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Biomedical subjects

R L Wortmann

Publications and source records attributed to R L Wortmann.

At least 19 recordsLinked to original sources

The clinical laboratory evaluation of the patient with noninflammatory myopathy.

The investigations used to diagnose an inflammatory muscle disease include history and physical examination, evaluation of serum levels of enzymes derived from skeletal muscle, electromyography, magnetic resonance imaging, and muscle histology. The evaluation of patients who may have noninflammatory myopathy includes, but is not limited to, these methods. Additional tools that may be useful include measurements of additional biochemistries, the forearm ischemic exercise test, magnetic resonance spectroscopy, and special tests on muscle tissue. Reports published in the past year have improved and expanded our understanding of the numerous noninflammatory myopathies and how these tools can be used more effectively.

Adult↗

Metabolic and mitochondrial myopathies.

Metabolic myopathies are the result of genetic defects that cause disordered energy metabolism. These diseases can cause a variety of myopathic syndromes and can become clinically manifest at any age. Recent advances in the understanding of the molecular and metabolic bases for these diseases have resulted in expanded clinical descriptions, recognition of additional entities, and development of new therapeutic approaches.

Humans↗

Joint replacement. The primary care physician's role.

Ideally, primary care physicians can successfully manage cases of arthritis in a manner that obviates the need for reconstructive surgery. However, that is not always possible. When surgical intervention is believed to be of potential benefit, the primary care physician needs to enlist the help of a surgeon and other health professionals to determine the best approach. Primary care physicians should take an active role in preoperative planning, perioperative management, and rehabilitation. The unique characteristics of the patient's specific type of arthritis and use of medications must be carefully considered. This approach should optimize the chances for a successful outcome.

Arthritis↗

Synovial fluid 5'-nucleotidase activity. Relationship to other purine catabolic enzymes and to arthropathies associated with calcium crystal deposition.

We measured 5'-nucleotidase (5NT) activity in synovial fluid from 159 patients with various diagnoses. The activity of 5NT was compared with activities of nucleotide pyrophosphohydrolase, alkaline and neutral phosphatases, and adenosine deaminase, in the same samples. Higher levels of 5NT activity occurred in synovial fluid from osteoarthritic joints than from joints of patients with gout, pseudogout, or rheumatoid arthritis. The highest levels of 5NT activity were found in synovial fluid from patients with Milwaukee shoulder syndrome and from osteoarthritis patients in whom deposition of calcium-containing crystals was also present.

5'-Nucleotidase↗

Influence of antihyperuricemic therapy on the clinical and radiographic progression of gout.

Ten years ago, we studied the clinical and radiographic manifestations of gout in 60 patients and described 3 patterns of disease. To determine the consequences of management over a 10-year period, we recently reassessed the 39 available patients of this population. We found that although reduced tophaceous deposition on physical examination correlated with normalization of the serum urate concentration, no correlation existed between radiographic changes and mean serum urate concentrations. Progression of gouty changes on radiography reflected progressive deformity on physical examination. We have described the radiographic changes that occurred in a well-characterized population of subjects with gout over 10 years and determined that serum urate concentrations alone may not provide an effective means of monitoring the progression of tophaceous disease in bone.

Aged↗

Pathogenesis of rheumatoid arthritis: basis for future therapies.

Despite an increase in the number of rheumatologists in clinical practice over the past 15 years, the outcome for patients with rheumatoid arthritis (RA) remains relatively poor. The poor prognosis for patients with this disease is due to a lack of effective therapies. Better therapies will be developed only after the cause and pathogenesis of RA are better understood. Although the precise cause is unknown, a variety of evidence indicates that RA results from the presentation of a relevant antigen to an immunogenetically susceptible host. This report reviews recognized potential antigens and known genetic variables affecting the immune response, as well as the various cellular and humoral immune responses that result from the antigen-host interaction. More successful therapy for RA will most certainly result from a better understanding of the pathobiology of the disease.

Antibody Formation↗

Metabolic myopathies.

The term metabolic myopathy refers to a heterogeneous group of conditions that have in common abnormalities of muscle energy metabolism that result in skeletal muscle dysfunction. Most recognized metabolic myopathies are considered primary, represent inborn errors of metabolism, and are associated with known or postulated defects that affect the ability of muscle fibers to maintain adequate ATP concentrations. Traditionally, these diseases are grouped into abnormalities of glycogen, lipid, purine, and mitochondrial biochemistry. This discussion reviews the basic metabolic pathways that regulate normal muscle function; recent observations involving glycogen storage diseases, carnitine deficiency states, and myoadenylate deaminase deficiencies; and lastly, newer techniques available to assess patients with myopathic disorders.

Humans↗

Clinical heterogeneity and treatment response in inclusion body myositis.

Inclusion body myositis has been described as an inflammatory myopathy with distinctive clinical and pathologic features that is refractory to treatment. Ten cases of inclusion body myositis, as defined by histopathologic findings, were reviewed to determine whether the clinical characteristics are different in patients whose disease has been defined by light and electron microscopic studies compared with those whose disease has been defined by light microscopic studies alone. The clinical characteristics of both groups of patients were similar, and 2 patients have had excellent responses to treatment. Although inclusion body myositis represents a histologic subset of polymyositis, from a clinical perspective, it must be considered a nonspecific designation. Despite a generally poor prognosis, therapeutic intervention is still warranted.

Adult↗

Differential deoxyadenosine toxicity to immature rabbit cartilage in vitro. A model for the chondro-osseous dysplasia of adenosine deaminase deficiency.

Deoxyadenosine metabolism was investigated in rabbit growth plate and articular cartilage to elucidate the biochemical basis for the chondro-osseous dysplasia observed in adenosine deaminase (ADA) deficiency. Models of ADA deficiency, the combination of deoxy-adenosine and either of 2 ADA inhibitors, were selectively toxic to immature cartilage, supporting the hypothesis that the chondro-osseous dysplasia of ADA deficiency is the consequence of the enzyme deficiency. Depletion of ATP may play a role in the altered chondrocyte viability and function observed in this model.

Adenosine Deaminase↗