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Biomedical subjects

K Griffith

Publications and source records attributed to K Griffith.

At least 19 recordsLinked to original sources
PubMed2002

Assessment of psychological distress in prospective bone marrow transplant patients.

Patient psychological distress is associated with many aspects of the bone marrow transplantation (BMT) process and has been linked with poor treatment outcomes. We assessed psychological distress in potential BMT candidates, and compared patient and nurse coordinator ratings of emotional distress at the time of initial BMT consultation. Fifty patients self-reported psychological distress using both the NCCN Distress Thermometer (DT) and the Hospital Anxiety and Depression Scale (HADS). Coordinators rated patient emotional distress using the DT and Coordinator Rating Scales that measure anxiety and depression. Fifty and 51% of patients self-reported clinically significant levels of emotional distress and anxiety, respectively, but only 20% self-reported clinically significant levels of depression. There was good correlation between ratings using the brief DT and the more comprehensive HADS. There was significant but only moderate agreement between patient and coordinator ratings of emotional distress and anxiety, with coordinators underestimating the number of patients with high levels of emotional distress. In addition, coordinator ratings of patient emotional distress primarily reflected anxiety, whereas anxiety and depression together only minimally accounted for patient self-reports of psychological distress. These findings suggest that: (1) the DT can be a useful screening device; (2) approximately half of patients at the time of initial consultation for BMT already experience significant levels of psychological distress; and (3) coordinators observe emotional distress primarily as anxiety, but patients experience psychological distress as something more than anxiety and depression.

Adult↗
PubMed2002

A randomised controlled trial of a self-management plan for patients with newly diagnosed angina.

BACKGROUND: There are approximately 1.8 million patients with angina in the United Kingdom, many of whom report a poor quality of life, including raised levels of anxiety and depression. AIM: To evaluate the effect of a cognitive behavioural disease management programme, the Angina Plan, on psychological adjustment in patients newly diagnosed with angina pectoris. DESIGN OF STUDY: Randomised controlled trial. SETTING: Patients from GP practices in a Northern UK city (York) between April 1999 and May 2000. METHOD: Recruited patients were randomised to receive the Angina Plan or to a routine, practice nurse-led secondary prevention educational session. RESULTS: Twenty of the 25 practices invited to join the study supplied patients' names; 142 patients attended an assessment clinic and were randomised There were no significant differences in any baseline measures. At the six month post-treatment follow-up, 130 (91%) patients were reassessed. When compared with the educational session patients (using analysis of covariance adjusted for baseline scores in an intention-to-treat analysis) Angina Plan patients showed a greater reduction in anxiety (P = 0.05) and depression (P = 0.01), the frequency of angina (reduced by three episodes per week, versus a reduction of 0.4 per week, P = 0.016) the use of glyceryl trinitrate (reduced by 4.19 fewer doses per week versus a reduction of 0.59 per week, P = 0.018), and physical limitations (P<0.001: Seattle Angina Questionnaire). They were also more likely to report having changed their diet (41 versus 21, P<0.001) and increased their daily walking (30 versus 2, P<0.001). There was no significant difference between the groups on the other sub-scales of the Seattle Angina Questionnaire or in any of the medical variables measured. CONCLUSION: The Angina Plan appears to improve the psychological, symptomatic, and functional status of patients newly diagnosed with angina.

Adaptation, Psychological↗
PubMed2001

Novel (4-piperazin-1-ylquinolin-6-yl) arylsulfonamides with high affinity and selectivity for the 5-HT(6) receptor.

The discovery of (4-piperazin-1-ylquinolin-6-yl) arylsulfonamides and their binding affinities for a selection of 5-HT and dopamine subreceptors is described. Many compounds show high affinity (pK(i)>8) for the 5-HT(6) receptor and >100-fold selectivity against a range of other receptors. Structure-activity relationships of these compounds are discussed.

Molecular Structure↗
PubMed2001

Phenyl benzenesulfonamides are novel and selective 5-HT6 antagonists: identification of N-(2,5-dibromo-3-fluorophenyl)-4-methoxy-3-piperazin-1-ylbenzenesulfonamide (SB-357134).

Substituted N-phenyl-4-methoxy-3-piperazin-1-ylbenzenesulfonamides and conformationally restricted analogues have been identified as high affinity and selective 5-HT6 antagonists. Compounds from this series had a range of pharmacokinetic profiles in rat and in general there was a correlation between clearance and CNS penetration. Based on its overall biological profile 2 (SB-357134) was selected for further pre-clinical evaluation.

Animals↗
PubMed2001

A computerised quality control testing system for B-mode ultrasound.

Current methods of ultrasound (US) imaging quality control involve an observer taking a series of measurements on test object images. This process is very labour-intensive, rapidly becoming more so as the complexity of US scanners increases. Also, many of the measurements are based on the subjective judgement of the operator and are, therefore, prone to an undesirable level of intraobserver and interobserver variation. We have developed a suite of programs to analyse captured US images to estimate a number of performance parameters, including resolution, high- and low-contrast penetration depths and high- and low-contrast sensitivity. In this system, images of the ATS Laboratories Multipurpose Phantom Model 539 are acquired on a PC with a video capture card, and analysed using the software developed. Automated tests have been developed for resolution, low- and high-contrast penetration and low- and high-contrast sensitivity. A preliminary validation of the system was carried out using images from two curvilinear probes and a linear-array probe operating at 5 MHz, 7.5 MHz and 10 MHz, respectively. The 95% confidence intervals ranged from +/- 17% to +/- 21% for resolution measurements and from 0% to +/- 1.5% for low-contrast penetration. The system provides an index of visibility for high- and low-contrast targets, as compared to the coarse visual assessment of a human observer, with 95% confidence intervals ranging from +/- 6% to +/- 13% for low-contrast sensitivity and from +/- 3% to +/- 25% for high-contrast sensitivity. Advantages of the system over the human observer include improved reproducibility and increased information regarding visibility of targets. A more detailed multicentre validation is currently being undertaken.

Automation↗
PubMed2001

A review of two alternative ultrasound quality assurance programmes.

OBJECTIVE: This study reviewed the results of B-mode Quality Assurance (QA) performance tests on 17 real-time ultrasound scanners, performed over a period of 3 years, in order to assess their value. Following this review we revised and simplified our testing schedules to include two tests for noise and sensitivity. The value of the new schedules was assessed. METHODS: Initially, testing schedules were similar to those recommended by two professional bodies. Results were reviewed to determine whether the tests predicted or confirmed faults. We then introduced a simplified testing programme using alternative measurements, attempting to demonstrate or predict noise related faults that affect the image, but were not demonstrated by current tests. These new tests have been performed on 24 ultrasound machines for up to 18 months. RESULTS: A review of results has shown that measurements occasionally fall outside tolerance due to chance, and that faults that significantly affect the image, e.g. probe faults and noise, are reported by the users without predictive or concomitant changes in test results using our original schedules. Faults occur that do not immediately affect image quality and are not reported by the users. Inappropriate settings, e.g. monitors, are frequently reset at QA, particularly where there are potentially untrained users. The additional tests showed consistent changes in noise (four) or sensitivity (one) on five machines. CONCLUSION: Our earlier tests were inadequate in demonstrating deterioration in the clinical performance of ultrasound imaging equipment. Introduction of a revised testing schedule has resulted in changes in equipment performance being detected and rectified.

Equipment Failure Analysis↗
PubMed2001

Trends in the incidence of nonmelanoma skin cancers in southeastern Arizona, 1985-1996.

This report describes trends in the incidence of various nonmelanoma skin cancers in a region of high ultraviolet exposure. The Southeastern Arizona Skin Cancer Registry routinely identified cases of skin cancer between 1985 and 1996 through pathology logs and reports from dermatology offices and laboratories in 3 Arizona counties. The incidence rates for squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) for non-Hispanic whites were 3 to 6 times higher than the incidence rates from more northern regions. The rates for non-Hispanic whites were approximately 11 times greater than rates for Hispanics. Furthermore, there was no constant increase in the incidence of nonmelanoma skin cancers. The incidence of SCC, in particular, demonstrated a plateau or even a modest decline between 1985 and 1996. Thus the incidence rates of both SCC and BCC in Arizona, although among the highest in the world, do not appear to be increasing as rapidly as predicted elsewhere.

Adolescent↗
PubMed2001

The use of a whole body index with bone scintigraphy to monitor the response to therapy in Paget's disease.

Bone scintigraphy has long been used to assess Paget's disease and investigate the response to therapy. Objective visual assessment is, however, difficult. The aim of this study was to derive, from a bone scintigram, an index which objectively measured the extent and severity of Paget's disease in the entire skeleton. This whole body index would provide a single numerical value which could be used to monitor the response to therapy in both monostotic and polyostotic disease. Comparison with other methods of assessing the condition, such as biochemical markers and pain scores, would also be possible. The whole body index was developed and used to retrospectively analyse 80 bone scintigrams on 40 patients. The majority of patients (36) received treatment with a bisphosphonate between the two scintigrams. Whole body index was compared with serum alkaline phosphatase measured at the same time; a significant correlation was found (before treatment P=0.001, after treatment P<0.001). The change in whole body index and alkaline phosphatase following treatment with various bisphosphonates was also investigated and a significant correlation found (P<0.001). Whilst performing the analysis it was also noted that the increase in uptake of the radiopharmaceutical was significantly greater in the cortical long bones than in the trabecular axial skeleton. This study suggests that a whole body index may be a suitable tool for assessing the response to treatment in Paget's disease.

Aged↗
PubMed1999

A back-propagation neural network predicts absorption maxima of chimeric human red/green visual pigments.

The absorption spectra of human red and green visual pigments have peak wavelengths, lambda max, that differ by 31 nm, yet the opsins differ in only 15 amino acids. Mutagenesis studies have demonstrated that seven of the 15 amino acids determine the spectral shift. We trained neural networks to predict the lambda max of any red/green chimeric protein. Seven mutants were excluded from the original training set. The trained networks were able to predict the lambda max for the excluded mutants. As an additional test, five new chimeric pigments were constructed and lambda max determined. The neural networks correctly predicted the lambda max of all five mutants. The use of neural networks is a novel approach to the problem of wavelength modulation in visual pigments.

Amino Acids↗
PubMed1998

Familial influences on gambling behavior: an analysis of 3359 twin pairs.

BACKGROUND: Pathological gambling is becoming an increasing problem in the United States as the number of legalized gambling establishments grows. To examine vulnerability to pathological gambling, we estimated the familial contributions (i.e. inherited factors and/or experiences shared by twin siblings during childhood) to DSM-III-R pathological gambling symptoms and disorder. METHODS: Data were obtained from a telephone interview performed in 1991-92 utilizing the Diagnostic Interview Schedule Version III-Revised. Interviews were administered to 6718 members of the nationally distributed Vietnam Era Twin Registry of male-male monozygotic and dizygotic twin pairs who served in the military during the Vietnam era. RESULTS: Inherited factors explain between 35% (95% CI: 28%, 42%) and 54% (95% CI: 39%, 67%) of the liability for the five individual symptoms of pathological gambling behavior that could be estimated statistically. In addition, familial factors explain 56% (95% CI: 36%, 71%) of the report of three or more symptoms of pathological gambling and 62% (95% CI: 40%, 79%) of the diagnosis of pathological gambling disorder (four or more symptoms). CONCLUSIONS: Familial factors have an important influence on risk for pathological gambling behavior. The increasing access to legalized gambling is likely to result in a higher prevalence of pathological gambling behavior among individuals who are more vulnerable because of familial factors.

Adult↗
PubMed1998

The clinical course of patients with acute myocardial infarction who are unsuitable for thrombolytic therapy because of the presenting electrocardiogram. UK Heart Attack Study Investigators.

OBJECTIVE: To examine the clinical characteristics and 30-day fatality rate among patients with electrocardiograms (ECGs) ineligible for fibrinolysis in a consecutive series in four general hospitals in the UK. METHODS: We studied 2439 consecutive patients who were identified from regular ward visits, surveillance of results from hospital laboratories, and hospital discharge coding. RESULTS: Thirty percent (732) of patients did not have ECGs eligible for fibrinolysis therapy, while indications were uncertain in 55 (2%). Within the ineligible group, patients presenting with ST depression (n = 294) had a higher 30-day fatality rate than those with ST elevation or left bundle branch block (26% versus 17%; P < 0.001); they represented 40% of the group ineligible for fibrinolysis therapy, or 12% of the total cohort. Thirty-day fatality rates in patients presenting with pathological Q waves and no diagnostic ST segment changes (n = 130), those with T wave changes but no other abnormality (n = 168) and those with a normal ECG (n = 128) were 10%, 5% and 3%, respectively. Despite their high fatality rate, fewer patients with ST depression were admitted to coronary care units than those with ECGs eligible for fibrinolysis therapy (61% versus 85%; P < 0.001) and 23% did not receive heparin. The coronary anatomy in a subset of patients with ST depression showed two- or three-vessel disease in 79% and left main stenosis in 9%. The rates of coronary revascularisation were low in all groups (< 10%). CONCLUSION: Patients with ECGs ineligible for fibrinolysis therapy are a disparate group, with a high rate of fatality occurring in patients who present with ST depression. The high prevalence of multiple vessel coronary disease in patients with ST depression suggests that a more active management strategy is required.

Aged↗
PubMed1998

Acute myocardial infarction: are there missed opportunities for reperfusion? UK Heart Attack Study Investigators.

AIMS: To investigate the current use of thrombolytic therapy in the management of patients with acute myocardial infarction and to determine the potential for an increased use of thrombolysis or percutaneous transluminal coronary angioplasty (PTCA). METHODS AND RESULTS: All hospitalised cases of acute myocardial infarction were identified in three health districts in the UK (population of 960,000) in patients under the age of 76 years during a 2-year period; 2439 patients had acute myocardial infarction, of whom 1264 (52%) received thrombolytic therapy. Failure to administer thrombolytic therapy was a result of the absence of diagnostic electrocardiograms in 712 (29.2%) patients, late presentation in 127 (5.2%), therapeutic error in 112 (4.6%), presence of a bleeding risk in 139 (5.7%) and other miscellaneous reasons in 80 (3.3%) patients. Thirty-eight of the 139 patients in whom bleeding risk was reported as a contra-indication could, in retrospect, have received thrombolytic therapy and a further 76 would have been suitable for primary PTCA. CONCLUSIONS: The potential for increasing the use of thrombolytic therapy seems to be limited and is unlikely to make a major impact on the in-hospital mortality from acute myocardial infarction. However, primary PTCA should be considered in those who are ineligible for thrombolysis because of bleeding risk as a contra-indication.

Adult↗
PubMed1996

The importance of rigorous testing of circumference measuring callipers.

On-screen circumference measurements are frequently made in obstetric ultrasound and are also made in other ultrasound specialties. The accuracy of electronic callipers is traditionally checked by linear measurement in a test object; this does not adequately test callipers used for nonlinear measurement. This technical note describes a simple test object designed for both linear and nonlinear calliper checks. Results show one machine to generate consistently large overmeasurements (15%). The clinical consequences of such overmeasurement may be serious. Appropriate quality control is essential.

Algorithms↗
PubMed1995

The estimation of administered activity of krypton-81m for lung ventilation studies.

Measurement or estimation of the activity of krypton-81m administered to a patient during lung ventilation imaging is difficult, due to the short half-life and continuous delivery via pipework, and no satisfactory method exists. Calculations based on generator activity have the disadvantages that this activity may not be accurately known and that not all activity eluted is inhaled by the patient. The aim of this study was to develop a simple method for estimating the administered activity from the number of counts in each patient image. A formula based on the ratio of counts in 81mKr and technetium-99m lung ventilation and perfusion images was developed and reduced so that administered activity could be directly calculated from the total 81mKr counts, the 99mTc count rate, the administered activity of 99mTc and a constant representing the ratio of counts expected from equal activities of each radioisotope. The formula allows a direct calculation from the image acquisition data following an initial set of experimental work to establish the constant for a particular gamma camera and collimator system.

Administration, Inhalation↗
PubMed1992

Analysis of local electrogram characteristics correlated with successful radiofrequency catheter ablation of accessory atrioventricular pathways.

UNLABELLED: Due to the limited myocardial lesions produced by radiofrequency current, the ablation of accessory pathways (AP) requires precise localization of such connections. The purpose of this study was to ascertain which characteristic(s) of the local bipolar electrogram, recorded from the ablation and adjacent electrode immediately prior to the application of radiofrequency current, correlated with precision in localization adequate to permit AP ablation. Signal analysis was performed for 326 sets of electrograms preceding the attempted ablation of 107 APs in 100 consecutive patients. For 80 antegrade APs, the following variables were evaluated: (1) the presence or absence of an AP potential; (2) the local atrial-AP interval; (3) the local atrioventricular (AV) interval; and (4) the relationship between the onset of local ventricular depolarization and onset of delta wave of the surface electrocardiogram. For the 27 concealed APs, the following characteristics were evaluated: (1) the presence or absence of an AP potential; and (2) the local VA interval during reciprocating tachycardia or ventricular pacing. RESULTS: Antegrade APs: By statistical analysis, the best correlate of successful ablation of an antegrade AP was a local AV interval less than or equal to 40 msec (positive predictive value = 94%; 95% confidence intervals [CI] = 81%-100%). Local AV intervals less than or equal to 50 msec preceded 88% of successful AP ablations, compared to only 8% of failed radiofrequency current applications. The positive predictive value of the other variables were: presence of an AP potential: 35% (95% CI = 27%-40%); local atrial-AP intervals less than or equal to 40 msec: 54% (95% CI = 43%-66%); and local ventricular depolarization preceding onset of the delta wave 43% (95% CI = 34%-52%). For concealed APs, the positive predictive value of a VA interval less than 60 msec was 71% (95% CI = 48%-88%); the positive predictive value for the presence of an AP potential was 58% (95% CI = 32%-81%). CONCLUSIONS: No single electrogram characteristic had a positive predictive value and a sensitivity greater than 90% for AP localization adequate for radiofrequency current ablation. For antegrade APs, the best correlate of adequate localization was a local AV interval less than or equal to 40 msec; as a corollary, radiofrequency current applications at sites where the local AV was greater than 60 msec, were unlikely to be effective. Objective criteria for the localization of concealed APs were less certain. Electrogram analysis, as a guide to AP localization and ablation, requires careful analysis of multiple variables, with analysis of the local AV interval a salient objective factor.

Adult↗
PubMed1990

Caffeine and ventricular arrhythmias. An electrophysiological approach.

Little information is known regarding caffeine's effect on the substrate supporting sustained ventricular arrhythmias. This prospective study evaluated the effect of coffee (275 mg of caffeine) on this substrate with programmed ventricular stimulation in 22 patients with a history of symptomatic nonsustained ventricular tachycardia, ventricular tachycardia, or ventricular fibrillation. Patients underwent electrophysiological testing before and 1 hour after coffee ingestion. Mean (+/- SEM) plasma caffeine level achieved after coffee consumption was 6.2 +/- 0.5 mg/L. Mean plasma catecholamine and potassium values were not altered significantly 1 hour following caffeine ingestion. The number of extrastimuli required to induce an arrhythmia was unchanged in 10 patients (46%), increased in six (27%), and decreased in six (27%). Rhythm severity was unchanged in 17 patients (77%), more severe in two (9%), and less severe in three (14%). In those patients with clinical ventricular arrhythmias, caffeine did not significantly alter inducibility or severity of arrhythmias, suggesting little effect on the substrate supporting ventricular arrhythmias.

Adult↗
PubMed1990

Combined medical and psychological treatment of hospitalized children with encopresis.

Sixteen children, all inpatients at a state psychiatric hospital, received combined medical and psychological treatment for encopresis. One-year follow-up showed significant improvement. The results suggest that encopresis can be treated in severely emotionally disturbed children with a multifaceted and multidisciplinary approach.

Behavior Therapy↗