Bile duct obstruction: radiologic evaluation of level, cause, and tumor resectability

In a prospective study of 65 patients with bile duct obstruction, various radiologic modalities were compared for their capability to demonstrate the level and cause of obstruction and to indicate accurately tumor resectability. Ultrasound (US) was performed in 65 patients, computed tomography (CT) in 51, direct cholangiography (DC) in 57, and angiography in 35. The level of obstruction was correctly indicated by US in 95% of patients and by CT in 90%, and the cause was correctly indicated by US in 88%, by CT in 63%, and by DC in 89%. In predicting tumor resectability, US was correct in 71% of patients, compared with 42% for CT, 58% for DC, and 25% for angiography. US therefore appears to be the single most useful modality in the evaluation bile duct obstruction.     

Molecular basis of altered red blood cell membrane properties in Southeast Asian ovalocytosis: role of the mutant band 3 protein in band 3 oligomerization and retention by the membrane skeleton

Southeast Asian ovalocytosis (SAO) is an asymptomatic trait characterized by rigid, poorly deformable red cells that resist invasion by several strains of malaria parasites. The underlying molecular genetic defect involves simple heterozygous state for a mutant band 3 protein, which contains a deletion of amino acids 400 through 408, linked with a Lys 56-to-Glu substitution (band 3-Memphis polymorphism). To elucidate the contribution of the mutant SAO band 3 protein to increased SAO red blood cell (RBC) rigidity, we examined the participation of the mutant SAO band 3 protein in increased band 3 attachment to the skeleton and band 3 oligomerization. We found first that SAO RBC skeletons retained more band 3 than normal cells and that this increased retention preferentially involved the mutant SAO band 3 protein. Second, SAO RBCs contained a higher percentage of band 3 oligomer-ankyrin complexes than normal cells, and these oligomers were preferentially enriched by the mutant SAO protein. At the ultrastructural level, the increased oligomer formation of SAO RBCs was reflected by stacking of band 3-containing intramembrane particles (IMP) into longitudinal strands. The IMP stacking was not reversed by treating SAO RBCs in alkaline pH (pH 11), which is known to weaken ankyrin-band 3 interactions, or by removing the cytoplasmic domain of band 3 from SAO membranes with trypsin. Finally, we found that band 3 protein in intact SAO RBCs exhibited a markedly decreased rotational mobility, presumably reflecting the increased oligomerization and the membrane skeletal association of the SAO band 3 protein. We propose that the mutant SAO band 3 has an increased propensity to form oligomers, which appear as longitudinal strands of IMP and exhibit increased association with membrane skeleton. This band 3 oligomerization underlies the increase in membrane rigidity by precluding membrane skeletal extension, which is necessary for membrane deformation.     

Gastrojejunostomy: is it helpful for patients with pancreatic cancer?

A retrospective review of palliative outcome of gastrojejunostomy in patients with pancreatic cancer was conducted. Eighty-one patients were analyzed in two groups depending on duodenal patency. Forty-five patients (group I) had no evidence of duodenal obstruction. Thirty-six patients (group II) had evidence of impingement on the duodenum by the pancreatic cancer. A third subset of patients was also studied for outcome. These 21 patients (five group I and 16 group II) had nausea and vomiting as major symptoms and were judged to have the most to gain from gastrojejunostomy. Patients were categorized by outcome. Poor outcome was defined as either death during the hospitalization for gastrojejunostomy or death within 30 days of operation even if the patient left the hospital. Risk for poor outcome depended on group. In group I, 18 of 45 patients (40%) had a poor outcome compared with 25 of 36 (70%) patients in group II (p less than 0.001). Nineteen of the 21 (90%) patients with nausea and vomiting had a poor outcome. It is an unfortunate paradox that the more patients need gastrojejunostomy for pancreatic cancer, the less likely they are to have a favorable outcome. Gastric outlet obstruction in pancreatic cancer appears to be a terminal event. A prospective study is needed to see if any true palliation of vomiting can be affected in these patients.     

胆碱能M受体拮抗剂：2α－（2＇，2＇－二取代基－2＇－羟基乙氧基）托品烷光学异构体合成

胆碱能Ｍ受体拮抗剂：２α－（２＇，２＇－二取代基－２＇－羟基乙氧基）托品烷光学异构体合成王林，恽榴红，张其楷（军事医学科学院毒物药物研究所，北京１００８５０）目前临床所用托品类抗胆碱药一般为３位取代托品酯类衍生物，这类药物作用较广泛，但选择性不高。Ａ...     

Foregut mucosal defects: an etiology of hyperamylasemia

To evaluate a preliminary correlation of hyperamylasemia to upper gastrointestinal bleeding, total serum amylase and serum isoamylase profiles were determined in 50 patients with upper gastrointestinal bleeding. Etiologies of the bleeding were determined in 46 patients including gastritis or duodenitis in 25, gastric ulcers in 12, duodenal ulcers in 3, Mallory-Weiss tears in 3, gastric carcinoma in 2, and esophageal varices in 1. Gastritis or duodenitis was seen incidentally in 14 more patients. Hyperamylasemia was seen in 38 patients, most commonly being due to a rise of both nonpancreatic and pancreatic isoamylases (18 patients). In 13 patients it was due to an elevation of nonpancreatic amylase alone, and in 7 patients secondary to elevated pancreatic isoamylase alone. Acute pancreatitis raises only the pancreatic component and cannot explain the hyperamylasemia in most of these patients. Hyperamylasemia did not correlate to etiology of the bleeding; gastritis or duodenitis present in the majority of these patients appears to be the unifying factor. Since both nonpancreatic and pancreatic amylases are present in the duodenum and the stomach with pyloric reflux, reabsorption of intraluminal amylase across damaged mucosa is postulated as a mechanism to explain the observed isoamylase patterns. The possibility of decreased amylase clearance as an explanation is unlikely. An alternative central nervous system mechanism might be invoked. It is concluded that hyperamylasemia is a complex event which the use of isoamylase analysis is beginning to elucidate. The hyperamylasemia seen commonly in patients presenting with upper gastrointestinal bleeding does not imply the presence of acute pancreatitis.