The ligament of Treitz (the suspensory ligament of the duodenum): anatomic and radiographic correlation.

The ligament of Treitz suspends the distal duodenum but it has not been identified on abdominal CT scans. Duodenal displacement by an extrinsic mass is not an uncommon finding and is not prevented by the ligament of Treitz. The purpose of this study was to evaluate the size and strength of the ligament of Treitz in autopsy cases and then its visibility on abdominal CT scans. The ligament of Treitz was examined in 18 autopsy cases. The ligament was studied in situ and dissected for macro and micro examination. Size, shape and strength of the ligament were studied. Following the autopsy examination, upper abdominal CT scans were reviewed to identify the ligament. The Ligament of Treitz is a thin membranous and weak structure varying in size and shape. It would not be recognized on a CT image. It would not prevent displacement of the duodenum by an extrinsic mass. Illustrations of the ligament of Treitz in anatomic textbooks often represent an inaccurate picture of the true size and relationship of the ligament to adjacent structures.

Use of serum theophylline level as a guide to optimum therapy in patients with chronic obstructive lung disease.

Blood and urine samples were collected simultaneously with measurements of pulmonary function at 2-hour intervals for 8 hours after oral administration of short-acting (SAT) and long-acting theophylline (LAT) preparations in 15 patients with stable chronic obstructive lung disease (COLD) on long-term maintenance theophylline therapy. The relationship between pulmonary function tests, serum theophylline level, plasma and urinary adenosine 3'5' cyclic monophosphate (cAMP) was examined. The highest forced expiratory volume in one second FEV1 was obtained with STL of 12.8 micrograms/ml +/- 5.21 SD and 9.14 micrograms/ml +/- 6.15 (P less than .05) after administration of SAT and LAT, respectively. A further increase in serum theophylline level (STL) offered no therapeutic benefit, and, in fact, was associated with a fall in FEV1 in many instances. Plasma or urinary cAMP measurements did not correlate with STL. STL at which the best pulmonary function is achieved is quite variable in patients with COLD on maintenance theophylline therapy, is frequently less than 10 micrograms/ml, and can be determined only by repeated measurements of pulmonary function at different STL. Therefore measurements of STL are of limited value in guiding treatment with theophylline.

Effect of nutritional status on propylthiouracil-induced protection against acetaminophen hepatotoxicity in the rat.

The effect of pair feeding of euthyroid rats compared with propylthiouracil (PTU) treated rats on acetaminophen (APAP)-induced hepatotoxicity was studied. Also, the effect of food deprivation of both the euthyroid and PTU-induced hypothyroid rats for 24 h, as well as forced feeding of the euthyroid rats after a toxic dose of APAP, was determined. Pair feeding decreased both protein and energy intake compared with ad libitum-fed controls and resulted in decreased growth rate similar to that for the PTU treated rats. In contrast to the protective effect of PTU pretreatment, decreased protein energy intake by the euthyroid rats either tended to make them more susceptible to acetaminophen-induced hepatotoxicity or had no effect as assessed by elevation of serum transaminases (SGOT,SGPT) and by hepatic necrotic score. Pair feeding also significantly altered drug disposition with an increase in the molar ratio of urinary APAP-mercapturic acid conjugate, but not the absolute amount, suggesting possible increased cytochrome P-450 dependent drug metabolizing enzyme activity. Compared with PTU-fed, in the pair-fed the molar ratio of glucuronide conjugate decreased and sulfate conjugate increased. Hepatic reduced glutathione (GSH) concentrations before and 4 h after a toxic dose of acetaminophen administration were higher in the PTU pretreated compared with euthyroid rats. Fasting of the PTU pretreated rats for 24 h after acetaminophen administration abolished the PTU-induced protective effect. Forced feeding of the euthyroid rats after a toxic dose of acetaminophen increased rather than decreased the toxicity when compared with euthyroid ad libitum-fed rats. Data suggest that higher concentrations of hepatic glutathione in the PTU pretreated compared with euthyroid rats before and 4 h after acetaminophen administration contribute to PTU-induced protection. Forced feeding of rats when the liver is severely damaged and its function compromised is harmful rather than protective. We conclude that the nutritional state of the animal significantly influences drug toxicity and should be taken into consideration in designing drug therapy and evaluation of drug toxicity.

Effect of acetaminophen toxicity on erythrocyte osmotic fragility in the Fisher rat.

The protective effect of propylthiouracil (PTU) pretreatment against acetaminophen-induced erythrocyte osmotic fragility was determined in the male Fisher rat. Hepatotoxicity was assessed for comparative purposes. PTU (0.15%) was fed in chow for a period of 12 days. Acetaminophen (1 g/kg body wt) was then administered orally by a stomach tube after an overnight fast. The rats were killed either 4 or 24 hr later. Erythrocyte osmotic fragility was determined by the extent of hemolysis in various concentrations of NaCl solutions. Hepatotoxicity was assessed by a rise in serum transaminases and by histological examination of hepatic tissue. PTU treatment when compared with control not only protected rats against acetaminophen-induced hepatotoxicity as reported before, but also protected against erythrocyte osmotic fragility. The time course of acetaminophen toxicity seems to be similar for liver and erythrocyte since both showed damage after 24 hr but not after 4 hr of acetaminophen administration. The data show that PTU pretreatment affords protection against acetaminophen-induced increased erythrocyte osmotic fragility even when their glutathione concentrations were not significantly different, suggesting that PTU per se has a protective effect.