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Biomedical subjects

S Burgess

Publications and source records attributed to S Burgess.

At least 19 recordsLinked to original sources
PubMed2001

[DOTA-bis(amide)]lanthanide complexes: NMR evidence for differences in water-molecule exchange rates for coordination isomers.

Two derivatives of 1,4,7,10-tetraazacyclododecane with trans-acetate and trans-amide side-chain ligating groups have been prepared and their complexes with lanthanide cations examined by multinuclear NMR spectroscopy. These lanthanide complexes exist in aqueous solution as a mixture of slowly interconverting coordination isomers with 1H chemical shifts similar to those reported previously for the major (M) and minor (m) forms of the tetraacetate ([Ln(dota)]-) and tetraamide ([Ln(dtma)]3+) complexes. As in the [Ln(dota)]- and [Ln(dtma)]3+ complexes, the m/M ratio proved to be a sensitive function of lanthanide size and temperature. An analysis of 1H hyperfine shifts in spectra of the Yb3+ complexes revealed significant differences between the axial (D1) and non-axial (D2) components of the magnetic susceptibility tensor anisotropy in the m and M coordination isomers and the energetics of ring inversion and m <==> M isomerization as determined by two-dimensional exchange spectroscopy (EXSY). (17)O shift data for the Dy3+ complexes showed that both have one inner-sphere water molecule. A temperature-dependent (17)O NMR study of bulk water linewidths for solutions of the Gd3+ complexes provided direct evidence for differences in water exchange rates for the two coordination isomers. The bound-water lifetimes (tauM298) in the M and m isomers of the Gd3+ complexes ranged from 1.4-2.4 micros and 3-14 ns, respectively. This indicates that 1) the inner-sphere water lifetimes for the complexes with a single positive charge reported here are considerably shorter for both coordination isomers than the corresponding values for the [Gd(dtma)]3+ complex with three positive charges, and 2) the difference in water lifetimes for M and m isomers in these two series is magnified in the [Gd[dota-bis(amide)]] complexes. This feature highlights the remarkable role of both charge and molecular geometry in determining the exchange rate of the coordinated water.

Chelating Agents↗
PubMed2001

Lithium for maintenance treatment of mood disorders.

BACKGROUND: Mood disorders are common, disabling and tend to be recurrent. They carry a high risk of suicide. Maintenance treatment, aimed at the prevention of relapse, is therefore of vital importance. Lithium has been used for some years as the mainstay of maintenance treatment in bipolar affective disorder, and to a lesser extent in unipolar disorder. However, the efficacy and effectiveness of prophylactic lithium therapy has been disputed. Low suicide rates in lithium-treated patients have led to claims that lithium has a specific anti-suicidal effect. If so, this is of considerable importance as treatments for mental disorders in general have not been shown convincingly to be effective in suicide prevention. OBJECTIVES: 1. To investigate the efficacy of lithium treatment in the prevention of relapse in recurrent mood disorders. 2. To examine the effect of lithium treatment on consumers' general health and social functioning, its acceptability to consumers, and the side-effects of treatment. 3. To investigate the hypothesis that lithium has a specific effect in reducing the incidence of suicide and deliberate self-harm in persons with mood disorders. SEARCH STRATEGY: The Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Register (CCDANCTR) and The Cochrane Controlled Clinical Trials Register (CCTR) were searched. Reference lists of relevant papers and major text books of mood disorder were examined. Authors, other experts in the field and pharmaceutical companies were contacted for knowledge of suitable trials, published or unpublished. Specialist journals concerning lithium were hand searched. SELECTION CRITERIA: Randomised controlled trials comparing lithium with placebo, where the stated intent of treatment was maintenance or prophylaxis. Participants were males and females of all ages with diagnoses of mood disorder. Discontinuation studies (in which all participants had been stable on lithium for some time before being randomised to either continued lithium treatment or placebo substitution) were excluded. DATA COLLECTION AND ANALYSIS: Data were extracted from the original reports independently by two reviewers. The main outcomes studied were related to the objectives stated above. Data were analysed for all diagnoses of mood disorder and for bipolar and unipolar disorder separately. Data were analysed using Review Manager version 4.0. MAIN RESULTS: Nine studies were included in the review, reporting on 825 participants randomly allocated to lithium or placebo. Lithium was found to be more effective than placebo in preventing relapse in mood disorder overall, and in bipolar disorder. The most consistent effect was found in bipolar disorder (random effects OR 0.29; 95% CI 0.09 to 0.93 ). In unipolar disorder, the direction of effect was in favour of lithium, but the result (when heterogeneity between studies was allowed for) did not reach statistical significance. Considerable heterogeneity was found between studies in all groups of patients. The direction of effect was the same in all studies; no study found a negative effect for lithium. Heterogeneity may have been due to differences in selection of participants, and to differing exposures to lithium in the pre-study phase resulting in variable influence of a discontinuation effect. There was little reported data on overall health and social functioning of participants under the different treatment conditions, or on the participants' own views of their treatment. Descriptive analysis showed that assessments of general health and social functioning generally favoured lithium. Small absolute numbers of deaths and suicides, and the absence of data on non-fatal suicidal behaviours, made it impossible to draw meaningful conclusions about the place of lithium therapy in suicide prevention. REVIEWER'S CONCLUSIONS: This systematic review indicates that lithium is an efficacious maintenance treatment for bipolar disorder. In unipolar disorder the evidence of efficacy is less robust. This review does not cover the relative efficacy of lithium compared with other maintenance treatments, which is at present unclear. There is no definitive evidence from this review as to whether or not lithium has an anti-suicidal effect. Systematic reviews and large scale randomised studies comparing lithium with other maintenance treatments (e.g. anti-convulsants, antidepressants) are necessary. Outcomes relating to death and suicidal behaviour should be included in all future maintenance studies of mood disorder.

Antimanic Agents↗
PubMed2000

Effectiveness of wound care products in the transmission of acoustic energy.

BACKGROUND AND PURPOSE: Ultrasound is often recommended in the treatment of people with partial and full-thickness wounds. Many treatments are performed over a hydrogel sheet or semipermeable film dressing. The purpose of this in vitro study was to examine the effectiveness of 4 hydrogels (Nu-Gel, ClearSite, Aquasorb Border, and CarraDres) and 4 film dressings (CarraSmart Film, J&J Bioclusive, Tegaderm, and Opsite Flexigrid) in ultrasound transmission. METHODS: The amount of sound energy transmitted through each product and interposed pig tissue was measured using an oscilloscope to display the intensity of sound energy delivered by the transducer. Five intensities at a frequency of 3.3 MHz were studied. RESULTS: Results were expressed as the mean ((SD) percentage of voltage transmitted compared with a gel baseline. Nu-Gel was the most efficient hydrogel (77.2%(4.6%), followed by ClearSite (72.0%(2.2%), Aquasorb Border (45.3%(2.1%), and CarraDres (42.8%(5.9%). The 4 film dressings, in order of efficiency, were CarraSmart Film (60.5%(4.4%), J&J Bioclusive (53.2%(2.4%), Tegaderm (47.1%(2.3%), and Opsite Flexigrid (31.5%(4.0%). CONCLUSION AND DISCUSSION: Transmissivity of wound care products used to deliver acoustic energy during ultrasound treatment of wounds varies greatly among dressing products. We believe that clinicians can use our findings as a part of the clinical reasoning process that they use to select an optimal wound dressing.

Animals↗
PubMed2000

Advanced practice 101: a "PERLL" for practice.

As advanced practice nursing students begin and continue their programs of study, they are often asked, "What is an advanced practice nurse, and what are the distinguishing characteristics?" For many students, articulating an answer is somewhat difficult, and some even fumble. Therefore, we have developed an acronym to help students organize their thinking in answering these questions. This acronym is a useful tool to help students discuss the characteristics of advanced practice nurses in an organized and well-thought-out manner, keeping in mind that some of these talking points should be customized to the individual state or regional requirements for advanced practice nursing.

Abbreviations as Topic↗
PubMed1999

A large-scale insertional mutagenesis screen in zebrafish.

It is estimated that approximately 2500 genes are essential for the normal development of a zebrafish embryo. A mutation in any one of these genes can result in a visible developmental defect, usually followed by the death of the embryo or larva by days 5-7 of age. We are performing a large-scale insertional mutagenesis screen in the zebrafish with the goal of isolating approximately 1000 embryonic mutations. We plan to clone a significant fraction of the mutated genes, as these are the genes important for normal embryogenesis of a vertebrate. To achieve this goal, we prepared approximately 36, 000 founder fish by injecting blastula-stage embryos with one of two pseudotyped retroviruses. We estimate that together these fish harbor between 500,000-1,000,000 proviral insertions in their germ lines. The protocol we have devised and the size of our facility allow us to breed approximately 80,000-150,000 of these insertions to homozygosity within 2 years. Because a pilot screen conducted earlier in our laboratory revealed that the frequency of mutations obtained with this type of insertional mutagen is 1 embryonic lethal mutation per 70-100 proviral insertions, screening 100,000 insertions should yield at least 1000 mutants. Here we describe the protocol for the screen and initial results with the first of the two retroviral vectors used, a virus designated F(5). We screened an estimated 760 insertions among F(3) progeny from 92 F(2) families and obtained 9 recessive embryonic lethal mutations. Thus, the efficiency of mutagenesis with this viral vector is approximately one-ninth that observed with the chemical mutagen ENU in zebrafish. We have also obtained two dominant mutations, one of which is described here. As expected, mutated genes can be readily identified. So far, genes mutated in four of the nine recessive mutants and one of the two dominant mutants have been cloned. Further improvements to this technology could make large-scale insertional mutagenesis screening and rapid gene cloning accessible to relatively small zebrafish laboratories.

Alleles↗
PubMed1999

A randomized, double-blinded comparison of Thymoglobulin versus Atgam for induction immunosuppressive therapy in adult renal transplant recipients.

BACKGROUND: The aim of this study was to compare the efficacy and safety of Thymoglobulin (a rabbit-derived polyclonal antibody) to Atgam (a horse-derived polyclonal antibody) for induction in adult renal transplant recipients. METHODS: Transplant recipients (n=72) were randomized 2:1 in a double-blinded fashion to receive Thymoglobulin (n=48) at 1.5 mg/kg intravenously or Atgam (n=24) at 15 mg/kg intravenously, intraoperatively, then daily for at least 6 days. Recipients were observed for at least 1 year of follow-up. RESULTS: By 1 year after transplantation, 4% of Thymoglobulin-treated patients experienced acute rejection compared with 25% of Atgam-treated patients (P=0.014). The rate of acute rejection was lower with Thymoglobulin than Atgam (relative risk=0.09; P=0.009). Rejection was less severe with Thymoglobulin than Atgam (P=0.02). No recurrent rejection occurred with Thymoglobulin compared with 33% with Atgam (P=NS). Patient survival was not different, but the composite end point of freedom from death, graft loss, or rejection, the "event-free survival," was superior with Thymoglobulin (94%) compared with Atgam (63%; P=0.0005). Fewer adverse events occurred with Thymoglobulin (P=0.013). Leukopenia was more common with Thymoglobulin than Atgam (56% vs. 4%; P<0.0001) during induction. The mean absolute lymphocyte count remained below baseline with Thymoglobulin throughout the study (P<0.007), but with Atgam, significant lymphocyte reductions occurred only at day 7. The incidence of cytomegalovirus disease was less with Thymoglobulin than Atgam at 6 months (10% vs. 33%; P=0.025). CONCLUSIONS: Brief (7-day) induction with Thymoglobulin resulted in less frequent and less severe rejection, a better event-free survival, less cytomegalovirus disease, fewer serious adverse events, but more frequent early leukopenia than induction with Atgam. These results may in fact be explained by a more profound and durable beneficial lymphopenia.

Adolescent↗
PubMed1998

Adolescents who take overdoses: outcome in terms of changes in psychopathology and the adolescents' attitudes to care and to their overdose.

Adolescent self-poisoners were followed up 3 months after taking an overdose. High levels of psychopathology were found, with 72% (18/25) of the adolescents having a diagnosable psychiatric disorder and 48% (12/25) major depression. All the adolescents were offered follow-up treatment from health or social services. Compliance with treatment was very high. Seventy-two per cent of the adolescents found treatment useful to them. The adolscents received a generally sympathetic response from their significant others. Fifty-four per cent of the adolescents thought that their overdose had resulted overall in improvements to their lives but 44% would consider taking an overdose again in similar circumstances.

Adolescent↗
PubMed1998

Web-based resources for clinical protocol management.

The data monitoring regulatory procedures, and administrative tasks associated with protocol management have become increasingly complex. Relational database technology and Internet-based connectivity offer resources to improve the quality and efficiency of protocol operations. At Fox Chase Cancer Center, we have developed a suite of database applications for protocol management and tracking of patient accrual. All data transactions and reporting occur through a graphical web browser interface using standard Internet technology. Security and confidentiality have been addressed through encryption, user authentication, address restriction, and database authority. Database management has been tightly integrated with protocol operations to avoid duplication of resources and effort. Data query functions also extend to other institutional resources, such as tumor registry and the hospital clinical laboratory, to further reduce the need for redundant data storage. Newer components, such as chemotherapy orders and toxicity reporting, have been incorporated in a modular fashion. Although custom software development can be expensive and time-consuming, it offers the best opportunity for successful integration with existing resources, staff, and procedures, as well as collaboration with other institutions.

Clinical Protocols↗
PubMed1997

In vitro and in vivo gene delivery mediated by a synthetic polycationic amino polymer.

A synthetic polyamino polymer with a glucose backbone was used for gene transfer in vitro and in vivo. Gene transfer in vitro to various human carcinoma cell lines was achieved with an efficiency superior to a commercially available cationic liposome preparation. The polymer was resistant to inhibition by serum, which allowed for efficient gene transfer in vivo. Direct Intracranial tumor injection using this reagent resulted in reporter gene expression levels comparable to those achieved by a recombinant adenoviral vector. Thus, this compound represents a new class of agent that may have broad utility for gene transfer and gene therapy applications.

Animals↗
PubMed1997

Neutralizing IGF-1 monoclonal antibody with cross-species reactivity.

We report the generation of a murine IGF-1 monoclonal antibody designated 35I17, which exhibits unique cross-species reactivity. The antibody recognizes recombinant human and rat IGF-1 in ELISA, Western blots, and in an 125I-recombinant human IGF-1 Scintillation Proximity Assay. In addition, 35I17 blocks cell proliferation induced by recombinant human and rat IGF-1, and inhibits cell proliferation induced by sera from human, rat, calf, dog, goat, or mouse. The antibody inhibits rat IGF-1 binding to IGF-1 receptors, and prevents IGF-1-stimulated receptor and IRS-1 phosphorylation in LISN C4 cells, an IGF-1 receptor-transfected cell line. The cross-species and neutralizing properties of 35I17 may be useful in in vitro and in vivo animal studies for elucidating the role of IGF-1 in cancer, rheumatoid arthritis, and other diseases.

3T3 Cells↗
PubMed1997

Delayed in vitro fertilization of zebrafish eggs in Hank's saline containing bovine serum albumin.

In zebrafish it is possible to create viable diploid fish whose genomic DNA is derived only from the female parent (parthenogenesis) or, as was more recently shown, only from the male (androgenesis). Androgenesis requires holding zebrafish eggs in an inactivated state in vitro for an hour or more. Previously this was achieved by placing the zebrafish eggs in ovary fluid obtained from rainbow trout (Onchorhynchus mykiss) or coho salmon (Onchorhynchus kisutch). Here we report that adding bovine serum albumin (BSA) to Hank's buffered saline prevents zebrafish egg activation in vitro. Of the zebrafish eggs placed in Hank's saline plus 0.5% BSA, 85% +/- 8.7% were fertilizable after incubation for one hour at room temperature (23 degrees C). Longer incubations are possible but with lower efficiency of fertilization. This technique not only could facilitate androgenesis, but also might be useful when making transgenics by microinjection, when performing antibody or RNA injections before fertilization, or for studying the mechanisms of egg activation in zebrafish.

Animals↗