The emptying curves were biphasic in nature. For solids, this represented an initial delay in emptying or lag phase followed by an equilibrium emptying phase characterised by a constant rate of emptying. The curves were analysed using a modified power exponential function of the form y(t)= 1 -(1 -e kt)l( where y(t) is the fractional meal retention at time t, k is the gastric emptying rate in min ', and Pi is the extrapolated y-intercept from the terminal portion of the curve. The length of the lag phase and half-emptying time increased with solid food density (31±8 min and 77 6±11-2 min for egg and 62±16 min and 94-1± +14i2 min for chicken liver, respectively). After the lag phase, both solids had similar emptying rates, and these rates were identical to those of the liquids. In vitro experiments indicated that the egg meal disintegrated much more rapidly than the chicken liver under mechanical agitation in gastric juice, lending further support to the hypothesis that the initial lag in emptying of solid food is due to the processing of food into particles small enough to pass the pylorus. We conclude that the modified power exponential model permits characterisation of the biphasic nature of gastric emptying allowing for quantification of the lag phase and the rate of emptying for both solids and liquids.

Clinical and genetic studies of familial nonmedullary thyroid cancer (FNMTC) have yielded conflicting results concerning the aggressiveness of the tumors, and uncertainty of their genetic makeup. In most reports of multiply affected families, the composition of the kindreds has favored families of 2 affected members. Using data for differentiated thyroid cancer (DTC) provided by the Surveillance Epidemiology and End Results (SEER) branch of the National Cancer Institute, and fine-needle aspiration data from Mayo Clinic, I found that the likelihood of 2 cases of sporadic DTC (RR) in a 9-member first-degree family was 1.25% of all DTC families, amounting to 39.4% of 306 multi-hit families reported in the literature. To study the remaining affected families I used the Bernouilli trials model of exact probability. The 60.6% of non-RR, multiply affected families are mostly concentrated in kindreds of 2 to 5 affected members. In 2-hit families, 62%-69% of affected members are sporadic (RR) cases. In families having 3 or more affected members, fewer than 6% have 1 or more sporadic (R) cases, and fewer than 0.15% have 2 or more. In families of 3 to 5 affected members, more than 96% of affected members have the familial (F) trait. Approximately 1 of 338 DTC cases carries the F-trait. Since approximately 40% of multiply affected member first-degree kindreds of DTC, and a significant majority of 2-hit families, are composed of clinically evident, sporadic cases only clinical and genetic investigations of FNMTC should center on families of 3 or more affected members.

Using a dual-headed gamma camera and a standardized egg test meal labeled with 99mTc-sulfur colloid, the quantitative emptying of the total, proximal and distal stomach in five normal subjects was characterized. The same egg meal was given to the volunteers in 3 different forms: homogenized, and as 2.5 mm and 5.0 mm cubes on 3 separate occasions for a total of 15 studies. For the total stomach emptying, the lag phase and half emptying time (T1/2) obtained using a power exponential model were significantly shorter for the homogenized test meal than for the 2.5 mm and 5.0 mm cubed egg particles; the lag phases were 29 +/- 19 min (mean +/- SD) vs 55 +/- 26 (P less than 0.05) and 64 +/- 24 min (P less than 0.01), the T1/2's were 71 +/- 30 min vs 91 +/- 26 (P less than 0.05) and 104 +/- 30 min (P less than 0.05), respectively. For the proximal stomach, no statistically significant difference was observed among the 3 test meals; the T1/2s for the homogenized, 2.5 mm and 5.0 mm cubed meals were 65 +/- 26 min, 53 +/- 18 min and 64 +/- 20 min, respectively. For the distal stomach, both the peak activity (%) and time to peak activity (min) were significantly higher for the 2.5 mm cubes (43%, 54 min) and the 5.0 mm cubes (38%, 60 min) than for the homogenized eggs (16.4%, 30 min) (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

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