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Biomedical subjects

R St Pierre

Publications and source records attributed to R St Pierre.

At least 19 recordsLinked to original sources
PubMed1999

Inducible expression of protein kinase CK2 in mammalian cells. Evidence for functional specialization of CK2 isoforms.

Protein kinase CK2 (formerly casein kinase II) exhibits elevated expression in a variety of cancers, induces lymphocyte transformation in transgenic mice, and collaborates with Ha-Ras in fibroblast transformation. To systematically examine the cellular functions of CK2, human osteosarcoma U2-OS cells constitutively expressing a tetracycline-regulated transactivator were stably transfected with a bidirectional plasmid encoding either catalytic isoform of CK2 (i.e. CK2alpha or CK2alpha') together with the regulatory CK2beta subunit in order to increase the cellular levels of either CK2 isoform. To interfere with either CK2 isoform, cells were also transfected with kinase-inactive CK2alpha or CK2alpha' (i. e. GK2alpha (K68M) or CK2alpha'(K69M)) together with CK2beta. In these cells, removal of tetracycline from the growth medium stimulated coordinate expression of catalytic and regulatory CK2 subunits. Increased expression of active forms of CK2alpha or CK2alpha' resulted in modest decreases in cell proliferation, suggesting that optimal levels of CK2 are required for optimal proliferation. By comparison, the effects of induced expression of kinase-inactive CK2alpha differed significantly from the effects of induced expression of kinase-inactive CK2alpha'. Of particular interest is the dramatic attenuation of proliferation that is observed following induction of CK2alpha'(K69M), but not following induction of CK2alpha(K68M). These results provide evidence for functional specialization of CK2 isoforms in mammalian cells. Moreover, cell lines exhibiting regulatable expression of CK2 will facilitate efforts to systematically elucidate its cellular functions.

Animals↗
PubMed1997

An efficient protocol for linker scanning mutagenesis: analysis of the translational regulation of an Escherichia coli RNA polymerase subunit gene.

A protocol has been developed that is capable of saturating regions hundreds of basepairs in length with linker scanning mutations. The efficacy of this method stems from the design of the linker scanning mutagenesis (LSM) cassette which is composed of a selectable marker flanked by two oligonucleotides, each of which contains a recognition site for a different restriction endonuclease. The cleavage site for one endonuclease is within its recognition site, while the second endonuclease cleaves in the target DNA beyond the end of the cassette. Digestion with these endonucleases and subsequent ligation results in the replacement of 12 bp of the original target sequence with 12 bp of the linker scanning oligonucleotide. We have used this protocol to mutagenize a span of approximately 400 bp surrounding the start site of the gene for the beta subunit (rpoB) of Escherichia coli RNA polymerase. The translation of the beta mRNA has been shown previously to be regulated by the intracellular concentration of either beta or beta'. Analysis of the linker scanning mutations indicates that sequences extending a considerable distance both upstream and downstream of the start site are required for normal translation. Also a site that appears to be involved in translational repression by excess beta' has been identified.

Bacteriophage lambda↗
PubMed1996

A set of compatible tac promoter expression vectors.

A series of expression vectors have been developed which all contain an identical expression cassette comprised of the lacIq gene, the tac promoter, a multiple cloning site (MCS) and a downstream transcriptional terminator. This cassette has been inserted into four distinct plasmid backbones, each of which is from a separate incompatibility group and carries a different drug resistance gene. Therefore, different combinations of these expression plasmids can be stably maintained together.

Escherichia coli↗
PubMed1996

A refined vector system for the in vitro construction of single-copy transcriptional or translational fusions to lacZ.

New single-copy vectors based on lambda phage have been developed for creating either transcriptional (operon) or translational (gene) fusions to the lacZ gene. The improvements of these vectors over the previous lambda TL61 vector include: (i) incorporation of a tetracycline-resistance-encoding gene (TcR) to permit direct selection of lysogens, (ii) low-background beta-galactosidase activity, (iii) the ability to accept DNA inserts up to 8 kb in size, and (iv) an expanded multiple cloning site (MCS). The new transcriptional fusion vector retains the RNase III processing site downstream from the MCS which ensures independent translation of lacZ. The set of three translational fusion vectors allow for convenient subcloning in any of the three translational reading frames.

Bacteriophage lambda↗
PubMed1996

Synthesis of the beta and beta' subunits of Escherichia coli RNA polymerase is autogenously regulated in vivo by both transcriptional and translational mechanisms.

Numerous experiments have indicated that the synthesis of RNA polymerase (beta beta' alpha 2 sigma 70) in Escherichia coli is autogenously regulated. In the present study, we have examined expression of the rpoB and rpoC genes which encode the beta and beta' subunits of RNA polymerase. These genes are the distal cistrons of the rplKAJLrpoBC ribosomal protein-RNA polymerase transcription unit. Both transcriptional (operon) and translational (gene) fusions of either rpoB or rpoC to the lacZ reporter were used to monitor their in vivo expression by inserting single copies of these fusions into the bacterial chromosome on integration-proficient lambda vectors. In order to examine the expression of the rpoBC genes in response to varied intracellular concentrations of the RNA polymerase subunits, a series of expression plasmids carrying the rpoB, rpoC, rpoA (alpha) and rpoD (sigma 70) genes in different combinations were then introduced into these cells. Elevated concentrations of either beta or beta' were found to repress the expression of both rpoB and rpoC at the translational level. However, the simultaneous increase in the concentration of all the subunits that comprise holoenzyme repressed the transcription of rpoBC. To determine the site of this repression, additional operon fusions were utilized which placed lacZ downstream of each of the transcriptional regulatory sites of this gene cluster, including two promoters, rplKp and rplJp, and a transcriptional attenuator in the rplL-rpoB intercistronic region. Expression from these fusions showed that transcriptional repression is achieved primarily by reducing initiation at both upstream promoters, coupled with a small increase in termination at the attenuator.

DNA-Directed RNA Polymerases↗
PubMed1994

Does occupational stereotyping still exist?

We surveyed 113 college students regarding their views of certain occupational stereotypes. Our results indicated that in this population gender was related to the subjects' views of occupations as either male, female, or neutral, and that the father's primary occupation significantly affected the subjects' views of only one occupation--clinical sociologist. The mother's occupational seemed to have no effect.

Employment↗
PubMed1990

Improved vector system for constructing transcriptional fusions that ensures independent translation of lacZ.

An improved vector system has been developed for the in vitro construction of transcriptional fusions to lacZ. The principal feature is an RNaseIII cleavage site inserted between the polylinker cloning site and the promoterless lacZ gene. When these vectors are used to construct transcriptional fusions, the subsequent cleavage of the hybrid mRNA at the RNaseIII site generates an unchanging 5' end for the lacZ mRNA. In contrast to earlier vectors, this feature helps to ensure independent translation of the lacZ mRNA and, thus, the level of beta-galactosidase produced should accurately reflect the frequency of transcription of the upstream DNA sequences. Additional modifications of the vectors include removal of a weak transcriptional terminator between the cloning site and lacZ, insertion of a terminator downstream of lac, and alteration of restriction endonuclease cleavage sites to facilitate the in vitro construction of fusions. Both multicopy plasmid (pTL61T) and single-copy lambda (lambda TL61) vectors have been assembled. These vectors should be generally useful in scanning for transcriptional regulatory signals.

Bacteriophage lambda↗
PubMed1986

Report of the 1984 ASHA membership survey.

The results of the most recent American School Health Association (ASHA) membership survey, conducted by ASHA to retain its continuing education units provider status granted in 1981 by the American Nurses' Association are reported. Results of the 1984 survey are compared to two previous surveys, conducted in 1980 and 1982. Topics examined include membership demographics, attendance at national meetings, continuing education needs and preferences, maintaining professional competence, professional issues of importance to readers, and options for improving the usefulness of the Journal of School Health. Several membership trends are discussed and implications for future planning are noted.

Data Collection↗
PubMed1986

Close relationship of the major excreted protein of transformed murine fibroblasts to thiol-dependent cathepsins.

Complementary DNA clones corresponding to 638 nucleotides of the messenger RNA encoding the major portion of murine major excreted protein have been isolated and sequenced. The amino acid sequence of a part of the murine major excreted protein deduced from the DNA sequence reveals substantial and significant homology with the cysteine proteases actinidin, rat cathepsin H, and papain. Since the amount of murine major excreted protein secreted by cultured cells is often enhanced by transformation, it is implicated in oncogenic phenomena and may play a role in the metastatic process by virtue of its proteolytic activity.

Amino Acid Sequence↗
PubMedDate not supplied

A review of lateral ankle ligamentous reconstructions.

We have performed on ongoing retrospective and prospective multi-institutional review of 50 patients who underwent 53 lateral ligamentous reconstructive procedures of the ankle. The point grading system used for postoperative evaluation of our patients allowed for classification of functional activity. The grading system included evaluation of the patient's return to preinjury activities and athletics, degree of pain, degree of swelling, number of recurrent sprains, and any disability that the patient incurred secondary to the tendon transfer. Preoperative and postoperative stress radiographs were obtained to evaluate the talar tilt angle. Of our 53 lateral ankle ligamentous reconstructions, we consider 45 to be excellent, with the patients returning to full activity and athletics. Our results show no statistically significant difference in long-term function among the five ligamentous repairs employed in this series (Pearson Chi-square test; chi 2 = 2.30, df = 4, P = 0.68). No correlation could be made between the long-term clinical response of the various procedures and the postoperative talar tilt angle. We conclude that lateral ligamentous reconstructive repairs of the ankle are indicated, and that good or excellent clinical results, greater than 91%, can be obtained with any of the five reconstructive procedures, performed correctly.

Adolescent↗
PubMedDate not supplied

A four-day workweek. A retrospective evaluation.

Respiratory therapy managers are expected to provide quality patient care while keeping operational expenses at a minimum. One method that has been proposed for achieving this objective is a four-day workweek. Such a system was tried at Samaritan Hospital, Troy, NY, with disappointing results.

Hospital Bed Capacity, 100 to 299↗