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Biomedical subjects

D Laws

Publications and source records attributed to D Laws.

At least 19 recordsLinked to original sources
PubMed2005

A prospective, randomised, controlled study examining binaural beat audio and pre-operative anxiety in patients undergoing general anaesthesia for day case surgery.

Pre-operative anxiety is common and often significant. Ambulatory surgery challenges our pre-operative goal of an anxiety-free patient by requiring people to be 'street ready' within a brief period of time after surgery. Recently, it has been demonstrated that music can be used successfully to relieve patient anxiety before operations, and that audio embedded with tones that create binaural beats within the brain of the listener decreases subjective levels of anxiety in patients with chronic anxiety states. We measured anxiety with the State-Trait Anxiety Inventory questionnaire and compared binaural beat audio (Binaural Group) with an identical soundtrack but without these added tones (Audio Group) and with a third group who received no specific intervention (No Intervention Group). Mean [95% confidence intervals] decreases in anxiety scores were 26.3%[19-33%] in the Binaural Group (p = 0.001 vs. Audio Group, p < 0.0001 vs. No Intervention Group), 11.1%[6-16%] in the Audio Group (p = 0.15 vs. No Intervention Group) and 3.8%[0-7%] in the No Intervention Group. Binaural beat audio has the potential to decrease acute pre-operative anxiety significantly.

Acoustic Stimulation↗
PubMed2005

A prospective, randomised controlled trial comparing the efficacy of pre-oxygenation in the 20 degrees head-up vs supine position.

We investigated whether positioning patients undergoing general anaesthesia for cholecystectomy in a 20 degrees head-up position, as opposed to supine, improved the efficacy of 3 min of standard pre-oxygenation via a circle breathing system. Following pre-oxygenation, patients received a standard induction of anaesthesia and the apnoea time (from administration of rocuronium to the arterial oxygen saturation to fall to 95%) was recorded. Mean (95% CI) apnoea time was 386 (343-429) s in the 20 degrees head-up position (n = 17) vs 283 (243-322) s in the supine position (n = 18; p = 0.002). Pre-oxygenation is significantly more efficacious and by inference more efficient in the 20 degrees head-up position than in the supine position.

Adult↗
PubMed2004

Respiratory bronchiolitis associated interstitial lung disease (RB-ILD): a case of an acute presentation.

Respiratory bronchiolitis associated interstitial lung disease (RB-ILD) is a recently described clinicopathological entity that occurs almost exclusively in current heavy cigarette smokers. Few cases have been reported in the literature and no studies have been carried out on the effect of treatment, which currently consists of smoking cessation with or without corticosteroids. We report the first case of an acute presentation of histologically proven RB-ILD in a young cigarette smoker whose diagnosis and management proved to be difficult. Smoking cessation alone was found to be inadequate so management was combined with corticosteroid therapy.

Acute Disease↗
PubMed2001

Reduced expression of TAP-1 and TAP-2 in posterior uveal melanoma is associated with progression to metastatic disease.

In order to determine the effects of the loss or reduced expression of molecules associated with antigen presentation (transporter associated with antigen presentation [TAP]-1, TAP-2, low molecular weight protein [LMP]-2 and LMP-7), we examined the expression of these molecules in primary uveal melanoma lesions. Paraffin-embedded sections from 29 primary uveal melanoma lesions were analysed for expression of TAP-1, TAP-2, LMP-2 and LMP-7 using specific primary antibodies followed by a three-stage immunoperoxidase technique. Microscopic examination was undertaken to determine differences in expression of these molecules on the tumour and the surrounding stroma. Overall, 72% (21 out of 29) of the tumours showed some loss or reduced expression of TAP-1, TAP-2, LMP-2 and/or LMP-7. Statistical analysis of these results showed that progression to metastatic disease was strongly associated with reduced expression of TAP-1 (P < 0.05) and TAP-2 (P < 0.01), taking patient age, tumour site and histology into account. We conclude that the reduced expression of molecules important in eliciting an immune response, such as TAP-1 and TAP-2, may facilitate the metastatic spread of uveal melanoma lesions and may have important implications for prospective immunotherapy.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2000

The influence of retinopathy of prematurity on ocular growth.

PURPOSE: Retinopathy of prematurity (ROP) stage 3 eyes that require treatment have a greater tendency to myopia compared with eyes with mild ROP. As the mechanisms controlling this myopia are as yet ill understood, we undertook this study to investigate what effect the initial stage of ROP and modality of treatment had on ocular growth. METHODS: Eighty-five children were assessed. All children were refracted and underwent 'through-the-lid' biometry using the Zeiss Humphrey biometer 820. The printout obtained was then recorded on video so that the scan could be captured on computer for formal calibration and measurement by a masked observer. Differences in the distribution of variables between the stages of ROP were analysed by one-way analysis of variance, non-parametric Kruskal-Wallis one-way analysis of variance or Mann-Whitney U-test as appropriate. RESULTS: A difference between the stages of ROP was apparent only for posterior segment length (PSL) (R: p = 0.03; L: p = 0.05) and a borderline difference for anterior chamber depth (ACD) (R: p = 0.06; L: p = 0.06). However, if stage 3 was divided into categories of treated and untreated, axial length (AL) achieved borderline significance (R: p = 0.07; L: p = 0.05) but with no difference between laser-treated and the other stages for AL. Lens thickness (LT) also appears to be influenced by type of treatment (R: p = 0.06; L: p = 0.13). Myopia was associated with stage 3 (R + L: p = 0.0001) and if stage 3 was subdivided the significance was maintained only for the laser- and cryotherapy-treated eyes. CONCLUSIONS: Laser-treated eyes were less myopic than those treated with cryotherapy. AL does not explain all the myopia found in stage 3 treated eyes. The study confirms the tendency towards anterior segment arrest in stage 3 ROP.

Biometry↗
PubMed1998

Assessment of a new through-the-eyelid technique for 'A' scan ultrasound ocular axial length measurement.

This study evaluated the repeatability both within one session and between two sessions of a new technique of axial length measurement using 'A' scan ultrasound through the eyelids. The validity of the technique was assessed by comparing the results to those taken through the cornea. The new technique was very reliable, the mean difference between two readings at the first visit being 0.01 mm and between the two visits being 0.01 mm with 95% of differences between two readings in both cases being less than two standard deviations. The axial length measurements through the lid were a mean of 0.05 mm longer than the corneal measurements. The standard deviation of the difference between the two forms of measurement was 0.16 mm and 95% of axial length readings through the eyelid were within two standard deviations (+/- = 0.32 mm) of the corneal measurement. Providing strict criteria are applied to the quality of the 'A' scan images we believe that satisfactory axial length values may be obtained using this technique.

Anisotropy↗
PubMed1997

Cryotherapy and laser treatment for acute retinopathy of prematurity: refractive outcomes, a longitudinal study.

BACKGROUND: Infants who require treatment for threshold retinopathy of prematurity are at increased risk of developing refractive errors. Following the introduction of laser treatment for threshold disease, the clinical impression was that the degree of myopia was reduced compared with cryotherapy. METHODS: A longitudinal study was carried out of refractive error at 3 and 12 months in 19 patients undergoing cryotherapy and 15 patients undergoing laser treatment. RESULTS: At 3 months the median spherical equivalent refractive error in the right eye was -3.25 dioptres after cryotherapy and +0.25 dioptres after laser therapy (similar results left eye). The median spherical equivalent refractive error in the right eye at 12 months was -5.25 dioptres following cryotherapy and -0.50 dioptres after laser (similar results left eye). There was a statistically significant difference in median spherical refractive error between the therapies at 3 months and 12 months (p < 0.05 Wilcoxon rank sum) in both eyes. CONCLUSION: Laser therapy is associated with lower degrees of myopia during the first year of life, which is clinically significant in terms of visual performance and development.

Acute Disease↗
PubMed1994

Fluorine-19 nuclear magnetic resonance spectroscopic study of fluorophenylalanine- and fluorotryptophan-labeled avian egg white lysozymes.

We report the 470-MHz (11.7 T) 19F solution nuclear magnetic resonance (NMR) spectra of 2-, 3-, and 4-fluorophenylalanine incorporated into the egg white lysozymes (EC 3.2.1.17) of chicken, pheasant, and duck, as well as spectra of 4-fluorotryptophan incorporated into chicken, California valley quail, and Bob White quail and 5- and 6-fluorotryptophan-labeled chicken lysozyme. The 19F solution NMR spectrum of [4-F]Phe hen egg white lysozyme (HEWL) consists of three sharp resonances, which span a total chemical shift range of 4.8 ppm (at p2H = 6.1). For [3-F]Phe HEWL, the chemical shift range is much smaller, 1.0 ppm (at p2H = 5.9), due presumably to the occurrence of fast phenyl ring flips about the C beta-C gamma bond axis. For [2-F]Phe HEWL, six resonances are observed, spanning a chemical shift range of 7.4 ppm (at p2H = 5.8), due to slow C beta-C gamma ring flips, i.e., both ring-flip isomers appear to be "frozen in" because of steric hindrance. Rotation of the [2-F]Phe residues remains slow up to 55 degrees C (p2H = 4.7). With the [F]Trp-labeled proteins, we find a maximal 14.6-ppm shielding range for [4-F]Trp HEWL but only a 2.8- and 2.4-ppm range for [5- and 6-F]Trp HEWL, respectively, due presumably to increased solvent exposure in the latter cases. Guanidinium chloride denaturation causes loss of essentially all chemical shift nonequivalence, as does thermal denaturation. Spectra recorded as a function of pH show relatively small chemical shift changes (< 1.4 ppm) over the pH range of approximately 1.2-7.8.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1992

Retinopathy of prematurity: a prospective study. Review at six months.

A cohort of infants of birthweight < or = 1700 g studied prospectively for retinopathy of prematurity (ROP) has been reviewed at 6 months corrected age and the findings related to the neonatal data. The overall incidence of strabismus was 6.4% (30/468), rising from 3.1% (7/229) without ROP to 29.2% (7/24) with stage 3. Strabismus and fusional ability were significantly related to presence and severity of ROP, and abnormal neonatal cranial ultrasound findings. Binocular visual acuity was measured in 340 infants between 20 and 40 weeks corrected age. Eight were subnormal, all due to neurological problems. For the remainder, despite falling within the normal range, there was a significant trend (p < 0.001) for lower acuities with increasing ROP severity. Cycloplegic refraction on 387 infants revealed, with increasing ROP severity: 1, a significant trend towards myopia; 2, increased magnitude of astigmatism; 3, alteration of the astigmatic axis; 4, increased incidence of anisometropia. For the first three categories there was an insignificant trend between no ROP and stage 2, reaching significance only between stage 2 and 3. The predominant axis of astigmatism in infants without ROP was between 60 degrees and 120 degrees, but with ROP there was a significant trend away from this direction.

Age Factors↗
PubMed1990

The reliability of palpation in the assessment of tumours.

There is now a joint UICC-AJC classification for cervical lymph nodes based mainly on the size of the nodes. There is a recognized error in palpation, not only for detecting the presence of tumour but also its size. This study used an animal tumour model system to compare the ability of 6 independent observers of varying experience to detect and stage superficially transplanted growths. A preclinical medical student was as good as a Consultant ENT Surgeon in predicting the presence of tumour but the ability to stage tumours accurately was related to experience. Whilst the most experienced observers accurately estimated the size of tumours less than 2 cm, they were less accurate for larger (greater than 2 cm) tumours which were constantly understaged. This phenomenon may have important clinical implications particularly related to current nodal staging criteria.

Animals↗
PubMed1990

Technetium-99m (v) dimercaptosuccinic acid: a clinical and scintigraphic study in an animal tumour model.

Technetium-99m (99mTc) (v) dimercaptosuccinic acid (DMSA) is a new tumour-imaging agent which has been used to image head and neck squamous carcinoma. This study used an established rabbit tumour model to compare palpation versus planar scintigraphy in the detection of superficially transplanted cancers. Palpation detected 83% of tumours measuring less than 2 cm compared with 58% for scintigraphy. Overall, the sensitivity for palpation was 88% (77% specificity) compared with 50% (63% specificity) for scintigraphy.

Animals↗
PubMed1990

A multicentre double-blind comparative trial of fluvoxamine versus lorazepam in mixed anxiety and depression treated in general practice.

Fluvoxamine, a selective serotonin reuptake inhibitor, was compared with lorazepam in a multicentre double-blind, parallel group study in 112 general practice patients with mixed anxiety and depression. For inclusion, patients were required to have minimum baseline scores of 21 on the Montgomery-Asberg Depression Rating Scale (MADRS) and 11 on the Clinical Anxiety Scale (CAS). Treatment was for 6 weeks. There were no significant differences between treatments at any point except in an elderly subgroup in whom anxiety improved more rapidly with lorazepam. There were significant improvements in MADRS, CAS and global ratings compared with baseline at all subsequent assessments. Improvement continued during the whole treatment period. Lorazepam produced more sedation, whilst fluvoxamine produced significantly more nausea and vomiting; this was usually early in onset and, if tolerated, resolved during the course of the study. As it is now widely recognized that benzodiazepines should only be given in short courses of 2-4 weeks, the continued improvement up to 6 weeks has implications regarding choice of treatment.

Adult↗
PubMed1990

Efficacy and tolerability of controlled-release trazodone in depression: a large multicentre study in general practice.

A double-blind, parallel-group study was carried out to compare the efficacy and tolerability of a controlled-release tablet formulation of trazodone with the standard trazodone tablet. Three hundred and forty-seven general practice patients with depressive symptoms were recruited into the trial. Patients were randomly allocated to receive either 1 controlled-release trazodone (150 mg) tablet at night or 1 standard trazodone (150 mg) tablet at night for a period of 6 weeks. Assessments of efficacy, tolerability and compliance were made at study entry and after 1, 2, 4 and 6 weeks of study medication. Seventy-seven patients withdrew from the study of whom 44 were in the standard trazodone tablet group and 33 were in the controlled-release trazodone tablet group. There were no statistically significant differences between treatment groups in any of the measures of efficacy (global severity, global improvement and Hamilton Depression Rating Scales 17- and 21-item). Major improvements in patients' condition were shown in all efficacy measures by the end of the study in comparison with study entry. Treatment differences were small but were numerically in favour of the controlled-release tablet formulation. As expected, a greater proportion of side-effects were reported during the first 2 weeks of treatment in both groups. Treatment differences, revealed in a five symptom adverse event checklist used throughout the study, were small, although in favour of the controlled-release tablet in the majority of cases, but not statistically significant.

Adolescent↗