Gadolinium-enhanced MR angiography of visceral arteries in patients with suspected chronic mesenteric ischemia

The purpose of this study was to evaluate accuracy of dynamic gadolinium-enhanced MR angiography (MRA) of the celiac, superior, and inferior mesenteric arteries in patients with suspected mesenteric ischemia compared with catheter angiography or surgery. Sixty-five patients with suspected mesenteric ischemia underwent three-dimensional spoiled gradient-recalled acquisition in the steady state (GRASS) gadolinium-enhanced MRA. Correlative studies were performed on 14 patients, catheter angiography alone was performed on 12 patients, and surgery alone was performed on two patients. Six patients had mesenteric ischemia. In all patients, the celiac artery (CA) and superior mesenteric artery (SMA) were seen well enough to evaluate; however, the inferior mesenteric artery (IMA) could be evaluated in only 9 of the 14 patients. MRA showed severe stenosis (> 75%) or occlusion of the celiac axis in seven patients, of the SMA in six patients, and of the IMA in four patients. The overall sensitivity and specificity were 100% and 95%, respectively, compared with catheter angiography and surgery. The two errors were caused by overgrading the severity of IMA disease. Three-dimensional gadolinium-enhanced MRA can accurately demonstrate the origins of the CA and SMA and is useful in evaluation of patients with suspected mesenteric ischemia.     

Implication of His68 in the substrate site of Bacillus subtilis adenylosuccinate lyase by mutagenesis and affinity labeling with 2-[(4-bromo-2,3-dioxobutyl)thio]adenosine 5'-monophosphate

Adenylosuccinate lyase of Bacillus subtilis is inactivated by 2-[(4-bromo-2,3-dioxobutyl)thio]adenosine 5'-monophosphate (2-BDB-TAMP) at pH 7.0. As the reagent concentration is increased, a maximum rate constant is approached, indicative of reversible enzyme-reagent complex formation (KR = 68 +/- 9 microM) prior to irreversible modification (kmax = 0.081 +/- 0.004 min-1). Complete inactivation occurs concomitant with about 1 mol of 2-BDB-[14C]TAMP incorporated/mol of enzyme subunit. Adenylosuccinate, or a combination of AMP and fumarate, decreases the inactivation rate and reduces incorporation of [14C] reagent, whereas either AMP or fumarate alone is much less effective. These observations suggest that 2-BDB-TAMP attacks the adenylosuccinate binding site. Proteolytic digestion of inactivated enzyme, followed by purification of the digest by HPLC, yields the radioactive peptide Ile62-Ala72, in which Arg67 and His68 are the most likely targets. Thus 2-BDB-TAMP reacts with adenylosuccinate lyase at a site distinct from the His141 attacked by 6-BDB-TAMP (Lee, Worby, Dixon, and Colman (1997) J. Biol. Chem. 272, 458-465). Site-directed mutagenesis was used to construct mutant enzymes with replacements for both Arg67 and His68, and either Arg67 or His68. The R67M mutant enzyme has almost the same specific activity as the wild-type enzyme under standard assay conditions, whereas the single mutant H68Q and double mutant R67M-H68Q enzymes exhibit specific activities that are decreased more than 100-fold. These results indicate that while Arg67 and His68 may both be in the region of the substrate site, only His68 is important for the catalytic activity of B. subtilis adenylosuccinate lyase. A role is proposed for His68 as a general acid-base catalyst.     

A scheme for designating enzymes that hydrolyse the polysaccharides in the cell walls of plants

Twelve neurologically normal infants (age 2.9+/-0.9 months) with peptic esophagitis (grade 2) who did not respond to cimetidine (in addition to positioning, cisapride, and Gaviscon) were treated with omeprazole, 0.5 mg/kg once a day, for 6 weeks. The effectiveness of omeprazole was evaluated in all infants by clinical assessment and endoscopy before and after treatment and by 24-hour gastric pH monitoring during treatment in seven infants. Omeprazole therapy led to a marked decrease in symptoms, endoscopic and histologic signs of esophagitis, and intragastric acidity.     

Serum oncostatin M in multiple myeloma: association with prognostic factors

Strongyloides stercoralis infection is of low prevalence in Malaysia. We report an unusual case presenting primarily with gastric symptoms. The patient was a 72 years old Chinese male admitted for progressive weight loss and abdominal bloating. Gastroscopic examination revealed mucosal prepyloric elevations in the gastric mucosa. Gastric strongyloidiasis was confirmed by the presence of adult forms, as well as ova and larval rhabditiform stages of the worm in the gastric mucosal crypts. We believe that this is the first histologically documented case of gastric strongyloidiasis in Malaysia.     

Concurrent engineering with delta files

We describe a test system in which we used a data management system and delta files to communicate engineering changes between two modeling systems: an ACIS-based solid modeling system running on a Sun Sparc workstation to create a part, and a CATIA system running on an IBM RS/6000 to design a fixture for it. The test system communicates the first version of the MBB part between the two engineers as a PDES/STEP (Product Data Exchange Standard/Standard for the Exchange of Product-Model Data) exchange file. The ACIS engineer then makes an engineering change to the part, thus creating, the second version (V2) of it, and a delta file communicates the V2 changes to the CATIA engineer. The CATIA engineer can use this delta file to highlight the changes to the part between the two versions. Although our test system/scenario is simple, it demonstrates the advantages of delta files. It also helped us identify several important issues for developing the method further. We first outline the STEP standard and how we used it to implement data exchange in our test system, then we discuss delta files and describe how we implemented them. We conclude with a discussion of the lessons learned from the test system and scenario     

Investigation of immune response in rubber workers at high risk for cancer

The study was concerned with immune response in the workers engaged in rubber manufacture which is a cancer hazard. A group of healthy donors were in control. The study group was divided into those free from carcinogen-protein adducts (CPA) and those who revealed them and, therefore, are considered at high risk for cancer. CPAs containing benzidine, 2-naphtylamine or 3-oxyanthranyl acid were assayed in blood serum. B- and T-immunity inhibition was shown to be present in both study sub-groups. A significant difference in immune response indices was established between the CPA-free and CPA-containing groups of the rubber workers. The latter group had relatively higher levels of IgA, IgM and globulins of immunocomplexes, and revealed inhibition of formation of antibody-forming cells to ovine erythrocytes following injection of CPA-containing blood serum into mice as well as relatively higher suppression of T-cell immunity in the workers at high risk.     

Sperm auto - antibodies and anti-nuclear antigen antibodies in chronic dioxin - exposed veterans

The authors studied anti-nuclear antibodies (ANA) in 25 chronic dioxin - exposed veterans by IIF technics with Hep-2 cell line and sperm autoantibodies by agglutination test of Franklin-Dukes. The site of antibody binding on spermatozoon is detected by IIF test. The control group for ANA detection is 63 healthy persons of the same age as that of dioxin - exposed veterans and the control group for sperm autoantibodies is 36 healthy males of 28-63 years old, having 1-2 children. Obtained results show that the rate of ANA positive in veterans group is normal, and sperm auto-antibodies is also at normal range. The site of antibody binding on spermatozoon is predominantly head - head, rarely head - neck or tail - tail.