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Biomedical subjects

H Logan

Publications and source records attributed to H Logan.

At least 19 recordsLinked to original sources
PubMed2001

Effects of stress and relaxation on capsaicin-induced pain.

A sizable body of research has been devoted to understanding the relationship between pain sensitivity and the psychological state of the individual. Considerable disagreement as to the direction of the association still exists. This study examines the effects of 2 experimental manipulations, cognitive/emotional stress and relaxation, on capsaicin-induced pain. Subjects were pretrained in relaxation and then randomized to experimental stress produced by a 20-minute Stroop test, relaxation (tape), or a control condition (neutral video), followed by a capsaicin injection in the forearm. Cardiovascular measures were taken at regular intervals, and cortisol, norepinephrine (NE), and self-reports of arousal (relaxation index) were taken immediately before and after the experimental task. The manipulation significantly interacted with sex to predict capsaicin-induced maximum pain. Women in the stress condition reported greater pain than both men in the stress condition and women in the relaxation condition. Pain was correlated negatively with task-induced changes in NE and cortisol and positively with self-reported arousal (decreased relaxation). However, separate analyses showed that some physiologic indexes of heightened arousal (increased blood pressure and NE) predicted lower pain only in men, whereas subjective increases in arousal predicted higher pain only in women. Multiple hierarchical regression analyses confirmed that physiologic and self-reported arousal predicted pain independently and in opposite directions, and a model including both accounted for 56% of the overall variance. These findings suggest that a unidimensional model of arousal may be insufficient to explain the effects of stress on pain and that these effects operate differently in men and women.

Clinical Trial↗
PubMed2000

Adjunctive non-pharmacological analgesia for invasive medical procedures: a randomised trial.

BACKGROUND: Non-pharmacological behavioural adjuncts have been suggested as efficient safe means in reducing discomfort and adverse effects during medical procedures. We tested this assumption for patients undergoing percutaneous vascular and renal procedures in a prospective, randomised, single-centre study. METHODS: 241 patients were randomised to receive intraoperatively standard care (n=79), structured attention (n=80), or self-hypnotic relaxation (n=82). All had access to patient-controlled intravenous analgesia with fentanyl and midazolam. Patients rated their pain and anxiety on 0-10 scales before, every 15 min during and after the procedures. FINDINGS: Pain increased linearly with procedure time in the standard group (slope 0.09 in pain score/15 min, p<0.0001), and the attention group (slope 0.04/15 min; p=0.0425), but remained flat in the hypnosis group. Anxiety decreased over time in all three groups with slopes of -0.04 (standard), -0.07 (attention), and -0.11 (hypnosis). Drug use in the standard group (1.9 units) was significantly higher than in the attention and hypnosis groups (0.8 and 0.9 units, respectively). One hypnosis patient became haemodynamically unstable compared with ten attention patients (p=0.0041), and 12 standard patients (p=0.0009). Procedure times were significantly shorter in the hypnosis group (61 min) than in the standard group (78 min, p=0.0016) with procedure duration of the attention group in between (67 min). INTERPRETATION: Structured attention and self-hypnotic relaxation proved beneficial during invasive medical procedures. Hypnosis had more pronounced effects on pain and anxiety reduction, and is superior, in that it also improves haemodynamic stability.

Adult↗
PubMed1997

Thyroid hormones and selenium status in breast cancer.

Within a case-control study of postmenopausal breast cancer patients (n = 99) and matched healthy controls (n = 105), thyroid hormone levels were compared and correlated with toenail selenium concentrations. Plasma triiodothyronine (T3) was significantly lower in cases (1.4 +/- 0.4 nmol/l) than in controls (1.6 +/- 0.4 nmol/l), and a strong inverse relationship with breast cancer was observed with an odds ratio of 0.17 (95% CI = 0.08-0.36) in the highest compared with the lowest tertile of T3. Plasma thyroxine and thyroid-stimulating hormone concentrations were similar between cases and controls. Plasma T3 concentration was positively associated with toenail selenium in cases (age-adjusted regression coefficient = 0.049) and controls (age-adjusted regression coefficient = 0.036). Toenail selenium concentrations tended to be lower in cases than in controls, but the differences did not reach statistical significance. Although the disease process per se may explain the lower plasma T3 concentrations, it is also possible, inasmuch as these patients were in early-stage breast cancer, that selenium status may be influencing T3 levels via changes in the activity of the selenoenzyme type 1 iodothyronine deiodinase.

Aged↗
PubMed1997

Ultrasound in the diagnosis and exclusion of intussusception.

Intussusception is a major cause of intestinal obstruction in infancy and childhood. Improved results of treatment have followed the increased use of ultrasound imaging and pneumatic reduction. We prospectively studied the value of ultrasound in both the diagnosis and exclusion of intussusception in a peripheral paediatric unit over a four year period from October 1990 to October 1994. In all, 24 patients had a suspected clinical diagnosis of intussusception of which 19 had typical ultrasound findings. The male to female ratio was 8:11 and age at presentation ranged from 2 to 38 months (mean 11.4 months). There were no false negatives and 2 false positives giving a sensitivity to 100% and specificity of 89%. Thus no intussusception was missed by ultrasound examination. Enema reduction was successful in 76% of cases and factors associated with failure of enema reduction included passage of blood per rectum and symptoms for greater than 24 hours. We conclude that ultrasound should be used as a rapid and sensitive screening procedure in the diagnosis and exclusion.

Child, Preschool↗
PubMed1994

Desire for control, felt control, and stress inoculation training during dental treatment.

Coping style research has typically assessed subjects' desire for a coping resource, but ignored whether subjects possess that resource. In this study 110 dental patients were categorized as to their desire for and feelings of control and were randomly assigned, just prior to dental treatment, to a 20-minute Stress Inoculation Training (SIT) session or a Filler condition. SIT significantly reduced pain and increased control only for patients who initially reported a high desire for control coupled with low perceived control. This finding supports the view that the discrepancy between high desire for control and low perceived control plays a causal role in the elevated distress and pain initially reported by patients with such control perceptions. These data indicate that consideration of patients' perceived coping resources as well as their coping preferences adds to our ability to predict reactions to stress reduction manipulations.

Adaptation, Psychological↗
PubMed1993

Emotional and sensory focus as mediators of dental pain among patients differing in desired and felt dental control.

Giving patients instructions to focus on sensory (vs. emotional) stimuli during a root canal procedure significantly reduced self-reported pain, but only among patients who were classified as having strong desire for control and low felt control in dental situations. Among patients with low felt control and low desire for control, sensory-focus instructions produced greater pain reports than did emotion-focus instructions. Finally, high desire-low felt patients reported higher levels of expected pain before treatment than did other patient subgroups. These data suggested limiting conditions for H. Leventhal's (1982) theory of emotion and supported the idea that desire for control might moderate the effects of perceived control.

Adaptation, Psychological↗
PubMed1992

Breast tumour thymidine kinase levels and disease recurrence.

Thymidine kinase (TK) exists in two forms, TK1 and TK2. TK levels and oestrogen receptor status (OR) were measured in tumours from 86 patients with operable breast cancer and the patients were monitored for recurrence over 24 months. During the monitored period, 13 patients showed recurrence. These patients also exhibited higher total TK levels per mg tumour (P < 0.01) and higher TK1 levels (P < 0.001) than those who did not show recurrence. TK1 levels relative to TK2 were significantly higher (P < 0.05) in OR-negative tumours (n = 29) than in OR-positive tumours (n = 57). OR-negative (n = 9) and OR-positive (n = 4) patients who recurred had significantly higher TK1 levels relative to TK2 than did those who not recur (n = 20 and n = 53, respectively). These preliminary results indicate that breast tumour TK levels may have value in determining prognosis.

Adult↗
PubMed1991

The analysis of 5-fluorouracil in human plasma by gas chromatography-negative ion chemical ionization mass spectrometry (GC-NICIMS) with stable isotope dilution.

5-Fluorouracil (5-FU) was extracted from plasma and converted to its di-N-ditrifluoromethylbenzyl (DTFMBz) derivative by treatment with DTFMBzBr. Under negative ion chemical ionization (NICI) conditions the derivative yielded a mass spectrum in which most of the ion current was carried by the M(-)-DTFMBz ion (m/z 355). Selected ion monitoring enabled detection of this derivative in amounts less than 1 pg, and the practical limit of detection for 5-FU extracted from plasma was ca 400 pg ml-1. 5-FU was quantified by adding a fixed amount of [15N2]5-FU to samples of plasma before extraction, and comparing the ratio of the ions of m/z 355 and 357 against a calibration curve constructed over the concentration range under investigation. The method was used to measure the variation in the concentration of 5-FU with time during continuous infusion of the drug via three, different protocols in patients with hepatic tumour.

Fluorouracil↗
PubMed1991

Development of radiolabelled albumin microspheres: a comparison of gamma-emitting radioisotopes of iodine (131I) and indium (111In/113mIn).

Biodegradable albumin microspheres have been prepared incorporating either 131I or 111In/111In. Using cDTPAA/albumin molar ratios of 1, 3 and 10, approx. 0.7, 2.1 and 7 molecules of DTPA could be coupled to an albumin molecule, labelling efficiency being constant over this range. Because 131I microspheres were more stable in plasma than the system labelled with radionuclides of indium it was selected for clinical evaluation: potential uses of this radiopharmaceutical are illustrated.

Biodegradation, Environmental↗
PubMed1990

Some variables affecting dentists' assessment of patients' distress.

Dental students estimated the pain distress and discomfort of their patients after patients received a Class II restoration (simple filing). Dentist's estimates of patient pain accounted for 36% of the variance in patient self-report responses. Dentist accuracy was significantly lower, however, for estimates of anxiety and distress. Dentist accuracy was unaffected by patient's degree of self-monitoring. There was a tendency for female dentists to demonstrate greater accuracy than male dentists, but this effect was nonsignificant. In addition, dentists' accuracy in assessing overall patient discomfort was significantly lower in that segment of the treatment procedure that was most stressful for the dentists. This article discusses theoretical explanations for this latter effect.

Adult↗
PubMed1989

A comparison of two different T-grain films in rare-earth screens with a standard film-screen combination for intravenous pyelography and bone examinations.

T-grain film is claimed to give significantly improved image quality, allowing the use of faster screens without loss of quality and thus reducing radiation dose. We tested this claim for two systems. In each case comparison was made with our usual screen-film combination, Agfa Curix RP1 film with Kodak Xomatic Regular screens (a nominally 200 speed system). The systems tested were Kodak TMatG in Kodak Lanex Medium screens (300 speed) and Agfa STG in Kodak Lanex Regular screens (400 speed). The Agfa STG-Lanex Regular system performed less well than the standard system for intravenous pyelograms (IVPs), bones and soft-tissue detail. Its speed advantage was not apparent below 70 kV. The Kodak TMatG-Lanex Medium system was better than the standard system for IVPs but not as good for bones. It gave virtually no speed advantage below 90 kV. Kodak T-grain film in a medium-speed, rare-earth screen was found to be better than the standard system for IVPs. Agfa T-grain film in a fast rare-earth screen was unsatisfactory for IVPs. Neither combination was as good as the standard system for bones.

Bone and Bones↗
PubMed1988

Detection of splenosis: 99Tcm tin colloid scanning and computed transmission tomography compared.

Ten patients who had been splenectomized for trauma between 1 and 11 years previously were studied by computed tomography (CT) and radionuclide scanning with 99Tcm tin colloid on the same day. Computed tomography detected splenic tissue in three patients. Radionuclide scanning detected splenic tissue in eight patients, including two cases of typical splenosis not identified by CT. Radionuclide scanning was found to be more sensitive in the detection of residual splenic tissue than CT.

Adult↗
PubMed1987

Simplified peripheral arteriography.

Demonstration of both iliofemoral arteries and their peripheral run-off is usually performed either by the translumbar approach, or by placing a pigtail catheter at the aortic bifurcation. A modified version of the old retrograde pressure method, simply using a cannula in one femoral artery, is described. There was considerable saving in materials, personnel and time. This method may once again be the method of choice in a busy radiology department.

Aged↗