In vivo and in vitro assessment of barium sulphate suspensions

In vitro methods of testing the efficiency of barium sulphate suspensions in delineating mucosal detail using canine cadaveric stomachs have been described in the literature. In this study a comparison is made between in vitro and in vivo tests in the stomach and small intestine of dogs, using several brands of barium sulphate. The results indicate that there is considerable variation in the behavior of these suspensions between the in vitro and in vivo tests particularly in the stomach. It is our view that in vitro tests of this sort are of little value for assessing the relative advantages and disadvantages of these suspensions in demonstrating mucosal detail.     

Primary carcinoma of duodenum--a case report

The toad gallbladder epithelium is much more selective than that of the rabbit especially as to the permeability of two molecules like urea and thiourea. These observations can probably be attributed to different permeation mechanisms of the 2 molecules. Neither active transport nor solvent drag can explain these phenomena. 10(-4) M phloretin strongly inhibits urea movement, but does not alter either thiourea fluxes or isotonic net water transport: these results suggest that a specific mechanism is involved in urea movement. The urea transport shows saturation kinetic which is consistent with the presence of a facilitated mechanism.     

Testing consistency of vapor-liquid equilibrium data in P-T-X space

A systematic method of calculating and presenting the results of consistency tests is given and illustrated on the methane-ethane system in the space of ?140 to 60°F and 100 to 700 psia. The results indicate incompatibility of error levels between isobars and isotherms. Also, different arrangements of terms in the thermodynamic differential equations were sometimes found to produce different levels of inconsistency for the same space. Results are analyzed and discussed.