Search PubMed⌕ Search

Biomedical subjects

R G Miller

Publications and source records attributed to R G Miller.

At least 37 records · Page 2Linked to original sources
PubMed2001

A placebo-controlled trial of gabapentin in spinal muscular atrophy.

OBJECTIVE: To evaluate the efficacy of gabapentin in increasing muscle strength of patients with spinal muscular atrophy (SMA). BACKGROUND: Preclinical data in experimental models of motor neuron disease suggest a neuroprotective effect of gabapentin. METHODS: Gabapentin (1200 mg), or placebo, was administered three times daily in a randomized, double-blind trial for 12 months. The primary outcome measure was the average percent change from baseline, based on the measurement of strength in four muscles (elbow flexion and hand grip bilaterally) for each patient. Drug efficacy was examined by comparing the percent change in strength for patients on drug vs. placebo. Secondary efficacy variables included: forced vital capacity (FVC), SMA functional rating scale (SMAFRS), and mini-Sickness Impact Profile (SIP). RESULTS: Eighty-four patients, with type II or III SMA, were enrolled at eight sites across the United States. There were no differences in baseline features. There was no difference between the placebo and drug groups in any outcome measure. CONCLUSIONS: This study demonstrates the feasibility of this trial design and provides data for the design of future clinical trials in SMA.

Acetates↗
PubMed2001

Current management of ALS: comparison of the ALS CARE Database and the AAN Practice Parameter. The American Academy of Neurology.

BACKGROUND: The American Academy of Neurology (AAN) ALS Practice Parameter was published in April 1999. The ALS CARE Database has been collecting data on the management of patients with ALS in North America since 1996. OBJECTIVE: To compare the management of patients with ALS in North America as recorded in the ALS CARE Database with the recommendations of the AAN ALS Practice Parameter. METHODS: Data were analyzed from 2018 patients at enrollment and from 373 of these patients who died between enrollment and May 1999. RESULTS: Eighty-two percent of the enrolled patients reported that they had been given enough information about ALS. Only 54% of patients with drooling were receiving medication for this problem. Only 41% of those who reported being depressed most of the time were receiving antidepressant medications. Only 28% of those with dyspnea and only 9.2% of those with a forced vital capacity <40% predicted were receiving noninvasive positive pressure ventilator support. Only 30% of those with moderate to severe dysphagia had a gastrostomy tube. Half of the patients who died did so at home, but only 47% of them received residential hospice services. Although 89% of patients who died were recorded as having done so peacefully, 17% were reported to have had breathing difficulties (i.e., respiratory distress), 8% anxiety, 3.3% pain, and 2.5% choking. Advance directives were in place for 90% of the patients who died, and in 97% of cases these directives were followed. CONCLUSIONS: These findings indicate that in the 3-year period prior to the publication of the AAN Practice Parameter, many but not all patients received the care that is recommended in that parameter; there were deficiencies, particularly in the key areas of gastrostomy and noninvasive positive pressure ventilation.

Amyotrophic Lateral Sclerosis↗
PubMed2001

Phase III randomized trial of gabapentin in patients with amyotrophic lateral sclerosis.

BACKGROUND: Preclinical and clinical studies of gabapentin in patients with ALS led the authors to undertake a phase III randomized clinical trial. METHODS: Patients were randomly assigned, in a double-blinded fashion, to receive oral gabapentin 3,600 mg or placebo daily for 9 months. The primary outcome measure was the average rate of decline in isometric arm muscle strength for those with two or more evaluations. RESULTS: Two hundred four patients enrolled, 196 had two or more evaluations, and 128 patients completed the study. The mean rate of decline of the arm muscle strength was not significantly different between the groups. Moreover, there was no beneficial effect upon the rate of decline of other secondary measures (vital capacity, survival, ALS functional rating scale, timed walking) nor was there any symptomatic benefit. In fact, analysis of the combined data from the phase II and III trials revealed a significantly more rapid decline of forced vital capacity in patients treated with gabapentin. CONCLUSION: These data provide no evidence of a beneficial effect of gabapentin on disease progression or symptoms in patients with ALS.

Acetates↗
PubMed2001

Serum insulin-like growth factor-I (IGF-I) does not correlate positively with isometric strength, fatigue, and quality of life in post-polio syndrome.

OBJECTIVES AND BACKGROUND: To determine if serum insulin-like growth factor-I (IGF-I) levels are associated with strength, body mass index (BMI), fatigue, or quality of life in post-poliomyelitis syndrome (PPS). PPS is likely due to a distal disintegration of enlarged post-polio motor units as a result of terminal axonal sprouting. Age-related decline in growth hormone and IGF-I (which support terminal axonal sprouts) is proposed as a contributing factor. METHODS: As part of the North American Post-Poliomyelitis Pyridostigmine Study (NAPPS), baseline data on maximum voluntary isometric contraction (MVIC), BMI, subjective fatigue (fatigue severity scale, Hare fatigue symptom scale), health-related quality of life (short form health survey-36; SF-36), and serum IGF-I levels were gathered on 112 PPS patients. Pearson correlation coefficients were calculated to evaluate the association between serum IGF-I and MVIC in 12 muscles, BMI, two fatigue scales, and SF-36 scale scores. RESULTS: There is a significant inverse correlation of IGF-I levels with MVIC in left ankle dorsiflexors (r=-0.30, P<0.01), and left and right knee extensors (r=-0.22, -0.25, P=<0.01, 0.01), but no significant correlations in other muscles. When men and women were evaluated separately, inverse correlations of IGF-I levels with MVIC were found only in men. IGF-I correlated inversely with BMI (r=-0.32, P=0006) and age (r=-0.32, P=0.0005). IGF-I did not correlate with the fatigue or SF-36 scales. CONCLUSIONS: In this exploratory study, we found that contrary to our expectations, IGF-I did not correlate positively with strength. IGF-I correlated negatively with strength in several lower extremity muscles, BMI, and age. IGF-I is likely not an important factor in the pathogenesis of fatigue and in determining quality of life in PPS, but its role on strength should be studied further.

Adult↗
PubMed2001

Palliative care in amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is the most common degenerative motor neuron disease in adults. The clinical picture consists of generalized fasciculations, progressive atrophy and weakness of the skeletal muscles, spasticity and pyramidal tract signs, dysarthria, dysphagia, and dyspnea. Pseudobulbar affect is common. Disease-specific treatment options are still unsatisfactory. Therapeutic nihilism is not justified as a large array of palliative measures available to enhance the quality of life of patients and their families. Because of its clinical characteristics, ALS represents a paradigm for palliative care in neurological diseases. Numerous projects are being undertaken worldwide in an effort to enlarge the evidence base for palliative interventions in ALS. Palliative care in ALS is a multidisciplinary effort requiring careful coordination. An open and empathic disclosure of the diagnosis is essential. Nutritional deficiency caused by dysphagia can be relieved by a percutaneous endoscopic gastrostomy. Respiratory insufficiency can be effectively treated by non-invasive home mechanical ventilation. The terminal phase of the disease should be discussed at the latest when symptoms of dyspnea appear, in order to prevent unwarranted fears of "choking to death." Psychological and spiritual care of patients and families are important. Collaboration with hospice institutions and completion of advance directives can be of invaluable help in the terminal phase.

Amyotrophic Lateral Sclerosis↗
PubMed2001

Clinical characteristics and management of ALS.

Amyotrophic lateral sclerosis (ALS) is the most common form of degenerative motor neuron disease in adulthood. The clinical picture was accurately described by Charcot over 125 years ago and consists of generalized fasciculations, progressive atrophy and weakness of the skeletal muscles, spasticity and pyramidal tract signs, dysarthria, dysphagia, and dyspnea. Pseudobulbar affect is common. Disease-specific treatment options are still unsatisfactory. However, therapeutic nihilism is not justified as a large array of palliative measures is available to enhance the quality of life of patients and their families. Palliative care in ALS is a multidisciplinary effort requiring careful coordination. An open and frank disclosure of the diagnosis is of paramount importance. Nutritional deficiency due to pronounced dysphagia can be relieved by a percutaneous endoscopic gastrostomy. Respiratory insufficiency can be effectively treated by noninvasive home mechanical ventilation. The terminal phase of the disease should be discussed, at the latest, when symptoms of dyspnea appear in order to prevent unwarranted fears of "choking to death." Collaboration with hospice and completion of advance directives can be of invaluable help in the terminal phase.

Adult↗
PubMed2001

Examining the evidence about treatment in ALS/MND.

The application of evidence-based medicine to the treatment of patients with amyotrophic lateral sclerosis (ALS) is just beginning. A small number of systematic reviews analyzing the pertinent evidence, grading the methodology and formulating recommendations to guide clinical decision-making have begun to appear. The American Academy of Neurology practice parameters for informing the patient and managing nutritional and respiratory issues and palliative care are discussed. In addition, the first systematic review in the field of ALS/MND from the Cochrane collaboration concerns riluzole treatment and this meta-analysis is also described. Some of the most important recommendations that have the potential to significantly prolong survival and enhance quality of life are the early institution of percutaneous endoscopic gastrostomy for patients with significant dysphagia, and the initiation of non-invasive positive pressure ventilation for patients with symptoms of early respiratory insufficiency. Assertive treatment of pain and dyspnea are also strongly recommended for patients with ALS. The North American ALS patient database, ALS C.A.R.E., is also described as a methodology for measuring clinical outcomes, and some early results are presented. The evidence on riluzole indicates effectiveness in prolonging survival with a good safety profile.

Clinical Trials as Topic↗
PubMed2001

Assessing health status quality of life in ALS: comparison of the SIP/ALS-19 with the ALS Functional Rating Scale and the Short Form-12 Health Survey. ALS C.A.R.E. Study Group. Clinical Assessement, Research, and Education.

BACKGROUND: The progressive loss of function affects the quality of life of the ALS patient. Quality of life depends on a spectrum of factors. Available instruments for assessment include questionnaires developed for generic illness-related disabilities and ALS-specific questionnaires that focus on function. METHODS: Comparisons were made between two ALS-specific questionnaires (ALS Functional Rating Scale and SIP/ALS-19) and a generic instrument (Short Form-12) given to 1,513 patients from the (North American) ALS Patient Care Database. RESULTS: The SIP/ALS-19 correlates well with the ALS Functional Rating Scale and less well with the Short Form-12. CONCLUSIONS: The SIP/ALS-19 can be used as an effective surrogate for the ALS Functional Rating Scale, with the advantage that the SIP/ALS-19 also includes questions that encompass the psychological and social domains of quality of life.

Activities of Daily Living↗
PubMed2001

The ALS Patient Care Database: insights into end-of-life care in ALS.

OBJECTIVE: To study clinical practices and patient outcomes near the end of life in amyotrophic lateral sclerosis (ALS). BACKGROUND: Patients, families, and healthcare providers face several dilemmas in selecting and delivering care near the end of life in ALS. Published data on clinical practices and their benefits during end-of-life care for ALS patients consist of anecdotal reports based on small case series or individual case reports. METHODS: Data were obtained from 1014 American and Canadian patients with ALS who died while participating in a large observational registry (the ALS Patient Care Database) during the past four years. Following death, a caregiver or family member provided data for each patient using a standard questionnaire. Data were principally generated through American and Canadian ALS multidisciplinary centers of excellence. RESULTS: Most patients died peacefully (90.7%) and 62.4% died in a hospice-supported environment. Advance directives were in place for 88.9% of patients and were followed in 96.8%. Among the 67 patients who exhibited distress in the dying process, symptoms included breathing difficulties (82.1%), fear/anxiety (55.2%), pain (23.9%), insomnia (14.9%), and choking (14.93%). Oxygen was given to 52.6% of patients, and pain medications were given to 74%. CONCLUSION: These data suggest that palliative care at the end of life was relatively well managed for most patients with ALS who participated in this study; nevertheless, several opportunities for improvement were identified.

Amyotrophic Lateral Sclerosis↗
PubMed2001

Characterization of four new monoclonal antibodies that recognize mouse natural killer activation receptors.

With the aim of identifying natural killer (NK) activation receptors, we immunized BALB/c mice with (BALB/cxB6)F1 NK LAK cells and made B-cell hybridomas. These were screened for monoclonal antibody (MAb) reacting with an NK activation receptor by using an antibody-induced redirected lysis (AIRL) assay against FcR-bearing P815 targets. Four hybridomas, clones 1C10, 1F10, 2D10 and 4G4, were selected for further characterization. Protein G-purified MAbs from these clones activated both resting and IL-2 activated B6 or F1 NK cells in the AIRL assay. 1F10 MAb, but not the other three MAbs, could compete for the binding of anti-NK1.1 (PK136) MAb to F1 NK cells. The four MAbs were screened for their ability to bind to or activate NK cells from the mouse strains SJL/J, DBA/2, 129/J, C3H/J, and BALB.K. None showed activity except IC10, which could bind to and activate SJL/J NK cells. When members of the NKR-P1 family from both B6 mice (A, B, and C genes expressed) and SJL mice (only A and B genes expressed) were expressed in Jurkat cells and tested for their antibody reactivity, PK136 MAb was found to recognize B6 NKR-P1C and SJL/J NKR-P1B; IC10 MAb was found to recognize NKR-P1-A, -B and -C from B6, but not NKR-P1A or -B from SJL/J; and 1F10 MAb was found to react only with B6 NKR-P1C.

Animals↗
PubMed2001

A central role for IL-2 in fate determination of mature T cells--I: role in determining the Th1/Th2 profile in primary T cell cultures.

IL-2 signaling appears to play a significant role in enabling the synthesis of T(h)2 cytokines in an in vitro system for studying primary T cell responses. When T cells from C57BL/6J or BALB/c strains of mice were activated in vitro and re-stimulated through their TCR complex 48 h later, CD4(+) T cells producing the T(h)2 cytokines IL-4 and IL-10 were found only when IL-2 was present. IL-2 also enhanced IFN-gamma synthesis in C57BL/6J cells but not in BALB/c cells. By up-regulating production of anti-inflammatory T(h)2 cytokines during a primary response, IL-2 may play a critical role in limiting T(h)1-mediated responses.

Animals↗
PubMed2000

Stress renders T cell blasts sensitive to killing by activated syngeneic NK cells.

Exposure of primary T cell blasts to stress in the forms of heat, hydrogen peroxide, or high-density growth conditions resulted in a state of enhanced susceptibility to killing by syngeneic IL-2-activated NK cells or lymphokine-activated killer cells, but not to killing by CTL. Cytotoxicity was perforin mediated and was not due to decreased target expression of total MHC class I. The levels of stress used had little effect on cell viability. For thermal stress, sensitization increased with temperature, required a minimum exposure time, and disappeared when cells were given a long enough recovery time. Our data support a model that predicts that activated NK cells play a role in the immunosurveillance of nontransformed stressed cells in normal animals.

Animals↗
PubMed2000

The ALS patient care database: goals, design, and early results. ALS C.A.R.E. Study Group.

OBJECTIVE: The ALS Patient Care Database was created to improve the quality of care for patients with ALS by 1) providing neurologists with data to evaluate and improve their practices, 2) publishing data on temporal trends in the care of patients with ALS, and 3) developing hypotheses to be tested during formal clinical trials. BACKGROUND: Substantial variations exist in managing ALS, but there has been no North American database to measure outcomes in ALS until now. METHODS: This observational database is open to all neurologists practicing in North America, who are encouraged to enroll both incident and prevalent ALS patients. Longitudinal data are collected at intervals of 3 to 6 months by using standard data collection instruments. Forms are submitted to a central data coordinating center, which mails quarterly reports to participating neurologists. RESULTS: Beginning in September 1996 through November 30, 1998, 1,857 patients were enrolled at 83 clinical sites. On enrollment, patients had a mean age of 58.6 years +/-12.9 (SD) years (range, 20.1 to 95.1 years), 92% were white, and 61% were men. The mean interval between onset of symptoms and diagnosis was 1.2+/-1.6 years (range, 0 to 31.9 years). Riluzole was the most frequently used disease-specific therapy (48%). Physical therapy was the most common nonpharmacologic intervention (45%). The primary caregiver was generally the spouse (77%). Advance directives were in place at the time of death for 70% of 213 enrolled patients who were reported to have died. CONCLUSIONS: The ALS Patient Care Database appears to provide valuable data on physician practices and patient-focused outcomes in ALS.

Activities of Daily Living↗
PubMed2000

Central fatigue during isometric exercise in amyotrophic lateral sclerosis.

While both upper and lower motor neuron dysfunction may contribute to impaired muscle function in amyotrophic lateral sclerosis (ALS), the precise mechanisms of muscle fatigue have not been clarified in this disease. Therefore, the central and peripheral factors in muscle fatigue were investigated during intermittent submaximal isometric ankle dorsiflexion in 7 patients with ALS and 6 healthy control subjects. Voluntary and electrically stimulated force, central and peripheral indices of muscle activation, and intramuscular energy metabolism were measured before and during exercise. At the end of exercise, only the ALS group had an increase in the "added force" in response to a stimulus train imposed during maximal voluntary contraction, indicating significant central fatigue in ALS. In support of this conclusion, patients with ALS had less intramuscular phosphocreatine depletion and less fatigue of stimulated tetanic force during exercise compared to control. Thus, due to the central failure, there was decreased muscle activation resulting in a smaller metabolic demand and less fatigue within the muscle itself. These data demonstrate a major contribution of central factors to muscle fatigue in ALS.

Amyotrophic Lateral Sclerosis↗
PubMed2000

Riluzole for amyotrophic lateral sclerosis (ALS)/motor neuron disease (MND).

BACKGROUND: Riluzole has been approved for treatment of patients with amyotrophic lateral sclerosis (ALS) in some countries but not others. Questions persist about its clinical utility because of high cost, modest efficacy and concern over adverse effects. OBJECTIVES: To examine the efficacy of riluzole in prolonging survival, and in delaying the use of surrogates (tracheostomy and mechanical ventilation) to sustain survival. SEARCH STRATEGY: Search of the Cochrane Neuromuscular Disease Group Register for randomized trials and enquiry from authors of trials and other experts in the field. The most recent search was conducted in June 1999. SELECTION CRITERIA: Types of studies: randomized trials TYPES OF PARTICIPANTS: adults with a diagnosis of ALS Types of interventions: treatment with riluzole or placebo Types of outcome measures: Primary: per cent mortality at 12 months with riluzole 100 mg Secondary: per cent mortality as a function of time with 100 mg and with all doses of riluzole, scales of neurologic function, quality of life, muscle strength and adverse events. DATA COLLECTION AND ANALYSIS: We identified two randomized trials. Each reviewer graded them for methodological quality. Data extraction was performed by a single reviewer and checked by the other two. We obtained some missing data from investigators. We performed meta-analyses with RevMan software using a fixed effects model. MAIN RESULTS: The two eligible trials included a total of 794 riluzole treated patients and 320 placebo treated patients. The methodological quality was acceptable and the trials were easily comparable. There were significant differences between the riluzole and placebo groups of both trials, in terms of the primary outcome measure, which was per cent mortality at 12 months with the 100 mg dose of riluzole. The odds ratio for the combined studies was 0.57 (95%CI 0.41 to 0.80) at 12 months. In the secondary outcome measures, there was a survival advantage with riluzole 100 mg at six, nine, 12 and 15 months, but not at three or 18 months. Pooled data from the 50, 100 and 200mg dose groups in the larger trial showed a lower per cent mortality with riluzole compared to placebo only at 12 months (odds ratio (OR) 0.64, 95% CI 0.47 to 0.88). There was no beneficial effect on bulbar function, or muscle strength. There were scant data on quality of life, but patients treated with riluzole remained in a more moderately affected health state significantly longer than placebo-treated patients (weighted mean difference (WMD) 35.5 days, 95% CI 5.9 to 65. 0). A threefold increase in serum alanine transferase was more frequent in riluzole treated patients than controls (WMD 2.65, 95% CI 1.51 to 4.65). REVIEWER'S CONCLUSIONS: Riluzole 100 mg per day appears to be modestly effective in prolonging survival for patients with ALS.

Amyotrophic Lateral Sclerosis↗
PubMed2000

Novel priming and crosslinking systems for use with isocyanatomethacrylate dental adhesives.

OBJECTIVES: (a) to design, formulate and evaluate prototype primers and a crosslinking agent for use with isocyanatomethacrylate-based comonomer adhesives and (b) to establish correlations between bond strength and solubility parameter differences between the adhesives and etched dentin, and the permeability coefficients of the adhesives. METHODS: Equimolar mixtures of 2-isocyanatoethyl methacrylate (IEM) and a methacrylate comonomer were formulated with tri-n-butyl borane oxide (TBBO) as the free radical initiator to have cure times of 6-10 min. Shear bond strengths to dentin were determined for each adhesive mixture (n = 7) using standard testing protocols. Shear bond strengths for the three systems were also determined after application of "reactive primers" to the dentin surface. The "reactive primers" contained 10-20 parts by weight of the respective comonomer mixture and 3.5 parts by weight TBBO in acetone. Solubility parameters difference values (delta delta) and permeability coefficients (P) were approximated for each adhesive system and correlated with shear bond strength values. Additionally, a crosslinking agent was prepared by bulk reaction of an equimolar mixture containing IEM and a methacrylate comonomer. The effects of crosslinker addition on: (a) the setting time of IEM; and (b) the setting times and initiator requirements of selected IEM/comonomer mixtures were determined. RESULTS: Shear bond strength values (MPa): IEM/HEMA 13.6 +/- 2.0 (no primer), 20.1 +/- 2.0 (with primer); IEM/HETMA 9.3 +/- 3.3 (no primer), 20.8 +/- 8.1 (with primer); IEM/AAEMA 13.6 +/- 1.9 (no primer), 17.3 +/- 3.2 (with primer). Also, approximated permeability coefficients showed a significant correlation (r = +0.867, p < 0.001) with shear bond strength values. Crosslinker addition studies with IEM/4-META: (a) at 5-9 mol% reduced the setting time of IEM polymerization by 79%; and (b) at 6 mol% reduced initiator level requirements 60-70% to achieve a comparable setting time, and decreased setting times by ca. 75% for a given initiator level with selected IEM/methacrylate adhesive systems. SIGNIFICANCE: The shear bond strengths of isocyanatomethacrylate-based dental adhesives can be enhanced by using reactive primers; their setting times and initiator requirements can be improved using a dimethacrylate crosslinker. Approximated permeability coefficients may be useful as indicators of bonding performance for dentin adhesive systems.

Adhesives↗