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Biomedical subjects

S L McGuire

Publications and source records attributed to S L McGuire.

At least 19 recordsLinked to original sources
PubMed2000

Extragenic suppressors of the nimX2(cdc2) mutation of Aspergillus nidulans affect nuclear division, septation and conidiation.

The Aspergillus nidulans NIMX(CDC2) protein kinase has been shown to be required for both the G(2)/M and G(1)/S transitions, and recent evidence has implicated a role for NIMX(CDC2) in septation and conidiation. While much is understood of its G(2)/M function, little is known about the functions of NIMX(CDC2) during G(1)/S, septation, and conidiophore development. In an attempt to better understand how NIMX(CDC2) is involved in these processes, we have isolated four extragenic suppressors of the A. nidulans nimX2(cdc2) temperature-sensitive mutation. Mutation of these suppressor genes, designated snxA-snxD for suppressor of nimX, affects nuclear division, septation, and conidiation. The cold-sensitive snxA1 mutation leads to arrest of nuclear division during G(1) or early S. snxB1 causes hyperseptation in the hyphae and sensitivity to hydroxyurea, while snxC1 causes septation in the conidiophore stalk and aberrant conidiophore structure. snxD1 leads to slight septation defects and hydroxyurea sensitivity. The additional phenotypes that result from the suppressor mutations provide genetic evidence that NIMX(CDC2) affects septation and conidiation in addition to nuclear division, and cloning and biochemical analysis of these will allow a better understanding of the role of NIMX(CDC2) in these processes.

Aspergillus nidulans↗
PubMed1999

Interaction between developmental and cell cycle regulators is required for morphogenesis in Aspergillus nidulans.

In Aspergillus nidulans, mutation of the transcriptional regulator brlA arrests formation of asexual spore-forming structures called conidiophores but does not hinder vegetative hyphal growth. During conidiophore development a 6-fold, brlA-dependent increase in the kinase activities of NIMX(cdc2) and NIMA occurs. A similar level of kinase induction was promoted by ectopic expression of brlA. Northern and Western analysis revealed marked induction of nimX(cdc2) mRNA after ectopic expression of brlA and increased amounts of NIMX(cdc2). Therefore, nimX(cdc2) is developmentally regulated by brlA indicating a direct role for brlA in the regulation of cell cycle genes. That correct regulation of nimX(cdc2) is important for normal development was further supported by analysis of conidiophore development and septation in cell cycle specific mutants. Most noticeably, the nimX(cdc2AF) mutation promoted inappropriate septation and hindered the switch from filamentous growth to budding growth seen during conidiophore development. Therefore, in contrast to the situation previously reported for other multicellular eukaryotes, interaction between developmental regulators and cell cycle regulators is essential for normal morphogenesis in A.nidulans.

Aspergillus nidulans↗
PubMed1999

Teaching students about nursing and the environment: Part 1--Nursing role and basic curricula.

Since the time of Nightingale, the phenomena of health, person, nursing, and environment have been considered central to nursing. However, of all the concepts, environment appears to have been the least explored, practiced, and researched. Nursing education does not adequately prepare nurses to understand the impact of the environment on health or to implement environmental interventions. This 2-part series is designed to assist faculty in teaching this content. Part 1 provides historical background, the role of nursing, a basic curriculum, and student learning activities.

Curriculum↗
PubMed1999

Teaching students about nursing and the environment: Part 2--Legislation and resources.

This 2-part series is designed to assist faculty in teaching students about the impact of the environment on health. Part 1 (Gerber & McGuire, 1999/this issue) provides historical background, the role of nursing, a basic curriculum, and student learning activities. Part 2 presents national environmental health objectives, pertinent legislation, organization of environmental health services, global environmental health, and student learning activities. We designed the material to be practical, so that this critical area becomes a routine part of assessment data for nurses as they care for clients.

Education, Nursing↗
PubMed1997

Perioperative nurses' guide to the library.

Nurses have a professional responsibility, both morally and ethically, to provide the most current and informed patient care possible. Nurses should maintain competence in nursing, exercise informed judgment, participate in activities that contribute to the ongoing development of their profession's body of knowledge, and participate in their profession's efforts to implement and improve standards of nursing care. Nurses should stay current with new information and share this information with coworkers to help disseminate new knowledge. Such practices help advance both the body of knowledge for perioperative nursing and the profession of nursing. Nurses are encouraged to make at least two visits each year to the library. During this time, they can take the opportunity to review current periodicals, recent publications, do a CINAHL search, and browse the Internet. Nurses need to be familiar with library resources, so go to the library. Share your findings with colleagues and students. Acquire the information-seeking skills that will best serve you and your patients in the twenty-first century.

Catalogs, Library↗
PubMed1995

Distinct ligand binding sites in the I domain of integrin alpha M beta 2 that differentially affect a divalent cation-dependent conformation.

The I domains of the leukocyte beta 2 integrins have been shown to be essential for ligand recognition. Amino acid substitutions of Asp140 and Ser142, which reside in a conserved cluster of oxygenated residues, abrogate divalent cation ligand binding function of alpha M beta 2. Presently, we evaluated the role of two I domain regions in alpha M beta 2 ligand recognition: 1) the conserved cluster of oxygenated residues (Asp134, Asp140, Ser142, and Ser144) and 2) a 7-amino acid region (Phe246-Tyr252), conserved in alpha M and alpha X but absent in alpha L of the beta 2 integrins. Recombinant alpha M beta 2 was expressed on COS-7 cells, and function was assessed by iC3b recognition. Alanine substitution at position Asp140, Asp140/Ser142, Ser142, or Ser144 produced a complete loss in the capacity of alpha M beta 2 to recognize iC3b and attenuated the binding of a divalent cation-dependent epitope recognized by monoclonal antibody 24. Moreover, alanine substitution at Asp248 or Tyr252 or deletion of Phe246-Tyr252 abolished iC3b ligand recognition as well as the binding of a blocking antibody. In contrast, these mutations did not affect the binding of the cation-dependent epitope. These data implicate a second region within the I domain important for alpha M beta 2 ligand binding function and suggest that this region does not affect a divalent cation-dependent conformation of alpha M beta 2.

Amino Acid Sequence↗
PubMed1995

The NIMA protein kinase is hyperphosphorylated and activated downstream of p34cdc2/cyclin B: coordination of two mitosis promoting kinases.

Initiation of mitosis in Aspergillus nidulans requires activation of two protein kinases, p34cdc2/cyclin B and NIMA. Forced expression of NIMA, even when p34cdc2 was inactivated, promoted chromatin condensation. NIMA may therefore directly cause mitotic chromosome condensation. However, the mitosis-promoting function of NIMA is normally under control of p34cdc2/cyclin B as the active G2 form of NIMA is hyperphosphorylated and further activated by p34cdc2/cyclin B when cells initiate mitosis. To see the p34cdc2/cyclin B dependent activation of NIMA, okadaic acid had to be added to isolation buffers to prevent dephosphorylation of NIMA during isolation. Hyperphosphorylated NIMA contained the MPM-2 epitope and, in vitro, phosphorylation of NIMA by p34cdc2/cyclin B generated the MPM-2 epitope, suggesting that NIMA is phosphorylated directly by p34cdc2/cyclin B during mitotic initiation. These two kinases, which are both essential for mitotic initiation, are therefore independently activated as protein kinases during G2. Then, to initiate mitosis, we suggest that each activates the other's mitosis-promoting functions. This ensures that cells coordinately activate p34cdc2/cyclin B and NIMA to initiate mitosis only upon completion of all interphase events. Finally, we show that NIMA is regulated through the cell cycle like cyclin B, as it accumulates during G2 and is degraded only when cells traverse mitosis.

Amino Acid Sequence↗
PubMed1995

Beta 2 (CD18) mutations abolish ligand recognition by I domain integrins LFA-1 (alpha L beta 2, CD11a/CD18) and MAC-1 (alpha M beta 2, CD11b/CD18).

The "I" domains of the beta 2 (CD18) leukocyte integrins are implicated in ligand binding function. Moreover, rather than recognizing linear peptide sequences, this class of integrins generally recognizes multiple discontinuous sites on immunoglobulin superfamily adhesion receptors. A conserved cluster of oxygenated residues is involved in ligand recognition by beta 1 and beta 3 integrins. In the present study, we evaluated the role of this region in the I domain-containing beta 2 integrins. Recombinant alpha L beta 2 (LFA-1, CD11a/CD18) and alpha M beta 2 (MAC-1, CD11b/CD18) were expressed on COS cells, and function was assessed by adhesion to ICAM-1 or iC3b, respectively. Alanine substitution at position Asp134 or Ser136 in beta 2 produced a complete loss in the capacity of both alpha L beta 2 and alpha M beta 2 to support cell adhesion. In contrast, substitution at Asp128 or Ser138 resulted in loss of beta 2 surface expression when co-transfected with alpha L (CD11a) or alpha M (CD11b). These data provide the first evidence for involvement of the beta 2 subunit in ligand binding to I domain integrins.

Amino Acid Sequence↗
PubMed1991

Parallel activation of the NIMA and p34cdc2 cell cycle-regulated protein kinases is required to initiate mitosis in A. nidulans.

We show that in Aspergillus nidulans, p34cdc2 tyrosine dephosphorylation accompanies activation of p34cdc2 as an H1 kinase at mitosis. However, the nimA5 mutation arrests cells in G2 with p34cdc2 tyrosine dephosphorylated and fully active as an H1 kinase. Activation of NIMA is therefore not required for p34cdc2 activation. Furthermore, mutation of nimT, which encodes a protein with 50% similarity to fission yeast cdc25, causes a G2 arrest and prevents tyrosine dephosphorylation of p34cdc2 but does not prevent full activation of the NIMA protein kinase. Mitotic activation of p34cdc2 by tyrosine dephosphorylation is therefore not required for activation of NIMA. These data suggest that activation of either the p34cdc2 protein kinase or the NIMA protein kinase alone is not sufficient to initiate mitosis. Parallel activation of both cell cycle-regulated protein kinases is required to trigger mitosis.

Aspergillus nidulans↗
PubMed1987

Aging education in schools.

Aging is a natural and lifelong process that begins at the moment of conception. If Americans are to adapt successfully to their own and others aging, they need to be educated to do so. Schools are the logical place for aging education to begin. Aging education has the potential for an exciting and rewarding future as it can increase the quality of life not only for future elderly, but for today's elderly as well. Education professionals need to be aware of the need for aging education and to advocate its integration into school curricula. In this article, the author presents an overview of aging education and identifies resources to help implement aging education in schools.

Aging↗
PubMedDate not supplied

Keeping current: ten important information resources to help rehabilitation nurses.

Rehabilitation nurses have a professional responsibility to provide the most current and informed client care possible. As a result, they must keep up with the emerging healthcare delivery system of the 21st century. This article describes how nurses can get access to and use 10 information resources--namely, journals, books, pamphlets, indexes and on-line databases, conferences, continuing education, professional organizations, standards of practice of interest to nurses in rehabilitation nursing, and networking.

Computer Communication Networks↗