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Biomedical subjects

S Payne

Publications and source records attributed to S Payne.

At least 91 records · Page 5Linked to original sources
PubMed1995

REM sleep deprivation alters dopamine D2 receptor binding in the rat frontal cortex.

REM sleep deprivation (RSD) of rats results in facilitation of dopaminergic behavior and an increase in striatal D2 receptor density. To determine whether RSD results in changes in D2 receptor in other brain regions, receptor affinity (Kd) and density (Bmax) were measured in the anteromediofrontal (AM), cingulate (CN), and sulcal cortex (SL) in four groups of rats: 1), RSD96 group (RSD for 96 h; small pedestal/water tank method), 2) RSD24 group (large pedestals for 72 h then small pedestals for 24 h), 3) tank control group (TC; large pedestals for 96 h), and 4) cage control group. In separate groups, ambulation was recorded for 30 min following treatments. Group RSD96 showed an increase in activity compared to TC, and TC was increased compared to CC (p < 0.05 for all). In group RSD24, the AM showed an increase in Bmax and Kd (p < 0.05), but there were no effects by RSD96. In the CN, Bmax and Kd were decreased by RSD96 (p < 0.05) but not RSD24. In the SL, Bmax was increased by RSD96, but not RSD24, whereas Kd was increased in both RSD groups (p < 0.05).

Animals↗
PubMed1995

A selective review of the literature on nurse-patient communication: has the patient's contribution been neglected?

The literature on nurse-patient communication is selectively reviewed. Previous research has been critical of the quality and quantity of nurse-patient communication, describing it as brief and superficial. Nurses are depicted as controlling and restricting the course and topics of conversations with patients. Communication skills training for nurses has been advocated as a solution for this apparent deficit. In this paper it is argued that research has over-emphasized nurses' roles in nurse-patient communication, particularly their communication skills. The patients' contribution to the content and organization skills. The patients' contribution to the content and organization of nurse-patient communication has been largely ignored. Assumptions have been made about nurses' and patients' intentions and motives during nurse-patient conversations, but the participants, particularly patients, are rarely asked for their views. There has been a tendency to view nurse-patient communication in terms of isolated excerpts of conversation. When environmental and organizational factors are included, it is their effect on nurses' communication capability, not the patients', that are the interest. It is suggested that future research consider both patients' and nurses' contributions to nurse-patient communication.

Attitude to Health↗
PubMed1995

Attitudinal survey of adverse drug reaction reporting by medical practitioners in the United Kingdom.

1. Attitudes of doctors to the Committee on Safety of Medicines' (CSM) adverse drug reaction (ADR) reporting scheme were investigated in order to assess their understanding of the purposes of the scheme and to identify reasons for failing to report suspected adverse drug reactions. 2. A postal questionnaire and letter of invitation were sent to 500 doctors who were randomly selected from the 1992 Medical Directory. A reminder letter and a second copy of the questionnaire were sent to non-responders after 4 weeks. 3. 284 (57%) responded to the questionnaire. Of these, 179 (63%) stated that they had previously reported an ADR to the CSM or a pharmaceutical manufacturer. 77% of general practitioners stated that they had reported one or more ADRs compared with 55% of hospital doctors. 4. Reasons for under-reporting included lack of time, lack of report forms and the misconception that absolute confidence in the diagnosis of an adverse reaction was important in the decision to send in a report. 5. An investigation of seven commonly proposed reasons for under-reporting showed that on the whole they did not apply. 6. Most doctors knew the types of reactions that the Committee on Safety of Medicines seeks reports for but only 38% knew the precise meaning of the Committee on Safety of Medicines' black triangle symbol. There also seemed to be confusion about some of the purposes of the adverse drug reaction reporting scheme. 7. The number of reporting doctors is much higher than has previously been estimated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adverse Drug Reaction Reporting Systems↗
PubMed1995

Aetiopathogenesis and management of impotence in diabetic males: four years experience from a combined clinic.

The contribution of organic and psychogenic factors in the aetiopathogenesis of impotence was studied in a large number of diabetic males, to develop an algorithm for its management. We examined 110 consecutive patients who were referred to the Impotence Clinic of the Diabetes Centre. All patients were initially evaluated by a diabetologist and then underwent psychosexual assessment by a specialized psychiatrist. Patients with primarily organic disease were referred to a urologist for further management while those with psychogenic impotence received psychosexual counselling. Peripheral neuropathy was present in 71 (65%) and two or more autonomic tests were abnormal in 22 (20%) patients. Neuropathy was the only cause detected in 29 (27%) patients, the main cause in 22 (20%), and contributing, but not the main factor, in 20 (18%). Psychogenic factors were the only cause detected in 12 (11%) patients, the main cause in 26 (24%) and contributed in 19 (17%). Marital disharmony, medical treatment, and peripheral vascular disease were the main aetiopathogenic factors in the remaining cases. Psychosexual counselling resulted in successful intercourse in 17 (60%) out of the 24 treated patients and papaverine injections in 31 (61%) out of 56 treated patients. It is concluded that although organic factors are mainly responsible for the development of impotence in diabetic males, psychological factors contribute significantly and psychosexual assessment and counselling are essential adjuncts to its management. Treatment with papaverine injections is generally inexpensive and effective to overcome the multifactorial causes of erectile dysfunction in this population. An algorithm which may facilitate the investigation and treatment of impotent diabetic males is proposed.

Adult↗
PubMed1994

Weak carcinogenicity of 2-hydroxyethyl carbamate in strain A mice: indication that this is not a proximal metabolite of ethyl carbamate.

Ethyl carbamate (EC, urethan) is carcinogenic probably because it is converted in vivo to vinyl carbamate and then to vinyl carbamate epoxide, which reacts with DNA bases. We hypothesized that vinyl carbamate arises from EC by oxidation to 2-hydroxy-EC (HEC) and dehydration of the HEC, rather than by direct dehydrogenation of EC. In that case, HEC should be more carcinogenic than EC. In a previous test, HEC showed only borderline initiating activity for mouse skin, but its synthesis was poorly described. In the present study, HEC was synthesized by reacting ethylene carbonate with ammonia and was characterized. A single dose of HEC or EC in saline was injected i.p. into adult male strain A mice, which were maintained for 16 weeks. HEC doses of 1.12, 4.6 and 11.2 mmol/kg induced 0.16, 0.32 and 0.32 lung adenomas/mouse, respectively. The 28% tumor incidence for the two highest doses was significantly (P < 0.05) greater than that in controls injected with saline alone. The number of tumors/mouse with 4.6 mmol HEC/kg was one-fortieth of that for an equimolar dose of EC. The weak activity of HEC supports the view that HEC is not a proximal carcinogenic metabolite of EC, i.e. that vinyl carbamate is produced directly from EC.

Animals↗
PubMed1994

Recovery of T cell populations after acute graft-vs-host reaction.

We previously have observed that T dependent immune functions were deficient for several months after induction of acute suppressive graft-vs-host-reaction (GVHR) by injection of parental C57BL/10 donor spleen cells into unirradiated (B10 x B10.BR) F, hosts. We therefore investigated whether new T cells matured after acute GVHR, and whether these were tolerant of host Ag. By 8 to 17 mo after GVHR, the frequencies of splenic CD4 and CD8 T cells were found to be comparable to age-matched untreated hosts, although the lymphoid organ size and hence the total number of T cells was significantly reduced. When GVHR was induced with a combination of C57BL/6 (Thy-1.2) mature lymphocytes and B6.PL (Thy-1.1) bone marrow stem cells, the mature donor Thy-1.2 T cells initially predominated during the acute GVHR. After several months, however, 75% of the CD4 and 50% of the CD8 T cell population was derived from donor Thy-1.1% pre-T cells that had matured in the host. Long term GVHR spleen cells were unresponsive to host Ag in CTL assays, but did not suppress anti-host CTL responses. Finally, host-reactive V beta 11 TCR expressing cells were found to be clonally deleted from splenic CD4 and CD8 populations, consistent with intrathymic negative selection. This evidence suggests that the post-GVHR thymus has the capacity to produce and negatively select phenotypically mature CD4 and CD8 T cells and that a failure to clonally delete self-reactive populations is not a contributing factor to the development of chronic GVHR in this system.

Animals↗
PubMed1994

Chronic nicotine reverses age-associated increases in tail-flick latency and anxiety in rats.

The chronic consumption of low doses of nicotine in drinking water for two years consistently increased the sensitivity of rats to a nociceptive thermal stimulus (tail-flick test), but reduced aversiveness in the elevated plus-maze test, relative to the responses of age-matched controls in these tests. The responses of aged nicotine-consuming rats were indistinguishable from those of young adult rats that did not receive nicotine. To determine whether these effects were due to a nicotine-induced retardation of age-related changes, young adult rats were similarly treated with nicotine for three months and similar changes in the tail-flick latency and performance in the plus-maze test were observed during nicotine consumption. These changes were reversed following withdrawal from nicotine. It is concluded that the maintenance of circulating low levels of nicotine (and/or its metabolites) increased the nociceptive sensitivity of the rats and reduced their aversions in the plus-maze test regardless of their age.

Aging↗
PubMed1994

Stress-related behavior and central norepinephrine concentrations in the REM sleep-deprived rat.

Rapid eye movement sleep deprivation (REMd) is a potent stressor in the rat. Behavioral abnormalities are among the earliest overt symptoms of REMd, the mechanisms for which remain largely unknown. The phenomena of hyperphagia and weight loss that are associated with REMd may contribute to its later morbidity; however, little is known about the onset of these phenomena or the neurotransmitter mechanisms that are involved. The aim of this study was to determine whether the earliest effects of REMd on consumatory behavior in the rat and its performance in the swimming cylinder of Porsolt are related to changes in norepinephrine (NE) concentrations in the cerebral cortex and selected areas of the hypothalamus. Sprague-Dawley rats were divided into three groups (n = 6): the REMd group resided in a water tank on 6.5-cm diameter pedestals for 96 h; the tank control (TC) group resided in the water tank on 15-cm pedestals for 96 h; the cage controls (CC) remained in their home cages for the duration of the study. In the first series of experiments, body weights and caloric intake were recorded daily, along with the performance of all animals in the swimming cylinder of Porsolt. In the second series of experiments, body weights and caloric intake were recorded, but the Porsolt test was not employed and the brains were dissected after 96 h for NE analysis by HPLC. It was observed that the REMd group had lower immobility times (p < 0.05) in the Porsolt test after only 24 h, compared to groups TC and CC.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

The assessment of need for bereavement follow-up in palliative and hospice care.

This paper describes a postal survey of palliative care services and teams which were identified in the 1992 Directory of Hospice Services in the UK and Ireland. Its aims were to investigate how units assess the need for bereavement follow-up, and to determine the nature and extent of services provided for bereaved adults. We sent out 397 questionnaires, of which 187 were returned, a response rate of 47%. Results indicate that 156 respondents (84%) provided follow-up and a further 13 (7%) were planning bereavement services. Only 48 (25%) units undertook formal standardized risk assessment procedures to allocate appropriate services; in 41 units (85%) this was done by a nurse. Of the remaining 125 units, 58 (46%) reported basing their decisions on clinical impressions. Content analysis of the formal assessment instruments revealed 39 subcategories, which were broadly grouped into three areas: circumstantial factors at or near to the time of death, personal factors and social factors. Recommendations are made for further study.

Bereavement↗
PubMed1993

Molecular cloning and expression of the ovine testicular follicle stimulating hormone receptor.

A sheep testicular cDNA library constructed in pcDNA1 vector was screened with a probe generated by polymerase chain reaction (PCR) and corresponding to a 1.6 kb fragment of the rat luteinizing hormone receptor cDNA. Several clones hybridizing to the rat probe at low stringency were sequenced to obtain 95% of the putative full-length ovine follicle-stimulating hormone receptor (oFSH-R) cDNA. The missing 5' region was obtained by PCR amplification of the cDNA library. Sequencing revealed a 2085 nucleotide open reading frame encoding a mature protein of 678 amino acids (74,580 daltons). The oFSH-R is remarkably similar (> 90%) to the human and rat FSH receptors, has a structural motif like the G protein-coupled family of receptors and contains 3 potential sites for N-linked glycosylation. RNA blot analysis revealed two major transcripts of 2.6 kb and 6.7 kb in size and a smaller transcript of about 1 kb in the sheep testis. A 53 residue segment in the extracellular domain unique to the receptor contains more than 50% of residues bearing functional side chains that could participate in ligand (FSH) interaction and/or signal transduction. Transfection of human fetal kidney cell line (293) with the cloned oFSH receptor cDNA based in pcDNA1/Neo vector revealed functional expression. Labeled oFSH bound to receptor expressed on the membrane with high affinity and specificity. In stably transfected 293 cells, purified oFSH and hFSH but not oLH stimulated cyclic AMP accumulation. Chemically deglycosylated oFSH (DG-oFSH) was inactive in these cells but it effectively blocked the action of native hormone.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1993

Constraints for nursing in developing a framework for cancer care research.

Oncology nursing has become an important and popular specialist area of care. Evidence indicates that there is a disappointingly low level of funded research. This paper seeks to identify some of the key constraints which have inhibited the development of cancer nursing research. It is proposed that there are two priorities to promoting research. First, there is a need to produce the next generation of research trained cancer nurses. Secondly, the need for a coordinated programme of basic and applied cancer nursing research. This paper discusses the difficulties of obtaining research funding and adequate supervision for higher degrees. In addition, key constraints in clinical nursing and nurse education are identified. In conclusion, it is proposed that there is an urgent need for specific cancer-care research funded studentships and the establishment of a coordinated programme of research.

Education, Nursing, Graduate↗
PubMed1992

The preparation of intermediates for the synthesis of 1D-myo-inositol 1,4,5-trisphosphate, a second messenger for signal transduction in cells.

Racemic 1,2,4-tri-O-benzyl-5,6-O-isopropylidene-myo-inositol was prepared by a new route involving crotyl (but-2-enyl) ethers and converted into the (-)-omega-camphanates to give the pure crystalline 1L-diastereoisomer and the chirally impure, syrupy 1D-diastereoisomer. The latter was converted via the 1-O-allyl or 1-O-p-methoxybenzyl ethers into chirally pure 1D-2,3,6-tri-O-benzyl-myo-inositol [required as an intermediate for the synthesis of 1D-myo-inositol 1,4,5-trisphosphate (1,4,5-IP3)], which was also prepared by de-p-methoxybenzylation of 1D-2,3,6-tri-O-benzyl-1,5-di-O-p-methoxybenzyl-myo-inositol. Racemic 2,4-di-O-benzyl-5,6-O-isopropylidene-1-O-p-methoxybenzyl-myo-inositol was prepared in a similar way to the analogous tribenzyl ether (using crotyl ethers) and the omega-camphanate esters behaved similarly, allowing efficient resolution by crystallisation of the (-)- and (+)-omega-camphanates. Racemic 1,2,4-tri-O-allyl-3-O-(but-2-enyl)-myo-inositol was resolved via the (-)-omega-camphanates and was also converted into 1,2,4-tri-O-(cis-prop-1-enyl)-myo-inositol, an alternative intermediate for the synthesis of 1,4,5-IP3.

Animals↗
PubMed1992

The preparation and phosphorylation of 2,5- and 1D-2,6-di-O-benzyl-myo-inositol.

1,3,4,6-Tetra-O-allyl-myo-inositol was converted into the 2,5-di-O-benzyl- and 2,5-di-O-p-methoxybenzyl ethers, and the products were deallylated to give the 2,5-di-O-benzyl (and p-methoxybenzyl) ethers of myo-inositol, which were converted into the mono-O-isopropylidene derivatives. Both the 2,5-di-O-benzyl ether and its mono-O-isopropylidene derivative were converted into the crystalline octa(2-cyanoethyl) ester of 2,5-di-O-benzyl-myo-inositol 1,3,4,6-tetrakisphosphate. (+-)-1,3,4,5-Tetra-O-allyl-myo-inositol was converted into (+-)-2,4-di-O-benzyl-myo-inositol which gave a separable mixture of the 1,6- and 5,6-O-isopropylidene derivatives. The 1,6-O-isopropylidene derivative was resolved via (-)- and (+)-omega-camphanates and was also converted into (+-)-2,6-di-O-benzyl-1,5-di-O-p-methoxybenzyl-myo-inositol, which was resolved via the (-)-omega-camphanates. The 5,6-O-isopropylidene derivative and 1,3-di-O-allyl-myo-inositol were converted into (+-)-1,3-di-O-allyl-2,6-di-O-benzyl-myo-inositol, which was resolved as the (-)-omega-camphanates. 1D-1,3,4,5-Tetra-O-allyl-myo-inositol and the above described, relevant diaste reoisomers were converted into 1D-2,6-di-O-benzyl-myo-inositol which gave the syrupy octabenzyl ester of 1D-2,6-di-O-benzyl-myo-inositol 1,3,4,5-tetrakisphosphate.

Benzyl Compounds↗
PubMed1992

Meningococcal disease in Wales: clinical features, outcome and public health management.

In Wales, in 1988, 119 patients with meningococcal disease were identified, so giving a crude annual incidence of 4.2 patients per 100,000 population. The combined classical clinical features of fever, vomiting, neck stiffness, headache and purpuric rash were identified in only 9% of patients. Fever and vomiting were the commonest symptoms, both being present in 60% of patients. A rash was noted in 77% of patients but neck stiffness in only 39%. Rash was more common in children, headache and photophobia in adults. A total of 13 patients died, the fatality rare increasing with age from 3% in infants to 20% in older teenagers and adults. Only 15% of 75 patients admitted to hospital by general practitioners were known to have received intravenous or intramuscular penicillin before admission as recommended by the Chief Medical Officers of the Health Departments in the U.K. Only 24% of patients received rifampicin to clear nasopharyngeal carriage before or at discharge from hospital. Altogether, 375 household contacts of patients were identified. At least 84% of them received chemoprophylaxis.

Acute Disease↗
PubMed1991

Repopulation of host lymphohematopoietic systems by donor cells during graft-versus-host reaction in unirradiated adult F1 mice injected with parental lymphocytes.

The graft-vs-host reaction (GVHR) generated by the injection of parental lymphocytes into unirradiated immune-competent F1 hosts is characterized by an acute loss of immune functions, an attack on host tissues, and a gradual recovery of function. Flow cytometric analysis of the donor- and host-derived splenic populations during the course of acute dysfunction and gradual recovery revealed a complex pattern of changes in lymphoid and myeloid populations that resulted in the repopulation of the host with donor-derived cells. Initially, donor-derived T cell populations expanded, particularly CD8+ T cells. Next, host T cell and B cell populations disappeared. Finally, donor-derived cells repopulated the lymphohematopoietic system in the sequence myeloid populations, B cells, and, after a protracted period, T cells. The recovery of immune functions following GVHR-induced immune deficiency was associated with this repopulation of the spleen by donor-derived cells. Donor repopulation of the host lymphohematopoietic system required the presence of both CD4 and CD8 cells in the original donor inoculum. Depletion of donor CD4 populations precluded development of GVHR or any donor engraftment; depletion of CD8 cells resulted in engraftment solely of donor CD4 populations.

Animals↗