Biomedical subjects

R Laxer

Publications and source records attributed to R Laxer.

8 recordsLinked to original sources

PubMed1995

Evaluation of therapeutic drug monitoring of methotrexate in saliva of children with rheumatic diseases.

Pediatric patients with leukemia, other malignancies, and rheumatological disease receive methotrexate chronically. Because of the documented correlation between methotrexate levels of compliance and clinical outcome, it is conceivable to verify appropriate systemic exposure to the drug. Saliva sampling may be of potential interest, especially in children, in whom blood sampling is ethically limited. Our study shows poor correlation between serum total/free methotrexate concentrations and saliva levels, precluding the clinical use of this test.

Adolescent↗

PubMed1994

Localized scleroderma: imaging features.

Localized scleroderma is distinct from the diffuse form of scleroderma and does not show Raynaud's phenomenon and visceral involvement. The imaging features in 23 patients ranging from 2 to 17 years of age (mean 11.1 years) were reviewed. Leg length discrepancy and muscle atrophy were the most common findings (five patients), with two patients also showing modelling deformity of the fibula. One patient with lower extremity involvement showed abnormal bone marrow signals on MR. Disabling joint contracture requiring orthopedic intervention was noted in one patient. In two patients with "en coup de sabre" facial deformity, CT and MR scans revealed intracranial calcifications and white matter abnormality in the ipsilateral frontal lobes, with one also showing migrational abnormality. In a third patient, CT revealed white matter abnormality in the ipsilateral parietal lobe. In one patient with progressive facial hemiatrophy, CT and MR scans showed the underlying hypoplastic left maxillary antrum and cheek. Imaging studies of areas of clinical concern revealed positive findings in half our patients.

Adolescent↗

PubMed1994

Hypoprothrombinemia in childhood systemic lupus erythematosus.

Three children with systemic lupus erythematosus who developed hemorrhagic tendencies as a consequence of a clotting factor II (prothrombin) deficiency are described. All three responded rapidly to treatment with corticosteroids. A literature review added 25 case reports, with the following findings. First, factor II deficiency occurs in the presence of the lupus anticoagulant, although the interrelationship between the two is not understood. Second, the deficiency is presumed to be secondary to rapid clearing of the antigen/antibody factor II complex in the liver. Finally, most cases respond to corticosteroid therapy with or without the coadministration of vitamin K or fresh frozen plasma. In corticosteroid-dependent patients, the addition of antimetabolites such as azathioprine has enabled reduction in steroid doses.

Adolescent↗

PubMed1994

Seroprevalence of Helicobacter pylori infection is not increased in pediatric inflammatory arthritides.

OBJECTIVE: To determine the seroprevalence of H. pylori infection among children with inflammatory arthritides receiving antiinflammatory drug therapy. METHODS: An enzyme linked immunosorbent assay (ELISA) was used to detect H. pylori specific immunoglobulin G antibody in 95 children with inflammatory arthritides, 53 children with chronic inflammatory bowel diseases and 47 parents of children with inflammatory arthritis. RESULTS: The frequency of seropositivity in children with arthritis (9/95, 9.5%) was not significantly higher than in children with chronic inflammatory bowel diseases (1/53, 1.9%; p = 0.16). Serum samples from parents were positive in 16 of 47 (34%), including 4 parents with children who also demonstrated a positive immune response. CONCLUSION: These data do not provide evidence for an increased frequency of H. pylori infection among children with inflammatory arthritides. The therapeutic use of ulcerogenic medications is likely to be an independent risk factor predisposing to dyspeptic symptoms and gastritis in this patient population.

Adolescent↗

PubMed1991

Short-chain L-3-hydroxyacyl-CoA dehydrogenase deficiency in muscle: a new cause for recurrent myoglobinuria and encephalopathy.

We report on a 16-year-old girl with short-chain L-3-hydroxyacyl-coenzyme A (CoA) dehydrogenase deficiency resulting in juvenile-onset recurrent myoglobinuria, hypoketotic hypoglycemic encephalopathy, and hypertrophic/dilatative cardiomyopathy. Urinary organic acids showed traces of 3-hydroxy-dodecanedioic acids and small amounts of suberic, sebacic, and adipic acids. There was a marked decrease in L-3-hydroxyacyl-CoA dehydrogenase activity in muscle with acetoacetyl-CoA as substrate (2.48 mumol/min/gm; normal = 6.90 +/- 1.80 mumol/min/gm of tissue; n = 11), contrasting with normal L-3-hydroxyacyl-CoA dehydrogenase activity with 3-ketooctanoyl-CoA and 3-ketopalmitoyl-CoA as substrates. Short-chain L-3-hydroxyacyl-CoA dehydrogenase activity was normal in fibroblasts, suggesting a tissue-specific defect.

3-Hydroxyacyl CoA Dehydrogenases↗

PubMed1991

Decreased protein binding of salicylates in Kawasaki disease.

Because patients with Kawasaki disease have low serum concentrations of salicylates despite high doses, and because the free (unbound) drug is responsible for the pharmacologic effects of salicylates, we assessed salicylate protein binding in patients with Kawasaki disease. During the acute phase of the disease, protein binding of salicylate in 36 children with Kawasaki disease was 73 +/- 12%, significantly lower than during the subacute phase (90.4 +/- 8.7%; p less than 0.0005). Mean serum albumin concentration was 29.2 +/- 6.4 gm/L during the acute phase and 36.7 +/- 7.8 gm/L during the subsequent subacute phase (p less than 0.005). Salicylate protein binding was affected independently by both serum albumin and total salicylate levels. During the acute phase of Kawasaki disease, children had an average twofold increase in free salicylate compared with normoalbuminemic control subjects. A nomogram has been devised to derive free salicylate levels from the known total salicylate and serum albumin concentrations.

Acute Disease↗

PubMed1991

Bowel perforation and interstitial cystitis in childhood systemic lupus erythematosus.

A 13-year-old girl presented with abdominal pain, fever, dysuria, incontinence and pyuria and was subsequently diagnosed as having systemic lupus erythematosus (SLE) with extensive gastrointestinal involvement and an associated interstitial cystitis. Despite aggressive therapy with high dose prednisone and cyclophosphamide she developed a small bowel perforation and subsequently died. The combination of bowel symptoms and interstitial cystitis seems unique to the population with SLE, while the separate complication of bowel perforation carries an extremely poor prognosis in this group of patients.

Adolescent↗

PubMed1991

Importance of the immune response to the Ro/La particle in the development of congenital heart block and neonatal lupus erythematosus.

Previous studies have suggested a role for anti-Ro antibodies in the pathogenesis of neonatal lupus erythematosus (NLE). We reexamined the role of the immune response to the Ro/La particle in the development of NLE using newer and more definitive assay techniques. All 15 infants with congenital heart block and NLE had both anti-Ro and anti-La antibodies. Of 8 patients with cutaneous NLE alone, 2 had anti-Ro antibodies alone while the remaining 6 had both anti-Ro and anti-La antibodies. One woman gave birth to 2 children; one had both Ro and La antibodies and developed congenital heart block, the other had only anti-Ro and anti-U1RNP antibodies and was clinically normal. Our study demonstrates that the presence of anti-Ro and anti-La antibodies define the immune response that is associated with the development of congenital heart block of NLE.

Antibodies, Antinuclear↗