Effects of posture on gastric emptying and satiety ratings after a nutritive liquid and solid meal.

To study the effects of posture and meal structure on gastric emptying and satiety, nine women ingested tomato soup and then immediately or 20 min later an egg sandwich, when seated and when supine. The lag time was not different, but the half-emptying time of the sandwich was 32% longer (P < 0.01) and the emptying rate after the lag phase was 39% slower (P < 0.01) when the subjects were supine than when they were seated. The half-emptying time of the soup was 50% longer (P < 0.01) when the subjects were supine and ingested the soup immediately before the sandwich than in the other three conditions. Postprandial hunger ratings recovered more slowly (P < 0.01) when the subjects ingested the soup 20 min before the sandwich than when they ingested the soup immediately before the sandwich. These results suggest that posture did not affect the intragastric distribution of the sandwich but affected propulsion of the meal into the intestine and that postprandial satiety was enhanced by the cumulative effect over time of a 20-min "head start" in stimulation of intestinal receptors by emptying of the soup.

Contribution of gastric and postgastric feedback to satiation and satiety in women.

Two parallel preload studies were conducted to determine the relative contributions of inhibitory feedback from the stomach and intestine to satiation (meal termination) and postprandial satiety. In the Gastric Emptying Study, five normal-weight women each ingested an egg sandwich (307 kcal) (1) immediately after a tomato soup preload (120 kcal), (2) 20 min after a tomato soup preload, and (3) with no preload. There was 125 g more of soup in the stomach when subjects began ingesting the sandwich immediately compared to 20 min after the soup, and the emptying of the sandwich was delayed when it was ingested immediately but not 20 min after the soup. The lag times for emptying of the sandwich were 76.5 (69.1-82.4), 47.2 (20.1-67.7), and 42.4 (17.8-65.1) min for the three conditions, respectively, p < 0.05. In the Food Intake Study, 16 normal-weight women ate significantly less (p < 0.01) in test meals offered immediately (978+/-246 kcal) and 20 min (1027+/-298 kcal) after the soup preload than in a test meal with no preload (1151+/-279 kcal). Despite the different amounts of soup in the stomach, subjects' test-meal intake in the two preload conditions was not significantly different. Subjects' fullness ratings following the preloads and the test meals were not different among the treatment conditions. The results suggest that feedback from neither the gastric nor the postgastric compartment is primary in determining meal size and postprandial satiety. Instead, signals from gastric and postgastric sources are combined to determine meal size and postprandial satiety.

Preliminary experience of infusional brachytherapy using colloidal 32P.

In the past, we have clinically evaluated radiolabelled antibodies in Hodgkin's disease and hepatocellular cancer. Increased tumour pressure, reduced vascularity and poor diffusion has limited significant radiolabelled antibody tumour dose deposition. Using intratumoural infusion of macroaggregated albumin to blockade exiting vasculature followed by colloidal chromic 32Phosphorous, we have been able to achieve 75% to 100% tumour dose deposition by interstitial tumour infusion under computerised tomographic guidance. Phase I studies in a variety of solid tumours indicate extremely high doses may be achieved without toxicity (i.e. non-resectable pancreas 900,000 cGy to 1.7 million cGy) with tumour control and remission. This is a review of those studies and how the technique was applied.

Quantitative bremsstrahlung single photon emission computed tomographic imaging: use for volume, activity, and absorbed dose calculations.

PURPOSE: To perform bremsstrahlung single photon emission computed tomographic (SPECT) imaging using 32P chronic phosphate for volume and activity quantitation to calculate absorbed dose estimates. METHODS AND MATERIALS: Seven cancer patients enrolled in clinical Phase I therapeutic protocols were injected with 2.5 million particles of macroaggregated albumin, followed by colloidal 32P chromic phosphate by direct interstitial injection into the tumor-bearing region under computed tomographic (CT) guidance. SPECT images were obtained in these patients. The patient body contour was defined through the use of two externally placed Compton backscatter 99mTc sources. A computer algorithm was written to facilitate region-of-interest volume and activity determination on the reconstructed SPECT slices based on a fixed threshold method. Three sequential SPECT studies were acquired in two of these patients, to determine the accuracy of activity quantitation for bremsstrahlung SPECT studies using Chang's postprocessing method of attenuation compensation with a computer-generated body contour based on the Compton backscatter sources, and an experimentally measured effective linear attenuation coefficient for 32P. The serial data in these two patients were used to calculate absorbed dose estimates. RESULTS: The 99mTc backscatter sources enabled the patient body outline to be clearly visualized in all the transaxial reconstructed slices and did not contribute significant counts to the patient 32P counts. The calculated activities from the SPECT studies were within 7.8% of the administered 32P activity. The two calculated patient absorbed doses were 4.2 x 10(3) Gy and 5.9 x 10(3) Gy for injected activities of 736 MBq and 920 MBq, respectively. CONCLUSION: We conclude that accurate quantitative bremsstrahlung SPECT imaging, for the case of high contrast well-localized activity distributions, with a commercially available postprocessing attenuation correction algorithm, can be performed in a clinical setting. Entirely SPECT-based measurements can be used to generate absorbed dose estimates.

A new method for delivering radioactive cytotoxic agents in solid cancers.

PURPOSE: Therapeutic agents such as monoclonal antibodies, radiopharmaceuticals, and radioactive growth factors are limited in effectiveness due to the inability to deposit significant quantities of the agents and for limited periods of time in solid cancer. A new technique based on knowledge of the pathophysiology of solid tumors allows for significant concentration of these agents to accumulate and for a prolonged period of time, thus allowing interaction with the tumor for potentially increased effectiveness. METHODS AND MATERIALS: Three agents have been studied: 131I antiferritin monoclonal antibody, colloidal 32P chromic phosphate, and 131I transferrin. The time required for maximal tumor uptake was determined in vitro in tissue culture and was 10 min, 25 min, and 40 min, respectively. The new method of in vivo tumor infusion consisted of a direct intratumoral injection of macroaggregated albumin (MAA) 10,000 particles, followed by the radioactive agents under study. Tumors were infused in vivo using the new technique and compared to intratumoral infused controls. In the instance of radiolabeled antiferritin antibody, intraperitoneal administration and intratumoral infusion were compared to the new technique. In the other two instances, intratumoral infusion was compared to the new method. RESULTS: In all instances the direct vascular blockade caused by MAA led to greater deposition of the agent under study for at least 24 h. These results were clinically applied with MAA followed by 32P colloidal chromic phosphate and were consistent with the experimental findings. CONCLUSION: A new technique is described that may be carried out in the experimental laboratory and clinic by direct tumor infusion of macroaggregated albumin (MAA), followed by other radioactive agents that will remain localized in solid cancers and will allow for high tumor dose deposition for potentially increased therapeutic efficacy.

Use of indium-111-labeled white blood cells in the diagnosis of diabetic foot infections.

The diagnosis of bone infection in the patient with nonvirgin bone is a diagnostic dilemma. This is especially true in the diabetic patient with a soft tissue infection and an underlying osteoarthropathy. The authors present a retrospective study using the new scintigraphic technique of indium-111-labeled white blood cells as a method of attempting to solve this diagnostic dilemma.

Comprehensive scrotal flow and scan technique for detection of varicoceles.

We describe a noninvasive modified radionuclide technique, the "comprehensive scrotal flow and scan," for the detection of varicoceles. The procedure utilizes in-vivo-labeled pyrophosphate red blood cells and 99mTc-pertechnetate as a blood pool scanning agent. The procedure includes an immediate flow study along with early and delayed static images, both in the upright and supine position. These studies were examined by visual inspection and by computer analysis. Data were obtained from 50 patients and 8 control subjects. The technique demonstrated a 91.1 per cent sensitivity when compared to physical examination and an 84.6 per cent sensitivity when compared to venography from patients with subclinical or poorly palpable varicoceles.

Scintigraphic detection of prosthetic joint and soft tissue sepsis secondary to tuberculosis.

In a 40-year-old Hispanic woman with pain and swelling in the left knee with a prosthesis, the combination of Ga-67 citrate and Tc-99m methylene diphosphonate (MDP) scans was used to indicate that there was a septic prosthetic joint. At surgery, the joint was infected and a foreign body was found. Cultures positive for tuberculosis were found also. The presence of an incongruent Ga-67 and Tc-99m (MDP) scan pattern suggests infection of the prosthetic joint, as in the following case.

A physiological approach to the assessment of disease activity in rheumatoid arthritis.

A method is described for assessing the in vivo oxygen consumption and lactate production rates of human knee joints. It is based on the rate of fall of P(o2) and the rate of rise in lactate concentration in an intra-articular saline pool after interruption of the circulation to the joint with an arterial tourniquet. Studies in 5 control patients with degenerative joint disease and 29 patients with rheumatoid arthritis showed a 2- to 3-fold higher mean oxygen uptake rate and a 10- to 12-fold higher mean lactate appearance rate in the saline in the rheumatoid joints with severe disease compared to the control joints. These metabolic variables correlated with tissue metabolic demand as estimated in synovial biopsies. (133)Xe washout from the intra-articular space, which reflects joint circulatory flow, showed a 3-fold greater mean washout rate from the rheumatoid joints (48 studies) than control joints (7 studies) with extensive overlap between the two groups. (133)Xe washout rate correlated with knee joint inflammation estimated both clinically and histologically. After synovectomy in four patients, the operated knee showed a greater fall in lactate production than the opposite knee in three of these patients. Neither knee joint oxygen uptake nor (133)Xe washout rate changed significantly. Intra-articular corticosteroid injection (eight patients) resulted in decreased lactate production and a decreased (133)Xe washout rate in the injected knee and variable results in the untreated knee. Oxygen uptake again was unchanged after therapy.