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Biomedical subjects

D Carroll

Publications and source records attributed to D Carroll.

At least 109 records · Page 6Linked to original sources
PubMed1996

A systematic review of antidepressants in neuropathic pain.

The objective of this study was to review the effectiveness and safety of antidepressants in neuropathic pain. In a systematic review of randomised controlled trials, the main outcomes were global judgements, pain relief or fall in pain intensity which approximated to more than 50% pain relief, and information about minor and major adverse effects. Dichotomous data for effectiveness and adverse effects were analysed using odds ratio and number needed-to-treat (NNT) methods. Twenty-one placebo-controlled treatments in 17 randomised controlled trials were included, involving 10 antidepressants. In six of 13 diabetic neuropathy studies the odds ratios showed significant benefit compared with placebo. The combined odds ratio was 3.6 (95% CI 2.5-5.2), with a NNT for benefit of 3 (2.4-4). In two of three postherpetic neuralgia studies the odds ratios showed significant benefit, and the combined odds ratio was 6.8 (3.5-14.3), with a NNT of 2.3 (1.7-3.3). In two atypical facial pain studies the combined odds ratio for benefit was 4.1 (2.3-7.5), with a NNT of 2.8 (2-4.7). Only one of three central pain studies had analysable dichotomous data. The NNT point estimate was 1.7. Comparisons of tricyclic antidepressants did not show any significant difference between them; they were significantly more effective than benzodiazepines in the three comparisons available. Paroxetine and mianserin were less effective than imipramine. For 11 of the 21 placebo-controlled treatments there was dichotomous information on minor adverse effects; combining across pain syndromes the NNT for minor (noted in published report) adverse effects was 3.7 (2.9-5.2). Information on major (drug-related study withdrawal) adverse effects was available from 19 reports; combining across pain syndromes the NNT for major adverse effects was 22 (13.5-58). Antidepressants are effective in relieving neuropathic pain. Compared with placebo, of 100 patients with neuropathic pain who are given antidepressants, 30 will obtain more than 50% pain relief, 30 will have minor adverse reactions and four will have to stop treatment because of major adverse effects. With very similar results for anticonvulsants it is still unclear which drug class should be first choice. Treatment would be improved if we could harness the dramatic improvement seen on placebo in some of the trials.

Antidepressive Agents↗
PubMed1996

Randomization is important in studies with pain outcomes: systematic review of transcutaneous electrical nerve stimulation in acute postoperative pain.

We set out to examine the evidence for the importance of randomization of transcutaneous electrical nerve stimulation (TENS) in acute postoperative pain. Controlled studies were sought; randomization and analgesic and adverse effect outcomes were summarized. Forty-six reports were identified by searching strategies. Seventeen reports with 786 patients could be regarded unequivocally as randomized controlled trials (RCT) in acute postoperative pain. No meta-analysis was possible. In 15 of 17 RCT, we judged there to be no benefit of TENS compared with placebo. Of the 29 excluded trials, 19 had pain outcomes but were not RCT; in 17 of these 19 TENS studies, the authors concluded that TENS had a positive analgesic effect. No adverse effects were reported. Non-randomized studies overestimated treatment effects.

Acute Disease↗
PubMed1996

Ambulatory monitoring of the impedance cardiogram.

The growing need for more advanced ambulatory monitoring has led to the development of an ambulatory monitor for impedance cardiography (VU-AMD). This paper presents two studies addressing the validity of the VU-AMD. In the first study, the cardiovascular responses of 25 subjects during various conditions were simultaneously recorded with the VU-AMD and a standard laboratory impedance device. Correlations between the responses of the ambulatory and laboratory devices were high, both inter- and intraindividually, except for stroke volume and cardiac output during exercise. In the second study, 26 subjects underwent 24-hr monitoring with the VU-AMD. The values obtained with the VU-AMD were realistic and varied in a predictable way over activity and posture. It is concluded that the VU-AMD is a valid device for the measurement of systolic time intervals in real-life situations, but its applicability for absolute stroke volume and cardiac output determination remains to be established.

Adult↗
PubMed1996

Daily events and somatic symptoms: evidence of a lagged relationship.

In order to examine the lagged relationship between daily events and somatic symptoms, 48 students completed the Students Assessment of Daily Experience Questionnaire and the Somatic Symptoms subscale of the General Health Questionnaire for five days. Undesirable events were correlated with somatic symptoms three to four days later.

Adolescent↗
PubMed1996

Recombination induced by triple-helix-targeted DNA damage in mammalian cells.

Gene therapy has been hindered by the low frequency of homologous recombination in mammalian cells. To stimulate recombination, we investigated the use of triple-helix-forming oligonucleotides (TFOs) to target DNA damage to a selected site within cells. By treating cells with TFOs linked to psoralen, recombination was induced within a simian virus 40 vector carrying two mutant copies of the supF tRNA reporter gene. Gene conversion events, as well as mutations at the target site, were also observed. The variety of products suggests that multiple cellular pathways can act on the targeted damage, and data showing that the triple helix can influence these pathways are presented. The ability to specifically induce recombination or gene conversion within mammalian cells by using TFOs may provide a new research tool and may eventually lead to novel applications in gene therapy.

Animals↗
PubMed1996

Secretory immunoglobulin A and cardiovascular responses to acute psychological challenge.

Cardiovascular activity and secretory immunoglobulin A (sIgA) in saliva were recorded at rest, during a 30-min computer game task, and during subsequent recovery. Blood pressure (BP) rose and remained elevated during the task and returned to resting levels during recovery. This pressor response was produced by increased total peripheral resistance rather than increased cardiac output. SIgA secretion rate also increased during the task, although the effect proved significant only toward the end of the task. As such, the data provide preliminary indication that sIgA is sensitive to acute psychological challenge in the laboratory. Although correlational analyses revealed that sIgA reactions were stable, they were not significantly correlated with pressor reactions. The influence of task uncertainty was explored by comparing individuals who had previously played the computer game with those who had not. Task-induced increases in BP and sIgA were a feature of individuals new to the computer game. In contrast to these novice players, experienced players showed minimal increases in BP and no increases in sIgA.

Journal Article↗
PubMed1996

Blood pressure reactions to the cold pressor test and the prediction of future blood pressure status: data from the Caerphilly study.

The prognostic significance of the cold pressor test in hypertension remains a matter of controversy. Following determination at an initial screening session, blood pressure (BP) was recorded at baseline rest and in reaction to a cold pressor test. Follow-up screening BP was determined 5 years later. The effective sample was 1039 men, with an average age of 56.6 years at initial screening. Step-wise multiple regression indicated that BP reactions to the cold pressor test provided minimal independent prediction of follow-up BP over and above that afforded by BP at initial screening. In the case of follow-up systolic pressure, a model including only age and initial screening systolic BP (SBP) accounted for 38% of the variance; SBP reactions to the cold pressor did not enter the regression equation. In the case of follow-up diastolic BP (DBP), diastolic pressure at initial screening accounted for 21% of the variance, and while DBP reaction to the cold pressor test entered the equation, it accounted for only an additional 1% of the variance. These results suggest that the cold pressor test may be of limited clinical use in older populations.

Blood Pressure↗
PubMed1995

Anticonvulsant drugs for management of pain: a systematic review.

OBJECTIVE: To determine effectiveness and adverse effects of anticonvulsant drugs in management of pain. DESIGN: Systematic review of randomised controlled trials of anticonvulsants for acute, chronic, or cancer pain identified by using Medline, by hand searching, by searching reference lists, and by contacting investigators. SUBJECTS: Between 1966 and February 1994, 37 reports were found; 20 reports, of four anticonvulsants, were eligible. MAIN OUTCOME MEASURES: Numbers needed to treat were calculated for effectiveness, adverse effects, and drug related withdrawal from study. RESULTS: The only placebo controlled study in acute pain found no analgesic effect of sodium valproate. For treating trigeminal neuralgia, carbamazepine had a combined number needed to treat of 2.6 for effectiveness, 3.4 for adverse effects, and 24 for severe effects (withdrawal from study). For treating diabetic neuropathy, anticonvulsants had a combined number needed to treat of 2.5 for effectiveness, 3.1 for adverse effects, and 20 for severe effects. For migraine prophylaxis, anticonvulsants had a combined number needed to treat of 1.6 for effectiveness, 2.4 for adverse effects, and 39 for severe effects. Phenytoin had no effect on the irritable bowel syndrome, and carbamazepine had little effect on pain after stroke. Clonazepam was effective in one study for temporomandibular joint dysfunction. No study compared one anticonvulsant with another. CONCLUSIONS: Anticonvulsants were effective for trigeminal neuralgia and diabetic neuropathy and for migraine prophylaxis. Minor adverse effects occurred as often as benefit.

Anticonvulsants↗
PubMed1995

Pressor reactions to psychological stress and prediction of future blood pressure: data from the Whitehall II Study.

OBJECTIVE: To examine whether reactions of blood pressure to psychological stress predict future blood pressure. DESIGN: Blood pressure was recorded at a medical screening examination after which pressor reactions to a psychological stress task were determined. Follow up measurement of blood pressure was undertaken, on average, 4.9 years later. SETTING: 20 civil service departments in London. SUBJECTS: 1003 male civil servants aged between 35 and 55 years at entry to the study. MAIN OUTCOME MEASURE: Blood pressure at follow up screening. RESULTS: Reactions of systolic blood pressure to stress correlated positively with systolic blood pressure at follow up screening (r = 0.22, P < 0.01). The dominant correlate of follow up blood pressure was blood pressure at initial screening (r = 0.60; P < 0.01 between initial and follow up systolic blood pressure; r = 0.59, P < 0.01 between initial and follow up diastolic blood pressure). Stepwise multiple regression analysis indicated that reactions to the stressor provided minimal prediction of follow up blood pressure over and above that afforded by blood pressure at initial screening. In the case of follow up systolic blood pressure, systolic reactions to stress accounted for only 1% of follow up variance; systolic blood pressure at initial screening accounted for 34%. With regard to diastolic blood pressure at follow up, the independent contribution from diastolic reactions to stress was less than 1%. CONCLUSION: Pressor reactions to psychological stress provide minimal independent prediction of blood pressure at follow up. Measurement of reactivity is not a useful clinical index of the course of future blood pressure.

Adult↗
PubMed1995

Endonuclease-induced, targeted homologous extrachromosomal recombination in Xenopus oocytes.

Homologous recombination in gene targeting in most organisms occurs by an inefficient mechanism. Inducing a double-strand break in the chromosomal target may increase this efficiency by allowing recombination to proceed by the highly efficient single-strand annealing mechanism. A gene targeting experiment was modeled in Xenopus oocytes by using a circular plasmid to mimic the chromosomal target site and a homologous linear molecule (pick-up fragment or PUF) as an analogue of the vector DNA. When those two molecules were simply injected together, no recombination was observed. In contrast, when the circular plasmid was cleaved in vivo by injection of the site-specific endonuclease, I-Sce I, relatively efficient intermolecular recombination occurred, involving up to 17% of the cleaved molecules. Recombination was dependent on the stability of the PUF; product yield was increased by using longer fragments and by injecting larger amounts of linear DNA, both of which increased the lifetime of the PUF in the oocytes. These results demonstrate that in vivo double-strand breaks can induce homologous recombination of reluctant substrates and may be useful in augmenting the efficiency of gene targeting.

Animals↗
PubMed1995

Comparison of the sensitivity to change of long and short form pain measures.

Our objective was to assess the sensitivity to change over time of three methods of assessing pain. We conducted a comparison of the sensitivity to change of three pain assessment measures in a double blind, double dummy parallel group study evaluating the efficacy of one of two doses of oral bromfenac and one of two doses of sublingual buprenorphine. Our subject pool consisted of 75 patients following general surgical and orthopaedic procedures. Pain intensity was measured by the affective, sensory and evaluative dimensions of the McGill Pain Questionnaire together with total score and word score, a 10 cm Visual Analogue Scale and by a four word scale. Effect size calculations indicated considerable variation in the sensitivity of the instruments to change. However, despite variation in the size of effect indicated by different measures, there was consistent agreement as to the most effective treatment regimen. This study suggests that simple measures of pain are sensitive to change and are worthwhile indicators of the impact of an intervention upon acute pain, although some care is needed in interpreting results from such instruments. More complex forms of assessment, such as the calculation of the MPQ sub-scales may not add anything to such data.

Adult↗
PubMed1995

Psychology, health promotion and aesthemiology. Paper one: Social cognition models as a framework for health promotion: necessary, but not sufficient.

Much of health promotion is premised on the notion that health-related behaviours are under individual control, and strongly influenced by intra-psychic factors, including knowledge and attitudes. The emphasis placed on such factors has led to a neglect of the social and material context in which the individual is situated. This paper describes a number of psychological theories which have influenced health promotion, and suggests ways in which a wider set of psychological theories and methods, which take into account social and material factors, may more usefully inform health promotion initiatives.

Cognition↗
PubMed1995

Intravenous regional sympathetic blockade for pain relief in reflex sympathetic dystrophy: a systematic review and a randomized, double-blind crossover study.

The first aim was a systematic review of intravenous regional sympathetic blocks (IRSBs) in patients with reflex sympathetic dystrophy (RSD). Randomized controlled trials (RCTs) of IRSBs in patients with RSD were identified by MEDLINE search (1966 to May 1993) and by hand search of 30 journals (1950 to May 1993). Authors of eligible trials were asked for information on additional trials and for unpublished data. Seven RCTs of IRSBs in RSD were found. Four used guanethidine; none showed significant analgesic effect in IRSBs to relieve pain due to RSD. Two reports, one using ketanserin and one bretylium, with 17 patients in total, showed some advantage of IRSBs over control. RCT results were not combined because of the variety of different drugs and outcome measures and because of methodological deficiencies in most of the reports. The second aim was a randomized, double-blind, crossover study to assess the effectiveness of IRSBs with guanethidine. Patients fulfilling diagnostic criteria for RSD and who had reported pain relief after an open IRSB with guanethidine received IRSBs with guanethidine high dose, guanethidine low dose, and normal saline. Pain intensity and relief, adverse effects, mood, duration of analgesia, and global scores were recorded. Sixteen patients with diagnosis of RSD were recruited, but only nine entered the double-blind phase. The trial was stopped prematurely because of the severity of the adverse effects. No significant difference was found between guanethidine and placebo on any of the outcome measures.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Novel organization of the site-specific integration and excision recombination functions of the Staphylococcus aureus serotype F virulence-converting phages phi 13 and phi 42.

Functions required for site-specific integration and excision of the Staphylococcus aureus serotype F virulence-converting phages phi 13 and phi 42 were localized and characterized. Like other temperate phages, integration of phi 13 and phi 42 sequences was found to require the product of an int gene located close to the phage attP site. Both int genes are almost identical, express proteins possessing characteristic features of the Int (integrase) family of recombinases, but share very little homology with previously described int genes, including those of the serotype B S. aureus phages L54a and phi 11. Nevertheless, all four S. aureus phages share an almost identical short sequence located immediately 5' to these distinct int genes, suggesting a common mechanism of int gene regulation. Upstream from these common sequences, the sequences of phi 13 and phi 42 are quite distinct from each other, and from the corresponding regions of phi 11 and L54a which encode the Xis proteins that are required with Int to mediate site-specific excision of the latter phages. Surprisingly, phi 13 and phi 42 sequences encompassing the attP sites and int genes, but lacking either an adjacent or more distant phage excision protein gene, were sufficient to mediate site-specific excision of integrated phage DNA sequences.

Amino Acid Sequence↗
PubMed1995

Effects of nitric oxide synthase inhibitors on murine infection with Mycobacterium tuberculosis.

We have recently demonstrated that the macrophage L-arginine-dependent cytotoxic pathway effectively kills the virulent Erdman strain of Mycobacterium tuberculosis in vitro via the generation of toxic reactive nitrogen intermediates by the enzyme nitric oxide synthase. This report demonstrates that two distinct inhibitors of nitric oxide synthase (aminoguanidine and NG-monomethyl-L-arginine) render similar deleterious effects on tuberculous infection in mice, as assessed by mortality, bacterial burden, and pathological tissue damage, thus confirming the importance of reactive nitrogen intermediates in resistance against M. tuberculosis.

Amino Acid Oxidoreductases↗