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Biomedical subjects

J F Chapman

Publications and source records attributed to J F Chapman.

34 records · Page 2Linked to original sources
PubMed1987

Post-transfusion purpura associated with anti-Baka and anti-PIA2 platelet antibodies and delayed haemolytic transfusion reaction.

The occurrence of post-transfusion purpura (PTP) in a 16-year-old girl with sickle/beta-thalassaemia is described. Clinically this was a typical case of PTP, but it was unusual serologically. Anti-Baka and anti-PIA2 platelet-specific antibodies were identified and the patient's platelets were typed as homozygous PIA1-positive and Baka-negative. The patient also developed red-cell, granulocyte and lymphocytotoxic antibodies in response to the blood transfusion and had a delayed haemolytic transfusion reaction.

Adolescent↗
PubMed1986

Clinical and economic considerations associated with testing for fetal lung maturity.

Performing multiple tests of fetal lung maturity on amniotic fluid samples may not use the individual test results and laboratory personnel most effectively. To determine the best strategy for fetal lung maturity testing, we analyzed our experience with use of a variety of procedures. Clinical usefulness was assessed according to sensitivity, specificity, predictive values, and efficiency. Economic and technical aspects analyzed included time and personnel requirements, availability of tests, and expense of each procedure. Several testing sequence approaches were compared for efficiency and cost. In our laboratory the foam stability index proved to be the most useful initial test of fetal lung maturity, reserving more expensive and time-consuming tests for instances in which the foam stability index is immature. Routine multiple testing did not enhance clinical usefulness and greatly increased costs. Development of a testing strategy using a rapid, inexpensive, and widely available test such as the foam stability index would promote clinical and economic efficiency.

Amniotic Fluid↗
PubMed1986

Autoimmune thrombocytopenia and neutropenia after remission induction therapy for acute leukaemia.

Patients with acute leukaemia who are exposed to intensive chemotherapy, with or without radiotherapy, may remain thrombocytopenic or neutropenic in remission. The incidence of these prolonged cytopenias was examined retrospectively in 46 patients in remission and prospectively in 14 patients. The patients were tested for the presence of autoantibodies to platelets and neutrophils using a fluorescent antihuman globulin technique with paraformaldehyde-fixed cells. In the retrospective study nine patients (20%) had neutrophil autoantibodies and seven (15%) had platelet autoantibodies; only one of the former had neutropenia and one of the latter thrombocytopenia. In the prospective study three (21%) had neutrophil autoantibodies and seven (50%) had platelet autoantibodies. One of the patients with platelet autoantibodies had transient thrombocytopenia, and shortened platelet survival was demonstrated. None of the patients with neutrophil autoantibodies had neutropenia. The rare occurrence of cytopenias in association with these autoantibodies was possibly due to bone marrow compensation for antibody-mediated cell destruction, although other possible mechanisms are discussed.

Acute Disease↗
PubMed1986

Uniform chromatographic conditions for quantifying urinary catecholamines, metanephrines, vanillylmandelic acid, 5-hydroxyindoleacetic acid, by liquid chromatography, with electrochemical detection.

Uniform liquid-chromatographic conditions were developed such that we could quantify norepinephrine, epinephrine, normetanephrine, metanephrine, vanillylmandelic acid, and 5-hydroxyindoleacetic acid in urine by using a single mobile phase of monochloroacetic acid and citric acid, 0.1 mol/L each. All compounds were separated on a C18 column and detected electrochemically at a potential of +0.800 V. Optimization of these uniform chromatographic conditions significantly shortens the changeover time required from one assay to another, resulting in a substantial savings of time and cost to the laboratory.

Catecholamines↗
PubMed1984

Sequential development of platelet, neutrophil and red cell autoantibodies associated with measles infection.

This study describes the development of autoimmune thrombocytopenia followed by autoimmune haemolytic anaemia in a Negro woman with measles. An IgM platelet autoantibody was detected using a fluorescent labelled antiglobulin technique. The thrombocytopenia resolved spontaneously, although the platelet autoantibody persisted and platelet survival remained shortened, suggesting a compensated thrombocytolytic state. An IgG granulocyte autoantibody was present transiently although the patient was never neutropenic. The haemolytic anaemia was due to an IgM cold autoantibody (anti-I), which was active up to 30 degrees C, and an IgG warm autoantibody, which was detectable only when she was severely anaemic. After an initial blood transfusion, the anaemia resolved and the red cell autoantibodies disappeared. The platelet, granulocyte and red cell autoantibodies were cell-specific and not a single cross-reacting antibody.

Adult↗
PubMed1983

Demonstration of an immune-mediated mechanism of penicillin-induced neutropenia and thrombocytopenia.

Severe neutropenia may be a more common complication of high-dose penicillin therapy than previously recognized. This report describes five such patients, one of whom also had thrombocytopenia. The neutrophil and platelet counts rapidly increased on stopping penicillin, and the bone-marrow, which was hypocellular in some cases, became normal. Further studies on one of these patients, using a fluorescent antiglobulin technique with paraformaldehyde-fixed cells, demonstrated a complement-fixing IgG penicillin antibody reacting with the patient's granulocytes and platelets in the presence of the drug. This suggested an immune mechanism similar to the well-recognized penicillin-induced immune haemolytic anaemia. The associated bone-marrow hypoplasia may also be due to antibody-mediated suppression of penicillin-coated precursor cells.

Adult↗
PubMed1982

Enhancement techniques for detecting trace and fluid-specific components in two-dimensional electrophoresis patterns.

Albumin and other serum-derived proteins were removed from several types of body fluids by affinity chromatography, to facilitate detection of trace or non-serum-derived proteins in two-dimensional electrophoresis patterns. Albumin was removed by the dye Cibacron Blue F3G-A coupled to Sepharose. Two-dimensional patterns of albumin-depleted serum lack the large albumin spot, and several families of spots become visible that ordinarily are partly or totally hidden by it. However, other proteins also bind to Cibacron Blue. Most serum proteins, including albumin, were effectively removed by anti-human serum antibodies coupled to Sepharose. Two-dimensional patterns of serum-depleted cerebrospinal fluid exhibit five clusters of probable nervous-system protein families not detected in serum. One additional family, probably antigenically related to transferrin, was removed by the affinity step. Two-dimensional patterns of serum-depleted prostatic fluid exhibit five major non-serum families, two of which may be creatine kinase B subunits and prostatic acid phosphatase. Two-dimensional patterns of serum-depleted malignant effusions exhibit one or more of three proteins that possibly are tumor products. Pattern matching suggests the presence of one non-serum-derived protein family common to cerebrospinal fluid, prostatic fluid, and malignant effusions. Prostatic fluid and malignant effusions have in common as many as three non-serum families of proteins.

Blood Proteins↗
PubMed1981

Creatine kinase BB and other markers of prostatic carcinoma.

Creatine kinase BB has been described to be elevated in the serum of patients with prostate cancer. The incidence of abnormal serum levels correlates with the degree of differentiation of the tumor; that is, the more poorly differentiated tumors are associated most frequently with elevated CK-BB levels. We have recently described two additional findings which involve CK-BB in prostate cancer: 1) the finding of abnormally migrating CK-BB bands reported to be IgG-CK-BB complexes in several Stage D patients and in 2/3 Stage B patients following 125I implants, and 2) significant differences between CK-BB purified from prostatic fluid from CK-BB of brain origin. In particular, we find two bands of prostatic CK-BB following purification as compared to a single band from brain, when the same purification protocol is used. While further characterization of these differences is proceeding, the two bands of CK-BB are being used to develop a prostate-specific antiserum for use in immunoassays to detect prostate cancer in conjunction with other traditional markers such as prostatic acid phosphatase. If serum detection of tumor markers is to be efficacious, tumor marker panels such as CK-BB and prostatic acid phosphatase may provide a significant advantage over individual markers.

Brain↗
PubMedDate not supplied

Amniotic fluid tests for fetal lung maturation--the good, the bad, and the promising.

OBJECTIVE: To assess promising laboratory tests for fetal lung maturity (FLM). DATA SOURCES: Professional literature. DATA EXTRACTION: Survey of literature. DATA SYNTHESIS: Traditional biochemical tests for FLM such as the LSR are reliable if performed properly but are difficult to perform, costly, and not widely available; most are not good predictors of respiratory distress syndrome. Many of the newer biochemical and biophysical FLM assays are more reliable, faster, require less personnel time, and are readily available. CONCLUSION: The development of laboratory tests to measure the presence or effects of pulmonary surfactant in amniotic fluid has contributed greatly to the management of premature deliveries; newer tests show promise but require more extensive evaluation.

Agglutination Tests↗
PubMedDate not supplied

Sensitivity of serum fructosamine in short term glycemic control.

The serum fructosamine concentrations measured in 64 diabetic patients correlated (r = 0.73) with glycated hemoglobins (HbA1c). However, 23 percent of the diabetic patients had normal fructosamine and abnormal HbA1c levels. In order to determine whether or not the discrepant values were the result of recent glycemic regulation by the diabetic patient, fructosamine levels of patients suffering from diabetic ketoacidosis (along with beta-hydroxybutyrate levels) were closely monitored. It was shown that short term alterations (one to three days) in serum glucose did not significantly affect fructosamine levels. Therefore, disagreements between fructosamine and HbA1c are most likely due to longer term improvement in glucose control by the diabetic or the result of the higher imprecision of the HbA1c assay.

3-Hydroxybutyric Acid↗
PubMedDate not supplied

Review of serum lipids and apolipoproteins in risk-assessment of coronary heart disease.

Coronary heart disease (CHD), the leading cause of death in the western world, is multifactorial in nature. Abnormal lipoprotein levels are among the risk factors that cause atherosclerosis and, therefore, have been used as biochemical markers in assessing risk of developing CHD. The measurement of serum cholesterol, lipoprotein cholesterol, and apolipoproteins accurately and reliably has been hampered with technical difficulties. In addition, the interpretation of these tests and the determination of their clinical values have been challenging for both physicians and laboratory scientists. This article addresses and reviews the major current analytical and clinical concerns in the testing of lipids as well as the prevention and treatment of CHD.

Adult↗