Purpura and leukopenia in a cocaine user.

A previously healthy 42-year-old woman presented to the emergency department (ED) for arthralgias and painful lesions on her ears, feet, and knee (Figures 1 and 2) that had developed over the last month. She had no significant past medical history and was not taking any prescribed medications. The rash was purpuric with violaceous borders and hemorrhagic bullae. While she had mild pain with movement, her joint examination was otherwise normal and without signs of infection. ED laboratory testing revealed leukopenia (2500/mm(3)) and cocaine metabolites in her urine.

Ethylmalonic encephalopathy: application of improved biochemical and molecular diagnostic approaches.

Ethylmalonic encephalopathy (EE, OMIM # 602473) is an autosomal recessive metabolic disorder of infancy affecting the brain, the gastrointestinal tract and peripheral vessels. It is caused by a defect in the ETHE1 gene product, which was recently shown to be part of a metabolic pathway devoted to sulphide detoxification. We report the application of improved biochemical and molecular approaches to the diagnosis of three cases of EE from two unrelated Cypriot families. The children presented all the typical biochemical hallmarks of the disease including elevated lactate and butyrylcarnitine in blood and elevated urinary excretion of ethylmalonic acid, 2-methylsuccinate, isobutyrylglycine and isovalerylglycine. We also detected an elevated level of thiosulphate in urine, which we propose as an additional biochemical marker of the disease. The proband of the first family was shown to be a compound heterozygote for a missense mutation in exon 5, L185R, and a deletion of exon 4. The deletion was identified using quantitative real-time polymerase chain reaction (qRT-PCR). Using the same technique, the proband of the second family was found to be homozygous for the exon 4 deletion. A prenatal diagnosis was performed for the second family using qRT-PCR, thus establishing the usefulness of RT-PCR in prenatal diagnosis.

The role of methionine in ethylmalonic encephalopathy with petechiae.

BACKGROUND: Among patients with ethylmalonic aciduria, a subgroup with encephalopathy, petechial skin lesions, and often death in infancy is distinct from those with short-chain acyl-coenzyme A dehydrogenase deficiency or multiple acyl-coenzyme A dehydrogenase deficiency. The nature of the molecular defect in this subgroup is unknown, and the source of the ethylmalonic acid has been unclear. OBJECTIVE: To determine whether the administration of candidate amino acids increased the excretion of ethylmalonic acid. DESIGN: Examination of patterns of organic acids excreted in the urine before and following loading doses of isoleucine and methionine. SETTING: General clinical research center. PATIENT: An infant with ethylmalonic aciduria, global developmental delay, acrocyanosis, and intermittent showers of petechiae. MAIN OUTCOME MEASURE: Excretion of ethylmalonic acid in the urine. RESULTS: Loading with methionine increased the excretion of ethylmalonic acid, whereas loading with isoleucine did not. Restriction of the dietary intake of methionine decreased ethylmalonic acid excretion. CONCLUSION: In ethylmalonic acid encephalopathy with petechiae, methionine is a precursor of ethylmalonic acid.

Analysis of dipeptides in urine by gas chromatography/mass spectrometry: implications for collagen breakdown in iminodipeptiduria following a study of the dipeptides by electron impact and chemical ionization.

Dipeptides in the urine of a patient suffering from dermatological purpura, associated with iminodipeptiduria , were determined by gas chromatography/mass spectrometry. The dipeptides were identified as R-proline and R'-hydroxyproline where R is any one of the residues, glycyl, alanyl, valyl, leucyl, isoleucyl, seryl, aspartyl, glutamyl, prolyl, phenylalanyl and R' is alanyl, valyl, leucyl or isoleucyl, seryl, prolyl, glutamyl, phenylalanyl. The predominance of proline- and hydroxyproline-containing dipeptides and the percentage distributions of the other amino acid residues, R and R', strongly implicate an abnormality of collagen metabolism. Structural assignments are confidently based on (a) gas chromatographic retention times, (b) electron impact mass spectra and automatic comparison with reference to spectra stored in a specialized library, (c) chemical ionization mass spectra with isobutane and methanol as reactant gases and (d) the use of deuteriated acetic anhydride as a derivatizing agent.

Urinary fibrin-fibrinogen degradation products in nephrotic syndrome.

The urinary concentration of fibrin-fibrinogen degradation products (F.D.P.) was measured in 90 patients with proteinuria above 2 g/1 and correlated with proteinuria, differential protein clearances, serum urea and creatinine, and renal biopsy findings. There was a linear correlation (r equals 0-7; P less than 0-001) between the urinary F.D.P. excretion and the selectivity of the proteinuria such that patients with highly selective proteinuria excreted only small amounts of F.D.P. whereas those with non-selective proteinuria excreted much higher levels. There was a significant correlation between the urinary F.D.P. excretion and the urine:serum (U:S) ratio of IgG excretion but not with the U:S ratio or urinary excretion of albumin or transferrin. Sephadex G200 column chromatography of the concentrated urine in 26 cases showed that patients with highly selective proteinuria excreted predominantly F.D.P. of low molecular weight in the urine whereas those with non-selective proteinuria excreted mainly fibrinogen and products of high molecular weight. Hence the type and quantity of F.D.P. in the urine are determined primarily by the differential filtration of fibrinogen and the various degradation products from the plasma through the glomerular basement membrane, which in turn is determined by the "pore size" of the basement membrane. In clinical nephrology measurement of the urinary F.D.P. level provides a rapid and convenient means of estimating the differential protein clearance.