Malignant potential of solid pseudopapillary neoplasm of the pancreas.

BACKGROUND: Solid pseudopapillary neoplasms of the pancreas are rare malignant lesions of the pancreas that typically occur in young women. Large series from any one centre are notably absent in the literature. The aim of this study was to determine long-term outcomes of operative therapy. METHODS: The records of all 14 patients diagnosed with pseudopapillary neoplasms of the pancreas over 17 years were reviewed. RESULTS: Thirteen of the 14 patients were female and the mean age at diagnosis was 30 years. Solid pseudopapillary neoplasm was suspected in only half of these patients before operation. On computed tomography, ultrasonography and/or magnetic resonance imaging, three lesions were solid, three were largely cystic, and five had solid and cystic components. All 14 patients underwent surgical exploration and curative resections were possible in 13, including distal pancreatectomy in nine, pancreaticoduodenectomy in three and resection of a local intraperitoneal recurrence in one patient. After follow-up ranging from 3 months to 20 years, 12 patients were alive, including one who had undergone re-exploration and resection of local and subcutaneous recurrences 9 years previously. CONCLUSION: Solid pseudopapillary neoplasm of the pancreas should be considered in the differential diagnosis of any solid or partly cystic pancreatic mass in women aged less than 35 years. An attempt at en bloc resection without formal lymphadenectomy should be undertaken, including resection of synchronous or metachronous distant metastases.

Beliefs in the paranormal: age and sex differences among elderly persons and undergraduate students.

Beliefs in the paranormal were rated stronger in younger as compared to elderly adults by Emmons and Sobal in 1981, and sex correlates of paranormal beliefs appeared to be stronger in women than in men by Irwin in 1994. This research studied possible linkages between age and sex with a comparative analysis between results of Vitulli and Luper's 1998 survey among undergraduate students and data from elderly men (M = 72 yr., SD = 9.2, n = 21) and women (M = 69.3 yr., SD = 7.7, n = 55). Crawford and Christensen's 1995 12-item Extrasensory Perception Survey was administered to elderly persons living in apartment complexes and private homes, participating in activities in a recreation center, or attending a continuing-education seminar. A 2 x 2 multivariate analysis of variance from responses on the 12-item survey showed that undergraduate men and elderly women had the highest ratings on paranormal beliefs. The self-selecting characteristics of a segment of the elderly sample led to a post hoc univariate analysis of variance by partitioning that sample into those who were attending a continuing-education seminar versus all other elderly persons. Summated ratings (total scores) for this survey showed main effects for these subsamples and for sex. Sex and age differences were discussed in the context of the hypothesis of social marginality.

Identification and molecular cloning of a gene encoding a fibronectin-binding protein (CadF) from Campylobacter jejuni.

Campylobacter jejuni, a Gram-negative bacterium, is a common cause of gastrointestinal disease. By analogy with other enteric pathogens such as Salmonella and Shigella, the ability of C. jejuni to bind to host cells is thought to be essential in the pathogenesis of enteritis. Scanning electron microscopy of infected INT407 cells suggested that C. jejuni bound to a component of the extracellular matrix. Binding assays using immobilized extracellular matrix proteins and soluble fibronectin showed specific and saturable binding of fibronectin to C. jejuni. Ligand immunoblot assays using 125I-labelled fibronectin revealed specific binding to an outer membrane protein with an apparent molecular mass of 37 kDa. A rabbit antiserum, raised against the gel-purified protein, reacted with a 37 kDa protein in all C. jejuni isolates (n = 15) as tested by immunoblot analysis. Antibodies present in convalescent serum from C. jejuni-infected individuals also recognized a 37 kDa protein. The gene encoding the immunoreactive 37kDa protein was cloned and sequenced. Sequencing of overlapping DNA fragments revealed an open reading frame (ORF) that encodes a protein of 326 amino acids with a calculated molecular mass of 36872Da. The deduced amino acid sequence of the ORF exhibited 52% similarity and 28% identity to the root adhesin protein from Pseudomonas fluorescens. Isogenic C. jejuni mutants which lack the 37 kDa outer membrane protein, which we have termed CadF, displayed significantly reduced binding to fibronectin. Biotinylated fibronectin bound to a protein with an apparent molecular mass of 37 kDa in the outer membrane protein extracts from wild-type C. jejuni as judged by ligand-binding blots. These results indicate that the binding of C. jejuni to fibronectin is mediated by the 37 kDa outer membrane protein which is conserved among C. jejuni isolates.

Identification of a functional homolog of the Escherichia coli and Salmonella typhimurium cysM gene encoding O-acetylserine sulfhydrylase B in Campylobacter jejuni.

The final step of L-cysteine biosynthesis in Escherichia coli and Salmonella typhimurium consists of the formation of L-cysteine from O-acetylserine and sulfide. This reaction can be catalyzed by two enzymes, O-acetylserine sulfhydrylase A and O-acetylserine sulfhydrylase B, the former of which has been more rigorously characterized. In contrast to O-acetylserine sulfhydrylase A, O-acetylserine sulfhydrylase B is preferentially used for cysteine biosynthesis during anaerobic growth and is able to utilize thiosulfate as a substrate. Campylobacter jejuni is a micro-aerophilic, Gram-negative bacterium, and a member of the epsilon subdivision of eubacteria. We have cloned, sequenced, and expressed a gene from C. jejuni that encodes a protein of 299 aa with a calculated molecular mass of 32,367 Da. Complementation analysis of an E. coli cysteine auxotroph with the pMEK34-14 recombinant plasmid containing a 1.2-kb insert of chromosomal DNA from C. jejuni revealed that transformants were capable of growth in medium containing either sulfide or thiosulfate as sole sulfur sources. These data indicate that the cloned C. jejuni gene is a functional homolog of the cysM gene that codes for O-acetylserine sulfhydrylase B in E. coli and S. typhimurium.

Chemical assay of glutaraldehyde incorporation into pericardial tissue.

This paper describes the development of a chemical assay to determine the incorporation of glutaraldehyde into pericardial tissue. The procedure is based upon the hydrolysis of the Schiff's bases formed between the glutaraldehyde and the E-amino groups of lysine, the liberated glutaraldehyde being determined as its 2,4-dinitrophenyl-hydrazone by high performance liquid chromatography (HPLC). The HPLC system uses a reverse phase column eluted with a gradient of aqueous acetonitrile (from 60%-70% over 30 minutes). The glutaraldehyde 2,4-dinitrophenylhydrazone is detected at 356 nm. The results show that the assay has sufficient sensitivity (minimum detectable limit 20 pmol of glutaraldehyde 2,4-dinitrophenyl-hydrazone) and reproducibility (+/- 9% at 100 pmol +/- 4% at 1 nmol) to estimate glutaraldehyde incorporation into pericardial tissue. A series of subsequent experiments have documented that temperature and buffer pH are the main determinants affecting glutaraldehyde incorporation into pericardial tissue. Immersion of pericardial tissue in glutaraldehyde solution of pH 9 and 37 degrees C yields an approximately six times greater incorporation than can be achieved if the reaction is performed at 0 degrees C. Further study is underway to relate the amount of Schiff's base bound to that of total incorporated glutaraldehyde.

Respiratory activity and maintenance of cell suspensions of rat liver.

Previous experimentation involving the use of dispersed rat liver cells have utilized suspending media common to fractionation and slicing methods. Cells in these media have not remained viable for prolonged periods of time and they have resisted culturing techniques. Suspensions of dispersed parenchymal cells were prepared from rat livers which had been perfused in situ via the dorsal aorta with an EDTA-sucrose solution. The maintenance of surviving cells was attempted in three different media: sucrose buffered with Tris-HCl, Waymouth medium, and Waymouth medium supplemented with 30% calf serum. Cells suspended in sucrose and buffered with Tris-HCl oxidized citrate, succinate, and alpha-kegoglutarate but did not respire in the presence of other citric acid cycle intermediates. When cells were suspended in Waymouth medium without glucose, they oxidized malate and glutamate plus the above-mentioned substrates. Glucose and pyruvate did not stimulate oxygen uptake in either medium. Cells exhibited respiratory activity for up to 8 hr when incubated in Waymouth medium supplemented with calf serum. Both the ability to oxidize succinate and the morphological integrity of the cells were retained for this period of time. When cells were incubated in Waymouth medium alone, the time interval was reduced to 6 hr. Sucrose-Tris-HCl in the presence of succinate was not satisfactory as an incubation medium, since many of the cells underwent breakdown.