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Biomedical subjects

P Yates

Publications and source records attributed to P Yates.

84 records · Page 5Linked to original sources
PubMed1984

A model study of fecapentaenes: mutagens of bacterial origin with alkylating properties.

Fecapentaene-14 and -12 are directly acting mutagens that do not require metabolic activation. Their unusual structure suggests a possible mechanism of action. A carbocation that is formed by the addition of an electrophilic species (such as a proton) to the enol ether is most probably the reactive species. A series of model enol ethers with conjugated systems of various lengths was prepared, and a correlation between mutagenicity and increasing reactivity of derived carbocations was found. The glycerol moiety does not play a crucial role in the overall reactivity of the fecapentaenes.

Alkylating Agents↗
PubMed1970

Effet of prostaglandin E1 alone and in combination with theophylline or aspirin on collagen-induced platelet aggregation and on platelet nucleotides including adenosine 3':5'-cyclic monophosphate.

1. Human platelet nucleotides were labelled by incubating platelet-rich plasma with [U-(14)C]adenine. With such platelets, the effects of prostaglandin E1, theophylline and aspirin were determined on collagen-induced platelet aggregation and release of platelet ATP and ADP. Intracellular changes of platelet radioactive nucleotides, particularly 3':5'-cyclic AMP, were also determined both with and without collagen treatment. 2. Prostaglandin E1, theophylline and aspirin inhibited collagen-induced aggregation of platelets in a dose-dependent manner. Collagen-induced release of ATP and ADP and breakdown of radioactive ATP were also inhibited in a dose-dependent manner. 3. Prostaglandin E1 stimulated the formation of platelet radioactive 3':5'-cyclic AMP in a dose-dependent manner. With a given dose of prostaglandin E1, maximum formation of radioactive 3':5'-cyclic AMP occurred by 10-30s and thereafter the concentrations declined. The degree of inhibition of aggregation produced by prostaglandin E1, however, increased with its time of incubation in platelet-rich plasma before addition of collagen, so that there was an inverse relationship between the radioactive 3':5'-cyclic AMP concentration measured at the time of collagen addition and the subsequent degree of inhibition of aggregation obtained. 4. Neither theophylline nor aspirin at a concentration in platelet-rich plasma of 1.7mm altered platelet radioactive 3':5'-cyclic AMP contents. In the presence of prostaglandin E1, theophylline increased the concentration of radioactive 3':5'-cyclic AMP over that noted with prostaglandin E1 alone, but aspirin did not. 5. Mixtures of prostaglandin E1 and theophylline had a synergistic effect on inhibition of platelet aggregation. The same was true to a lesser extent with mixtures of prostaglandin E1 and aspirin. Such mixtures also inhibited collagen-induced release of platelet ATP and ADP and breakdown of platelet radioactive ATP. 6. Certain concentrations of either theophylline or aspirin and mixtures of small concentrations of prostaglandin E1 with either theophylline or aspirin caused little or no increase of radioactive 3':5'-cyclic AMP at the time of collagen addition, but inhibited aggregation to a marked degree, whereas higher concentrations of prostaglandin E1 alone caused a much greater increase of radioactive 3':5'-cyclic AMP at the time of collagen addition but inhibited aggregation to a lesser extent. With these compounds there does not appear to be a correlation between these parameters.

Adenine Nucleotides↗
PubMedDate not supplied

Factors influencing nurses' decisions to use non-pharmacological therapies to manage patients' pain.

This study investigated nurses' beliefs and attitudes toward the use of non-pharmacological therapies as adjunct pain management strategies. Registered nurses (RNs) (n=37) from the medical, surgical, oncology/palliative care and critical care areas of two Australian hospitals participated in a series of focus group discussions that explored the use of non-pharmacological therapies to help manage patients' pain in a hospital setting. Results from the discussions identified that nurses believe non-pharmacological therapies offer several advantages to the management of patients' pain and general well being. For example non-pharmacological therapies were recognised to be useful as adjuncts while waiting for medications to take effect. However significant barriers such as lack of organisational and professional support were also identified as hindering nurses' current usage of non-pharmacological therapies. Further investigation of the key issues from this study is recommended to improve non-pharmacological pain management and enhance patient outcomes.

Attitude of Health Personnel↗
PubMedDate not supplied

Families' awareness of and response to dying.

PURPOSE/OBJECTIVES: To explore how family care-givers develop and respond to an awareness that their relative is dying. DESIGN: Qualitative, interpretive. SETTINGS: Four major providers of cancer services in Brisbane, Australia, including a hospital, hospice, homecare nursing service, and oncologist's office. SAMPLE: 20 recently bereaved adult family caregivers (mean age = 48.5): 11 females, 9 males--16 spouses, 2 daughters, and 2 mothers of adults. METHODS: Semistructured interviews transcribed verbatim and content analyzed. MAIN RESEARCH VARIABLE: Developing and responding to an awareness of dying. FINDINGS: Five major themes emerged from the analysis. Two core categories, Being Uncertain and Agonizing, depict the emotional struggles that characterize the process of developing an awareness of dying. Three additional categories-Hoping, Pretending, and Preparing-represent strategies used by family caregivers to manage these emotional struggles. CONCLUSIONS: Developing an awareness of dying is a gradual process for family caregivers. Uncertainty and anguish characterize this process. Several factors contribute to this uncertainty and agony, including interactions with healthcare providers. Family caregivers attempt to manage this developing awareness by hoping, pretending, and preparing for death. IMPLICATIONS FOR NURSING PRACTICE: Nurses need to identify processes to ensure that family caregivers' needs for information and support are given high priority and that supportive interventions identified are based on a sensitive understanding of the experience of the family caregiver. The processes may include assisting family caregivers to maintain hope, sustain social relationships, and make preparations for the death. Further research into how family caregivers use these strategies for managing their developing awareness of dying is required.

Adult↗