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S Davison

Publications and source records attributed to S Davison.

At least 37 records · Page 2Linked to original sources
PubMed2000

Identification and characterization of the Trichoplusia ni single capsid nuclear polyhedrosis virus p10 gene.

The p10 gene was identified and characterized from the Trichoplusia ni single capsid nuclear polyhedrosis virus (TniSNPV). The p10 open reading frame (ORF) sequence was identified following sequencing of the ends of the EcoRI-G clone. Subsequent sequencing of an EcoRI-SmaI subclone identified the entire p10 and a portion of a p26 homologue. The p10 ORF of 264 basepairs (bps), encoded a predicted protein of 88 amino acids (aas) with Mr 9527 Da. The putative late transcription initiation motif (TAAG) was found upstream of the translation initiation codon at position -46. Downstream of the translation stop codon, a putative poly(A) signal was identified. The p10 amino acid sequence contained the three conserved domains reported for all other p10 genes. The p10 amino acid sequence was most homologous (85% similarity and 67% identity) to that of Buzura suppresaria NPV p10 sequence.

Amino Acid Sequence↗
PubMed2000

Staphylococcal toxin-induced T cell proliferation in atopic eczema correlates with increased use of superantigen-reactive Vbeta-chains in cutaneous lymphocyte-associated antigen (CLA)-positive lymphocytes.

Staphylococcal superantigens have been implicated in the pathogenesis of atopic dermatitis (AD). This may occur through superantigenic activation of T lymphocytes and their subsequent induction of the skin homing receptor CLA on activated cells. We investigated the proliferative responses of peripheral blood mononuclear cells (PBMC) from 10 patients with an infective exacerbation of AD and six normal controls to the staphylococcal superantigens, staphylococcal enterotoxin A and B (SEA, SEB) and toxic shock syndrome toxin-1 (TSST-1), and the mitogens phytohaemagglutinin (PHA) and concanavalin A (Con A). We also assessed CLA and T cell receptor (TCR) Vbeta-chain expression by immunofluorescence and flow cytometry before and after stimulation. PBMC from AD patients showed two-fold increased proliferation to SEA and SEB (P < 0.01) compared with normals, whereas the response to mitogenic stimulation was identical. Analysis of (TCR) Vbeta-chain expression demonstrated increased use of superantigen-reactive Vbeta families in freshly isolated PBMC in AD patients compared with controls. This pattern of Vbeta-chain expression was only observed in the CLA+ but not the total population of T cells. Furthermore, there was a positive correlation between the enhanced PBMC proliferative response and increased expression of superantigen-reactive Vbeta families in atopic patients. These data support the concept that superantigens are important in the pathogenesis of this common condition, and also provide evidence that the increased use of certain Vbeta families in circulating, CLA+, skin homing lymphocytes is of functional significance.

Adult↗
PubMed1999

Economic analysis of an outbreak of avian influenza, 1997-1998.

OBJECTIVE: To determine economic losses associated with an outbreak of avian influenza in flocks in Pennsylvania during 1997 and 1998. SAMPLE POPULATION: 5 premises containing avian influenza-infected layer, pullet, and turkey flocks. PROCEDURE: Losses incurred before depopulation, those incurred at the time of depopulation, and those that were attributable to depopulation (unrealized loss of income) were evaluated. Results were extrapolated to provide values for all infected flocks. RESULTS: Extrapolating the costs determined on the basis of age and number of birds from the 5 sample flocks to all other flocks infected with nonpathogenic avian influenza H7N2 yielded an estimated total cost to the Pennsylvania poultry industry of $3.5 million. CLINICAL IMPLICATIONS: The H7N2 virus is not highly pathogenic. If the pathogenicity of the virus does not change, then the poultry industry and state and federal governments will not have severe economic losses for the 1997-1998 outbreak similar to those for the 1983-1984 avian influenza outbreak in Pennsylvania. To decrease the potential for financial losses that could result from future outbreaks of avian influenza, it is essential that the commercial industry and livebird market system be separated via increased use of biosecurity measures.

Animals↗
PubMed1999

The characterization and phylogenetic relationship of the Trichoplusia ni single capsid nuclear polyhedrosis virus polyhedrin gene.

The polyhedrin gene (polh) was identified from the Trichoplusia ni (Tni) single capsid nuclear polyhedrosis virus (SNPV). An EcoRI fragment containing the truncated polyhedrin gene was detected by hybridization with an AcMNPV expression vector probe; the remaining portion of the gene was amplified by reverse PCR. An open reading frame (ORF) of 741 nucleotides (nt), encoding a putative protein of 246 amino acids (a.a) with Mr 28,780 Da was identified. The 5'-noncoding region contained the putative late (TAAG) transcription initiation motif. The 3' end, downstream of the translation stop codon, lacked an obvious putative poly (A) signal. Nucleotide and amino acid homology are greater than 80% to that of Mamestra brassicae polyhedrin sequences. Results suggest that T. niSNPV is a member of the group II nuclear polyhedrosis viruses.

Amino Acid Sequence↗
PubMed1999

Increased T-cell receptor vbeta2 chain expression in skin homing lymphocytes in psoriasis.

Studies have shown over-representation of certain T-cell receptor (TCR) Vbeta chains in lesional psoriatic skin, implying selection or expansion, possibly by bacterial superantigen. We investigated the pattern of TCR Vbeta chain usage in peripheral blood lymphocytes (PBL) bearing the skin homing receptor cutaneous lymphocyte associated antigen (CLA) in psoriasis patients. Results showed increased expression of TCR Vbeta2 in CLA-positive PBL in psoriasis patients (n = 15) compared with normals (n = 10); P < 0.002. As Vbeta2 is preferentially expressed by lymphocytes responding to certain bacterial superantigens, this study could possibly indicate a role for superantigens in the pathogenesis of psoriasis.

Adult↗
PubMed1999

Combination treatment with methotrexate and cyclosporin for severe recalcitrant psoriasis.

An increasingly important approach to the management of patients with severe psoriasis is the concurrent use of two systemic treatments. Previous guidelines have advised against the use of methotrexate and cyclosporin in combination. We report the successful use of a combination of methotrexate and cyclosporin in the treatment of 19 patients with severe, recalcitrant psoriasis, 15 of whom had psoriatic arthropathy. Most patients had previously received two or more systemic treatments. Before combination treatment was started nine of the patients were taking methotrexate and 10 were taking cyclosporin at the maximum tolerated doses. The duration of combination treatment was bimodally distributed, with seven patients having short-term treatment (mean +/- SD duration 18. 9 +/- 15.7 weeks) and 12 patients having long-term treatment (mean +/- SD duration 193.2 +/- 160.6 weeks). Those patients who received short-term treatment did not develop any evidence of toxicity from either agent. Of those patients on long-term treatment, three developed mild impairment of renal function that returned to normal following a reduction in dose of cyclosporin, and three had impairment of renal function (following long-term cyclosporin monotherapy) that improved, but did not normalize, following a reduction in dose of cyclosporin. In each case, combination treatment for psoriasis resulted in good control of both skin and joint problems using lower doses of each agent than would have been used for monotherapy. We conclude that the combination of methotrexate and cyclosporin is an effective treatment for this group of patients.

Adult↗
PubMed1999

A PCR detection method for rapid identification of Paenibacillus larvae.

American foulbrood is a disease of larval honeybees (Apis mellifera) caused by the bacterium Paenibacillus larvae. Over the years attempts have been made to develop a selective medium for the detection of P. larvae spores from honey samples. The most successful of these is a semiselective medium containing nalidixic acid and pipermedic acid. Although this medium allows the growth of P. larvae and prevents the growth of most other bacterial species, the false-positive colonies that grow on it prevent the rapid confirmation of the presence of P. larvae. Here we describe a PCR detection method which can be used on the colonies that grow on this semiselective medium and thereby allows the rapid confirmation of the presence of P. larvae. The PCR primers were designed on the basis of the 16S rRNA gene of P. larvae and selectively amplify a 973-bp amplicon. The PCR amplicon was confirmed as originating from P. larvae by sequencing in both directions. Detection was specific for P. larvae, and the primers did not hybridize with DNA from closely related bacterial species.

Animals↗
PubMed1999

Route of discharge for special (high-security) hospital patients with personality disorder. Relationship with re-conviction.

BACKGROUND: A considerable proportion of patients with personality disorder are discharged directly to the community from special (high-security) hospitals. AIMS: To examine whether patients with personality disorder discharged directly to the community are more likely to be re-convicted than those transferred to psychiatric hospitals of lesser security. METHOD: Re-conviction data for a five- to nine-year follow-up were collected for a four-year (1988-1991) special hospital discharge cohort of patients with personality disorder. RESULTS: Individuals discharged directly to the community were not significantly more likely to be re-convicted than those transferred to less secure psychiatric hospitals. However, patients discharged to the community without formal conditions of supervision were more likely to be re-convicted than those discharged to the community with conditions or those transferred to other psychiatric hospitals. CONCLUSIONS: Formal supervision after discharge may be more important than actual destination in influencing the likelihood of re-conviction.

Adult↗
PubMed1998

A PCR detection method for rapid identification of Melissococcus pluton in honeybee larvae.

Melissococcus pluton is the causative agent of European foulbrood, a disease of honeybee larvae. This bacterium is particularly difficult to isolate because of its stringent growth requirements and competition from other bacteria. PCR was used selectively to amplify specific rRNA gene sequences of M. pluton from pure culture, from crude cell lysates, and directly from infected bee larvae. The PCR primers were designed from M. pluton 16S rRNA sequence data. The PCR products were visualized by agarose gel electrophoresis and confirmed as originating from M. pluton by sequencing in both directions. Detection was highly specific, and the probes did not hybridize with DNA from other bacterial species tested. This method enabled the rapid and specific detection and identification of M. pluton from pure cultures and infected bee larvae.

Animals↗
PubMed1997

Ectopic expression of Bcl-2, but not Bcl-xL rescues Ramos B cells from Fas-mediated apoptosis.

The human Burkitt lymphoma Ramos B cell line can be induced to undergo apoptosis in response to a variety of different agents, including calcium ionophores, anti-immunoglobulin (Ig) and macromolecular synthesis inhibitors. In addition, following up-regulation of the Fas (CD95) surface receptor by CD40 ligation, these cells also become susceptible to apoptosis induction by Fas ligation. We have previously shown that protection from calcium ionophore- and macromolecular synthesis inhibitor-induced apoptosis by CD40 ligation is associated with a rapid up-regulation of Bcl-xL followed by a more moderate and delayed up-regulation of Bcl-2. We show here that overexpression of Bcl-xL, like Bcl-2, protects Ramos cells from apoptosis induction in response to calcium ionophore, anti-Ig and macromolecular synthesis inhibition. However, in contrast to Bcl-2, ectopic overexpression of Bcl-xL does not rescue from Fas-mediated apoptosis. Thus, in Ramos B cells, the Fas apoptotic pathway exhibits differential sensitivity to inhibition by Bcl-2 family members. These findings also suggest that CD40 signaling provides a switch which renders the cells susceptible to Fas-ligand mediated apoptosis through up-regulation of Fas whilst affording protection from anti-Ig-induced apoptosis through up-regulation of Bcl-xL.

Apoptosis↗
PubMed1995

Biliary complications after paediatric liver transplantation: Birmingham's experience.

Between 1983 and 1992, 112 children underwent liver transplantation. Of 138 grafts, 60 (43.4%) were whole livers, 77 (55.6%) were reduced livers, and 1 (0.7%) was a split liver. Biliary complications (BC) were defined as any abnormality, even minor, related to the biliary tract. Results were analysed with a minimum follow-up of 9 months. Some 36 grafts (26.1%) in 34 patients (30.4%) presented with BC: bile leaks (17 grafts), biliary obstructions or dilatations (16 grafts), and other complications (3 grafts). Management was mainly surgical with biliary reconstruction via a Roux-en-Y loop. Interventional radiology had an increasing role in recent years. BC were associated with a mortality of 1.8% (2/112), a graft loss rate of 4.3% (6/138), and significant morbidity. Among the various factors whose association with BC was studied, the date of transplantation, the use of reduced grafts and the use of gallbladder conduits appeared to be the main determining factors for BC. From multivariate analysis the use of reduced grafts emerged as the most important factor in reducing BC. We therefore conclude that BC are associated with significant morbidity, but general improvements in both surgical and medical management seem to account for better results in recent years.

Adolescent↗
PubMed1995

The efficacy of a nursing challenge to patients: testing a new intervention to decrease self-harm behaviour in severe personality disorder.

This paper describes the study of a new intervention, which was intended to increase therapeutic engagement with patients and to decrease self-harm behaviour. As a result of nursing observations in a unit that specialized in severe personality disorders, a psychodynamic perspective to treatment was introduced in the form of a nursing challenge. The intervention was evaluated in a new service for young adults at a psychiatric hospital in the south of England, as part of a clinical research apprenticeship. The care and treatment of persons with severe personality disorders present a major challenge to coherent and cohesive teamwork. A test and retrospective comparison study is described and its findings reported. Data from the study point to the need for more than a single challenge, to achieve a sustained reduction in self-harm, along with staff training to ensure working knowledge of a particular framework.

Adult↗