normal range a particular organ volume lays. Organ volumes may be useful as quantitative indices of pathologic conditions.

Monte Carlo assessment of computed tomography dose to tissue adjacent to the scanned volume.

The assessment of the radiation dose to internal organs or to an embryo or fetus is required on occasion for risk assessment or for comparing imaging studies. Limited resources hinder the ability to accurately assess the radiation dose received to locations outside the tissue volume actually scanned during computed tomography (CT). The purpose of this study was to assess peripheral doses and provide tabular data for dose evaluation. Validated Monte Carlo simulation techniques were used to compute the dose distribution along the length of water-equivalent cylindrical phantoms, 16 and 32 cm in diameter. For further validation, comparisons between physically measured and Monte Carlo-derived air kerma profiles were performed and showed excellent (1% to 2%) agreement. Polyenergetic x-ray spectra at 80, 100, 120, and 140 kVp with beam shaping filters were studied. Using 10(8) simulated photons input to the cylinders perpendicular to their long axis, line spread functions (LSF) of the dose distribution were determined at three depths in the cylinders (center, mid-depth, and surface). The LSF data were then used with appropriate mathematics to compute dose distributions along the long axis of the cylinder. The dose distributions resulting from helical (pitch = 1.0) scans and axial scans were approximately equivalent. Beyond about 3 cm from the edge of the CT scanned tissue volume, the fall-off of radiation dose was exponential. A series of tables normalized at 100 milliampere seconds (mAs) were produced which allow the straight-forward assessment of dose within and peripheral to the CT scanned volume. The tables should be useful for medical physicists and radiologists in the estimation of dose to sites beyond the edge of the CT scanned volume.

Comparison of US utilization and technical costs before and after establishment of 24-hour in-house coverage for US examinations.

PURPOSE: To compare data regarding the cost and number of ultrasonographic (US) examinations performed for 6 months, before and after institution of 24-hour in-house sonographer coverage. MATERIALS AND METHODS: Data for a 6-month period during which US services were provided by a sonographer on call from 11 PM to 7 AM were compared with data for a 6-month period during which a sonographer was in house during this shift. RESULTS: With 11 PM to 7 AM on-call coverage, the sonographers performed 147 examinations in a 6-month period, an average of 0.81 examination per shift. After institution of in-house coverage for this shift, 792 US examinations were performed in 6 months, an average of 4.3 examinations per shift. The cost for 11 PM to 7 AM in-house sonographer coverage for 6 months was approximately $16,000 more than that for on-call coverage. This cost would be offset by revenues from one additional examination per night. The cost per examination for the 11 PM to 7 AM shift decreased from $124.70 to $43.33. CONCLUSION: At the authors' institution, 24-hour in-house sonographer coverage resulted in additional cost, which was offset by revenues from additional examinations. There was nearly a fivefold increase in the number of US examinations performed per shift. These examinations were performed more expediently, enabling more rapid patient triage.

The hemodynamics of vacuum constriction erections: assessment by color Doppler ultrasound.

Duplex ultrasound with pulsed Doppler and color flow sonography were used to image the penis and conduct blood flow velocity studies in 5 patients. Cavernous body cross sectional area, cavernous artery diameters and peak systolic velocities were measured in the flaccid shaft, after transient exposure to negative pressure in a vacuum constriction device, and with a vacuum constriction device band applied to the tumescent shaft. We found that exposure to vacuum transiently increased central cavernous arterial blood flow velocities compared to baseline values in all patients. After a trial of a vacuum constriction device and application of the constricting band cavernous body cross sectional areas doubled. Despite increased cavernous arterial diameters in 4 of 5 patients and increased blood flow in all patients after vacuum-induced tumescence alone, we could not visualize arterial inflow in the penile shaft once the constricting band was in place. Color Doppler ultrasound can detect cavernous artery systolic flow as low as 2 to 9 cm. per second. Our data suggest that the erectile state maintained distal to the vacuum constriction device band is low flow and relatively ischemic.

Deep-vein thrombosis after fracture of the pelvis: assessment with serial duplex-ultrasound screening.

Sixty patients who had had a major fracture of the pelvis and were in stable condition on the orthopaedic ward three to five days after the injury were tested serially with duplex ultrasound, beginning approximately seven days after the injury, in order to determine the incidence of deep-vein thrombosis. Contrast venography was performed to confirm all positive non-invasive studies. Deep-vein thrombosis developed in eight patients (approximately 15 per cent). The thrombosis was in the popliteal or a more proximal vein in six of the eight patients, whereas in two it was distal to the popliteal vein. In four patients, evidence of thrombosis developed after one or more normal duplex-ultrasound studies. In one patient, symptoms that were suggestive of deep-vein thrombosis developed fifty-two days after the injury (four days after the fourth normal duplex-ultrasound examination), and ascending venography was entirely normal. Another patient had a pulmonary embolus fifteen days after the injury, and on the same day a duplex-ultrasound study was positive for thrombosis. During six weeks of follow-up after discharge from the hospital, symptoms of deep-vein thrombosis or pulmonary embolism did not develop in any patient in whom serial duplex-ultrasound studies had been negative.

Laboratory assessment of ultrasonic needle and catheter visualization.

In the first portion of this experiment, seven different catheter materials were tested as to their sonographic visualization in vitro. While five of the seven catheter materials had good to excellent sonographic detection, nylon and polyethylene catheters were poorly visualized. Additionally, various methods of improved needle visualization were tested. Sonographic needle visualization was aided by a variety of methods including either roughening or scoring the outer needle or inner stylet and placement of a guidewire through the needle. When the needle was placed in solid tissue, injection of water through the needle tip was thought to be more advantageous for tip visualization than use of air as an acoustic marker.

Ultrasonic assessment of fetal growth in the nonhuman primate (Macaca mulatta).

Serial ultrasound measurements of fetal growth were made during uncomplicated pregnancy in 28 time-mated rhesus monkeys. Gestational sac (GS) size, crown-rump length (CRL), biparietal diameter (BPD), head circumference (HC), head area (HA), abdominal circumference (AC), abdominal area (AA), and femur length (FL) were measured. Average longitudinal growth curves for each parameter were obtained from individual fetal growth curves. Data analysis indicated that the linear model was optimal for GS, CRL, HA, AA, and FL. The linear-quadratic model was optimal for AC, and the linear-cubic model was optimal for BPD and HC.

Assessment of cerebral blood flow in man by video dilution technique: a preliminary report.

Video dilution technique (VDT) is currently performed in conjunction with routine cerebral angiography to determine carotid blood flow in humans. Preliminary results indicate that the blood flows (as a percentage of cardial output) of the common, internal, and external carotid arteries are 8.5%, 5.5%, and 3.0%, respectively (SD less than 1%). In contradistinction to previous techniques, VDT provides a safe and highly accurate method of determining carotid blood flow in human subjects. The usefulness of this technique in normal and pathologic states is discussed.