Suprascapular nerve block for chronic shoulder pain in rheumatoid arthritis.
Explore the source record for details and available documents.
Aged↗
Biomedical subjects
S Bowman
Publications and source records attributed to S Bowman.
Oxidative inactivation of rhodanese by hydrogen peroxide produces states that show differential reactivation.
Controlled conditions have been found that give complete reactivation and long term stabilization of rhodanese (EC 2.8.1.1) after oxidative inactivation by hydrogen peroxide. Inactivated rhodanese was completely reactivated by reductants such as thioglycolic acid (TGA) (100 mM) and dithiothreitol (DTT) (100 mM) or the substrate thiosulfate (100 mM) if these reagents were added soon after inactivation. Reactivability fell in a biphasic first order process. At pH 7.5, in the presence of DTT inactive rhodanese lost 40% of its reactivability in less than 5 min, and the remaining 60% was lost more gradually (t 1/2 = 3.5 h). TGA reactivated better than DTT, and the rapid phase was much less prominent. If excess reagents were removed by gel filtration immediately after inactivation, there was time-independent and complete reactivability with TGA for at least 24 h, and the resulting samples were stable. Reactivable enzyme was resistant to proteolysis and had a fluorescence maximum at 335 nm, just as the native protein. Oxidized rhodanese, Partially reactivated by DTT, was unstable and lost activity upon further incubation. This inactive enzyme was fully reactivated by 200 mM TGA. Also, the enzyme could be reactivated by arsenite and high concentrations of cyanide. Addition of hydrogen peroxide (40-fold molar excess) to inactive rhodanese after column chromatography initiated a time-dependent loss of reactivability. This inactivation was a single first order process (t 1/2 = 25 min). Sulfhydryl titers showed that enzyme could be fully reactivated after the loss of either one or two sulfhydryl groups. Irreversibly inactivated enzyme showed the loss of one sulfhydryl group even after extensive reduction with TGA. The results are consistent with a two-stage oxidation of rhodanese. In the first stage there can form sulfenyl and/or disulfide derivative(s) at the active site sulfhydryl that are reducible by thioglycolate. A second stage could give alternate or additional oxidation states that are not easily reducible by reagents tried to date.
Arsenic↗
Detection of time-dependent and oxidatively induced antigens of bovine liver rhodanese with monoclonal antibodies.
Rhodanese has been extensively utilized as a model protein for the study of enzyme structure-function relationships. An immunological study of conformational changes occurring in rhodanese as a result of oxidation or thermal inactivation was conducted. Three monoclonal antibodies (MABs) to rhodanese were produced. Each MAB recognized a unique epitope as demonstrated by binding of the MABs to different proteolytic fragments of rhodanese. While none of the MABs significantly bound native, soluble, sulfur-substituted bovine rhodanese, as indicated in indirect enzyme-linked immunosorbent assay experiments, each MAB was immunoadsorbed from solution by soluble rhodanese as a function of the time rhodanese was incubated at 37 degrees C. Thus, as rhodanese was thermally inactivated, conformational changes resulted in the expression of three new epitopes. Catalytic conformers demonstrated different rates of thermally induced antigen expression. Each MAB also recognized epitopes expressed when rhodanese was immobilized on microtiter plates at 37 degrees C. Two conformers resulting from oxidation of rhodanese by hydrogen peroxide were identified immunologically. All MABs recognized rhodanese that was oxidized with peroxide and allowed to undergo a secondary cyanide-dependent reaction which also resulted in a fluorescence shift and increased proteolytic susceptibility. Only one MAB was capable of recognizing an epitope expressed when rhodanese was oxidized with peroxide and then separated from the reactants to prevent induction of the secondary conformational changes.
Animals↗
Oxidation increases the proteolytic susceptibility of a localized region in rhodanese.
For the first time, the enzyme rhodanese has been proteolytically cleaved to give species that most likely correspond to individual domains. This indicates cleavage can occur in the interdomain tether. Further, the conditions for cleavage show that availability of the susceptible bond(s) depends on conformational changes triggered by oxidative inactivation. Rhodanese, without persulfide sulfur (E), was oxidized consequent to incubation with phenylglyoxal, NADH, or hydrogen peroxide. The oxidized enzyme (Eox) was probed using the proteolytic enzymes endoproteinase glutamate C (V8), trypsin, chymotrypsin, or subtilisin. The proteolytic susceptibility of Eox, formed using hydrogen peroxide, was compared with that of E and the form of the enzyme containing transferred sulfur, ES. ES was totally refractory to proteolysis, while E was only clipped to a small extent by trypsin or V8 and not at all by chymotrypsin or subtilisin. Eox was susceptible to proteolysis by all the proteases used, and, although there were some differences among the proteolytic patterns, there was always a band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis corresponding to Mr = 16,500. This was the only band observed in addition to the parent species (Mr = 33,000) when Eox was digested with chymotrypsin, and conservation of total protein was observed after digestion up to 90 min. No additional species were observable on silver staining, although there was some indication that the band at 16,500 might be a doublet. The results are consistent with the occurrence of a conformational change after oxidation that results in increased exposure and/or flexibility of the interdomain tether which contains residues that meet the specificity requirements of the proteases used.
Chymotrypsin↗
Conformational changes accompany the oxidative inactivation of rhodanese by a variety of reagents.
Rhodanese is oxidatively inactivated by several reagents, some of which are not normally considered oxidants. Rhodanese, in a form not containing persulfide sulfur (E), was inactivated by phenylglyoxal under conditions where disulfides are formed. There was the concomitant increase in the fluorescence of the apolar probe 1,1'-bi(4-anilino)naphthalene-5,5'-disulfonic acid (bisANS). At 0.2 mg/ml protein, there was no turbidity, while at 1 mg/ml, turbidity formed after an induction period of 23 min. Phenylglyoxal-inactivated E was extensively digested by endoproteinase glutamate C (V8 protease) to give two discrete high molecular weight fragments (Mr = 29,500 and 16,000). Enzymatically active E or ES, the form of rhodanese containing transferred sulfur (Mr = 33,000) was totally refractory to V8 protease and gave only small fluorescent enhancement of bisANS. Phenylglyoxal inactivated ES (reaction at arginine) gave very little fluorescence enhancement of bisANS and was not digested by V8. Hydrogen peroxide rapidly inactivated E (t1/2 less than 2 min) giving a slow increase in bisANS fluorescence (t1/2 greater than 10 min) identical to that observed with phenylglyoxal. The turbidity also increased after an induction period of approximately 30 min. Inactivation of E by hydrogen peroxide gave the same digestion pattern as that observed with phenylglyoxal inactivation. The turbidity was associated with the formation of disulfide-bonded structures that formed with the stoichiometry of E, 2E, 4E, 6E, 8E, etc. relative to the native enzyme, E. E was inactivated with several other reagents that lead to oxidatively inactivated rhodanese including NADH, dithiothreitol, mercaptoethanol, and m-dinitrobenzene. Enzyme inactivated with dithiothreitol or NADH gave an identical digestion pattern as above. In addition, with the exception of NADH which could not be used due to optical interference, each of the reagents gave rise to increased fluorescence of bisANS after inactivation. The results are consistent with a model in which the oxidized rhodanese resulting from diverse treatments is in a new conformation that has extensive exposed apolar surfaces and can form both noncovalent and disulfide-bonded aggregates.
Dithiothreitol↗
Reversible thermal denaturation of immobilized rhodanese.
For the first time, the enzyme rhodanese had been refolded after thermal denaturation. This was previously not possible because of the strong tendency for the soluble enzyme to aggregate at temperatures above 37 degrees C. The present work used rhodanese that was covalently coupled to a solid support under conditions that were found to preserve enzyme activity. Rhodanese was immobilized using an N-hydroxymalonimidyl derivative of Sepharose containing a 6-carbon spacer. The number of immobilized competent active sites was measured by using [35S]SO3(2-) to form an active site persulfide that is the obligatory catalytic intermediate. Soluble enzyme was irreversibly inactivated in 10 min at 52 degrees C. The immobilized enzyme regained at least 30% of its original activity even after boiling for 20 min. The immobilized enzyme had a Km and Vmax that were each approximately 3 times higher than the corresponding values for the native enzyme. After preincubation at high temperatures, progress curves for the immobilized enzyme showed induction periods of up to 5 min before attaining apparently linear steady states. The pH dependence of the activity was the same for both the soluble and the immobilized enzyme. These results indicate significant stabilization of rhodanese after immobilization, and instabilities caused by adventitious solution components are not the sole reasons for irreversibility of thermal denaturation seen with the soluble enzyme. The results are consistent with models for rhodanese that invoke protein association as a major cause of inactivation of the enzyme. Furthermore, the induction period in the progress curves is consistent with studies which show that rhodanese refolding proceeds through intermediate states.
Animals↗
Ion-enhanced fluorescence staining of sodium dodecyl sulfate-polyacrylamide gels using bis(8-p-toluidino-1-naphthalenesulfonate).
A method for the sensitive fluorescent staining of sodium dodecyl sulfate (SDS) gels that extends the applicability and sensitivity of existing procedures has been developed. SDS-protein complexes are able to bind the noncovalent hydrophobic probe, bis(8-p-toluidino-1-naphthalenesulfonate) (bisANS) with an increase in quantum yield that is considerably larger than that observed with the commonly used monomeric form, 1-anilinonaphthalene-8-sulfonic acid (1,8-ANS). The quantum yield of bisANS bound to the SDS-protein complex is greatly enhanced by incubation with one of a number of cations including potassium and barium. The use of bisANS with metal ion enhancements provides a method for staining SDS gels that can be more sensitive than commonly used methods based on the binding of Coomassie blue, and provides a simple and rapid method for the detection and quantitation of proteins. The use of metal ion enhancements also greatly increases the sensitivity of staining methods based on the use of 1,8-ANS. The present method is much more sensitive than previous noncovalent, flourescent, postelectrophoresis stains, but it retains their considerable advantages of speed, simplicity, and the ability to perform secondary procedures on the separated materials.
Anilino Naphthalenesulfonates↗
Support for those who stutter needs support.
Explore the source record for details and available documents.
Humans↗
Induction of human cutaneous mast cell degranulation by opiates and endogenous opioid peptides: evidence for opiate and nonopiate receptor participation.
In order to examine the capacity of pharmacologically useful opiates to stimulate human mast cell secretion, subjects were skin tested with morphine, codeine, or meperidine hydrochloride. All three agents acted equipotently in eliciting positive immediate skin reactions from all subjects tested. Each agent demonstrated 10 mm of net whealing at 5 to 10 micrograms base (16.7 to 40.4 nmol) injected intradermally. The ability to elicit immediate skin test reactions with endogenous opioid peptides was examined with the use of dynorphin, [D-Ala, 2-D-Leu5] enkephalin, beta-endorphin, and morphiceptin . All four compounds induced wheal-and-flare reactions with the order of potency: dynorphin, greater than beta-endorphin, and greater than [D-Ala, 2-D-Leu5] enkephalin approximately equal to morphiceptin at dose ranges of 0.3 to 8.45 nmol. The inhibition of reactivity by hydroxyzine and the demonstration of mast cell degranulation by electron microscopy suggest that the immediate skin responses to opioid stimulation occur as a consequence of mast cell degranulation. Experiments with the opioid receptor antagonist, naloxone, suggest that both opioid and nonopioid receptors may be involved. These results imply that endogenous opioid peptides possibly may play a role in mast cell function and/or degradulation .
Codeine↗
A youthful outlook. 2. A student's perspective.
Explore the source record for details and available documents.
Humans↗
Kinetic analysis of the specificity of human natural cytotoxicity.
Distribution-free analysis of kinetic data for cellular cytotoxicity reactions enables the precise determination of kinetic parameters for the lysis of target cells by individual lymphocyte preparations. This report presents results obtained when this method was used to quantitate the inhibition of human natural cytotoxicity by unlabelled (cold) target cells. In agreement with previous studies, we found that the natural cytotoxicity of a given target cell can be inhibited by heterologous as well as homologous unlabelled cells; however, the strongest inhibition was usually produced when the unlabelled inhibitor cells were homologous to the labelled target cells. The general pattern of inhibition observed for the target and inhibitor cells tested in these experiments was competitive, and when inhibitor cells were homologous to the labelled cells, the observed increase in Kappm agreed with theoretical predictions based on equations derived previously. These results support earlier reports of limited but not absolute antigenic specificity by subsets of human NK cells. Moreover, while Kappm values for cytotoxicity reactions are not simply related to antigen binding, quantitative analysis of the relative inhibition of cytotoxicity by heterologous versus homologous unlabelled cells provides useful estimates of the relative affinity of the effector cell subset(s) that kill a given target cell for various NK target cells.
Adult↗
Position statement on the role of health care assistants who are involved in direct patient care activities within critical care areas.
Intensive care has developed as a speciality since the 1950s, and during this time, there have been major technological advances in health care provision, leading to a rapid expansion of all areas of critical care. The ongoing problem in recruiting qualified nurses in general has affected, and continues to be a problem for, all aspects of critical care areas. During the past decade, nursing practice has evolved, as qualified nurses have expanded their own scope of practice to develop a more responsive approach to the complex care needs of the critically ill patient. The aim of this paper is to present the British Association of Critical Care Nurses (BACCN) position statement on the role of health care assistants involved in direct patient care activities, and to address some of the key work used to inform the development of the position statement.
Clinical Competence↗
Health care assistants' role, function and development: results of a national survey.
Intensive care has developed as a speciality since the 1950s; during this time there have been major technological advances in health care provision leading to a rapid expansion of all areas of critical care. The ongoing problem of recruiting appropriately qualified nurses has affected staffing levels in many units and continues to be a national problem. For many, the answer lies in employing health care assistants to support the work of registered nurses. A key aim of the British Association of Critical Care Nurses is to promote the art and science of critical care nursing by providing representation for its members, by responding to political and professional change and by producing and publishing position statements. A primary component of the work surrounding the development of this second position statement was the gathering of contemporary information in relation to the role of health care assistants within critical care units throughout the UK, through a survey of 645 critical care units within the UK. At present the impact upon the role of the critical care nurse is not fully understood, with research in this area suggesting that although there is a role for the health care assistant in the critical care environment, this should only be undertaken with a full analysis of this impact upon the work of the registered nurse.
Allied Health Personnel↗
Vancomycin-resistant enterococci; the ultimate nosocomial pathogen?
Explore the source record for details and available documents.
Anti-Bacterial Agents↗
The role of interleukin-8 and other cytokines in the pathogenesis of Felty's syndrome.
OBJECTIVE: Felty's syndrome (FS) is defined as rheumatoid arthritis (RA) with neutropenia and, in some cases, splenomegaly; the outcome is primarily determined by the risk of infection, which is related to the degree of neutropenia. We analysed whether the clinical manifestations of FS, especially neutropenia, could be explained by abnormalities in cytokine production. METHODS: We examined the production in FS of five cytokines involved in the maturation and activation of polymorphonuclear cells (PMNs): IL-1 beta, TNF alpha, IL-8, G-CSF and GM-CSF. Because of the role of systemic IL-8 in neutrophil migration, serum IL-8 levels were also evaluated. RESULTS: Spontaneous and anti-CD16 stimulated cytokine production was similar in FS, RA and healthy controls (NC). However, anti-CD3 stimulated IL-8 production was significantly increased compared to NC in both RA and FS. FS patients who spontaneously produced G-CSF in culture were protected from bacterial infections. Serum IL-8 levels were elevated in FS and RA compared to NC (p < 0.001 for both groups). In FS, serum IL-8 was higher in patients with a history of bacterial infections compared to those without (p < 0.01) and there was a weak inverse correlation between neutropenia and serum IL-8 levels (Kendal's tau B = -0.31, p = 0.05). CONCLUSION: The neutropenia of FS cannot be explained by changes in peripheral blood cytokine production, although changes in the bone marrow microenvironment cannot be excluded. Our data do suggest a possible role for G-CSF and IL-8 in the development of certain FS complications.
Arthritis, Rheumatoid↗
Radiography education in the United Kingdom.
The U.S. system of educating radiologic technologists is changing to meet the demands of an evolving health care work force. As a result, the educational standards and role of tomorrow's radiologic technologist will be very different from those of today. Many of the changes being considered by radiologic science professionals in the United States already have occurred in the United Kingdom. Beginning this year, for example, all entry-level radiographers in the United Kingdom must be graduates of a baccalaureate degree program. This article describes how radiography programs in the United Kingdom made the transition to a baccalaureate degree standard. It also examines how the role and scope of practice of U.K. technologists changed following the increase in educational standards.
Education, Continuing↗