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M Phipps

Publications and source records attributed to M Phipps.

8 recordsLinked to original sources
PubMed1997

How the neighborhood coherence principle (NCP) can give rise to tissue homeostasis: a cellular automaton approach.

Gap junctional intercellular communication (GJIC) might provide a key mechanism for tissue homeostasis. Using a three-dimensional cellular automaton, a model was designed to probe the capacity of the particular cell-cell interaction rule known as the neighborhood coherence principle (NCP) to produce a control mechanism whereby a cell would be told by its neighbors whether or not to enter a division cycle. A numerical experiment using this model showed that a potent feedback control maintaining a local balance between mitoses, cell differentiation, and death emerged from the sequence of cell growth and maturation events. This regulation stemmed from the interplay of the juvenile and the senescent fractions of a tissue. The regulatory loops shows a variable periodicity which depends on the proportion of daughter cells that take the shortcut to re-enter a division cycle immediately. A distinctive tissue patchiness, an intrinsic feature of systems endowed with the NCP interaction rule, constitutes a predictable feature of real cell systems and allows the formulation of empirically testable hypotheses about the role of GJIC in growth regulation.

Animals↗
PubMed1996

Learning from patients: a discharge planning improvement project.

BACKGROUND: In 1991 Beth Israel Hospital (Boston) joined nine other hospitals in using the Picker/Commonwealth survey instrument to tap patients perceptions of their hospitalization experience. Beth Israel focused on one of the nine dimensions of the instrument-continuity and transition (discharge planning). FOUR WORK TEAMS: In 1992 four multidisciplinary work teams were formed-for cardiac surgical patients, stroke patients, patients on a medical unit, and patients on a medical and surgical unit. Each team conducted a patient/family discussion group, during which recently discharged patients and their families were asked about their preparation for discharge and asked for input on how to improve the process. INTERVENTIONS: Each work team developed interventions on the basis of information specific to their patients. The cardiac work team, for example, developed interdisciplinary practice guidelines for patient care management for the entire postoperative period; the guidelines include a patient education component on what patients and families can expect during hospitalization. OUTCOMES: Clinicians practice differently, inviting more patient feedback and other involvement in care, as a results of their involvement in the project. On the first annual patient survey, administered in 1994, only 6% of 1,179 randomly selected patients (versus 20% of the 100 patients first surveyed in 1993) indicated that they did not receive the information they needed to help themselves recover. CURRENT PROGRESS AND FUTURE DIRECTIONS: A standardized teaching packet containing material developed during the discharge planning improvement project is now distributed. In May 1995 the nursing department launched a patient and family learning center to better meet the health education needs of patients.

Aftercare↗
PubMed1995

Possible virulence factors involved in bacteraemia caused by Aeromonas hydrophila.

Eighteen strains of Aeromonas hydrophila from patients with bacteraemia were investigated for possible virulence factors. Cytotoxin and haemolysin were produced by all strains, whereas cholera toxin-like factor was produced by 33% of strains only. Enterotoxin production was not detected. Haemagglutination of guinea-pig, fowl and rabbit erythrocytes was demonstrated by 83%, 67% and 61% of strains, respectively. Fucose- and mannose-sensitive haemagglutinins were predominant. None of the strains agglutinated sheep erythrocytes. Extrachromosomal DNA was detected in 17 strains, 16 of which had a plasmid (3.6-5.1 MDa), the majority being between 4.6 and 5.1 MDa.

Adolescent↗
PubMed1991

Plasmid incidence rate and conjugative chloramphenicol and tetracycline resistance plasmids in Malaysian isolates of Salmonella typhi.

Seven (6.1%) of 115 strains of Salmonella typhi isolated from Malaysian patients harbored a single large plasmid of 71 to 166 mD. Two of the seven plasmid-bearing strains were resistant to chloramphenicol (Cm) and tetracycline (Tc) and they transferred Cm and Tc resistance traits to Escherichia coli K12 at frequencies from 1.6 x 10(-7) to 1.9 x 10(-6). Agarose gel electrophoresis provided evidence that the resistance traits were cotransferred on a conjugative plasmid. The significance and importance of these results are discussed.

Chloramphenicol Resistance↗
PubMed1990

Carcinogenic implications of the neighborhood coherence principle (NCP).

A new hypothesis on carcinogenesis is set forth on the basis of the neighborhood coherence principle (NCP). NCP constitutes a general rule of pattern formation and maintenance. According to this principle, a system of interacting cells can produce and maintain a spatial organization by virtue of cell-cell communication. This hypothesis suggests that this homeostasis primarily results from a NCP-like process implying cell-cell communication. Each cell is constrained by its neighbors to maintain the mature phenotype despite its inherent individual variability. If the cell-cell mature communication happens to be impaired, tissue homeostasis is disrupted and a proliferative state can be initiated. A further potential effect may result from the establishment of NCP-like communication specific for proliferative cells allied to paracrine and outocrine factors which can lock the cells into the proliferative mode. Most mechanisms implied in this hypothesis have already been investigated. There is a large body of experimental results supporting the role of junctional communication in cooperative metabolism, growth, differentiation and tumour-related events. This new hypothesis provides a framework within which these known facts may be put in a theoretical perspective; it might well constitute the unifying theory--as yet missing--in carcinogenesis.

Animals↗