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Biomedical subjects

L M Pachman

Publications and source records attributed to L M Pachman.

At least 73 records · Page 4Linked to original sources
PubMed1985

Quantification of keratan sulfate in blood as a marker of cartilage catabolism.

We have developed an enzyme-linked immunosorbent-inhibition assay which makes use of a monoclonal antibody specific for keratan sulfate to quantify keratan sulfate present as single chains in adult human serum. In adults hospitalized with conditions not thought to affect the turnover of keratan sulfate-containing tissues, the serum levels varied from individual to individual (53-1,009 ng/ml) but did not show significant differences with respect to age, sex, or disease category. There were no significant differences between the serum levels of adult hospitalized patients and those of nonhospitalized normal adults. In contrast, the concentration of keratan sulfate in the sera of children aged 5-12 was significantly higher. No keratan sulfate was detected in the sera of 3 adult patients with macular corneal dystrophy, an inherited disorder of the cornea. This may indicate that individuals with macular corneal dystrophy have no keratan sulfate-containing proteoglycans in their cartilage. Adult patients with osteoarthritis have significantly higher concentrations of circulating keratan sulfate. This suggests that the assay could prove valuable in monitoring increased cartilage catabolism in joint diseases.

Adolescent↗
PubMed1984

Juvenile dermatomyositis and polymyositis.

Myositis in childhood is characterized by elevated serum levels of muscle-derived enzymes, proximal symmetrical muscle weakness, abnormal EMG and a muscle biopsy which frequently documents an inflammatory process. In the paediatric age group, JDMS is much more common than PM and occurs more frequently among females. Mortality has been reduced from 33 per cent to 7 per cent following the use of steroids. The development of calcifications (33 per cent) can be the most debilitating consequence of JDMS . It is our premise that JDMS is a distinct disease entity and that the increase in HLA-B8 and -DR3 in JDMS places this disease in the company of other immunopathic disorders. There are conflicting data concerning immunological abnormalities in JDMS , but there appears to be impairment of natural killing and evidence of complement activation. The frequent positive ANA in JDMS raises the speculation of its relationship to the antinuclear antibody, Jo-1, found in some adults with PM, which has specificity for tRNAHis. Most newly diagnosed JDMS patients have antibodies to Coxsackie B which may be related to the pathogenesis of this disease. Specific pathological findings of endothelial cells containing reticulotubular inclusions are associated with vessel occlusion, subsequent obliteration and increased Factor VIII levels in clinically active disease. In addition to physical therapy, prednisone is the drug most used, but immunosuppressive agents and plasmapheresis have been tried in severely ill children. Rigorous evaluation of the efficacy of these modalities is needed.

Adolescent↗
PubMed1983

Prostaglandin biosynthesis by a human macrophage-like cell line, U937.

The human macrophage-like cell line, U937, produced significant amounts of prostaglandin (PG) E2 when incubated with exogenous arachidonic acid (AA). The synthesis of PGE2 was completely inhibited by pretreatment with indomethacin (20 micrograms/ml). Another major metabolite, unidentified, which was released during incubation with AA, was not inhibited by indomethacin, but was decreased by nordihydroguaiaretic acid (NDGA) (10(-5)M) or BW755C (10(-4)M). These results confirm the presence of cyclooxygenase and perhaps lipoxygenase activities in this macrophage-like cell line. Challenge of U937 cells with zymosan, opsonized zymosan, phorbolmyristate acetate (PMA), heat-aggregated human IgG (AHG), or calcium ionophore A23187 failed to stimulate synthesis and release of either PGE2 or the above mentioned metabolite. The inability of U937 cells to release endogenous AA from cell lipid for PG synthesis constitutes an important functional difference between these cells and normal macrophages.

Arachidonic Acids↗
PubMed1983

Immunogenetic studies of juvenile dermatomyositis. HLA antigens in patients and their families.

Typing for HLA-A and -B antigens was performed on 87 children with definite juvenile dermatomyositis (JDMS). A significantly increased frequency of HLA-B8 (estimated relative risk = 2.8, Pc less than 0.01) was observed among White patients, but not among Blacks or Latin Americans with JDMS. No abnormality of HLA haplotype segregation was observed among 38 healthy siblings of the JDMS probands.

Adolescent↗
PubMed1983

Natural and antibody-dependent cellular cytotoxicity in children with systemic lupus erythematosus and juvenile dermatomyositis.

Thirteen children with systemic lupus erythematosus (SLE) and 5 with juvenile dermatomyositis (JDM) were studied for natural cytotoxicity (NK) and antibody-dependent cellular cytotoxicity (ADCC). In vitro prednisolone at pharmacological levels failed to alter NK or ADCC in adult controls, nor did it alter ADCC in any children studied. ADCC was normal, but NK was decreased in SLE (p less than .005) and JDM (p less than .05) compared to controls. Since NK but not ADCC is decreased in these patients, different lymphocyte populations may mediate these 2 cytotoxic functions.

Adolescent↗
PubMed1982

Gamma-carboxyglutamate excretion and calcinosis in juvenile dermatomyositis.

Proteins containing gamma-carboxyglutamic acid (Gla) are present in subcutaneous calcifications of adults with dermatomyositis or scleroderma. Sixteen children with juvenile dermatomyositis, including 7 with subcutaneous calcifications, were studied to determine if abnormal synthesis or turnover of Gla-containing proteins occurred. All study children had increased excretion of the amino acid that was greater than that of age- and sex-matched controls. Patients who had juvenile dermatomyositis with calcifications had a 3-fold increase in Gla excretion, and those without calcinosis had a 2-fold increase. Five other children with various connective tissue disorders and subcutaneous calcification had 2-fold increased Gla excretion. Decreased excretion of this amino acid was associated with salicylate therapy (80 mg/kg/24 hours). The data suggest an abnormal turnover of Gla-containing proteins in juvenile dermatomyositis. Metabolism of these proteins may be involved in the pathophysiology of soft-tissue calcification in children.

1-Carboxyglutamic Acid↗
PubMed1980

Synovial fluid in seronegative juvenile rheumatoid arthritis: studies of immunoglobulins, complements, and alpha 2-macroglobulin.

Synovial fluid of 20 children with seronegative juvenile rheumatoid arthritis (JRA) and 20 patients with other joint pathology was examined for levels of total hemolytic complement and selected components, immune complexes, and alpha 2-macroglobulin (alpha 2-M). When adjusted for total protein, synovial levels of total hemolytic complement, C3, C4, and alpha 2-M did not differ significantly in the two groups. The concentrations of IgM and IgG were elevated in the JRA synovial fluid, but immune complexes were not increased when compared with non-JRA group as determined by the Raji cell technique. alpha 2-M activity against substrates of C1 esterase was absent. therefore, evidence of specific increase in immune complexes and complement activation was sought but not found, suggesting that they may not be a major factor in the pathogenesis of seronegative, pauciarticular JRA.

Adolescent↗
PubMed1980

Juvenile dermatomyositis: a clinical and immunologic study.

Twenty-one children were diagnosed as having juvenile dermatomyositis on the basis of the strict criteria of Bohan and Peter. In addition to the typical skin and muscle changes, abnormalities of esophageal motility (eight of 19), pulmonary function (14 of 17), ECG (10 of 20), and gastrointestinal absorption of D-xylose (two of eight) with active disease were observed. Clinical signs of other collagen vascular disease appeared in five children. Serologic evaluation demonstrated that ANA and rheumatoid factor were transiently positive in six; one child developed a persistently positive rheumatoid factor after four years of disease inactivity. Antibody to ENA was negative in all, but antibody to PM-1 antigen was present in four of 18. Six had a low C3 or C4; evidence of immune complexes was demonstrated by Clq or Raji binding in eight with active disease. One child was IgA deficient. The HLA-B8 antigen was present in 72% of the Caucasian children as compared with the expected incidence of 21%. Therefore, classical dermatomyositis in children has more systemic involvement then previously appreciated, may be related to the presence of circulating immune complexes, and appears to be under immunogenetic control.

Adolescent↗
PubMed1979

Pharmacokinetic monitoring of salicylate therapy in children with juvenile rheumatoid arthritis.

Free and total (sum of free and protein bound) salicylate concentrations in serum were determined in 17 children (age: 4-17 years) with definite juvenile rheumatoid arthritis. These measurements were carried out immediately before and 2, 4, and 8 hours after the morning dose during a strict 8 hourly aspirin treatment regimen (regular tablets) started 5 days earlier. The ratio of the 0 to 8 hour total salicylate concentrations was 0.95 +/- 0.10 (mean +/- SD), indicating that steady state had been attained. The ratio of the maximum to minimum concentrations during the dosing interval ranged from 1.05 to 2.26 and decreased with increasing average concentration. The concentration ratio was less than 1.3 at average salicylate concentrations above 20 mg/100 ml. It is concluded that the timing of a blood sample is not critical for monitoring steady state serum salicylate concentrations in the usual therapeutic range if the dosing interval is 8 hours or less. Free salicylate concentrations increased more than proportionately with increasing total concentrations due to the concentration dependent protein binding of the drug in serum.

Adolescent↗
PubMed1978

Plasma levels, half-life values, and correlation with physiologic assays for growth and immunity.

Plasma prednisolone levels have been measured hourly in children receiving a single dose of oral prednisone. Peak prednisolone levels occurred one to two hours after ingestion; half-life studies gave a mean value of 132 minutes in most children. Some children had marked variability in absorption and metabolism of prednisone. Somatomedin activity and cell-mediated immunity were inhibited by plasma prednisolone values which were achieved by single doses of prednisone of 0.5 mg/kg or higher. Monitoring prednisolone levels may be of value in identifying those children who accumulate excessively high levels on moderate dosage regimens.

Administration, Oral↗
PubMed1977

PMN chemotactic inhibition associated with a cryoglobulin.

A child with recurrent pyogenic infections, eczema, markedly elevated serum concentrations IgA, and totally absent PMN chemotactic acticity is described. The chemotactic defect was characterized as a humoral inhibitor present in serumand plasma, directed toward autologous as well as homologous PMN's. Immunochemical studies revealed the purified inhibitor to be a cryoglobulin composed of an IgM-IgA complex. Incubation of the cryoglobulin complex with PMN's resulted in a quantitative dose-response curve.

Antibody Specificity↗
PubMed1977

Occult lupus nephropathy: a correlated light, electron and immunofluorescent microscopic study.

Renal biopsies obtained from four adolescent girls who developed symptomatic thrombocytopenia with serologic evidence of systemic lupus erythematosus, without clinical signs of renal involvement, showed glomerular disease by electron and immunofluorescent microscopy with light microscopic changes in two cases. Subsequently, three of the patients developed proteinuria, and repeat biopsies from all four showed appearances ranging from resolution to significant glomerulitis. The findings illustrate the variable patterns of occult glomerulitis in lupus, and highlight the value of correlating light, electron and immunofluorescent studies in renal pathology.

Adolescent↗