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Biomedical subjects

R D Craver

Publications and source records attributed to R D Craver.

At least 19 recordsLinked to original sources
PubMed1997

Capillary isoelectric focusing of hemoglobin variants in the pediatric clinical laboratory.

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.

Child↗
PubMed1997

Dipstick only urinalysis screen for the pediatric emergency room.

To determine if microscopic urinalysis is needed in all pediatric emergency room patients screened for urinary tract infections (UTI), we compared the dipstick urinalysis and complete urinalysis (dipstick and microscopy) with urine cultures in 236 children, aged 3 weeks to 21 years. The ability to detect UTI by dipstick only and by complete urinalysis was the same, however microscopic evaluation added many false-positive results without detecting additional UTIs. Because the ability to detect UTI (sensitivity) is maintained, we now offer a dipstick only urinalysis to our emergency room for children 2 years of age or older, with a microscopic analysis performed automatically if dipstick results are positive. If no microscopic urinalysis is required, testing turn-around time is reduced by 12.3 min/test and the hospital charge is reduced from U.S. $32 to U.S. $12.

Adolescent↗
PubMed1997

Cure of hypoglycemic hyperinsulinism by enucleation of a focal islet cell adenomatous hyperplasia.

During pancreatectomy for refractory neonatal hyperinsulinemic hypoglycemia, a well-delineated focal adenomatous hyperplasia was enucleated. Intraoperative glucose levels returned to normal and pancreatectomy was averted. Seven months later the child is euglycemic. This experience suggests that during surgery for neonatal refractory hypoglycemia, a focal lesion should be sought, and if found, enucleated, and blood glucose monitored. If the glucose rises to euglycemic levels or above, the child should be monitored clinically. If sustained elevation is not maintained, a search for an additional focal lesion or pancreatectomy should be performed. Saving the pancreas may prevent future development of diabetes mellitus.

Adenoma, Islet Cell↗
PubMed1997

Florid reactive periostitis.

An 11-year-old boy developed florid reactive periostitis several years after minor trauma. The symptoms responded initially to antibiotics, but after cessation, rapidly recurred and progressed, requiring a ray amputation to relieve the pain and to achieve a functional hand. The reactive periostitis affected the volar aspect of two adjacent phalanges with sparing of the intervening joint, confirming that this is a reactive process rather than a benign neoplasm.

Biopsy↗
PubMed1997

Fibrous cortical defect with bizarre nuclear features.

A femoral neck fibrous cortical defect with typical radiographic features had bizarre nuclear features on histological examination. Recognition of the benign radiographic appearance, similar bizarre features of accompanying macrophages, and paucity of mitoses led us to consider this a pseudoanaplastic ischemic or degenerative change in an old fibrous cortical defect. Because the biological behavior was not known with certainty, we closely followed this case. After 25 months, there has been no recurrence or regrowth. The close cooperation between the pathologist and other disciplines facilitates recognition of these pseudoanaplastic lesions and development of treatment strategies for lesions of unknown or uncertain biological behavior.

Adult↗
PubMed1997

Deregulation of the platelet-derived growth factor B-chain gene via fusion with collagen gene COL1A1 in dermatofibrosarcoma protuberans and giant-cell fibroblastoma.

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.

Chromosome Breakage↗
PubMed1997

Hemoglobin A2 levels in healthy persons, sickle cell disease, sickle cell trait, and beta-thalassemia by capillary isoelectric focusing.

Simultaneously measuring major and minor hemoglobin (Hb) variants by capillary isoelective focusing, we obtained HbA2 intervals in healthy volunteers (n = 412) (reference value) and patients with HbS or beta-thalassemia. We classified normal HbA2 reference intervals into three age groups: 5 months or younger (1.2% +/- 1.5%), 6 months to 1 year (2.2% +/- 0.9%), and 1 year or older (2.4% +/- 0.9%). These intervals were comparable to those used with other methods. Patients 1 year of age or older with HbS had significantly higher HbA2 levels (sickle cell trait, 2.9% +/- 0.9%; sickle cell anemia, 2.8% +/- 1.0%; P < .05). Although reference HbA2 intervals overlapped those in patients with HbS, no overlap in HbA2 levels was noted between these groups and patients with beta-thalassemia (observed range, 4.3% to 7.5%). The higher than normal HbA2 interval in patients with HbS must be considered before a diagnosis of sickle cell trait or sickle cell disease with beta-thalassemia is made.

Anemia, Sickle Cell↗
PubMed1996

Renal collecting duct carcinoma in an 8-year-old child.

A fatal collecting duct carcinoma, presenting with pleural metastases, arose from the right kidney in an 8-year-old child. A distal nephron origin of the tumor is supported by positive tumor staining with Ulex europaeus and Arachis hypogaea, and a lack of staining with Tetragonolobus lotus. The ultrastructural features of short stubby microvilli, smooth basal cell membranes, and lateral membrane infoldings also support a distal nephron origin (inner most inner medullary collecting duct). This rare childhood renal neoplasm behaved similarly to that reported in adults with metastatic disease at presentation and a short fatal clinical course.

Carcinoma↗
PubMed1996

Familial dystonia and choreoathetosis in three generations associated with bilateral striatal necrosis.

Nine cases of dystonia and choreoathetosis (six females and three males) have developed in three generations of a single family. There has been one death. Neuropathologic examination disclosed bilateral striatal necrosis. In this family, the neurologic disorder has evolved gradually or in association with a febrile illness. There has been no neurologic recovery. The disease is worse in females, has been transmitted only through females, and shows incomplete penetrance and anticipation. The maternal inheritance pattern suggests either an autosomal dominant trait also affecting male reproductive ability or a defect involving the mitochondrial genome.

Adult↗
PubMed1996

Laboratory evaluation of pediatric bone and soft-tissue tumors.

This article discusses how specimens are approached and handled by the laboratory. Basic histology is reviewed. Contributions by electron microscopy and immunoperoxidase staining are briefly discussed. Current uses of DNA indices, cytogenetic analysis, and new molecular diagnostic advances are highlighted. Proper communication between the pathologist and the orthopedist is the cornerstone for optimal use of laboratory resources.

Biopsy↗
PubMed1995

Nephroblastoma and end-stage renal failure with bilateral cystic kidneys.

A child of 10 years 5 months presenting with chronic renal failure had bilateral cystic kidneys. Biopsy of a right lower-pole solid mass revealed nephroblastoma. At bilateral nephrectomy, both kidneys were both replaced by variable-sized cysts with a unifocal nephroblastoma on the right. Renal failure with nephroblastoma is uncommon and is usually either a manifestation of the Drash syndrome or a complication of chemotherapy. The need to assess both kidneys in a child with any other renal abnormality in addition to a renal mass should always be considered.

Child↗
PubMed1995

Dermatofibrosarcoma protuberans with 46,XY,t(X;7) abnormality in a child.

A 9-year-old child with dermatofibrosarcoma protuberans demonstrated a balanced translocation, 46,XX,t(X;7)(q21l2;q11.2), in the untreated tumor, an abnormality not previously reported. Unlike seven of eight other reports of dermatofibrosarcoma protuberans, no ring chromosomes were present.

Child↗
PubMed1994

Curvularia urinary tract infection: a case report.

A healthy 5-year-old child had recurrent symptomatic urinary tract infections, the last of which was accompanied by black specks in her urine. These specks were identified as Curvularia species, a dermatiaceous mold. Symptoms resolved and fungi disappeared with long-term hydration, without specific antifungal treatment.

Child, Preschool↗