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Biomedical subjects

M S Wood

Publications and source records attributed to M S Wood.

10 recordsLinked to original sources

IS406 and IS407, two gene-activating insertion sequences for Pseudomonas cepacia.

We have determined the nucleotide sequences of IS406 (1368 bp) and IS407 (1236 bp), two insertion sequence (IS) elements isolated from Pseudomonas cepacia 249 on the basis of their abilities to activate the expression of the lac genes of Tn951. IS406 and IS407 when inserted into the lac promoter/operator region of Tn951 generated, respectively, duplications of 8 and 4 bp of target DNA. IS406 had 41-bp terminal inverted repeat (IR) sequences with eleven mismatches. IR-L (left) contained a 12-bp motif present at the ends of Tn2501. In other respects, IS406 was distinct from previously described bacterial IS elements listed in the GenBank and EMBL databases. IS407 had 49-bp terminal IRs with 18 mismatches. IR-R (right) contained an outwardly directed sigma 70-like promoter. IS407 was closely related to IS476 and ISR1 from Xanthomonas and Rhizobium sp., respectively.

Amino Acid Sequence

Activation of the lac genes of Tn951 by insertion sequences from Pseudomonas cepacia.

We have identified three transposable gene-activating elements from Pseudomonas cepacia on the basis of their abilities to increase expression of the lac genes of the broad-host-range plasmid pGC91.14 (pRP1::Tn951). When introduced into auxotrophic derivatives of P. cepacia 249 (ATCC 17616), this plasmid failed to confer the ability to utilize lactose. The lac genes of Tn951 were poorly expressed in P. cepacia and were not induced by isopropyl-beta-D-thiogalactopyranoside. Lac+ variants of the pGC91.14-containing strains which formed beta-galactosidase at high constitutive levels as a consequence of transposition of insertion sequences from the P. cepacia genome to sites upstream of the lacZ gene of Tn951 were isolated. Certain of the elements also increased gene expression in other bacteria. For example, IS407 strongly activated the lacZ gene of Tn951 in Pseudomonas aeruginosa and Escherichia coli, and IS406 (but not IS407) did so in Zymomonas mobilis. The results indicate that IS elements from P. cepacia have potential for turning on the expression of foreign genes in a variety of gram-negative bacteria.

Blotting, Southern

Criteria-based evaluation of group 3 level memory telefacsimile equipment for interlibrary loan.

The Interlibrary Loan, Document Delivery, and Union List Task Force of the Health Sciences Libraries Consortium (HSLC)--with nineteen libraries located in Philadelphia, Pittsburgh, and Hershey, Pennsylvania, and Delaware--accepted the charge of evaluating and recommending for purchase telefacsimile hardware to further interlibrary loan among HSLC members. To allow a thorough and scientific evaluation of group 3 level telefacsimile equipment, the task force identified ninety-six hardware features, which were grouped into nine broad criteria. These features formed the basis of a weighted analysis that identified three final candidates, with one model recommended to the HSLC board. This article details each of the criteria and discusses features in terms of library applications. The evaluation grid developed in the weighted analysis process should aid librarians charged with the selection of level 3 telefacsimile equipment.

Evaluation Studies as Topic

Characterisation of kappa-opioid binding sites in rat and guinea-pig spinal cord.

The binding of radiolabelled ligands with high affinity for kappa-opioid binding sites has been studied in homogenates of lumbo-sacral spinal cord from the rat. The unselective ligands [3H]bremazocine and [3H]diprenorphine labelled a large number of sites which could not be fully resolved in terms of mu-, delta- and kappa-types by displacement assays. In particular binding at the kappa-site appeared anomalous in that sites which could be identified as high affinity kappa-type represented only 40% of total kappa-binding, defined using the unselective [3H]ligands. This was confirmed by the low levels of binding seen with the kappa-agonists [3H]dynorphin A(1-9) and [3H]U-69593. In guinea-pig cord, under conditions in which binding to mu- and delta-sites was suppressed, [3H]dynorphin A(1-9) and [3H]U-69593 labelled only 60% of the kappa population, defined by the [3H]unselective ligands. The reasons for the observed discrepancies are discussed.

Animals

[3H]diprenorphine binding to kappa-sites in guinea-pig and rat brain: evidence for apparent heterogeneity.

The binding of the unselective opioid antagonist [3H]diprenorphine to homogenates prepared from rat brain and from guinea-pig brain and cerebellum has been studied in HEPES buffer containing 10 mM Mg2+ ions. Sequential displacement of bound [3H]diprenorphine by ligands with selectivity for mu-, delta-, and kappa-opioid receptors uncovers the multiple components of binding. In the presence of cold ligands that occupy all mu-, delta-, and kappa-sites, opioid binding still remains. This binding represents 20% of total specific sites and is displaced by naloxone. The nature of these undefined opioid binding sites is discussed.

Animals

Isolation and characterization of a penicillinase from Pseudomonas cepacia 249.

Pseudomonas cepacia has an inducible beta-lactamase which is responsible for its novel ability to catabolize beta-lactam compounds. The gene encoding this enzyme, penA, was cloned from a genomic library of P. cepacia 249 on the broad-host-range cosmid pLAFR. This separated the penA gene from the gene encoding a second beta-lactamase in P. cepacia 249. Expression of penA was inducible in an Escherichia coli host strain by low levels of penicillin. The 33,500-molecular-weight enzyme had penicillinase activity not inhibited by clavulanic acid or sulbactam and was highly active against piperacillin and azlocillin. In comparison with other inducible beta-lactamases produced by gram-negative organisms, the penA enzyme had many properties which were similar to those of the penicillinase produced by Alcaligenes faecalis. It was unlike the ampC-type cephalosporinase produced by Pseudomonas aeruginosa.

Cloning, Molecular

Kappa opioid binding sites in rat spinal cord.

The spinal cord of the rat is shown to contain only a low level of kappa-binding sites, comparable to rat brain. [3H]Bremazocine appears to label an additional class of sites which do not appear to be of mu, delta, or kappa specificity.

Animals

Departmental libraries: why do they exist?

In response to an increasing concern on the part of the library staff over the role of the departmental libraries at The Milton S. Hershey Medical Center of The Pennsylvania State University, a questionnaire was developed by the George T. Harrel Library and sent to departmental libraries. From the analyzed responses, the authors were able to define the role of departmental libraries in a medical school/hospital situation, to analyze the Hershey Medical Center situation in an objective manner, to outline areas of possible cooperation between the main and departmental libraries, and to delineate some trends which appear to result from inadequate finding of a central library. Overall, the library found that departmental libraries at Hershey are currently maintaining collections consistent with the functional role of a departmental library.

Book Collecting

Distribution of opioid binding sites in spinal cord.

Opioid binding sites have been demonstrated in the spinal cords of four species (rat, guinea-pig, cow, pig). Similar numbers of sites, as measured with the unselective ligand [3H] bremazocine, are seen along the length of the rat spinal cord. Binding in the dorsal horn is three times greater than in ventral horn. The distribution of mu, delta and kappa sites is similar in all regions. The results are discussed in terms of reported distributions of peptides.

Animals