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Biomedical subjects

L Ornstein

Publications and source records attributed to L Ornstein.

5 recordsLinked to original sources
PubMed1992

c-myc protein distribution. Neoplastic tissues of the human colon.

There is an extensive literature documenting the increased or deregulated expression of the c-myc oncogene in human malignancies. The authors have recently devised a sensitive immunocytochemical method for studying the tissue localization of c-myc protein in tissue sections of human colon. We have compared nuclear c-myc staining using a polyclonal rabbit anti-c-myc antibody and a mouse monoclonal myc antibody NCM II 274. Microscopic observation of the tissue specific pattern of c-myc protein distribution shows that nuclear staining intensity varies in normal and neoplastic crypt cell nuclei in parallel with morphologic criteria of neoplasia. These studies yield further information on the usefulness of c-myc protein as a prognostic indicator.

Cell Nucleus↗
PubMed1976

Automatic leukocyte classification using cytochemically stained smears.

A leukocyte classification algorithm suitable for automated differential counting has been developed for blood smears stained with a new three-component cytochemical stain which has relatively narrow absorption bands centered at 460, 540 and 640 nm, respectively. The classification procedure is the result of a pattern recognition experiment using a sample of 223 leukocytes distributed evenly over the five normal cell types. The basic data for each cell were three digital microscopic images obtained with narrow band illumination at the above central wavelengths using a TV-digitizer system interfaced to a PDP-15 computer. The classification algorithm involves a sequential decision procedure utilizing five pattern features computed from the intensity histograms of the green and blue digital images. Thus the number of arithmetic operations and the number of computer memory words necessary to perform the classification into one of the five normal white blood cell types are both proportional to n where n is the number of gray levels into which the intensity scale is divided. In this experiment, n equals 256. Comparison of our results with work of others on smears prepared with Romanowski-type stains indicates that such narrow-band, spectrally well separated cytochemical multiple stains can permit the use of algorithms which are approximately ten times faster.

Autoanalysis↗
PubMed1975

C3, GBG, orosomucoid and haptoglobin polymorphisms. Improved staining methods.

C3, GBG, and orosomucoid polymorphisms were electrophoresed in a high-voltage agarose method which permitted the typing of 15-20 samples. The increased sensitivity of the dye Coommassie blue was used to stain the protein, and yielded higher resolution than amido black. The typing of haptoglobin samples, was facilitated by devising a method which utilizes the peroxidase activity of the haptoglobin-hemoglobin complex with 90-tolidine and hydrogen peroxide as substrates and 4-chloro-1-naphthol as coupler.

Complement System Proteins↗
PubMed1975

Basophil counting with a new staining method using alcian blue.

Difficulties in obtaining reproducible and accurate enumeration of circulating basophils with existing techniques have hampered investigation of this infrequent cell population. A new basophil staining method is described that employs alcian blue dye for staining of heparin within basophils at low pH and in the presence of lanthanum ions. Basophil recognition is facilitated by reducing nonspecific nuclear staining. This objective is achieved because of the differences in stability of alcian blue-heparin, alcian blue-nucleic acid, lanthanum-heparin, and lanthanum-mucliec acid complexes. Reduction of pH after staining also favors solubilization of leukocyte cytoplasmic proteins, providing greater contrast between stained and unstained cells by reducing light scattering of the unstained leukocytes . The alcian blue staining method is suitable both for chamber basophil counting and automated basophil counting using continuous-flow sampling and electro-optical detection. The new staining method was evaluated by comparing it with the chamber counting method using toluidine blue in a triple-blind study in which the results of basophil counting by the alcian blue chamber method, alcian blue automated instrument method, and the toluidine blue chamber method were analyzed for reproducibility and compared with an indirect basophil count obtained from a 1000-cell leukocyte differential and a total leukocyte count. Both alcian blue staining methods gave greater reporducibility that toluidine blue and were more accurate, as evidinced by a significantly higher correlation with the indirect basophil count. The improved reproducibility, accuracy, and convenience of this method over existing methods should facilitate the collection of more meaningful information about circulating basophil levels in health and disease.

Alcian Blue↗