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Biomedical subjects

M Williams

Publications and source records attributed to M Williams.

At least 181 records · Page 10Linked to original sources
PubMed2000

Applications of informatics in veterinary medicine.

This study used the peer-reviewed biomedical literature to define the veterinary informatics knowledgebase and associated subspecialties, and assesses the level of activity in the field over the thirty-year period from 1966 through 1995. Grateful Med was used to search the MEDLINE bibliographic database for articles that shared one or more Medical Subject Headings (MeSH) keywords from the veterinary and medical informatics subject headings. Each of ninety-five MeSH medical informatics terms was assigned to one of twelve veterinary informatics subspecialties. The number of articles retrieved by each MeSH keyword and subspecialty was calculated. A total of 611 articles were retrieved, representing the contributions of 1,338 authors published in 153 journals. The field experienced slow growth over the twenty-year period from 1966 through 1985. In the following decade, the cumulative number of veterinary informatics articles almost tripled and the percentage of veterinary-related articles that included an informatics component increased almost two-and-one-half fold. Despite this recent growth, the number of veterinary-related articles with an informatics component has never exceeded 1% of either the veterinary or medical informatics literature over the past thirty years, and representation of veterinary subspecialties in the literature varied widely.

Animals↗
PubMed2000

Assessing dopamine concentrations: an evidence-based approach.

BACKGROUND: Both overmedication and undermedication can be potentially life threatening. If the actual volume of a 100-mL intravenous bag used to mix dopamine solutions is greater than the labeled volume, overdilution of medication can occur, resulting in an ineffective hemodynamic response in patients and thus an unintended adverse drug event. OBJECTIVES: To determine the actual fluid volumes of 100-mL intravenous bags, compare the actual volumes of 100-mL bags from the 3 major manufacturers of intravenous bags, and determine if the excess volume is sufficient to cause a clinically significant overdilution of dopamine. METHODS: A comparative descriptive design was used. The volumes of 162 intravenous bags of 100 mL of 5% dextrose in water (32 lot numbers with various expiration dates) were measured. Visual volume was confirmed by using a 250-mL graduated cylinder. Volume by weight was determined with a calibrated laboratory-quality electronic scale. On the basis of a mathematical model, any overfill greater than 110 mL was considered clinically significant. RESULTS: The difference between actual and labeled volumes was statistically and clinically significant. Mean visual volume was 110.20 mL (range, 107-114 mL). Mean weighed volume was 109.26 mL (range, 106.15-112.09 mL). The fluid volumes among bags from the 3 major IV companies differed significantly (P < .001). CONCLUSIONS: The overfill in sufficient numbers of 100-mL intravenous bags was enough to cause clinically significant overdilution of dopamine. When dopamine or other vasoactive medications are mixed, either an in-line buret or premixed bags of the drugs should be used to prevent an unintended adverse drug event.

Bias↗
PubMed2000

Monoclonal reagents for rhesus-D typing of Irish patients and donors: a review.

Polyclonal anti-D reagents have been largely replaced by monoclonal reagents; however, although generally very potent, they can exhibit some variation in activity, particularly in the detection of weak Rhesus (Rh) D-positive cells. Hence, although patients and donors previously typed as Rh-D-negative (Du positive) are now being typed as Rh-D-positive, it is likely that two monoclonal reagents selected for Rh-D typing may give anomalous results. This has led to confusion in testing patients and donors in Irish laboratories. To address this problem, 29 commercially available monoclonal and monoclonal/polyclonal anti-D reagents were evaluated for reactivity with partial D and efficiency of weak-D detection, using the manual tube technique. The anti-D reagents used in column technologies (Biovue and Diamed) also were evaluated. Testing was limited by the availability of partial-D cells. The reagents directly agglutinated the majority of partial-D cells, with the exception of DVI, which required the indirect antiglobulin test for detection. Totem (Diagast) and Z039 (Scottish National Blood Transfusion Service) both directly agglutinated DVI. The weak-D detection rate for a number of immunoglobulin M (IgM) reagents was improved by incubation of initially negative tests. Sedimentation techniques, recommended for a number of reagents, were unsuitable for weak-D or partial-D detection. There were indications that IgM/IgG reagents gave lower direct-agglutination weak-D detection rates than did IgM reagents, although Totem and Novaclone produced results matching those of the IgM reagents. Laboratories should be aware of the guidelines for Rh-D typing of patients and donors, and select anti-D reagents accordingly.

Antibodies, Monoclonal↗
PubMed2000

ABT-702 (4-amino-5-(3-bromophenyl)-7-(6-morpholinopyridin-3-yl)pyrido[2, 3-d]pyrimidine), a novel orally effective adenosine kinase inhibitor with analgesic and anti-inflammatory properties: I. In vitro characterization and acute antinociceptive effects in the mouse.

Adenosine (ADO) is an inhibitory neuromodulator that can increase nociceptive thresholds in response to noxious stimulation. Inhibition of the ADO-metabolizing enzyme adenosine kinase (AK) increases extracellular ADO concentrations at sites of tissue trauma and AK inhibitors may have therapeutic potential as analgesic and anti-inflammatory agents. ABT-702 is a novel and potent (IC(50) = 1. 7 nM) non-nucleoside AK inhibitor that has several orders of magnitude selectivity over other sites of ADO interaction (A(1), A(2A), A(3) receptors, ADO transporter, and ADO deaminase). ABT-702 was 1300- to 7700-fold selective for AK compared with a number of other neurotransmitter and peptide receptors, ion channel proteins, neurotransmitter/nucleoside reuptake sites, and enzymes, including cycloxygenases-1 and -2. ABT-702 was equipotent (IC(50) = 1.5 +/- 0. 3 nM) in inhibiting native human AK (placenta), two human recombinant isoforms (AK(long) and AK(short)), and AK from monkey, dog, rat, and mouse brain. Kinetic studies revealed that AK inhibition by ABT-702 was competitive with respect to ADO and noncompetitive with respect to MgATP(2-). AK inhibition by ABT-702 was demonstrated to be reversible after 4 h of dialysis. ABT-702 is orally active and fully efficacious in reducing acute somatic nociception (ED(50) = 8 micromol/kg i.p.; 65 micromol/kg p.o.) in the mouse hot-plate assay. ABT-702 also dose dependently reduced nociception in the phenyl-p-quinone-induced abdominal constriction assay. The antinociceptive effects of ABT-702 in the hot-plate assay were blocked by the nonselective ADO receptor antagonist theophylline, and by the A(1)-selective antagonist cyclopentyltheophylline (10 mg/kg i.p.), but not by a peripherally selective ADO receptor antagonist 8-(p-sulfophenyl)-theophylline (50 mg/kg i.p.), by the A(2A)-selective antagonist 3, 7-dimethyl-1-propargylxanthine (1 mg/kg i.p.) or the opioid antagonist naloxone (5 mg/kg i.p.). Thus, ABT-702 is a novel and potent non-nucleoside AK inhibitor that effectively reduces acute thermal nociception in the mouse by a nonopioid, non-nonsteroidal anti-inflammatory drug, ADO A(1) receptor-mediated mechanism.

Adenosine Kinase↗
PubMed2000

ABT-702 (4-amino-5-(3-bromophenyl)-7-(6-morpholino-pyridin- 3-yl)pyrido[2,3-d]pyrimidine), a novel orally effective adenosine kinase inhibitor with analgesic and anti-inflammatory properties. II. In vivo characterization in the rat.

Adenosine kinase (AK; EC 2.7.1.20) is a key intracellular enzyme regulating intra-and extracellular concentrations of adenosine (ADO), an endogenous neuromodulator, antinociceptive, and anti-inflammatory autocoid. AK inhibition provides a means of potentiating local tissue concentrations of endogenous ADO, and AK inhibitors may have therapeutic potential as analgesic and anti-inflammatory agents. The effects of ABT-702, a novel, potent (IC(50) = 1.7 nM), and selective non-nucleoside AK inhibitor were examined in rat models of nociception and acute inflammation. ABT-702 was orally effective and fully efficacious to suppress nociception in a spectrum of pain models in the rat, including carrageenan-induced thermal hyperalgesia, the formalin test of persistent pain, and models of nerve injury-induced and diabetic neuropathic pain (tactile allodynia after L5/L6 spinal nerve ligation or streptozotocin injection, respectively.) ABT-702 was especially potent at relieving inflammatory thermal hyperalgesia (ED(50) = 5 micromol/kg p.o.). ABT-702 was also effective in the carrageenan-induced paw edema model of acute inflammation (ED(50) = 70 micromol/kg p.o.). The antinociceptive and anti-inflammatory effects of ABT-702 were blocked by selective ADO receptor antagonists, consistent with endogenous ADO accumulation and ADO receptor activation as a mechanism of action. The antinociceptive effects of ABT-702 were not blocked by the opioid antagonist naloxone. In addition, ABT-702 showed less potential to develop tolerance to its antinociceptive effects compared with morphine. ABT-702 had no significant effect on rotorod performance or heart rate (at 30-300 micromol/kg p.o.), mean arterial pressure (at 30-100 micromol/kg p.o.), or exploratory locomotor activity (at </=10 micromol/kg p.o.). Thus, ABT-702 is a novel, non-nucleoside AK inhibitor, with a nonopioid, non-nonsteroidal anti-inflammatory drug mechanism of action, which shows antinociceptive and anti-inflammatory activity in vivo.

Adenosine Kinase↗
PubMed2000

Characterization of lipoxygenase isoforms in olive callus cultures.

Lipoxygenase activity is critical for the development of flavours and aromas in olive oils. We have partly purified isoforms of molecular mass 95 kDa that have activity against linoleic or alpha-linolenic acids by a simple procedure from olive callus cultures.

Cell Fractionation↗
PubMed2000

Controlling the processes. Legislation governing decontamination and sterilisation.

Time was, in the not so distant past, that any piece of equipment we wanted to re-use in the Theatre Sterile Services Unit (TSSU) was either autoclaved or 'sterilised' in chemicals. The words 'single use' were virtually never used, and I certainly knew very little about the legislation surrounding the whole issue. Indeed, just a little while further back than that, we used to wash and pack and autoclave whole sets of instruments ourselves (it was a good way of learning the sets for the student nurses!). Now we have the whole issue of traceability and responsibility to consider. Martin Williams discusses some of the legislation and issues arising. I wonder who my Authorised Person is? Do you know yours?

Disposable Equipment↗
PubMed1999

The tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone is a beta-adrenergic agonist and stimulates DNA synthesis in lung adenocarcinoma via beta-adrenergic receptor-mediated release of arachidonic acid.

Lung cancer is the leading cause of death in the United States, and it demonstrates a strong etiological association with smoking. The nicotine-derived nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) reproducibly induces pulmonary adenocarcinomas (ACs) in laboratory rodents and is considered an important contributing factor to the high lung cancer burden observed in smokers. It has been shown that the development of NNK-induced ACs in mice is reduced by inhibitors of cyclooxygenase and lipoxygenase and that the growth of human AC cell lines is regulated by beta-adrenergic receptors. On the basis of structural similarities of NNK with classic beta-adrenergic agonists, we tested the hypothesis that NNK stimulates the growth of human AC cells via agonist-binding to beta-adrenergic receptors, resulting in the release of arachidonic acid (AA). In support of this hypothesis, radioreceptor assays with transfected CHO cell lines stably expressing the human beta1- or beta2-adrenergic receptor demonstrated high affinity binding of NNK to each of these receptors. Two human AC cell lines expressed beta1- and beta2-adrenergic receptors by reverse transcription-PCR and responded to NNK with the release of AA and an increase in DNA synthesis. Beta-adrenergic antagonists completely blocked the release of AA and increase in DNA synthesis. The cyclooxygenase inhibitor aspirin and the 5-lipoxygenase inhibitor MK-886 both partially inhibited DNA synthesis in response to NNK. Our findings identify the direct interaction of NNK with beta-adrenergic, AA-dependent pathways as a novel mechanism of action which may significantly contribute to the high cancer-causing potential of this nitrosamine. Moreover, NNK may also contribute to the development of smoking-related nonneoplastic disease via this mechanism.

Adenocarcinoma↗
PubMed1999

NHS attitudes to good medical practice.

Perceptions of good medical practice among senior NHS staff were collected through a survey. There are differences between the perceived seriousness of poor communication skills and poor technical skills.

Attitude of Health Personnel↗
PubMed1999

Synthesis and serotonergic activity of substituted 2, N-benzylcarboxamido-5-(2-ethyl-1-dioxoimidazolidinyl)-N, N-dimethyltryptamine derivatives: novel antagonists for the vascular 5-HT(1B)-like receptor.

The synthesis and vascular 5-HT(1B)-like receptor activity of a novel series of substituted 2, N-benzylcarboxamido-5-(2-ethyl-1-dioxoimidazolidinyl)-N, N-dimethyltryptamine derivatives are described. Modifications to the 5-ethylene-linked heterocycle and to substituents on the 2-benzylamide side chain have been explored. Several compounds were identified which exhibited affinity at the vascular 5-HT(1B)-like receptor of pK(B) > 7.0, up to 100-fold selectivity over alpha(1)-adrenoceptor affinity and 5-HT(2A) receptor affinity, and which exhibited a favorable pharmacokinetic profile. N-Benzyl-3-[2-(dimethylamino)ethyl]-5-[2-(4,4-dimethyl-2, 5-dioxo-1-imidazolidinyl)ethyl]-1H-indole-2-carboxamide (23) was identified as a highly potent, silent (as judged by the inability of angiotensin II to unmask 5-HT(1B)-like receptor-mediated agonist activity in the rabbit femoral artery), and competitive vascular 5-HT(1B)-like receptor antagonist with a plasma elimination half-life of approximately 4 h in dog plasma and with good oral bioavailability. The selectivity of compounds from this series for the vascular 5-HT(1B)-like receptors over other receptor subtypes is discussed as well as a proposed mode of binding to the receptor pharmacophore. It has been proposed that the aromatic ring of the 2, N-benzylcarboxamide group can occupy an aromatic binding site rather than the indole ring. The resulting conformation allows an amine-binding site to be occupied by the ethylamine nitrogen and a hydrogen-bonding site to be occupied by one of the hydantoin carbonyls. The electronic nature of the 2,N-benzylcarboxamide aromatic group as well as the size of substituents on this aromatic group is crucial for producing potent and selective antagonists. The structural requirement on the 3-ethylamine side chain incorporating the protonatable nitrogen is achieved by the bulky 2, N-benzylcarboxamide group and its close proximity to the 3-side chain.

Animals↗
PubMed1999

Adherence by African American men to prostate cancer education and early detection.

BACKGROUND: This study was designed to identify factors that predict adherence by African American men to prostate cancer education and early detection. METHODS: In the spring of 1995, the authors identified 548 African American men who were patients at the University Health Services of the University of Chicago, were ages 40-70 years, and did not have a personal history of prostate cancer. Baseline telephone survey data were collected from 413 men (75%). Participants were randomly assigned to either a minimal or an enhanced intervention group. Men in the former group were mailed a letter and a reminder that invited them to a urology clinic for prostate cancer education and early detection. Men in the enhanced intervention group were sent the same correspondence and were also given print material and telephone contacts, which were tailored to each recipient. RESULTS: Adherence was significantly higher (OR = 2.6, CI: 1.7-3.9) in the enhanced intervention group than in the minimal intervention group (51% and 29%, respectively). Men who were age 50 years or older (OR = 1.7, CI: 1.1-2.8), were married (OR = 1.8, CI: 1.2-2.9), believed that prostate cancer early detection examination should be performed in the absence of symptoms (OR = 2.3, CI: 1.3-4.0), and self-reported an intention to have an early detection examination (OR = 1.9, CI: 1.2-2.9) were also more likely to adhere. CONCLUSIONS: A tailored behavioral intervention can influence adherence to prostate cancer early detection among African American men. Individual background and cognitive and psychosocial characteristics may also affect behavior. Future studies should assess the impact of this type of intervention on cognitive and psychologic correlates of decision-making and behavior along the continuum of prostate cancer care. [See editorial on pages 1-2, this issue.]

Adult↗