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J M Keith

Publications and source records attributed to J M Keith.

At least 55 records · Page 3Linked to original sources
PubMed1986

Molecular cloning of pertussis toxin genes.

We have cloned a 4.5 kb EcoRI/BamHI DNA fragment from Bordetella pertussis which contains at least two genes responsible for expression of pertussis toxin. The S4 subunit of the toxin was isolated by high pressure liquid chromatography and the NH2-terminal amino acid sequence determined. Using a mixed synthetic oligonucleotide probe designed by reverse translation of a portion of the protein sequence, a cloned DNA fragment was identified which contains the coding information for at least the S4 structural subunit of the toxin. Sequence analyses indicate that the mature protein is derived by proteolytic cleavage of a precursor molecule. Southern blot analyses of Tn5-induced B. pertussis toxin-deficient mutants show that the Tn5 DNA is inserted 1.3 kb downstream from the S4 subunit gene. This second gene could code for another subunit required for assembly of the mature toxin or a non-structural transport protein, possibly in the same polycistronic operon. The molecular cloning of pertussis toxin genes provides the basis for development of a safer recombinant "new generation" vaccine for whooping cough.

Amino Acid Sequence↗
PubMed1986

Molecular cloning and complete sequence of prion protein cDNA from mouse brain infected with the scrapie agent.

The prion protein (PrP) is a scrapie-associated fibril protein that accumulates in the brains of hamsters and mice infected with the scrapie agent, and also in the brains of persons affected with kuru or Creutzfeldt-Jakob disease. It has been previously proposed that PrP could be either the primary transmissible agent of scrapie or a secondary component involved in the pathogenesis of scrapie. At present, the second possibility seems more likely, for the PrP-specific mRNA is present in both infected and uninfected brains. We have isolated and sequenced the complete PrP-specific cDNA from mRNA isolated from infected mouse brains. Comparison of the mouse PrP with the hamster PrP reveals a high homology in the amino acid sequence and the presence of a conserved octapeptide repeated four times, whose function is unknown at present. Structural features are discussed and compared with other proteins. Except for its homology with the hamster PrP, mouse PrP has no significant homology to any known protein sequence, including neurofilaments, neuropeptides, and amyloid proteins of Alzheimer disease. Some features of the PrP, however, are similar to structures found in aggregating proteins, such as the wheat glutenin, keratin, and collagen.

Amino Acid Sequence↗
PubMed1984

Personalized care helps facilities compete.

Catholic health facilities may believe that they provide personalized care, since this value is a part of their mission statement. In the face of shrinking inpatient services and competition for patients, however, formal efforts to provide such care are essential. Personalized care can be a primary factor in differentiating Catholic health care facilities in the marketplace. St. Edward Mercy Medical Center implemented marketing surveys to determine patients' perceptions of personalized care. Using the results, the medical center instituted employee education programs and physical improvements in order to meet patients' needs and thus maintain and improve the facility's patient market share.

Arizona↗
PubMed1982

Purification and characterization of the messenger ribonucleic acid capping enzyme GTP:RNA guanylyltransferase from wheat germ.

A GTP:RNA guanylyltransferase or capping enzyme has been purified approximately 2000-fold from wheat germ. The enzyme catalyzes the transfer of the GMP residue from GTP to the 5' end of RNA or synthetic polyribonucleotides. Diphosphate-ended polymers were capped more efficiently than molecules with triphosphate ends, and molecules with monophosphate ends were not capped at all. There appears to be little specificity since RNAs with purine or pyrimidine ends served as acceptors. Other features of the wheat germ RNA guanylyltransferase include relatively low Km values for GTP (2.7 microM) and ppA (pA)n (14.2 nM), a divalent cation requirement satisfied by low (0.5 mM) concentrations of MnCl2 or higher (5 mM) concentrations of MgCl2, and a pH optimum around neutrality.

Kinetics↗
PubMed1980

Dinucleotide Sequences at the 5' Ends of Vaccinia Virus mRNA's Synthesized In Vitro.

The diversity of dinucleotide sequences at the 5' ends of vaccinia virus mRNA's was determined by a two-dimensional electrophoresis procedure. RNA labeled with S-adenosyl[methyl-(3)H]methionine was synthesized in vitro by enzymes present in vaccinia virus cores. The RNA, ending in m(7)G(5')pppN(m)pN-, was beta-eliminated and treated with alkaline phosphatase. After digestion with RNases T(2), T(1), and A, all eight possible dinucleotides containing G(m) and A(m) were identified. They are, in decreasing order of abundance: G(m)pUp (22%), A(m)pCp (18%), G(m)pAp (16%), G(m)pCp (15%), A(m)pAp (11%), A(m)pUp (10%), A(m)pGp (7%), and G(m)pGp (2%).

Journal Article↗
PubMed1980

Centralized transcription reduced costs, increases productivity.

By centralizing transcription services, a 340-bed hospital stabilized personnel turnover and absenteeism, eliminated equipment duplication, and improved output. A well-planned implementation and a financial incentive program contributed to increased productivity.

Arizona↗
PubMed1978

HeLa cell RNA (2'-O-methyladenosine-N6-)-methyltransferase specific for the capped 5'-end of messenger RNA.

A novel enzyme involved in the post-transcriptional modification of the 5'-end of mRNA has been partially purified from HeLa cells. Termed an S-adenosyl-L-methionine:RNA(2'-O-methyladenosine-N4)-methyltransferase, the enzyme specifically catalyzes the transfer of a methyl group from S-adenosylmethionine to the N6 position of a 2'-O-methyladenosine residue located within the "capped" 5'-end of mRNA. The dimethylated nucleoside, N6,2'-O-dimethyladenosine, is formed as indicated by the following reaction in which m7G(5')pppAm- represents the capped and methylated 5'-end of mRNA: AdoMet + m7G(5')pppAm- leads to AdoHcy + m7G(5')pppm6A7- Greatest activity is obtained with RNA acceptors ending in m7G(5')pppAm-; less activity is found with RNA ending in m7G(5')pppA-; and barely detectable and no activity is found with RNA ending in G(5')pppA- and ppA-, respectively. Furthermore, no activity is found with oligonucleotides such as m7G(5')pppA, m7G(5')pppAm, and m7G(5')pppAmpN indicating that a longer polymer is required. It can be concluded from the substrate specificity of the enzyme that the formation of N6,2'-O-dimethyladenosine follows the biosynthesis of molecules containing m7G(5')pppAm-N-. The molecular weight of the methyltransferase, as determined by sedimentation in sucrose gradients, is approximately 65,000.

Adenosine↗
PubMed1978

Effect of methylation of the N6 position of the penultimate adenosine of capped mRNA on ribosome binding.

An RNA(2'-O-methyladenosine-N6)-methyltransferase isolated from HeLa cells was used to convert the ends of vaccinia virus mRNAs containing m7G(5')pppAm-to m7G(5')pppm6Am-. Under competitive conditions, there was no preferential binding of mRNAs containing m6Am residues within the capped ends relative to those containing Am either to wheat germ ribosomes at 70 mM potassium acetate or to reticulocyte ribosomes at 120 mM potassium acetate. Only at high concentrations of potassium acetate (200 mM) and at near-saturating mRNA concentrations, was a slight enrichment of mRNAs containing m6Am over those containing Am detected on reticulocyte ribosomes. It appears that unlike methylation of the N7 position of the terminal guanosine, methylation at the N6 position of the penultimate adenosine of mRNA has, at most, a small effect on binding to ribosomes under present in vitro conditions.

Adenosine↗
PubMed1978

Common sequence at the 5' ends of the segmented RNA genomes of influenza A and B viruses.

Guanylyl- and methyltransferases, isolated from purified vaccinia virus, were used to specifically label the 5' ends of the genome RNAs of influenza A and B viruses. All eight segments were labeled with [alpha-(32)P]guanosine 5'-triphosphate or S-adenosyl[methyl-(3)H]methionine to form "cap" structures of the type m(7)G(5')pppN(m)-, of which unmethylated (p)ppN- represents the original 5' end. Further analyses indicated that m(7)G(5')pppA(m), m(7)G(5')pppA(m)pGp, and m(7)G(5')pppA(m)pGpUp were released from total and individual labeled RNA segments by digestion with nuclease P1, RNase T1, and RNase A, respectively. Consequently, the 5'-terminal sequences of most or all individual genome RNAs of influenza A and B viruses were deduced to be (p)ppApGpUp. The presence of identical sequences at the ends of RNA segments of both types of influenza viruses indicates that they have been specifically conserved during evolution.

Base Sequence↗
PubMedDate not supplied

Identification of scrapie prion protein-specific mRNA in scrapie-infected and uninfected brain.

To date no nucleic acid has been found in the purified infectious agent which causes the spongiform encephalopathy known as scrapie. In an attempt to identify a unique scrapie virus-associated messenger RNA in tissues of infected animals, we have synthesized an oligonucleotide probe complementary to the mRNA sequence corresponding to the amino-acid sequence of the prion protein, PrP27-30 (ref. 1). We report here that, with this probe, a complementary DNA clone representing PrP27-30 was obtained from scrapie-infected mouse brain; the DNA sequence of this clone could be translated into a protein that matches exactly the published sequence of PrP27-30. The cDNA clone hybridized to a single 2.4-2.5-kilobase (kb) mRNA from both normal and scrapie-infected brain. Thus, the PrP27-30 mRNA is not uniquely associated with scrapie infectivity, suggesting that PrP27-30 may be a normal component of mouse and hamster brain.

Amino Acid Sequence↗
PubMedDate not supplied

A trust relationship. A medical advisory board builds physician commitment to a healthcare facility.

Today physicians and hospitals are in competition. To ensure consistent physician input and a forum for two-way communication, St. Edward Mercy Medical Center, Fort Smith, AR, has established a medical staff board. The medical staff board was organized so physicians could formally address managers' concerns without duplicating work done by other medical staff committees (e.g., executive committee, medical staff sections, hospital committees). Membership on the 24-member board was limited to the active staff. A two-year term was established, allowing for two consecutive terms to ensure continuity. The chief of staff and chief executive officer (CEO) are ex-officio members. Some of the issues of interest to physicians include how well informed operating room personnel were on current technology and procedures, how effective the emergency department could be, having been designed almost 20 years ago, and how volume purchasing affects physician familiarity with certain products. St. Edward's medical staff board has the potential to enhance the physician-hospital relationship and to serve as an effective tool in building commitment to the medical center.

Arkansas↗
PubMedDate not supplied

Flattening the hierarchy. A hospital streamlines managerial layers to meet market demands.

In the early 1990s it became clear to the leaders of St. Edward Mercy Medical Center, Fort Smith, AR, that the traditional ¿functional¿ model of organization, on which their hospital was based, did not allow it to meet new market demands. A core group of managers was formed to design a new organizational model and engineer the move toward it. Analyzing the hospital's structure, the core group found that it had too many administrative layers above too many specialized departments. In 1994 the group decided to adopt a span-of-control model of organization, which would give St. Edward a higher ratio of workers per manager. In 1995 the core group streamlined the hospital's managerial layers, deciding there would be no more than five. It reduced the number of supervisory positions by 36, including one vice president's slot. No manager was fired, though some were reassigned. St. Edward's reorganization continues at present. The new structure, which has cut personnel costs, fosters more open communication and empowers its workers, leading them to think in terms of ¿us and our hospital¿ rather than ¿me and my department.¿

Arkansas↗