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J F Walker

Publications and source records attributed to J F Walker.

At least 19 recordsLinked to original sources
PubMed1992

Articulation rate in 3- and 5-year-old children.

The major purposes of this study were to provide normative data on articulation rate in preschool children and to examine the influence on articulation rate of age, gender, context, and utterance length. The subjects were twenty 3-year-old children and twenty 5-year-old children, equally balanced for gender. Durational measures of utterances were analyzed in syllables and phones per second in both spontaneous and imitated speech contexts. The articulation rate of the 5-year-old subjects was significantly faster than that of the 3-year-olds. Spontaneous speech was significantly faster and more variable than imitated speech. Some gender differences were found. Measures in syllables per second and phones per second, although not always yielding identical results, were found to be highly correlated.

Age Factors↗
PubMed1991

Long-term safety and efficacy profile of simvastatin.

Simvastatin, a 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor, has been administered to approximately 2,400 patients with primary hypercholesterolemia with a mean follow-up of 1 year in controlled clinical studies and their open extensions. Approximately 10% of this population received simvastatin for a period of greater than or equal to 2 years. The population on whom this safety analysis is based had a mean age of 50 years; 62% were men and approximately 27% had preexisting coronary artery disease. Simvastatin was titrated to the maximal daily dose of 40 mg each evening in 56% of the study population (last recorded dose). The most frequently reported drug-related clinical adverse experiences were constipation (2.5%), abdominal pain (2.2%), flatulence (2.0%) and headaches (1%). Persistent elevations of serum transaminase levels greater than 3 times the upper limit of normal were observed in only 1% of this cohort with only 0.1% of the total population requiring discontinuation of therapy. There were no clinically apparent episodes of hepatitis. Discontinuation of therapy due to myopathy was extremely rare (0.08%). Only minimal increases in the frequency of lens opacities (1%) were observed from baseline to the last lens examination during follow-up, consistent with the expected increase in lens opacity development due to normal aging. Patients who were greater than or equal to 65 years old had a clinical and laboratory safety profile comparable to the nonelderly population.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

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Communication Barriers↗
PubMed1991

Respiratory failure associated with myasthenia gravis.

Dysphagia and respiratory muscle weakness are the two most potentially dangerous findings in patients with neuromuscular disease because they predispose to aspiration pneumonia and respiratory failure. Myasthenia gravis is unique among the neuromuscular disorders for the variety of exacerbating factors that may lead to such clinical deterioration. While the major cause of ventilatory failure remains intensification of the underlying autoimmune process, well intentioned therapy may also lead to situations that necessitate ventilatory support. This report describes a patient with myasthenia gravis and respiratory failure and reviews the various etiologies of pulmonary dysfunction that are associated with the natural course of this disease and its treatment.

Adult↗
PubMed1990

Hydroxymethylglutaryl coenzyme A reductase inhibitors as monotherapy in the treatment of hypercholesterolemia.

A variety of double-blind studies have compared the efficacy of hydroxymethylglutaryl coenzyme A reductase inhibitors (lovastatin and simvastatin) with that of control agents (cholestyramine, fibrates and probucol) in patients with type IIA or IIB primary hypercholesterolemia. Results have shown that both lovastatin and simvastatin are more effective than the standard therapies with regard to reducing total and low-density lipoprotein cholesterol. Decreases in triglycerides and increases in high-density lipoprotein cholesterol were generally greater with fibrates. Ongoing studies are assessing the benefits of lovastatin and simvastatin in reducing the incidence of mortality from coronary artery disease, as well as causing regression of coronary atheroma.

Bezafibrate↗
PubMed1990

The relationship of the internal security system to group level organization in Miller's living systems theory.

It has been suggested that a 20th subsystem, the internal security subsystem, should be added to Miller's 19 matter-energy and information processes that are critical to living systems (Bosserman, 1982). This subsystem protects all levels of living systems from error and disruption resulting from internal and external sources. Yet many characteristics of the proposed security subsystem already are found in existing ones, that is, the reproducer, channel and net, and distributor. Therefore, a discrete internal security subsystem is not justified. There are, however, dormant aspects of the security system that are not described within the existing taxonomy that perhaps best fit as a mirror system across the organizational levels.

Animals↗
PubMed1989

Simvastatin: the clinical profile.

Simvastatin is the second in the class of compounds known as hydroxy-methylglutaryl-coenzyme A reductase inhibitors to be extensively studied in humans. The drug has now been given to over 1,800 patients with primary hypercholesterolemia for periods of up to two years. In the range of dosage from 10 to 40 mg once daily, therapy is associated with reductions of up to 30 percent in total cholesterol and 40 percent in low-density lipoprotein cholesterol levels, as well as with increases of approximately 10 percent in high-density lipoprotein cholesterol levels. The most common clinical adverse experiences are mild gastrointestinal effects and headache, which seldom require discontinuation of therapy. Elevations of creatine kinase (skeletal muscle isoenzyme) levels to more than three times the upper limit of the normal range have been seen in about 3 percent of patients, but also have seldom required discontinuation of therapy. Conversely, elevations of hepatic transaminase levels to more than three times the upper limit of the laboratory normal range have been seen in about 1.5 percent of patients and have caused discontinuation of therapy in 0.6 percent of patients treated. Simvastatin appears to be an effective and well-tolerated agent for the treatment of primary hypercholesterolemia and, as further study confirms long-term safety and efficacy, it should become a useful addition to the therapeutic armamentarium.

Aged↗