Purpose:The purpose is to understand the expression of ecto-5-nucleotidase (eN), an adenosine producing enzyme with potential roles in angiogenesis, growth, and immunosuppression, in estrogen receptor (ER)-negative and -positive breast cancer.Experimental Design: We investigated the regulation of eN expression at the mRNA and protein levels by ␣ in a panel of breast cancer cell lines that differ in ER status and invasive and metastatic potential. We also determined rates of adenosine formation in cells with high and low eN expression and in ER؉ cells treated with estradiol.Results: ER-negative cells express high eN protein and mRNA levels and produce up to 104-fold more adenosine from AMP and ATP. Estradiol and antiestrogen treatments confirm that eN mRNA and protein expression and adenosine generation are negatively regulated through the ER. Endogenous expression of eN in ER؊ cells transfected with ER␣ and phorbol ester-induced eN expression in ER؉ cells

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An automated complete blood count with white blood cell differential was performed yearly on successive groups of healthy second-year medical students from 1979 through 1987. For three classes (1984-1987), the counts were repeated on the same people nine months later. These data demonstrated that the mean value of all hematologic parameters was quite stable over nine years. This allowed for an estimation of the upper limit for the combined effects of drift in accuracy, precision, and biologic stability. The stability was achievable despite an evolution in technology and quality assurance methods over that period. A comparison of intraindividual versus interindividual variation demonstrated that a normal range based on population statistics may be less sensitive than a normal range established for a person during routine health maintenance, especially for the platelet count.

Karyotype and bcr/abl recombinant DNA analyses are two means of detecting the chromosomal aberration in chronic myeloid leukemia. The authors compared these two methods in a retrospective study of 36 patients with CML in which they found the bcr/abl DNA recombinant event in 100% (29 of 29) of those patients who had the Philadelphia chromosome. To achieve this sensitivity, a battery of two bcr probes and three restriction enzymes is necessary. The authors propose a sequential algorithm for efficient use of these probes and enzymes. In 76% of the patients, bcr/abl rearrangement can be detected with a Bgl II digest and a 3' commercial probe. An additional 21% of patients can be detected by a second assay in which the same membrane is rehybridized to a 3' and 5' combination bcr probe. One patient (3%) required an additional restriction enzyme digest with BamH I to detect the recombinant event by the same 3' probe. Karyotype analysis is used to determine cytogenetic remission in patients with CML under therapy. The authors studied the use of DNA analysis by the Southern blot technique to detect a decrease in the relative number of leukemic cells. By dilution studies and densitometric scanning of autoradiographs, the authors were able to detect a 15% decrease in the relative number of cells having the bcr/abl recombinant event. The authors report the preliminary results of three patients in whom they compared the karyotype and recombinant DNA analysis at multiple time points in their clinical course. In conclusion, the bcr/abl recombinant DNA analysis is superior to karyotype for the diagnosis of CML and can be used for monitoring treated patients.

The automation of platelet counting is essential in laboratories performing a large number of procedures with high precision. Maintaining this precision and establishing accuracy require an understanding of the special problems of counting platelets, including: (1) the large dynamic range of the measurement, (2) the variable size and aggregability of platelets, and (3) the specific requirements of a quality-control method. In evaluating these problems, we designed experiments that measured the linearity and precision of two types of platelet counters, light scattering and electronic aperture impedance, and that evaluated the suitability of commercially available reference materials. The results show that the instrumentation is excellent and the reference materials are good; such that, given a well-planned quality-control method as presented here, the automated platelet count gives a rapid result with precision and accuracy.