Postsurgical bile leaks: endoscopic obliteration of the transpapillary pressure gradient is enough

OBJECTIVES: Bile leaks are a well documented complication of biliary surgery, occurring more frequently with laparoscopic procedures. Endoscopic therapy with a long biliary endoprosthesis traversing the site of the leak is effective. We have evaluated the hypothesis that equalizing biliary and duodenal pressures with a short transpapillary stent is an equally effective therapy for bile leaks. METHODS: Thirty one consecutive patients presenting over a 52-month period with postsurgical bile leaks were evaluated. Patients had been treated with long endoprostheses (stents or nasobiliary tubes), sphincterotomy, or short transpapillary stents. The success, complication rate, need for additional therapy, and hospitalization time of each therapeutic approach were determined. RESULTS: Endoscopic therapy was successful in all 25 patients in whom a bile leak could be documented. The clinical success, need for radiological drainage, length of hospitalization, and incidence of pancreatitis were similar for all methods of treatment. CONCLUSIONS: These results confirm that endoscopic therapy is highly successful in the treatment of postoperative bile leaks and suggest that the mechanism of healing is the equalization of bile duct and duodenal pressures, allowing flow of bile into the duodenum. The endoscopic placement of short transpapillary stents without sphincterotomy is a temporary, effective, and technically simple method of pressure equalization. This should be considered as the primary therapy for most postoperative bile leaks.     

Prevention of T cell anergy by signaling through the gamma c chain of the IL-2 receptor

When stimulated through their antigen receptor without requisite costimulation, T cells enter a state of antigen-specific unresponsiveness termed anergy. In this study, signaling through the common gamma chain of the interleukin-2 (IL-2), IL-4, and IL-7 receptors in the presence of antigen was found to be sufficient to prevent the induction of anergy. After culture with IL-2, IL-4, or IL-7, Jak3 kinase was tyrosine-phosphorylated, which correlated with the prevention of anergy. Therefore, a signal through the common gamma chain may regulate the decision of T cells to either clonally expand or enter a state of anergy.     

Apolipoprotein (apo) B and apoII gene expression are both estrogen-responsive in chick embryo liver but only apoII is estrogen-responsive in kidney

Estrogen regulates the hepatic synthesis of a variety of proteins required for egg yolk production in oviparous vertebrates. In chickens, two of these proteins, apolipoprotein (apo) B and apoII, comprise the major protein components of specialized very low density lipoprotein particles that transport triacylglycerols and cholesterol to the developing egg yolk. In the adult, apoB is synthesized constitutively in liver, small intestine, and kidney but is estrogen-responsive only in the liver. In this work we have examined the embryonic expression of the apoB and apoII genes in yolk sac, liver, kidney, and small intestine. The 14 kb apoB mRNA was first detected at day 3 of development in vascular yolk sac, a tissue involved in the transfer of yolk lipids into the embryonic circulation. Constitutive apoB mRNA expression was detectable in liver at day 6.5 and in kidney at day 7.5, but in intestine was barely detectable before hatching. The hepatic apoB gene acquired estrogen-responsiveness at day 6.5 and its hormone-dependent expression increased throughout development in concert with the estrogen-responsive expression of the apoII gene. In contrast, the constitutively expressed apoB gene in kidney remained unresponsive to estrogen. Surprisingly, the apoII gene was found to be responsive to estrogen in both the embryonic kidney and small intestine. ApoII mRNA induction by estrogen in kidney at day 11 was at 10% of the level in the liver but estrogen-responsiveness decreased later in development and was low in the adult.(ABSTRACT TRUNCATED AT 250 WORDS)     

Learning disabilities, low achievement, and mild mental retardation: more alike than different?

Children identified with learning disabilities (LD), low achievement (LA), or mild mental retardation (MMR) were contrasted on 41 measures of ability, academic achievement, social skills, problem behavior, academic engaged time, perceptual-motor skills, and school history. Both multivariate, univariate, and meta-analytic comparisons among the three groups showed relatively large differences on measures of aptitude and achievement, with the LD group scoring higher on measures of cognitive ability than the LA and MMR groups and the LA group showing higher tested academic achievement than the LD and MMR groups. Teacher ratings of academic competence showed similar levels of functioning for the LD and LA groups. No differences among the groups were found on measures of social skills, problem behaviors, or academic engaged time, or on most indices reflecting school history. Results were interpreted in light of studies contrasting LD and LA groups. Comparisons with earlier studies were difficult in light of demographic differences in samples and the lower cognitive and academic functioning of children in the present study. The current study showed that 61% of the LD group could be differentiated from the LA group, with LD-MMR and LA-MMR differentiation levels being 68.5% and 67.5%, respectively.     

Two isozymes of P450nor of Cylindrocarpon tonkinense: molecular cloning of the cDNAs and genes, expressions in the yeast, and the putative NAD(P)H-binding site

The cDNAs and genes for two isozymes of cytochrome P450nor of the fungus Cylindrocarpon tonkinense, P450nor1 and P450nor2, were cloned and sequenced. Their deduced amino acid sequences respectively showed 83 and 70% identity to that of P450nor of Fusarium oxysporum, and 69% identity to each other. The genes for P450nor1 and P450nor2 were termed, respectively, CYP 55A2 and CYP 55A3. The cDNA for P450nor1 contained a targeting-like presequence upstream the N-terminus of mature protein whereas that for P450nor2 did not, suggesting their different intracellular localisations. We also succeeded in expressing these P450nor isoforms in the host-vector system of the yeast Saccharomyces cerevisiae. We purified one of the recombinant proteins, P450nor of F oxysporum. Little difference could be observed between the native and recombinant proteins in catalytic and spectroscopic properties. We constructed chimeric proteins of P450nor of F oxysporum and P450nor2 which are different in their specificity against the electron donors: reduced pyridine nucleotides. The specificity of chimeric proteins against NADH/NADPH showed that the specificity is determined by the N-terminal half of protein. We found a consensus amino acid sequence between three isoforms of P450nor, A-X-G-X-X-A, similar to the NAD-binding motif G-X-G-X-X-G/A in the region that corresponds to the B'-helix in P450cam.     

Expression of CYP71B7, a cytochrome P450 expressed sequence Tag from Arabidopsis thaliana

c-Yes was purified 322-fold from a rat liver plasma membrane fraction to a single 60-kDa band on SDS-PAGE. The purified protein contained essentially no phosphotyrosine residues and was autophosphorylated with Mg2+. ATP exclusively at tyrosine residues with a concomitant increase in the protein-tyrosine kinase activity. The autophosphorylated c-Yes was extensively digested by trypsin and the resultant two major phosphopeptides, peptides I and II, were purified by HPLC on a reversed-phase C-18 column. The amino acid sequence of peptide I was determined to be LIEDNEYTAR, which is identical with the sequence from Leu-418 through Arg-427 of mouse c-Yes, indicating that one of the autophosphorylation sites corresponds to Tyr-424 of the mouse c-Yes. After partial determination of the N-terminal sequence of 10 amino acid residues of peptide II, the 230 bp sequence of rat cDNA that encodes the N-terminal 76 amino acid residues of c-Yes covering peptide II, was determined. From the predicted amino acid sequence, the sequence of peptide II was assumed to be from Tyr-16 through Lys-46, YTPENPTEPVNTSAGHYGVEHATAATTSSTK. The purified c-Yes phosphorylated the tyrosine residue of synthetic peptides covering Tyr-32 and its surrounding sequence but did not phosphorylate peptides covering Tyr-16 and its surrounding sequence, suggesting that the other autophosphorylation site is Tyr-32.     

Recombinant expression and characterization of the major beta-lactamase of Mycobacterium tuberculosis

New antibiotic regimens are needed for the treatment of multidrug-resistant tuberculosis. Mycobacterium tuberculosis has a thick peptidoglycan layer, and the penicillin-binding proteins involved in its biosynthesis are inhibited by clinically relevant concentrations of beta-lactam antibiotics. beta-Lactamase production appears to be the major mechanism by which M. tuberculosis expresses beta-lactam resistance. beta-Lactamases from the broth supernatant of 3- to 4-week-old cultures of M. tuberculosis H37Ra were partially purified by sequential gel filtration chromatography and chromatofocusing. Three peaks of beta-lactamase activity with pI values of 5.1, 4.9, and 4.5, respectively, and which accounted for 10, 78, and 12% of the total postchromatofocusing beta-lactamase activity, respectively, were identified. The beta-lactamases with pI values of 5.1 and 4.9 were kinetically indistinguishable and exhibited predominant penicillinase activity. In contrast, the beta-lactamase with a pI value of 4.5 showed relatively greater cephalosporinase activity. An open reading frame in cosmid Y49 of the DNA library of M. tuberculosis H37Rv with homology to known class A beta-lactamases was amplified from chromosomal DNA of M. tuberculosis H37Ra by PCR and was overexpressed in Escherichia coli. The recombinant enzyme was kinetically similar to the pI 5.1 and 4.9 enzymes purified directly from M. tuberculosis. It exhibited predominant penicillinase activity and was especially active against azlocillin. It was inhibited by clavulanic acid and m-aminophenylboronic acid but not by EDTA. We conclude that the major beta-lactamase of M. tuberculosis is a class A beta-lactamase with predominant penicillinase activity. A second, minor beta-lactamase with relatively greater cephalosporinase activity is also present.