PubMed Health⌕ Search

Biomedical subjects

W Z Borer

Publications and source records attributed to W Z Borer.

9 recordsLinked to original sources

Differential expression of adenosine deaminase isozymes in acute leukemia.

Total adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) activities were measured in cell samples from 13 cases of de novo acute leukemia and from three cases of chronic myeloid leukemia in blast crisis (CMLBC). These cases could be separated into lymphoid and nonlymphoid types on the basis of enzyme activity, with two misclassifications. However, PNP activity added little or no discriminatory information. Analysis for expression of the various molecular weight (mol wt) ADA isozymes, ADA1 (40 Kd) and ADA2 (110 Kd), revealed that ADA2 was expressed exclusively in nonlymphoid cells whereas ADA1 was found in both lymphoid and nonlymphoid cell types. Identification of ADA2 divided these leukemia cases into lymphoid and nonlymphoid types with no misclassifications (P = .0002; Fisher's exact test). Acute nonlymphoblastic leukemia (ANLL) with a monocytic component tended to have a greater percentage of ADA2 than ANLL without a monocytic component. These studies suggest that ADA2 may be a novel biochemical marker for an immature nonlymphoid cell.

Adenosine Deaminase↗

Enzymatic differences between chronic lymphocytic leukemia and prolymphocytic leukemia.

Chronic lymphocytic leukemia and prolymphocytic leukemia of the B-cell immunophenotype are closely related disorders, but differ in their cytomorphologic and clinical features. In an attempt to differentiate further between these two forms of leukemia, we measured adenosine deaminase and purine nucleoside phosphorylase activities by using a linked-enzyme spectrophotometric assay on peripheral-blood leukemic cells from seven patients with chronic lymphocytic leukemia, three patients with prolymphocytic leukemia, and one patient with prolymphocytoid transformation of chronic lymphocytic leukemia. By using discriminant analysis, we were able to distinguish the two groups only on the basis of purine nucleoside phosphorylase activity (F1,9; p less than 0.001). The purine nucleoside phosphorylase activity in leukemic cells with prolymphocytic cytomorphology was significantly elevated (mean = 58.6 nM/min/mg protein) compared to the activity in leukemic cells with lymphocytic cytomorphology (mean = 25.6 nM/min/mg protein). There was only one patient with chronic lymphocytic leukemia who was assigned to the prolymphocytic leukemia group on the basis of her purine nucleoside phosphorylase activity. Our study suggests that purine nucleoside phosphorylase activity in leukemic cells may be useful in the distinction of prolymphocytic leukemia from chronic lymphocytic leukemia, and that it may be an enzymatic marker for the early detection of prolymphocytoid transformation of chronic lymphocytic leukemia.

Adenosine Deaminase↗

Ectopic hormones as tumor markers.

Certain cancers are able to synthesize, store, and secrete peptide hormones. In some cases the hormones possess sufficient biologic activity to produce identifiable paraneoplastic syndromes. Occasionally the measurement of one or more of these hormones in the plasma or serum is clinically useful for monitoring tumor activity.

Adrenocorticotropic Hormone↗

Optimizing reference values for the measurement of alpha 1-antitrypsin in serum: comparison of three methods.

We studied three methods (rate nephelometry, radial immunodiffusion, and trypsin-inhibitory capacity) for their ability to detect those individuals with a deficiency of alpha1-antitrypsin. The phenotype represented in 170 serum samples was determined by isoelectric focusing as the reference method. All three methods correctly identified Pi Z, Pi S, and Pi SZ phenotypes but varied in their ability to detect Pi MZ and Pi MS phenotypes. The rate-nephelometric method was the least sensitive in detecting Pi MZ and Pi MS variants because of the inappropriately low reference interval suggested by the manufacturer. We found that the three screening methods are comparable when the limiting values are properly selected. We suggest that the reference value for the rate-nephelometric method be increased from 0.85 g/L to 1.40 g/L to improve the sensitivity of the test.

Humans↗

Histochemical demonstration of terminal deoxynucleotidyl transferase in leukemia.

White blood cells from 22 patients with leukemia and lymphoma were studied for the presence of terminal deoxynucleotidyl transferase with a peroxidase-antiperoxidase method. The enzyme was detected in leukemic cells of 5 patients with acute lymphoblastic leukemia and 1 patient with chronic myelogenous leukemia, whereas 16 patients with different forms of leukemia or lymphoma were negative for this enzyme. Comparative studies using a biochemical and an indirect immunofluorescence assay revealed complete concordance between these three methods.

Animals↗

Myocardial infarction?--a conflict between electrocardiographic changes and biochemical data.

We present a case of hypovolemic shock accompanied by electrocardiographic changes classically associated with acute myocardial infarction. Prompt therapeutic intervention, which included correction of the hypovolemic shock, resulted in stabilization of the patient's clinical course, increased activities of the cardiac-specific enzymes in serum were not documented. Serial electrophoretic determinations of the isoenzymes of serum lactate dehydrogenase did not show the characteristic changes associated with myocardial infarction. Accurate determination of the serum isoenzymes provided valuable diagnostic information which, accompanied by the patient's clinical improvement, militated strongly against the occurrence of myocardial infarction.

Aged↗