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Biomedical subjects

G Murray

Publications and source records attributed to G Murray.

At least 37 records · Page 2Linked to original sources
PubMed2000

Long-term ACE-inhibitor therapy in patients with heart failure or left-ventricular dysfunction: a systematic overview of data from individual patients. ACE-Inhibitor Myocardial Infarction Collaborative Group.

BACKGROUND: We undertook a prospective systematic overview based on data from individual patients from five long-term randomised trials that assessed inhibitors of angiotensin-converting enzyme (ACE) in patients with left-ventricular dysfunction or heart failure. METHODS: Three of the trials enrolled patients within a week after acute myocardial infarction. Data were combined by use of the Peto-Yusuf method. FINDINGS: Overall 12,763 patients were randomly assigned treatment or placebo and followed up for an average of 35 months. In the three post-infarction trials (n=5,966), mortality was lower with ACE inhibitors than with placebo (702/2995 [23.4%] vs 866/2971 [29.1%]; odds ratio 0.74 [95% CI 0.66-0-83]), as were the rates of readmission for heart failure (355 [11.9%] vs 460 [15.5%]; 0.73 [0.63-0.85]), reinfarction (324 [10.8%] vs 391 [13.2%]; 0.80 [0.69-0.94]), or the composite of these events (1049 [35.0%] vs 1244 [41.9%]; 0.75 [0.67-0.83]; all p<O.001). For all five trials the ACE inhibitor group had lower rates of death than the placebo group (1,467/6,391 [23.0%] vs 1,710/6,372 [26.8%]; 0.80 [0.74-0.87]) and lower rates of reinfarction (571 [8.9%] vs 703 [11.0%]; 0.79 [0.70-0.89]), readmission for heart failure (876 [13.7%] vs 1202 [18.9%]; 0.67 [0.61-0.74]), and the composite of these events (2161 [33.8%] vs 2610 [41.0%]; 0.72 [0.67-0.78]; all p<0.0001). The benefits were observed early after the start of therapy and persisted long term. The benefits of treatment on all outcomes were independent of age, sex, and baseline use of diuretics, aspirin, and beta-blockers. Although there was a trend towards greater reduction in risk of death or readmission for heart failure in patients with lower ejection fractions, benefit was apparent over the range examined.

Aged↗
PubMed2000

Fraud in medical research: an international survey of biostatisticians. ISCB Subcommittee on Fraud.

The characteristics of scientific fraud and its impact on medical research are in general not well known. However, the interest in the phenomenon has increased steadily during the last decade. Biostatisticians routinely work closely with physicians and scientists in many branches of medical research and have therefore unique insight into data. In addition, they have methodological competence to detect fraud and could be expected to have a professional interest in valid results. Biostatisticians therefore are likely to provide reliable information on the characteristics of fraud in medical research. The objective of this survey of biostatisticians, who were members of the International Society for Clinical Biostatistics, was to assess the characteristics of fraud in medical research. The survey was performed between April and July 1998. The participation rate was only 37%. We report the results because a majority (51%) of the participants knew about fraudulent projects, and many did not know whether the organization they work for has a formal system for handling suspected fraud or not. Different forms of fraud (e.g., fabrication and falsification of data, deceptive reporting of results, suppression of data, and deceptive design or analysis) had been observed in fairly similar numbers. We conclude that fraud is not a negligible phenomenon in medical research, and that increased awareness of the forms in which it is expressed seems appropriate. Further research, however, is needed to assess the prevalence of different types of fraud, as well as its impact on the validity of results published in the medical literature.

Biometry↗
PubMed2000

Medical complications after stroke: a multicenter study.

BACKGROUND AND PURPOSE: This prospective, multicenter study was performed to determine the frequency of symptomatic complications up to 30 months after stroke using prespecified definitions of complications. METHODS: We recruited 311 consecutive stroke patients admitted to hospital. Research nurses reviewed their progress on a weekly basis until hospital discharge and again at 6, 18, and 30 months after stroke. RESULTS: Complications during hospital admission were recorded in 265 (85%) of stroke patients. Specific complications were as follows: neurological-recurrent stroke (9% of patients), epileptic seizure (3%); infections-urinary tract infection (24%), chest infection (22%), others (19%); mobility related-falls (25%), falls with serious injury (5%), pressure sores (21%); thromboembolism-deep venous thrombosis (2%), pulmonary embolism (1%); pain-shoulder pain (9%), other pain (34%); and psychological-depression (16%), anxiety (14%), emotionalism (12%), and confusion (56%). During follow-up, infections, falls, "blackouts, " pain, and symptoms of depression and anxiety remained common. Complications were observed across all 3 hospital sites, and their frequency was related to patient dependency and duration after stroke. CONCLUSIONS: Our prospective cohort study has confirmed that poststroke complications, particularly infections and falls, are common. However, we have also identified complications relating to pain and cognitive or affective symptoms that are potentially preventable and may previously have been underestimated.

Accidental Falls↗
PubMed2000

[Renal scleroderma crisis. Role of scleroderma vasculopathy in the induction of cutaneous and visceral fibrosis in 2 cases].

Although fibrosis and vasculopathy coexist in most patients with progressive systemic sclerosis, it is not clear if these events are the result of an unique etiologic factor or if one is consequence of the other. We report two cases of progressive systemic sclerosis that evolved to a renal scleroderma crisis. A 36 years old female presented with a Sjögren syndrome and painful subcutaneous nodules whose biopsy showed perivascular lymphocytic infiltration, perivascular thickening and normal skin. The ESR was 100 mm/h. She developed an hypertensive crisis and progressive renal failure, followed by a rapidly evolving progressive systemic sclerosis. The patient died in the course of this crisis. A 32 years old female with a progressive systemic sclerosis refractory to D-penicillamine treatment, receiving cyclosporin, presented a renal scleroderma crisis, that was successfully treated, with complete recovery of renal function. We highlight the different evolution of these cases, probably due to an early diagnosis and a better experience in the management of this condition.

Acute Kidney Injury↗
PubMed2000

[Severe Henoch-Schonlein purpura in a patient with multiple myeloma].

A Multiple Myeloma (MM), IgG-lambda stage III-A was diagnosed in a 41-year-old-man. After VAD cycles IgG decreased from 7.5 to 2.4 g/dL. were mobilized with cyclophosphamide and 10 micrograms/Kg G-CSF. Three days after the collection of peripheral stem cell, the patient had fever, nausea, vomiting, liquid stools, shoulder and knee arthralgia and dehydration. Upper GI endoscopy showed esophageal candidiasis and ulcerative necrotic lesions both in stomach and duodenum; the biopsy confirmed necrosis. Simultaneously, the appearance of purpura with maculopapular lesions of diverse sizes appeared in the feet progressing to the limbs and trunk. Hematuria and proteinuria were also observed. Skin biopsy showed leukocytoclastic vasculitis. Renal biopsy showed focal and segmental glomerulonephritis. Serum ANCA, cryoglobulins, anti-HCV and RF were negative, and serum monoclonal IgG was 1290 mg/dL. Daily treatment with i.v. methylprednisolone pulses for 3 days improved skin lesions and digestive involvement. Macroscopic hematuria and proteinuria improved after two months of steroid treatment.

Adult↗
PubMed1999

The role of biostatistics in the prevention, detection and treatment of fraud in clinical trials.

Recent cases of fraud in clinical trials have attracted considerable media attention, but relatively little reaction from the biostatistical community. In this paper we argue that biostatisticians should be involved in preventing fraud (as well as unintentional errors), detecting it, and quantifying its impact on the outcome of clinical trials. We use the term 'fraud' specifically to refer to data fabrication (making up data values) and falsification (changing data values). Reported cases of such fraud involve cheating on inclusion criteria so that ineligible patients can enter the trial, and fabricating data so that no requested data are missing. Such types of fraud are partially preventable through a simplification of the eligibility criteria and through a reduction in the amount of data requested. These two measures are feasible and desirable in a surprisingly large number of clinical trials, and neither of them in any way jeopardizes the validity of the trial results. With regards to detection of fraud, a brute force approach has traditionally been used, whereby the participating centres undergo extensive monitoring involving up to 100 per cent verification of their case records. The cost-effectiveness of this approach seems highly debatable, since one could implement quality control through random sampling schemes, as is done in fields other than clinical medicine. Moreover, there are statistical techniques available (but insufficiently used) to detect 'strange' patterns in the data including, but no limited to, techniques for studying outliers, inliers, overdispersion, underdispersion and correlations or lack thereof. These techniques all rest upon the premise that it is quite difficult to invent plausible data, particularly highly dimensional multivariate data. The multicentric nature of clinical trials also offers an opportunity to check the plausibility of the data submitted by one centre by comparing them with the data from all other centres. Finally, with fraud detected, it is essential to quantify its likely impact upon the outcome of the clinical trial. Many instances of fraud in clinical trials, although morally reprehensible, have a negligible impact on the trial's scientific conclusions.

Biometry↗
PubMed1999

The impact of obesity and disease on busulfan oral clearance in adults.

The apparent oral clearance (CL/F, mL/min) of busulfan was measured in 279 adolescent and adult patients. Significant (P <.05) determinants of CL/F by linear regression were: actual body weight (BW; r2 = 0.300), body surface area (BSA; r2 = 0.277), adjusted ideal body weight (AIBW; r2 = 0.265), and ideal body weight (IBW; r2 = 0.173); whereas body mass index (BMI), height, age, gender, and disease were less important predictors. CL/F (mL/min) for normal weight patients (BMI, 18 to 27 kg/m2) was 16.2% lower (P <.001) than for obese patients (BMI, 27 to 35 kg/m2). Thus, expressing CL/F relative to BW did not eliminate statistically significant differences between normal and obese patients. However, busulfan CL/F expressed relative to BSA (110 +/- 24 v 110 +/- 24 mL/min/m2, P = 1.0) or AIBW (3.04 +/- 0.65 v 3.19 +/- 0.67 mL/min/kg, P =.597) were similar in normal and obese patients. Non-Hodgkin's lymphoma patients (n = 10) had approximately 32% lower mean busulfan CL/F expressed relative to BW, BSA, or AIBW compared with patients with chronic myelogenous leukemia (n = 73). Routine dosing on the basis of BSA or AIBW in adults and adolescents does not require a specific accommodation for the obese. However, dosing based on BSA may be improved by considering CL/F differences in certain diseases. Adjusting dose for body size or disease does not diminish interpatient variability sufficiently to obviate plasma level monitoring in many indications.

Administration, Oral↗
PubMed1999

An inexpensive sensor for measuring surface geometry.

A technique to measure surface geometry using a conductive ink sensor is described. In the human system distorted cylinders are common, and geometry can be reconstructed from local measures of curvature. An algorithm is presented to reconstruct the shape of a surface from a series of curvature measurements. The Abrams Gentile Entertainment patented bend sensor was evaluated as a curvature transducer. The sensor was tested at the extremes of the likely measurement range, from curvatures below 0.01 mm(-1) up to a curvature of 0.1 mm(-1). The upper curvature limit proved beyond the design specification of the sensor. The technique was applied at the lower curvature range to reconstruct one quadrant of the chest of a volunteer and record breathing movement. The bend sensor is inexpensive and can be applied to obtain an approximate reconstruction of surface geometry in the human system.

Adult↗
PubMed1999

The carvedilol hibernation reversible ischaemia trial; marker of success (CHRISTMAS). The CHRISTMAS Study Steering Committee and Investigators.

BACKGROUND: Carvedilol improves left ventricular (LV) function when heart failure is due to LV systolic dysfunction, but the magnitude of the response is heterogeneous among patients with coronary disease, possibly reflecting the presence or volume of hibernating myocardium. AIMS: The primary objective of the study is to determine whether the presence of hibernating myocardium predicts the magnitude of improvement in LV ejection fraction in response to carvedilol among patients with heart failure and LV systolic dysfunction due to coronary disease. METHODS: The study is a prospective, randomised, parallel-group, double-blind, multi-centre study comparing carvedilol and placebo over a period of approximately 6 months in the above patient population. The primary end-point is the comparison of the mean change, from baseline to the final visit, in radionuclide-determined LV ejection fraction among patients on placebo with those on carvedilol stratified according to the presence of hibernating myocardium. Hibernating status will be determined by a combination of echocardiographic and myocardial perfusion (technetium-99m sestamibi) imaging. RESULTS: 255 patients have undergone screening tests of which 207 have been randomised so far. The study intends to randomise 400 patients and the first report of results is expected in 2000. CONCLUSIONS: As far as we are aware this is the first randomised controlled trial to investigate the effects of treatment in patients stratified according to the presence of hibernating myocardium. The study will provide insights into the prevalence of myocardial hibernation, its natural history, and its influence on prognosis as well as the interaction between the presence of hibernating myocardium and the effects of treatment with carvedilol.

Adrenergic beta-Antagonists↗
PubMed1999

Treatment of community-acquired pneumonia in the elderly: the role of cefepime, a fourth-generation cephalosporin.

In a prospective, multicentre double-blind trial, 151 patients over the age of 65 years were randomly assigned to receive either cefepime 2 g every 12 h for a minimum of 3 days and up to 14 days or ceftriaxone 1 g every 12 h for a minimum of 3 days and up to 14 days. Antibiotics were maintained until 48 h after fever had resolved; no other antibiotics were permitted. The average age in each group exceeded 77 years and significant co-morbidity was found in the majority of patients. The mean total duration of therapy was 5.8+/-2.4 days for the cefepime group and 6.7+/-2.7 days for the ceftriaxone group (P = 0.06). The clinical success rate at the end of therapy was 79.1% with cefepime and 75.4% with ceftriaxone (P = 0.62). At the end of follow-up, 91.7% of the cefepime-treated patients and 86.5% of the ceftriaxone patients had a satisfactory clinical response (P = 0.38). In 35 bacteriological evaluable patients, potential pathogens were eradicated in all but one patient receiving cefepime. Seven patients in each group died during the study period but in each case the death was unrelated to study drug. The commonest side-effect was diarrhoea (cefepime, five patients; ceftriaxone, two patients). The clinical and microbiological efficacy of cefepime is similar to that of ceftriaxone in elderly patients with community-acquired pneumonia requiring hospitalization. Cefepime is an appropriate choice for the treatment of community-acquired respiratory tract infections in the elderly.

Aged↗
PubMed1999

Gabapentin as add-on therapy in children with refractory partial seizures: a 12-week, multicentre, double-blind, placebo-controlled study. Gabapentin Paediatric Study Group.

PURPOSE: To evaluate the efficacy and safety of gabapentin (Neurontin; GBP) as add-on therapy for refractory partial seizures in paediatric patients aged 3-12 years. METHODS: After a 6-week baseline period, 247 patients (54 centres) entered a 12-week double-blind phase and were randomized to receive either GBP (t.i.d., titrated to 23-35 mg/kg/ day) or placebo. Seizure activity and type were recorded daily. Efficacy variables included Response Ratio (RRatio), responder rate, and percentage change in frequency (PCH) for all partial seizures; PCH and RRatio for individual types of partial seizures; and investigator and parent/guardian global assessments of seizure frequency and patient well-being. RESULTS: RRatio for all partial seizures was significantly lower (better) for GBP-treated patients (p = 0.0407). Responder rate favored GBP, but the difference between treatment groups was not statistically significant. Median PCH for all partial seizures for the GBP treatment group (-17.0%) was better than that for the placebo group (-6.5%). Median PCH for specific seizure types showed GBP to be most effective in controlling complex partial seizures (-35%) and secondarily generalized seizures (-28%) when compared with placebo (-12%, +13%, respectively). A greater percentage of GBP-treated patients exhibited improvement according to investigator and parent/guardian global assessments, with a statistically significant difference observed in the parent/guardian global assessment of seizure-frequency reduction (p = 0.046). Three GBP patients and one placebo patient were seizure free during the double-blind treatment period. GBP was well tolerated. CONCLUSIONS: GBP was effective and well tolerated as an add-on therapy for partial seizures in paediatric patients with previously drug-resistant seizures.

Acetates↗
PubMed1999

Human herpesvirus 8 DNA load in leukocytes of human immunodeficiency virus-infected subjects: correlation with the presence of Kaposi's sarcoma and response to anticytomegalovirus therapy.

Specific human herpesvirus 8 (HHV-8) DNA sequences were found in leukocytes of 12 of 29 (41.4%) AIDS subjects with Kaposi's sarcoma (KS), whereas they were found in 4 of 43 (9.3%) AIDS subjects without KS (P = 0.003), although the peak HHV-8 DNA load in PCR-positive subjects with KS (mean, 425 copies per 0.2 microgram of DNA) did not significantly differ from the one found in PCR-positive patients without KS (mean, 218 copies). The use of intravenous ganciclovir or foscarnet therapy to treat cytomegalovirus disease did not affect the HHV-8 DNA load in seven patients for whom serial samples were analyzed.

AIDS-Related Opportunistic Infections↗
PubMed1999

Osseoperception: sensory function and proprioception.

Tooth loss and its replacement have significant functional and psychosocial consequences. The removal of intra-dental and periodontal mechanoreception accompanying tooth loss changes the fine proprioceptive control of jaw function and influences the precision of magnitude, direction, and rate of occlusal load application. With the loss of all teeth, complete denture restoration is a compromise replacement which only partially restores function. Implant-supported prostheses restore jaw function more appropriately, with improved psychophysiological discriminatory ability and oral stereognosis. Osseoperception is defined as depending on central influences from corollary discharge from cortico-motor commands to jaw muscles, and contributions from peripheral mechanoreceptors in orofacial and temporomandibular tissues. The processing of central influences is considered with the recognition of the plasticity of neuromotor mechanisms that occurs to accommodate the loss of dental and periodontal inputs.

Bite Force↗