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Biomedical subjects

C M Pearson

Publications and source records attributed to C M Pearson.

At least 37 records · Page 2Linked to original sources
PubMed1979

Muscle breakdown and lysosomal activation (biochemistry).

Muscle tissue levels of lysosomal catheptic enzymes, such as cathepsins D, A, B1, C, and dipeptidyl peptidase II, were measured in control subjects and patients with muscular dystrophies, polymyositis, and certain denervating diseases. The results show that, in general, the activities of these enzymes are increased in muscles of patients with muscular dystrophies and other diseases. The increases in cathepsin D and autolytic activities are not significant until the late stage of the disease process. Cathepsins A, B1, and C are, however, significantly elevated in mildly affected dystrophic and other diseased muscles. Of these catheptic enzymes, cathepsin B1 displays the highest rise at an early stage, suggesting that it may be one of the rate-controlling enzymes of proteolysis. Dipeptidyl peptidase II is increased slightly in dystrophic and other myopathic muscles but is unchanged in denervated muscle. These data clearly implicate the lysosomal group of proteinases as largely responsible for mediating muscle breakdown in the muscular dystrophies and certain other muscle and neuromuscular diseases in man.

Animals↗
PubMed1978

Dipeptidyl peptidases in human muscle disease.

With the use of selective inhibitors of arylamidase, four dipeptyl peptidases (I, II, III, and IV) capable of hydrolyzing the beta-naphthylamides of Gly-Arg, Lys-Ala, Arg-Arg and Gly-Pro, respectively, were distinguished in homogenates of human muscle. Dipeptidyl peptidase I showed maximum activity at pH 5.0-6.0. Dipeptidyl peptidase II was maximally active at pH 5.0 and inhibited by cations. Dipeptidyl peptidases III and IV were most active at pH 8.5 and 7.5, respectively. When compared to controls, significant increases in muscle dipeptidyl peptidases I and II were observed in patients with muscular dystrophies and polymyositis. Dipeptidyl peptidase III was not altered in the neuromuscular disease examined. Dipeptidyl peptidase IV showed marked increase in a variety of muscle wasting conditions. The increase in dipeptidyl peptidases I and II may be attributed to lysosomal activation that is known to occur in conditions of muscle degeneration. However, the striking increase in a variety of muscle diseases of dipeptidyl peptidase IV, an enzyme shown to be associated with microsomal membranes in other tissues, suggest that in addition to lysosomes other sources also contribute to the total hydrolytic potential of diseased muscles. Dipeptidyl peptidases II and IV were found to be present in human serum. Their levels were not altered in serum of patients with Duchenne dystrophy.

Dipeptidases↗
PubMed1978

Scleromyxedema myopathy. Histochemical and electron microscopic observations.

A biopsy-proven case of scleromyxedema (papular mucinosis) with IgG lambda light chain paraproteinemia, eosinophilia and severe proximal myopathy is presented. Muscle biopsy revealed an atypical necrotizing vacuolar myopathy. Histochemical studies of cryostat sections revealed fiber necrosis, severe type II fiber atrophy, and fiber vacuolization with NADH tetrazolium reductase hyperactivity. Electron microscopy showed myocytolysis, reduplication of the basement membrane, and unit membrane-lined vacuoles negative for acid mucopolysaccharide.

Biopsy↗
PubMed1978

Recurrent myoglobinuria due to muscle carnitine palmityl transferase deficiency.

Three new cases of carnitine palmityl transferase deficiency are described. The syndrome consists of recurrent attacks of muscle cramps, weakness, malaise, and myoglobinuria. These attacks are especially likely to occur during prolonged exercise after fasting, eating a high-fat diet, or during cold weather. Occasionally after fasting alone, spontaneous muscle breakdown may occur. One patient studied in detail was excessively slow in producing ketones when he fasted. His mylagias and weakness appeared to be alleviated by beta-hydroxybutyrate. Of eight other patients thought to have idiopathic recurrent myoglobinuria, three were found to have myophosphorylase deficiency, whereas five did not have deficiency of either enzyme. Carnitine palmityl transferase deficiency may be more common than previously supposed, may be in part amenable to dietary therapy, can be easily distinguished from myophosphorylase deficiency, and may provide insight into the metabolism of fatty acids and ketone bodies as well as energy requirements of skeletal muscle.

Acyltransferases↗
PubMed1977

Papular mucinosis with myopathy, arthritis, and eosinophilia. A histopathologic study.

A patient with biopsy-proven papular mucinosis, plus the characteristic IgG lambda light chain paraproteinemia, also developed a severe proximal myopathy, seronegative inflammatory polyarthritis, and marked eosinophilia. Muscle enzymes were elevated, EMG was compatible with polymositis, and muscle biopsy revealed an atypical necrotizing vacuolar myopathy. Synovial biopsy revealed an inflammatory synovitis with Class II synovial fluid. No mucin deposition was detectable in muscle or synovium. During 7 years of observation, corticosteroids and various immunosuppressive agents were successively administered with little benefit. Recently, weekly intravenous methotrexate and low-dose oral corticosteroids have resulted in clinical and laboratory improvement. It is suggested that the pathology in papular mucinosis may include serious rheumatic manifestations in addition to the cutaneous involvement.

Arthritis↗
PubMed1977

Preparation of arthritogenic hydrosoluble peptidoglycans from both arthritogenic and non-arthritogenic bacterial cell walls.

Cell wall lytic enzyme (Kyowa lytic no. 2 enzyme) liberated arthritogenic hydrosoluble peptidoglycans from both arthritogenic and non-arthritogenic bacterial cell walls. From these cell walls, mutanolysin (peptidoglycan-degrading enzyme) also liberated hydrosoluble peptidoglycans which, however, lacked arthritogenicity. Based on the chemical composition of these peptidoglycans, it was suggested that their arthritis-inducing ability depends on a relatively long chain of glycan units that consists of repeated units of N-acetylglucosaminyl-N-acetylmuramic acid. However, the glycan chain lengths on these peptidoglycans appeared to be related to their adjuvancy rather than to an antigen(s) responsible for development of arthritis in rats.

Animals↗
PubMed1977

Arthritogenicity of wax D from various mycobacteria related to oil vehicle composition and to the combination with poly I:C, cord factor and acetylated wax D.

Most of wax D (peptidoglycolipid) used here appeared to be ineffective for production of arthritis when given in a water-in-oil emulsion, while the same wax D in squalane was very effective for production of arthritis. Arlacel A as an emulsifier appeared to suppress the arthritogenicity of wax D in squalane, probably through some interaction with the arthritogenic portion of wax D. Poly 1:C seemed to remarkedly enhance the arthritogenicity of wax D, even in water-in-oil emulsion. Acetylated wax D and cord factor (trehalsoe-dimycolate) were much less effective than poly 1:C. Delayed skin hypersensitivity to PPD, peptidoglycan and poly 1:C was also remarkedly affected by oil composition. However, there was no correlation between these delayed hypersensitivities and development of arthritis.

Adjuvants, Immunologic↗
PubMed1977

Human lymphocyte subpopulations: rosette formation with sheep, human and horse red blood cells.

Rosette formation between human lymphocytes and horse red blood cells could be promoted by a low pH medium, overnight incubation and a temperature of 4 degrees C. The percent of sheep, horse and human rosette-forming cells in the peripheral blood were 71.7 +/- 1.8, 30.5 +/- 2.8 and 28.3 +/- 3.4 respectively. However, their percentages in thymuses were 97.1 +/- 1.1, 91.4 +/- 2.4 and 89.0 +/- 3.4. Using preparations of isolated subpopulations, it was observed that the horse and human red cell rosette-forming cells were probably also "early" sheep red cell rosette-forming cells. Rosette formation with all three types of red blood cells were inhibited by a preparation of Fetuin-glycopeptide.

Animals↗
PubMed1977

Effect of corticosteroids on exercise-induced lymphocytosis.

Eight subjects ran on a treadmill at 8 miles per hr for 10 min. All developed lymphocytosis with predominant effect on the B cells. This was repeated 5 hr after receiving 60 mg of Prednisone. The lymphocytosis of both T and B cells were suppressed. When this was repeated 2 hr after receiving Prednisone, only lymphocytosis of the T subpopulation was suppressed. It was concluded that corticosteroid administration could suppress entry of lymphocytes into the circulation, with preponderant effect on the T subpopulation.

Adult↗
PubMed1977

Human monocyte-lymphocyte interaction: a new technique.

A rosette-type assay of the physical interaction between lymphocytes and monocytes after treatment with neuraminidase-galactose oxidase (NGAO) is reported. Monocyte-lymphocyte (ML) rosette formation and subsequent lymphocyte proliferation occurred when either lymphocytes or homologous monocytes were treated with NGAO and cultured together. Maximal ML rosette formation took place at 37 degrees C 4 hr after culture in media containing 10% serum at lymphocyte to monocyte ratios of 10:1 to 20:1. The percentage of rosette formation correlated with the extent of thymidine incorporation when increasing concentrations of NGAO were used. When NGAO-treated monocytes were added to untreated T and non-T lymphocytes, they bound preferentially to T lymphocytes and induced proliferation only in the T subpopulation. These results indicate that the ML rosette assay measures a highly specific monocyte-lymphocyte physical interaction after a mitogenic stimulus which is an early event in lymphocyte activation since it reflects the degree of subsequent lymphocyte proliferation.

Cell Separation↗