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Biomedical subjects

R J Gray

Publications and source records attributed to R J Gray.

At least 55 records · Page 3Linked to original sources
PubMed1994

Physiotherapy in the treatment of temporomandibular joint disorders: a comparative study of four treatment methods.

Temporomandibular joint pain dysfunction syndrome (TMJPDS) comprises of a constellation of signs and symptoms including joint tenderness and pain on function, restricted jaw movement, clicking, jaw locking and tenderness in the muscles of mastication. Headache may also be a feature. Physiotherapy is commonly employed in the treatment of this condition but there is little published material reporting the relative efficacy of the different types of treatment currently available. Further, no attempt seems to have been made to compare the costs of physiotherapy with other forms of treatment of this disorder such as occlusal splint therapy. This paper reports a comparative evaluation of four different physiotherapy treatments and placebo in the management of TMJPDS and comments on their cost benefit aspects compared with that of splint therapy. The four methods of physiotherapy tested were short-wave diathermy, megapulse, ultrasound and soft laser. There was no statistically significant difference in success rate between any of the four tested (range 70.4-77.7%) although each individually was significantly better than placebo treatment. The time of improvement appeared to vary between the four methods.

Chi-Square Distribution↗
PubMed1994

Linkage analysis of the genetic determinants of high density lipoprotein concentrations and composition: evidence for involvement of the apolipoprotein A-II and cholesteryl ester transfer protein loci.

We have tested for evidence of linkage between the genetic loci determining concentrations and composition of plasma high density lipoproteins (HDL) with the genes for the major apolipoproteins and enzymes participating in lipoprotein metabolism. These genes include those encoding various apolipoproteins (apo), including apoA-I, apoA-II, apoA-IV, apoB, apoC-I, apoC-II, apoC-III, apoE, and apo(a), cholesteryl ester transfer protein (CETP), HDL-binding protein, lipoprotein lipase, and the low density lipoprotein (LDL) receptor. Polymorphisms of these genes, and nearby highly polymorphic simple sequence repeat markers, were examined by quantitative sib-pair linkage analysis in 30 coronary artery disease families consisting of a total of 366 individuals. Evidence for linkage was observed between a marker locus D16S313 linked to the CETP locus and a locus determining plasma HDL-cholesterol concentration (P = 0.002), and the genetic locus for apoA-II and a locus determining the levels of the major apolipoproteins of HDL, apoA-I and apoA-II (P = 0.009 and 0.02, respectively). HDL level was also influenced by the variation at the apo(a) locus on chromosome 6 (P = 0.02). Thus, these data indicate the simultaneous involvement of at least two different genetic loci in the determination of the levels of HDL and its associated lipoproteins.

Apolipoprotein A-II↗
PubMed1994

Ten-year experience of cardiac surgery in patients aged 80 years and over.

Five hundred twenty-eight consecutive patients aged 80 years and over (mean age, 83.1 +/- 2.7 years) underwent cardiac operations with hypothermia (mean, 21.9 degrees +/- 2.2 degrees C), hyperkalemic cardioplegia, and cardiopulmonary bypass in a 10-year period. Fifty-six percent of the patients were male. Preoperatively, 68% of the patients were in New York Heart Association functional class IV, and 31% were in class III. Among them, 303 patients had isolated coronary artery bypass grafting (CABG) (group I), 132 had aortic valve replacement only or combined with CABG (group II), 42 had mitral valve replacement only or combined with CABG (group III), 31 had mitral valve repair and CABG (group IV), and 20 had double-valve procedure only or combined with CABG (group V). The 30-day or in-hospital mortality was 8.3% in group I, 4.5% in group II, 29% in group III, 23% in group IV, and 30% in group V. Total 30-day or in-hospital mortality was 10.6%. One-year and 5-year actuarial survival rates were as follows: group I, 82% and 62%; group II, 85% and 58%; group III, 61% and 37%; group IV, 56% and 19%; and group V, 63% and 15%. Total 1-year and 5-year actuarial survival were 79% and 54%. At follow-up (mean, 2 years), 70% of overall survivors reported that their general health had improved. Our experience demonstrates that for select patients aged 80 years and over with unmanageable cardiac symptoms, CABG and aortic valve replacement groups had better results in improving quality of life as compared with patients having mitral or combined procedures.

Actuarial Analysis↗
PubMed1994

Condylar hyperplasia: correlation of histological and scintigraphic features.

Scintigaphy using 99mTc-MDP is widely advocated as a method of diagnosis and presurgical assessment of patients with condylar hyperplasia. A previous study has demonstrated that hyperplasia of the mandibular condyle is characterized histologically by the presence of an uninterrupted layer of undiffentiated germinative mesenchyme cells, a layer of hypertrophic cartilage and the presence of islands of chondrocytes in the subchondral trabecular bone. This study was undertaken to determine whether there was any association between the degree of 99mTc-MDP uptake and the histological features of condylar hyperplasia. The parameters examined were trabecular bone volume, depth of cartilage islands and the presence of forming and resorbing surfaces. The images were analyzed by three experienced observers, who ranked the images according to degree of asymmetry between sides and the degree of uptake on the affected side. There was a significant correlation between the proportions of resorbing and osteoid covered bone surfaces and scintigraphic appearances. The rank correlations were rs = 0.55 (P = 0.3) between the resorptive surfaces and degree of symmetry and rs = 0.53 (P = 0.04) between the osteoid surfaces and absolute uptake. The correlation was higher for both methods (rs = 0.64 in each case) when the osteoid surface and resorptive surface measurements were combined. The results indicate that visual examination of radioisotope bone scans by experienced observers is a valid form of assessment of bone activity in condylar hyperplasia.

Adolescent↗
PubMed1994

Spline-based tests in survival analysis.

This paper examines a method for testing hypotheses on covariate effects in a proportional hazards model, and also on how effects change over time in regression analysis of survival data. The technique used is very general and can be applied to testing many other aspects of parametric and semiparametric models. The basic idea is to formulate a flexible parametric alternative using fixed knot splines, together with a penalty function that penalizes noisy alternatives more than smooth ones, to focus the power of the tests toward smooth alternatives. The test statistics are the analogs of ordinary likelihood-based statistics, only computed from a penalized likelihood formed by subtracting the penalty function from the ordinary log-likelihood. Large-sample approximations to the distributions are found when the number of knots is held fixed as the sample size increases. Numerical results suggest these approximations may be adequate with moderate sized samples.

Analysis of Variance↗
PubMed1994

A Bayesian analysis of institutional effects in a multicenter cancer clinical trial.

This paper examines a Bayesian method for investigating the amount of institutional variation in a multicenter clinical trial with a censored failure time endpoint. A hierarchical structure is used to model the institutional effects in a proportional hazards model, with the posterior distributions calculated using Gibbs sampling. The methods are applied to data from a lung cancer trial conducted by the Eastern Cooperative Oncology Group. In this trial there appears to be substantial variation in the treatment effect across institutions. Although the reasons for this have been identified, it would be possible to investigate this further through a detailed examination of the data from institutions with extreme effects.

Altretamine↗
PubMed1994

Anemia therapy: individual benefit and societal cost.

The US health care system is under increasing pressure to lower costs while maintaining quality of care. Providers will be forced to (1) measure the benefits of a particular therapy, and (2) demonstrate that the benefits justify the costs. The major components of therapeutic benefit are survival and quality of life. Chronic anemia may have little impact on survival, but studies have measured significant decrements in quality of life without therapy and increments in quality of life with therapy. This disease also presents important societal financial concerns due to its many competing therapies. The annual cost of treatment can vary from an average of a few dollars for iron supplementation to an average of $6,000 for a course of recombinant human erythropoietin. Physicians need to integrate information on therapeutic outcomes and cost to maximize individual benefit and justify the costs. The choice of therapy for anemia associated with cancer is complex because the onset of the anemia is multifactorial, and the effects of anemia may be masked by the underlying malignancy. There are insufficient data supporting a specific recommendation for transfusion or recombinant human erythropoietin therapy. The current cost-conscious environment in the United States presents an opportunity for health care providers to formally document the benefits of anemia therapy and justify the societal costs based on those benefits. Anemia is an excellent example of a condition that allows the formal analysis of disease impact and the effectiveness and cost of therapy because (1) it has multiple therapies, (2) the cost of therapy varies widely, and (3) the therapies have variable benefit depending on the individual patient. Using a model based on chronic renal failure, an outcomes structure was developed by which the impact of anemia and the therapies used to manage it can be measured. Its potential application to anemia in patients with cancer is discussed.

Anemia↗
PubMed1993

Syntheses of 5'-substituted analogues of carbocyclic 3-deazaadenosine as potential antivirals.

Various 5'-substituted derivatives (2, 3, 6a, 6b, 9a, 9b, 12, 13b, and 15) of carbocyclic 3-deazaadenosine (3-deaza CAdo, 1) were prepared from 3-deaza CAdo (1) and evaluated as antiviral agents against a number of viruses, including HIV-1. Several of the compounds had moderate to good antiviral activity against vaccinia (VV) and vesicular stomatitis (VSV) viruses; however, the antiviral activity of the analogues did not exceed that of the parent compound. No anti-HIV activity was detected.

Antiviral Agents↗
PubMed1992

Directional atherectomy treatment for hemodialysis access: early results.

The Simpson atherectomy device was used to treat 12 intragraft stenoses, six complete subclavian vein occlusions, and 14 venous outflow stenoses in 24 patients undergoing hemodialysis. Patients were followed up clinically and by means of venography at approximately 1, 3, 6, 9, and 12 months after treatment. Twenty-eight atherectomy specimens were examined histologically. Twenty-six (81%) of 32 lesions were treated with initial technical success. Including technical failures, seven (58%) of 12 intragraft stenoses are angiographically patent at a mean of 5.0 months and five (50%) of 10 are clinically patent at 6 months. Three (50%) of six subclavian veins are angiographically patent at a mean of 5.6 months, and four (67%) of six are clinically patent at 6 months. Three (21%) of 14 venous outflow stenoses are angiographically patent at a mean of 5.0 months and five (38%) of 13 are clinically patent at 6 months. Histologic examination showed neointimal fibromuscular hyperplasia in 26 of 28 lesions. When 30% or less angiographic residual stenosis is used as the criterion for initial technical success, directional atherectomy appears to be effective therapy for intragraft stenoses and, with balloon angioplasty, for some catheter insertion-related subclavian occlusions. Directional atherectomy appears to have a recurrence rate for venous outflow stenoses similar to that for balloon angioplasty when the same criterion is used.

Arteriovenous Shunt, Surgical↗
PubMed1992

Combined retrograde-antegrade ureteral stent passage: salvage procedure for a ureteral leak.

The authors describe a stent placement procedure for treatment of an infected ureteral leak after failure of traditional antegrade and retrograde approaches. In this procedure, a guide wire was placed across the distal ureteral segment into a urinoma with use of cystoscopic guidance. Thereafter, an antegrade approach was used to pass a wire loop snare, capture the guide wire, and withdraw it through the proximal ureter for subsequent stent passage. This approach allowed percutaneous stabilization of a ureteral leak in a patient who would have otherwise required immediate surgical repair.

Aged↗
PubMed1991

Acyclic analogues of pyrazofurin: syntheses and antiviral evaluation.

Acyclic analogues of pyrazofurin, including 4-hydroxy-3(5)-[( 2-hydroxy-1-(hydroxymethyl)-ethoxy]methyl)-1H-pyrazole-5 (3)-carboxamide (36) and 4-hydroxy-3(5)-[(2-hydroxyethoxy)methyl]-1H-pyrazole-5(3)-carboxamide (27), that possess the side chains of ganciclovir and acyclovir, respectively, were prepared by heating methyl 4-acetoxy-1-acetyl-3-bromomethyl-1H-pyrazole-5-carboxylate (15) and sodium acetate in the requisite alcohols or, for 36, with the sodium alkoxide in dry tetrahydrofuran. These analogues have no antiviral activity, except 4-hydroxy-3(5)-[(3-hydroxypropoxy)methyl]-1H-pyrazole-5(3)-carboxamide (28), which exhibited slight activity against human cytomegalovirus.

Amides↗