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Biomedical subjects

S Edwards

Publications and source records attributed to S Edwards.

At least 73 records · Page 4Linked to original sources

Chronic systemic administration of 5-HT produces weight loss in mature adult male rats.

Adult male rats were allowed to free-feed until their body weights had stabilised. They were next trained onto a 4 h per day feeding regimen, until further stabilisation occurred. All rats then received saline injections for 5 days, to establish baseline body weights. One group was then injected with 5.0 mg/kg 5-HT daily for 30 days while the other group continued with saline. Progressive and significant weight loss occurred in the drug-treated animals. After 30 days, the 5-HT-treated rats had lost 7.0% of their baseline body weights, whereas the control group had gained 1.3%. At this point, the 5-HT treated rats were switched back to saline injections to investigate rebound effects. Although the group that had received 5-HT treatment showed evidence of rebound weight gain, mean weights at the end of the 10 day rebound period were still 4.5% lower than baseline values. These data clearly indicate that chronic systemic administration of 5-HT can produce considerable weight loss in rats.

Animals

Antigenic differences among pestiviruses.

Monoclonal antibody typing of pestiviruses, supplemented with genetic sequence comparisons, has shown that at least four antigenic clusters can be identified within the genus. One cluster represents "classic" bovine viral diarrhea strains, which also have been isolated occasionally from sheep and pigs, whereas a second group corresponds to classic swine fever (hog cholera) strains. A distinct group of "true" border disease isolates is found in sheep and has been isolated occasionally from swine. The fourth group is antigenically quite distinct form the others and has been isolated from sheep, pigs, and cattle. It includes recent American isolates from cases of acute severe hemorrhagic disease. The implications of these findings for diagnosis and control are discussed.

Animals

Elevated numbers of proliferating mononuclear cells in the peripheral blood of psoriatic patients correlate with disease severity.

Although psoriasis is characterized by the accumulation of activated proliferating lymphoid cells in the psoriatic skin lesion, it is not known whether these cells are activated and proliferating before entry into the psoriatic plaque. The current study evaluates the number and phenotype of proliferating lymphoid cells in the blood of psoriatic patients. Proliferation of peripheral blood mononuclear cells was evaluated on cytospun preparations of these cells using autoradiographic techniques after pulsing the mononuclear cells with 3H-methyl thymidine for 2 h. The phenotypes of the labeled peripheral blood mononuclear cells were determined combining autoradiography and immunohistochemistry with monoclonal antibodies directed at CD3, CD4, CD8, CD11c, CD22, and human leukocyte antigen-DR. The data demonstrated elevated numbers of proliferating lymphoid cells in the blood of psoriatic patients compared with normal nonpsoriatic volunteers (p < 0.01). Furthermore, the number of circulating proliferating mononuclear cells increased significantly with increasing psoriasis skin disease severity (correlation coefficient 0.95; p < 0.0001). When the phenotype of the proliferating cells in the blood was examined, the numbers of T cells (CD3+, CD4+, CD8+ cells), B cells (CD22+ cells), monocytes (CD11c+ cells), and human leukocyte antigen-DR+ cells were significantly elevated compared with nonpsoriatic skin (p < 0.01) and increased with increasing disease activity (correlation coefficient range 0.48-0.74; p < 0.05). The data suggest a generalized systemic activation of T, B, and monocytic cells that results in labeling of up to 0.16% of the circulating mononuclear cells with 3H-methyl thymidine (i.e., proliferating and presumably activated) when assayed in vitro.

Cell Division

Evaluation and application of an indirect ELISA for the detection of antibodies to bovine respiratory syncytial virus in milk, bulk milk, and serum.

An indirect enzyme-linked immunosorbent assay (ELISA) was developed at the National Veterinary Institute (NVI), Uppsala, to detect antibodies to bovine respiratory syncytial virus (BRSV) in serum and milk. For the evaluation of the NVI ELISA, field sera collected from cattle in England and Sweden were tested in parallel with an ELISA in use at the Central Veterinary Laboratory (CVL), Weybridge. The tests showed 96% agreement. The sensitivity and specificity of the NVI ELISA relative to the CVL ELISA were 94% and 100%, respectively. There was evidence that the difference in sensitivity between the 2 tests was due to the detection of both IgG and IgM class antibodies by the CVL ELISA, whereas the NVI ELISA was designed specifically to detect IgG1. Milk and serum samples from individual cows were tested by the NVI ELISA for presence of antibodies to BRSV. There was a good correlation between the ability to detect antibodies in serum and the ability to detect them in milk, although the antibody titer was generally lower in milk than in serum. Bulk milk samples were collected from farms with severe clinical symptoms of respiratory distress and from farms with no history of respiratory disease. There was a clear distinction between antibody levels in diseased and healthy herds. The NVI ELISA is a rapid and reliable test for detecting antibodies to BRSV in milk, bulk milk, and serum samples.

Animals

Profiling fluent aphasic spontaneous speech: a comparison of two methodologies.

Grammatical features of fluent aphasic speakers have not received as much attention as those exhibited by non-fluent aphasic speakers. In part, this neglect reflects the difficulty of applying consistent analytical procedures to fluent aphasic speech. For the analytical process to be meaningful, the methodology must be robust, replicable and capable of dealing with the voluble and non-specific output which is often typical of these speakers, and yet be sensitive enough to reveal subtle grammatical differences between aphasic and normal speech. In this paper the methodological problems encountered in applying analytical procedures to spontaneous speech data are discussed. Two different procedures for analysing speech data are compared and applied to samples of fluent aphasic and normal speech. Both procedures reveal that (compared with normal speakers), although these aphasic speakers are capable of producing some well-constructed grammatical structures, the distribution of these structures may differ compared with the distribution exhibited by normal speakers. These results suggest that complex aspects of grammatical organisation may be compromised in some fluent aphasic speakers.

Aphasia

Designing a game to assist learning about HIV.

A game can be educational in a non-threatening way. Games can help to build group cohesion. A fresh approach can allow complex topics such as HIV/AIDS to be explored from a different perspective.

Attitude of Health Personnel

A proposed division of the pestivirus genus using monoclonal antibodies, supported by cross-neutralisation assays and genetic sequencing.

Sixty-six pestiviruses from ruminant and porcine hosts were analysed with a panel of 76 monoclonal antibodies raised against 9 different viruses. Reactivity was used to construct epitope similarity maps for all of the viruses. Four principal virus subgroups were demonstrated. One subgroup equated to classical swine fever virus (CSFV) and included most porcine pestiviruses but none from ruminants. A second subgroup contained mainly viruses of bovine origin, including reference bovine viral diarrhoea viruses (BVDV) such as NADL; however viruses from pigs and sheep were also represented. A third subgroup represented by reference strains of border disease virus (BDV) comprised mainly ovine isolates, but also viruses from pigs. The fourth and most recently defined subgroup contained no reference strains of CSFV, BVDV or BDV, but included atypical viruses from cattle, sheep and pigs. The subgrouping scheme was supported by genetic comparisons between representative viruses from the 4 subgroups and by virus neutralisation with polyclonal sera.

Animals

Objective system for interviewer performance evaluation for use in epidemiologic studies.

In this paper, the authors present an objective system to evaluate interviewer performance for use in epidemiologic studies. With this quality control system, all study interviews are audio-taped, and a random sample of interviews are coded according to interviewer behaviors, such as whether the interviewer asked the questions exactly as written and used the probes appropriately. With the use of data obtained from a large case-control study of colon cancer, the authors observed that 94.2% of all questions were asked in the same manner by all interviewers and that 89.5% of all probing behaviors were appropriate. They show that questions that required additional interviewer behaviors were more likely to result in variation in response that can be attributed to the interviewer. These findings have implications for study design and interpretation of study results. From simulations, the authors have estimated the impact of uncorrected interviewer variability on study power and ability to detect disease associations. Uncorrected interviewer variability could decrease study power from 84% to 56%. From simulations, the authors observed that odds ratios could be biased downward from 1.8 to 1.3. These findings illustrate the importance of using a continuous quality control program in epidemiologic research.

Epidemiologic Methods

The membrane destabilising action of the antibacterial agent chlorhexidine.

The antibacterial agent chlorhexidine has long been used as an agent for medical antisepsis. This compound is a membrane active agent which probably has its major antibacterial action by interference with the function of cellular membranes. The results demonstrated an inhibition of oxygen utilisation by bacteria which was related to falls in cellular ATP levels. There was an effect on the outer membranes of Gram-negative bacteria which allowed the release of periplasmic enzymes. The inner membrane was not ruptured but its functionality was breached and there was an inhibition of active uptake of small molecules which did not appear to be related to cellular ATP levels.

Adenosine Triphosphate

Border disease virus: delineation by monoclonal antibodies.

Many ovine pestiviruses from Britain and a number of atypical porcine isolates are largely unrecognised by monoclonal antibodies (mAbs) specific for reference strains of classical swine fever virus and bovine viral diarrhoea virus (BVDV). Additional mAbs have therefore been produced using some of these "unreactive" pestiviruses. Two of the viruses used were atypical porcine isolates (strains 87/6 and Vosges), whilst another had been isolated from a sheep (59386). Thirty-three mAbs were selected, none of which recognised two reference strains of BVDV, but three of which recognised the Alfort strain of classical swine fever. On the basis of radioimmunoprecipitation they were considered to be directed at one of three different pestivirus proteins (gp 53, gp 48 or p 125). Three virus subgroups were evident when the mAbs were used to type 16 ovine and two atypical porcine pestiviruses. One subgroup contained the Vosges and 59386 viruses and four ovine field isolates. The second subgroup comprised the 87/6 virus, the Moredun and Aveyron reference strains of border disease virus and four further ovine field isolates. Three of four ovine viruses making up the third subgroup had been previously categorised as BVDV-like and were largely unrecognised by the new mAbs. The findings were in agreement with previous attempts to segregate some of the same viruses using partial genomic comparisons or cross-neutralization tests.

Animals

Comparison of pestivirus multiplication in cells of different species.

Twenty-four pestiviruses, comprising 11 from pigs, eight from cattle and five from sheep, were tested for their ability to replicate in cells of porcine, bovine and ovine origin. Seven of the viruses were successfully passaged in all three cell types. Four porcine isolates (hog cholera virus) replicated to significant titres only in porcine cells. One bovine virus grew well in bovine cells but only poorly in ovine cells and not at all in porcine cells. The remaining 12 viruses could replicate in cells from two of the three host species. The pattern of replication in different cell types varied between different isolates of the same virus species.

Animals

Effects of chronic systemic administration of 5-HT on food intake and body weight in rats.

The effects of chronic peripheral administration of 5-HT on food intake and body weight was investigated. In normal male Wistar rats, normal female Wistars, obese Zucker males, ovariectomised Wistar females, or normal Wistar males free fed a cafeteria diet, suppression of the creeping weight gain typical of control animals is observed. In females, this effect is not dependent on the local hormonal environment, because intact and ovariectomised females showed similar responses to treatment. One sex difference is that the weight suppressive effect in males is accompanied by an anorectic effect, whereas this anorectic effect is absent in females. Thus, although reduced food intake may partially explain the suppression of weight gain in males, in females it must be due to other, perhaps metabolic, effects. It is possible that these metabolic effects may also occur in males, suggesting one possible explanation of why the effect was typically larger in males than females.

Animals

Nursing ethics.

This paper begins by answering a question recently posed by Hunt 'What is nursing ethics?'. Then, a distinction is drawn between principle-based and principle-invoking approaches to nursing ethics. Following an outline of both principle-invoking and care-based approaches, it is proposed that the two approaches may fruitfully be combined in the teaching of nursing ethics.

Education, Nursing