Dermatofibrosarcoma protuberans (DP), an infiltrative skin tumour of intermediate malignancy, presents specific features such as reciprocal translocations t(17;22)(q22;q13) and supernumerary ring chromosomes derived from the t(17;22). In this report, the breakpoints from translocations and rings in DP and its juvenile form, giant cell fibroblastoma (GCF), were characterised on the genomic and RNA level. These rearrangements fuse the platelet-derived growth factor B-chain (PDGFB, c-sis proto-oncogene) and the collagen type I alpha 1 (COL1A1) genes. PDGFB has transforming activity and is a potent mitogen for a number of cell types, but its role in oncogenic processes is not fully understood. COL1A1 is a major constituent of the connective tissue matrix. Neither PDGFB nor COL1A1 have so far been implicated in any tumour translocations. These gene fusions delete exon 1 of PDGFB, and release this growth factor from its normal regulation.

Background: Cardiac damage is frequently referred to in patients with SARS-CoV-2, is usually diagnosed by enzyme elevations, and is generally thought to be due to underlying coronary artery disease. There are references to cardiomyopathies accompanying coronavirus, but there has been no histologic confirmation. Case report: A previously healthy 17 year male old presented in full cardiac arrest to the emergency department after a 2 day history of headache, dizziness, nausea and vomiting. Autopsy demonstrated an enlarged flabby heart with eosinophilic myocarditis. There was no interstitial pneumonia or diffuse alveolar damage. Postmortem nasopharyngeal swabs detected severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) known to cause coronavirus disease 2019 . No other cause for the eosinophilic myocarditis was elucidated. Conclusion: Like other viruses, SARS-CoV-2 may be associated with fulminant myocarditis.

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NMDA receptor subunit expression is increased in short-term gentamicin animals, and the receptor likely mediates cell damage via the endothelin-ETBR-nitric oxide pathway. NMDA antagonism ameliorated renal damage after exposure to short-term gentamicin.

Background: This was a retrospective analysis of children in one center who had primary (idiopathic) FSGS. Design, setting, participants, and measurements: There were 41 patients: 34.1% female, 65.9% male, 80.5% black, and 19.5% white. At presentation, the mean age was 10.9 ؎ 0.9 yr. The mean time of follow-up was 3.9 ؎ 0.5 yr.Results: During the observation period, the systolic BP (SBP) and diastolic BP (DBP) remained stable, serum albumin rose slightly, and the GFR was stable. Among those who received corticosteroids at presentation, 21.2% were steroid sensitive. At last follow-up among all patients, 71% were in remission, 78% had stage 1 or 2 chronic kidney disease, and 4.9% had reached ESRD. At last follow-up, the GFR was significantly higher (P ‫؍‬ 0.01) in patients who were initially steroid sensitive. Ethnicity had no effect on clinical data or response to therapy. The pathologic variants were as follows: Cellular, 32%; collapsing, 24%; and not otherwise specified (NOS), 44%. The chronicity scores were as follows: Cellular, 4.3; collapsing 6.4; and NOS, 4.0 (significantly higher, P ‫؍‬ 0.02, in collapsing versus NOS). At presentation, SBP (P ‫؍‬ 0.03) and DBP (P ‫؍‬ 0.03) were significantly higher and GFR was lower (P ‫؍‬ 0.03) in patients with the collapsing compared with NOS variant. Remission after the initial course of corticosteroids was less common with the collapsing variant. At last follow-up, SBP (P ‫؍‬ 0.02) and DBP (P ‫؍‬ 0.04) were significantly higher in patients with the collapsing versus NOS variant.Conclusions: The short-term outcome in pediatric primary FSGS is generally favorable, but a more guarded prognosis exists for patients with collapsing FSGS.

Painless hematochezia in a school-age child is the hallmark of a juvenile colorectal polyp. Rarely do malignant gastrointestinal (GI) neoplasms present with painless rectal bleeding in childhood. We describe the clinical and pathological features of a PEComa of the sigmoid colon with regional metastases in an 11-year-old boy with painless hematochezia and mild anemia. The PEComa is a recently described tumor of unknown cellular origin and low-grade malignancy characterized by both smooth muscle and melanocytic differentiation. Most cases affect adult women, and most tumors are found in the uterus (1). To the best of our knowledge, this is the first report of a metastatic PEComa involving the GI tract of a child.

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We have used capillary isoelectric focusing (cIEF) to diagnose and monitor hemoglobinopathies in children for over three years. This report describes a major revision of our original method (Clin. Chem. 1994, 40, 2288-2295) that improves the analysis of hemoglobin (Hb) variants by cIEF, especially capillary performance and quantitation precision for minor variants. The revised method uses mixed ampholytes (2% pH 6-8:3-10; 10:1), lower viscosity methylcellulose (0.375%) solution, between-sample capillary conditioning with methanol, and hemolysates prepared from red blood cells (RBC) instead of whole blood. Collectively, these changes prolonged capillary life by minimizing capillary exposure to NaOH, standardized the sample matrix, and improved the precision of peak autointegration. The between-run quantitation imprecision (% relative standard deviation) of the revised method was 0.1-3.5% for all diagnostically important major and minor Hb variants present at normal or abnormal levels. The results show the use of the revised method for (i) posttranslationally modified Hb present at low concentrations in normal blood, (ii) Hb oxidation products produced by improper sample storage, (iii) differential diagnosis of S/beta + thalassemia, G-Philadelphia trait, S/C-Harlem disease, and Hb H disease, (iv) sensitive detection of minor variants like Hb A2' as indicators of an alpha globin mutation, and (v) neonatal screening using dried blood collected on filter paper. The results show that high-efficiency separation and precise quantitation of Hb variants over a wide range of concentrations makes cIEF a comprehensive assay that can be used without adjunct analyses for the automated primary evaluation of hemoglobinopathies and thalassemias.