PubMed Health⌕ Search

Biomedical subjects

S Sweeney

Publications and source records attributed to S Sweeney.

18 recordsLinked to original sources

Signal transduction networks in rheumatoid arthritis.

Signal transduction pathways regulate cellular responses to stress and play a critical role in inflammation. The complexity and specificity of signalling mechanisms represent major hurdles for developing effective, safe therapeutic interventions that target specific molecules. One approach is to dissect the pathways methodically to determine their hierarchy in various cell types and diseases. This approach contributed to the identification and prioritisation of specific kinases that regulate NF-kappa B and the mitogen activated protein (MAP) kinase cascade as especially attractive targets. Although significant issues remain with regard to the discovery of truly selective kinase inhibitors, the risks that accompany inhibition of fundamental signal transduction mechanisms can potentially be decreased by careful dissection of the pathways and rational target selection.

Antirheumatic Agents↗

Quality of life of patients with Fabry disease.

This paper is the first of its kind to study the impact of Fabry disease (FD) in affected males, and shows that FD is associated with a significant decline in several domains. Using the medical outcomes study (MOS) SF-36 and a FD-specific questionnaire, we compared the observations found among these patients with that obtained for the general US population and other chronic disease states, including Gaucher disease (GD) (another lysosomal storage disorder), end-stage renal disease, stoke and AIDS. Patients with FD have a score profile most similar to patients with AIDS. In comparison with patients with GD, Fabry patients score substantially lower across all domains. Using simple linear regression, potential predictors of health-related quality of life (HRQOL) for Fabry patients were also determined. As in the general population, stroke, cardiac problems and renal disease lead to substantial decrement in HRQOL. In addition, two disease specific symptoms (acroparesthesia and anhidrosis) and pain are also predictors of decreased quality of life. Currently, no specific therapy for FD exists. As enzyme therapy for FD becomes increasingly available, it will be interesting to evaluate the therapy's impact on the quality of life of patients.

Adult↗

Chick ciliary neurotrophic factor is secreted via a nonclassical pathway.

In contrast to mammalian ciliary neurotrophic factors (CNTFs), chick CNTF is secreted, although it lacks an N-terminal signal. We determined that a 52 aa region of chick CNTF containing an internal hydrophobic domain could direct secretion of rat CNTF. Using a stable cell line that overexpressed chick CNTF, we found that chick CNTF immunoreactivity was punctate throughout the cytosol. Cellular fractionation confirmed chick CNTF to be protected by vesicles. Chick CNTF did not colocalize with fibronectin, calreticulin, wheat germ agglutinin binding sites, or with transferrin receptor. The distribution of chick CNTF was altered neither by brefeldin A nor by chloroquine treatment. Although the punctate pattern of chick CNTF immunoreactivity was not due to reuptake, chick CNTF could be found in a cellular compartment labeled after a brief incubation with dextran microbeads. When synthesized in vitro, chick CNTF did not translocate into microsomes. We conclude that chick CNTF is secreted via a nonclassical pathway.

Animals↗

Total hip arthroplasty in ankylosing spondylitis: outcome in 340 patients.

OBJECTIVE: The longterm outcome of total hip arthroplasty (THA) in ankylosing spondylitis (AS) remains unclear. Concern has been expressed regarding joint survival, given that recipients are young and active. We present outcome data on 340 THA after a mean followup of 14 years. METHODS: The 6.7% of patients (n = 309: 237 contactable) who had undergone THA were identified from our database of 4569 subjects. Responses were received from 166 subjects (112 men, 54 women, M:F = 2:1) who were assessed for employment status and outcome [i.e., pain, mobility, satisfaction, disease activity (BASDAI), function (BASFI), and global well being (BAS-G)]. A non-THA AS control group was matched for age, sex, and disease duration. RESULTS: The mean age at AS disease onset for THA recipients was 19.5 yrs compared to 24.4 yrs for the total database (p < 0.05). The mean age at the first THA was 40.0 yrs. Of the 340 THA, 276 were primary (bilateral in 66%) and 64 were revisions. The mean followup for THA was 14.0 yrs (range 1-52). Overall, for the 340 THA, the patients considered outcome to be very good in 85%. In relation to the matched control group, THA patients were comparable for BASDAI, but had poorer function (p < 0.05) and lower global well being (p < 0.05). Of the 80 men under 60 years of age, 39 (49%) were employed compared to 49 (68%) of the control group (p < 0.01). Survival of original THA and revisions after 10, 15, and 20 yrs was 90%, 78%, 64%, respectively (originals), and 73%, 55%, 55%, respectively (revisions). CONCLUSION: The longterm outcome of THA in AS is outstanding. THA recipients have a younger age at onset than nonrecipients. The longterm survival characteristics of THA in young patients with AS is excellent.

Adult↗

Crystallization and preliminary X-ray diffraction analysis of MspI restriction endonuclease in complex with its cognate DNA.

The MspI restriction endonuclease is a type II restriction enzyme. Unlike all other restriction enzymes with known structures, MspI recognizes the palindromic tetranucleotide sequence 5'-C/CGG and cleaves it as indicated by the '/' to produce DNA products with 5' two-base overhangs. Owing to the nature of its cleavage pattern, it is likely that MspI would represent a new structural class of restriction endonucleases. Crystals of the dimeric MspI restriction enzyme bound to a duplex DNA molecule containing the specific recognition sequence have been obtained by vapor-diffusion techniques in the presence of polyethylene glycol as precipitant. The crystals belong to the monoclinic space group P2(1), with unit-cell parameters a = 50.2, b = 131.6, c = 59.3 A, beta = 109.7 degrees. The crystals contain one dimeric complex in the asymmetric unit. A complete native data set has been collected to a resolution of 2.05 A by cryo-crystallographic methods, with an R(merge) of 4.0%.

Crystallization↗

HIV seroincidence and risk factors among patients repeatedly tested for HIV attending sexually transmitted disease clinics in the United States, 1991 to 1996. STD Clinic HIV Seroincidence Study Group.

To assess the incidence of HIV infection and risk factors associated with HIV seroconversion among patients attending clinics for sexually transmitted diseases (STD), medical record reviews were conducted in 12 clinics in 7 U.S. cities. The records of all patients who initially tested negative for HIV from 1991 through 1996 and who received at least one additional HIV test during the study period were reviewed. In each of 7 cities, 5 to 112 patients seroconverted. Of the 286 seroconverters identified in total, 53% (152 of 286) were heterosexual men and 28% (81 of 286) were women. HIV incidence rates among men who have sex with men (MSM) ranged by city from 0.81 to 7.0 new infections/100 person-years. Rates among heterosexual men and women ranged from 0.018 to 1.2 infections/100 person-years. Multivariate analyses showed that drug use was associated with HIV seroconversion only among heterosexuals. Most new HIV infections in these clinics are being transmitted heterosexually and are associated with drug use. Nevertheless, MSM, particularly young MSM, are at greatest risk for HIV in this population: 1 of 47 seroconvert/year. The effective use of targeted prevention efforts depends upon the continued ability to monitor the incidence of HIV infection.

Adult↗

Vasculitis carcinomatosa occurring in association with adenocarcinoma of the stomach.

Invasion of vascular walls by cancer cells is a well-known phenomenon in lymphoid malignancies. However, its occurrence in epithelial tumors is less well known. This report documents the occurrence of such invasion of vascular walls by an adenocarcinoma of the stomach in a 68-year-old woman. This rare event differs histopathologically from inflammatory vasculitis associated with malignant disease, lymphangitis carcinomatosa, and carcinomatous arteriopathy. In inflammatory vasculitis associated with malignant disease, the main histopathologic feature is fibrinoid necrosis and ordinary pan arteritis-like vasculitis. In lymphangitis carcinomatosa, the main feature is plugging of vascular lumina by tumor cells, a finding not encountered in our case, while in carcinomatosa arteriopathy, the main event is an obliterative fibrointimal hyperplasia, apparently resulting from arterial tumor emboli. In none of these three conditions has direct invasion of vascular walls by tumor cells been previously reported.

Adenocarcinoma↗

Cisplatin increases meiotic crossing-over in mice.

Genetic mapping of traits and mutations in mammals is dependent upon linkage analysis. The resolution achieved by this method is related to the number of offspring that can be scored and position of crossovers near a gene. Higher precision mapping is obtained by expanding the collection of progeny from an appropriate cross, which in turn increases the number of potentially informative recombinants. A more efficient approach would be to increase the frequency of recombination, rather than the number of progeny. The anticancer drug cisplatin, which causes DNA strand breakage and is highly recombinogenic in some model organisms, was tested for its ability to induce germ-line recombination in mice. Males were exposed to cisplatin and mated at various times thereafter to monitor the number of crossovers inherited by offspring. We observed a striking increase on all three chromosomes examined and established a regimen that nearly doubled crossover frequency. The timing of the response indicated that the crossovers were induced at the early pachytene stage of meiosis I. The ability to increase recombination should facilitate genetic mapping and positional cloning in mice.

Animals↗

Cell cycle alterations, apoptosis, and response to low-dose-rate radioimmunotherapy in lymphoma cells.

PURPOSE: In an attempt to elucidate some aspects of the radiobiological basis of radioimmunotherapy, we have evaluated the in vitro cellular response patterns for malignant lymphoma cell lines exposed to high- and low-dose-rate radiation administered within the physiological context of antibody cell-surface binding. METHODS AND MATERIALS: We used two different malignant lymphoma cell lines, a Thy1.2+ murine T-lymphoma line called EL-4 and a CD20+ human B-lymphoma line called Raji. Cells were grown in suspension cultures and exposed to high-dose-rate gamma radiation from an external 137Cs source or low-dose-rate beta radiation from DTPA-solubilized 90Y in solution. In some experiments, cells were pre-incubated with an excess of nonradioactive antibody in order to assess the effects of immunoglobulin surface binding during radiation exposure. Irradiated cells were evaluated for viability, cell-cycle changes, patterns of post-radiation morphologic changes, and biochemical hallmarks of radiation-associated necrosis and programmed cell death. RESULTS: The EL-4 line was sensitive to both high-dose-rate and low-dose-rate irradiation, while the Raji showed efficient cell kill only after high-dose-rate irradiation. Studies of radiation-induced cell cycle changes demonstrated that both cell lines were efficiently blocked at the G2/M interface by high-dose-rate irradiation, with the Raji cells appearing somewhat more susceptible than the EL-4 cells to low-dose-rate radiation-induced G2/M block. Electron microscopy and DNA gel electrophoresis studies showed that a significant proportion of the EL-4 cells appeared to be dying by radiation-induced programmed cell death (apoptosis) while the Raji cells appeared to be dying primarily by classical radiation-induced cellular necrosis. CONCLUSION: We propose that the unusual clinical responsiveness of some high and low grade lymphomas to modest doses of low-dose-rate radioimmunotherapy may be explained in part by the induction of apoptosis. The unusual dose-response characteristics observed in some experimental models of radiation-induced apoptosis may require a reappraisal of standard linear quadratic and alpha/beta algorithms used to predict target tissue cytoreduction after radioimmunotherapy.

Animals↗

Substance use and mental health problems among sons of alcoholics and controls.

Data from a questionnaire sent to 864 university male students and nonacademic staff were used to compare self-reports of substance intake patterns and problems as well as family histories of depression and substance abuse across four groups: Group 1, 682 men (79%) who had no alcoholic first or second-degree relative; Group 2, 101 men (12%) who reported an alcoholic second-degree relative only; Group 3, 59 men (7%) who reported an alcoholic first-degree relative only and Group 4, 22 men (3%) with alcoholism in both first- and second-degree relatives. Although few men were already alcoholics or drug abusers and the groups did not differ significantly on the quantity and frequency of alcohol intake, there was an increase in the personal history of alcohol-related problems from Group 1 to Group 4. There were no significant differences across the groups on the proportion of nonalcoholic relatives demonstrating drug abuse or depressive disorders.

Adult↗

Hyperactivity and the risk for alcoholism.

Thirty-two young adult sons of alcoholic fathers and 32 controls filled out a questionnaire regarding childhood and adult symptoms of hyperactivity. There were no significant family group differences on any of the 48 childhood items or on three scales constructed from those questions. The two groups differed significantly on only 3 of the 56 items regarding adult or residual hyperactivity and on only one of seven possible adult scales, with alcoholics' sons tending to report more evidence of a hot temper and a self-perception of a short attention span. Using DSM-III criteria, the authors found that 2 (6%) of the alcoholics' sons and 4 (12%) of the controls fulfilled criteria for attention deficit disorder (ADD) with hyperactivity in childhood and that none met the criteria for ADD, residual type, in adulthood. For the studied men, the findings do not indicate an elevated risk for ADD in the sons of alcoholics.

Adult↗

A model to evaluate the cost-effectiveness of oral therapies in the management of patients with major depressive disorders.

The introduction of a new antidepressant, venlafaxine, a serotonin norepinephrine reuptake inhibitor (SNRI), has provided researchers with the opportunity to take a closer look at the issues involved in selecting a product for a formulary. To aid decision makers in considering the adoption of this new therapy, a pharmacoeconomic simulation model was developed to evaluate the cost-effectiveness of SNRIs versus traditional oral therapies in the management of patients with major depressive disorders (MDDs) from a cost-based payer perspective. Four treatment regimens for MDD were compared: tricyclic antidepressants, selective serotonin reuptake inhibitors, heterocyclic antidepressants, and SNRIs. The principles of decision analysis were used to calculate outcome probabilities based on data from a meta-analysis. The expected cost of each regimen was calculated using cost data from a survey of three health maintenance organizations located in Missouri, Massachusetts, and California. The model suggests that SNRI therapy demonstrates the highest level of cost-effectiveness in an inpatient setting when using both brand and generic acquisition costs of the drugs. When comparing treatment regimens for out-patients, the generic heterocyclic antidepressants demonstrate the highest level of cost-effectiveness: when using band acquisition costs, the SNRIs demonstrate the highest level of cost-effectiveness. Sensitivity analysis calculated the robustness of the conclusions to all major parameters.

Administration, Oral↗

Historical, ethical, and legal aspects of assisted suicide.

This article explores the historical, ethical, and legal antecedents of assisted suicide. Following a differentiation between assisted suicide and euthanasia, the historical aspects of suicide in the United States and other countries are described. Four cardinal principles form the basis for the ethical consideration of practice: autonomy, beneficence, nonmaleficence, and justice. Respect for autonomy is essential to the care of dying patients. However, the exercise of autonomy does not necessarily place an obligation to act on others. This could be important in the consideration of a request to a nurse for assistance in suicide. Nonmaleficence may also be a principle involved in decisions to discontinue treatments that are unwanted by the individual. Beneficence, the prevention of harm or the doing of good, may be in conflict with the respect for autonomy when one considers assisted suicide. Although one may wish to alleviate the suffering, assisting with death as a means of ending the suffering may violate the principle of beneficence even though the individual may, in his or her autonomy, request death. Justice describes what individuals are legitimately entitled to, but individual justice may be abridged by the utilitarian model of justice for society overall. Most states send ambivalent messages about the legal status of assisted suicide. Although many states criminalize assisted suicide, state prosecution of assisted suicide is not common. Furthermore, many juries have found those accused of murder or manslaughter in these instances "not guilty." A summary of the laws of each state related to assisted suicide is included.

Ethics, Nursing↗

The feasibility of the detection and quantitation of beta-adrenergic blockers by solid-phase extraction and subsequent derivatization with methaneboronic acid.

Urine specimens containing 11 common beta blockers were processed using solid-phase extraction technology to extract the drugs from the urine matrix, then converted to their cyclic methaneboronates by treatment with methaneboronic acid in ethyl acetate. The compounds tested included acebutolol, atenolol, alprenolol, bisoprolol, betaxolol, carteolol, penbutolol, propranolol, pindolol, timolol, nadolol, sotalol, labetolol, metoprolol, and oxprenolol. The extraction efficiencies were greater than 90% for all drugs tested. The cyclic methaneboronates formed by this procedure generally possessed good chromatographic properties. The mass spectral behavior of the methaneboronates was excellent, with all compounds containing several high mass fragments and every tested compound possessing a unique mass spectrum.

Adrenergic beta-Antagonists↗