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Biomedical subjects

C Poole

Publications and source records attributed to C Poole.

At least 73 records · Page 4Linked to original sources
PubMed1989

Proviral position effects: possible probes for genes that suppress transcription.

Rous sarcoma virus, an oncogenic avian retrovirus, readily causes morphological transformation of chick cells, but in infected rat cells transformation is rare because proviral transcription is inefficient. This constraint is not due to a lack of positive transcriptional factors, or an excess of negative ones, but reflects the site of proviral integration in rat cell DNA. In most sites the provirus is almost invariably silent, in others it is correspondingly active, whilst in a third category expression fluctuates in concert with transitions in chromatin structure. Transcriptional fluctuations are mediated both by flanking cell DNA in cis and by trans-acting cell genes, suggesting that proviral position effects are sensors for genes that down-regulate transcription, perhaps by determining chromatin configuration. We have tried to identify such genes by gene transfer, karyology and insertional mutagenesis. The variable success of these three approaches indicates that the transcriptional down-regulator(s) need act only transiently. This is consistent with a function that operates in ontogeny or differentiation to down-regulate genes whose silence is then perpetuated by other means. The loss of such functions may predispose to neoplasia.

Animals↗
PubMed1988

A strengthening programme for weak associations.

The strength of a causal association depends on the relative prevalence of other component causes for the same disease. Weak associations may sometimes be strengthened by restricting attention to people at low risk. This technique may lead to fewer subjects to study, but nevertheless may provide more information by which to evaluate a causal relation. A second method for strengthening associations is to reduce non-differential misclassification, which tends to dilute associations. Increasing the specificity of measurement for exposure, disease, and the timing between causal action and disease onset should produce stronger associations that are easier to interpret and more descriptive of the underlying causal mechanism.

Epidemiologic Methods↗
PubMed1988

Invariants and noninvariants in the concept of interdependent effects.

In two of his publications [Causal and preventive interdependence: Elementary principles. Scand J Work Environ Health 8 (1982) 159-168 and Theoretical Epidemiology, John Wiley & Sons, New York, NY 1985], Miettinen put forth basic definitions of causal and preventive interdependence of effects involving binary exposure indicators and outcomes. This paper shows that the identification of interdependence using Miettinen's definitions varies with the choice of the reference categories for the exposures. In particular, Miettinen's concepts of synergism and antagonism are not invariant under exposure recoding. It is also shown that, when both exposures affect risk in some individuals, the effects will appear interdependent under some choice of referent. In the deterministic case, invariant properties of joint effects may be identified through the formation of equivalence classes of response types. In the stochastic case, invariant properties may be identified through the averaging of individual hazards, rather than risks. In both cases, additivity of risk or rate differences emerges as an elementary criterion for the independence of effects.

Epidemiologic Methods↗
PubMed1988

The marketing audit: a new perspective on library services and products.

A marketing audit enables a library to look at audiences, services, and products with a structured approach. The audit can be used to assess operations and to provide a framework for ongoing decision making, evaluation, and long-range planning. An approach to the audit process is presented and its application is demonstrated in a case study featuring the American Hospital Association Resource Center.

American Hospital Association↗
PubMed1987

Adolescent pregnancy and unfinished developmental tasks of childhood.

Adolescent pregnancy may occur when developmental needs have not been met adequately during earlier childhood stages. Reasons adolescents give for becoming pregnant may indicate which developmental needs were not met. Once developmental needs have been identified, professionals can help the adolescent and her child by tailoring interventions to fill gaps that occurred during earlier stages of development. This article explores the potential relationship between adolescent pregnancy and unfinished developmental tasks of childhood. Implications for intervention are addressed.

Adolescent↗
PubMed1986

Toxic shock syndrome, contraceptive methods, and vaginitis.

To elucidate further the etiology of toxic shock syndrome, we assessed the effects of certain contraceptive methods and recent history of vaginal infection on the incidence of toxic shock syndrome, with confounding effects of other risk factors controlled. We found a strong but imprecise positive association between toxic shock syndrome and tubal ligation (rate ratio = 7.9, 90% confidence interval 1.4 to 42.7). We also observed a negative association with oral contraceptives (rate ratio = 0.49, 90% confidence interval 0.22 to 1.1) and a positive association with a recent history of vaginitis (rate ratio = 2.1, 90% confidence interval 1.2 to 3.9).

Contraceptive Devices, Female↗
PubMed1986

Allergic reaction to sulfiting agents.

Sodium metabisulfite (MBS) is a commonly used food and drug preservative. We report the case of a 32-year-old man with a documented history of allergy to MBS who developed an anaphylactic reaction after ingestion of MBS-treated foods. The patient had a prolonged clinical course requiring two emergency department visits and three weeks of outpatient steroid therapy. It is believed that this patient's relapse and delayed recovery may have been related to his continued exposure to sulfites during treatment. The emergency physician should be aware that some medications commonly used to treat allergic reactions and asthma contain MBS.

Adult↗