Glucose and glycogen metabolism in erythrocytes from normal and glycogen storage disease type III subjects

Active glycogen metabolism has been demonstrated in both normal and glycogen-rich erythrocytes taken from patients with type III glycogen storage disease. Activity of all enzymes catalyzing the reactions required for the synthesis and degradation of glycogen have been demonstrated in the mature erythrocytes. Uniformly labeled glucose-(14)C is incorporated into glycogen in intact cells of both types during incubation. Replacement of the glucose-(14)C by unlabeled glucose in the medium resulted in a significant loss of radioactivity from cellular glycogen. In the absence of the substrate a progressive shortening of outer branches occurred during incubation of intact glucogen-rich cells. Using cells from patients with type III glycogen storage disease, which have sufficient glycogen content to be analyzed by beta-amylolysis, we demonstrated that the glucosyl units are first incorporated in the outer tiers, then transferred to the core where they tend to accumulate due to the absence of amylo-1,6-glucosidase.The glycogen-rich cells have a more rapid rate of glucose utilization upon incubation which is not reflected by a higher lactate production. The increased rate of glucose utilization did not result from an increased rate of glucose incorporation into glycogen in affected cells. The rate of (14)CO(2) production from glucose-1-(14)C during incubation was not significantly different in the two types of cells unless methylene blue was added as an electron acceptor, in which case the glycogen-rich cells oxidized glucose to CO(2) more rapidly.     

Effect of the leukotriene B4 receptor antagonist SC-41930 on colonic inflammation in rat, guinea pig and rabbit

Inflammatory bowel disease is a chronic inflammatory disorder of the gastrointestinal tract that includes ulcerative colitis and Crohn's disease. Leukotriene B4 is thought to be a prominent proinflammatory mediator in these diseases, in that leukotriene B4 levels are increased in the colonic mucosa of inflammatory bowel disease patients and there is increased polymorphonuclear leukocyte infiltration of these tissues. We evaluated the efficacy of 7-[3-(4-acetyl-3-methoxy-2-propylphenoxy)-3,4-dihydro-8-propyl -2H-1-benzopyran-2-carboxylic acid (SC-41930), a potent, orally active leukotriene B4 receptor antagonist, in a model of inflammatory bowel disease. Colonic mucosal inflammation was induced in rats, guinea pig and rabbits by rectal instillation of a dilute solution of acetic acid. Twenty-four hours later, mucosal levels of myeloperoxidase (a marker enzyme for neutrophil infiltration) and extravasation of i.v. administered Evans blue dye (a marker of vascular disruption and increased permeability) were measured. Tissues were also evaluated histologically. The animals received either SC-41930 or vehicle, intrarectally, 30 min after or 1 hr before and 1 hr after the acetic acid. When given 30 min after acetic acid instillation SC-41930 prevented the rise in myeloperoxidase and dye extravasation observed in the acetic acid inflammed tissue. The SC-41930-treated tissues were less edematous and had fewer neutrophils within the subepithelial space. Median effective dose (ED50) values for vascular protection were approximately 20 mg/kg for both rat and guinea pig. ED50 values for inhibition of granulocyte accumulation were 20 mg/kg for rat, 24 mg/kg for guinea pig and 30 mg/kg for rabbit. These data indicate that SC-41930 is effective locally to prevent acute colonic inflammation.     

PLATELETS AND THE SHWARTZMAN PHENOMENON

Studies are reported on the effect of immunologically induced thrombocytopenia upon the local and generalized Shwartzman phenomena. Intravenous injection of antiplatelet serum to rabbits produced profound but transient thrombocytopenia unaccompanied by significant changes in circulating leucocytes. Platelet antiserum alone given to rabbits prepared with thorotrast produced renal lesions characteristic of the Shwartzman reaction. Thrombocytopenia induced by platelet antiserum did not inhibit the cutaneous hemorrhagic lesion of the local Shwartzman phenomenon produced by sequential injections of endotoxin intracutaneously and intravenously. The implications of these observations in the pathogenesis of the local cutaneous and generalized Shwartzman reaction are discussed.     

Recurrent enteric gallstone obstruction

Small bowel gallstone obstruction may recur, most often within a few days after surgery, due to an overlooked intraenteric stone or subsequent passage of another gallstone via the cholecystoenteric fistula. In the case reported herein there was a 6-month interval. A critical review of the radiologic signs of gallstone ileus is presented.