American journal of clinical pathology
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Am. J. Clin. Pathol. · Sep 1988
Comparative StudyHemoCue system for hemoglobin measurement. Evaluation in anemic and nonanemic children.
The HemoCue system measures the hemoglobin level in undiluted capillary or venous blood after conversion of hemoglobin to azide methemoglobin. The authors have compared this system, designed primarily for office use, with the Coulter S-Plus III in a study of 200 than or equal to 105 g/L (10.5 g/dL) and 47 children with sickle cell disease. ⋯ Discrepancies of more than 10 g/L (1.0 g/dL) occurred in 13 of 200 measurements (6%); the HemoCue system gave the lower reading in all instances. The HemoCue system is comparable to standard laboratory techniques for measurement of hemoglobin level in normal and anemic children and is well suited for use in the outpatient care of healthy pediatric patients as well as those with hematologic disorders.
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Urine microscopic evaluation of hematuria has traditionally been used to determine the need for an intravenous pyelogram (IVP) in individuals with blunt abdominal trauma. An IVP is generally advocated in cases where greater than 5-10 red blood cells per high power field (RBC/HPF) are identified. Various laboratories have advocated the use of dipstick examination of these urine specimens as a replacement for microscopic examination. ⋯ Poor correlation was seen between the degree of positivity by dipstick testing and the actual degree of microscopic hematuria. It is concluded that specimens which are negative for hematuria by dipstick do not need further testing by microscopic examination. All specimens which contain blood by dipstick evaluation need to be examined microscopically to predict the need for IVP.
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Am. J. Clin. Pathol. · Jun 1987
Case ReportsFailure of the Bactec 460 radiometer to detect Cryptococcus neoformans fungemia in an AIDS patient.
Cryptococcus neoformans fungemia occurred in a patient with the acquired immunodeficiency syndrome (AIDS). The BACTEC 460 radiometer failed to detect Cryptococcus neoformans in eight aerobic BACTEC 6B culture bottles inoculated with the patient's blood. The diagnosis of cryptococcemia was established by terminal (seven-day) subculturing of 6B broth to chocolate agar, which was positive for all eight radiometrically negative blood culture bottles. It appears that radiometric measurement is not optimal for the laboratory detection of cryptococcal fungemia.
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Am. J. Clin. Pathol. · Jan 1987
Comparative StudyMeasurement of plasma fibrin D-dimer levels with the use of a monoclonal antibody coupled to latex beads.
Recently, monoclonal antibody (DD-3B6) to fibrin D-dimer was prepared and coupled to latex beads to provide a specific test (Dimertest) for fibrinolysis. The purpose of this study was to evaluate the Dimertest assay as a clinical laboratory test for the measurement of plasma fibrin D-dimer derivatives. The Dimer-test assay specifically detected 2 micrograms/mL of purified fibrin D-dimer or fibrin D-dimer/fragment E complex added to afibrinogenemic plasma but did not detect 500 micrograms/mL of either fibrinogen fragments X, D, E, or 160 micrograms/mL cross-linked fibrinogen. ⋯ Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and protein blotting with the use of monoclonal antibody DD-3B6 demonstrated a protein band with similar mobility to purified D-dimer. The measurement of plasma fibrin D-dimer derivatives by the Dimertest assay is a rapid, sensitive, and specific laboratory test for fibrinolysis. The Dimertest assay has proven to be a useful addition to the clinical laboratory and should be helpful in the diagnosis and management of patients with diseases associated with fibrinolysis.
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Am. J. Clin. Pathol. · Jul 1986
Case ReportsColonic biopsy in verotoxin-induced hemorrhagic colitis and thrombotic thrombocytopenic purpura (TTP).
Sporadic cases and occasional outbreaks of hemorrhagic colitis recently have been associated with the rare Escherichia coli serotype O157:H7, which is now recognized as an important identifiable cause of bloody diarrhea in patients in whom more common gut pathogens cannot be detected. The authors report such a case in a 49-year-old woman who developed thrombotic thrombocytopenic purpura (TTP) and hemorrhagic transverse and descending colitis with a lesion having many of the features of pseudomembranous colitis. While pseudomembrane formation has been described in the hemolytic uremic syndrome (HUS), these features have not, to the authors' knowledge, been described in a patient with hemorrhagic colitis and TTP secondary to a verotoxin-producing serotype of E. coli.