BRCA1 protein and nucleolin colocalize in breast carcinoma tissue and cancer cell lines.

The breast and ovarian cancer susceptibility gene BRCA1 encodes a tumor suppressor. BRCA1 protein, which is involved in DNA damage response, has been thought to be found primarily in cell nuclei. In the present investigation, immunohistological studies of BRCA1 protein in frozen breast cancer tissue and MCF7 and HeLa cell lines revealed BRCA1 expression in both nucleoli and nucleoplasmic foci.

Nucleolar localization of BRCA1 protein in human breast cancer.

Both a rabbit polyclonal BRCA1 antibody, K-18, and a mouse monoclonal BRCA1 antibody, AP 16, produced nucleolar epithelial cell staining on frozen tissue sections of human infiltrating mammary carcinomas. There was much less BRCA1 antibody staining in normal tissues; however, 2 intraductal tumors and a papilloma, found in proximity to the carcinomas showed considerable nucleolar immunoreactivity. MCF-7 cells fixed in methanol and immunostained with the same two antibodies also revealed nucleolar staining, however, after 4% paraformaldehyde fixation for three minutes, there were many fewer nuclei stained.

Immunohistologic c-myc protein in benign breast disease and cancer.

We have studied the histopathology and differential distribution of the c-myc protein (Myc) in human breast tissues including 17 cases of infiltrating mammary carcinoma, 4 cases of fibroadenoma, 5 cases with fibrocystic changes, and 1 case of reduction mammoplasty (as a control). Using a sensitive immunohistochemical method on frozen tissue sections, both a rabbit polyclonal anti-c-myc antibody and a mouse monoclonal anti-c-myc antibody, H51C116, produced high levels of Myc staining in the nuclei of epithelial cells of infiltrating mammary carcinomas (30-90% of cells stained). In contrast, the nuclei of epithelial cells of fibroadenomas, and breast tissues with fibrocystic changes stained infrequently.

C-myc protein distribution - mammary adenocarcinomas of mtv/myc transgenic mice.

Transgenic mice have been used to demonstrate that the myc transgene, fused to the murine mammary tumor virus LTR promoter, leads to development of mammary tumors. To study the role of the Myc protein in these tumors, a sensitive immunohistochemical method was used to compare the Myc protein expression in mammary tumors and normal mammary gland from two independent MTV/myc transgenic lines. The highest levels of staining for Myc were found in the epithelial cell nuclei of mammary tumors and foci of mammary hyperplasia.

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.

Distribution of the c-myc oncoprotein in normal and neoplastic tissues of the rat colon.

A rat model of 5-azoxymethane induced colon cancer was studied in order to correlate histopathological changes and the differential distribution of the c-myc protein. Weanling Fisher 344 rats were injected with three, one week apart, subcutaneous injections of 5-azoxymethane (AOM) (15 mg kg-1) and the animals were divided into low and high fat diet groups. Nine colon tumors, of varying degrees of malignancy, that developed in the AOM-treated rats, and sections of normal colonic mucosa were examined.

Subtyping lymphocytes in peripheral blood by immunoperoxidase labeling and light scatter/absorption flow cytometry.

Lymphocyte subpopulations in a whole-blood sample can be detected by adapting mouse monoclonal antibodies (MAbs) and peroxidase (EC 1.11.1.

Glycogen utilization in wheelchair-dependent athletes.

Seven wheelchair-dependent endurance athletes (5 males, 2 females, mean age = 27 years, mean VO2 max = 2.01 1/min) consented to maximal and submaximal (SM) testing on a wheelchair ergometer for the purpose of determining aerobic capacity, plasma substrate concentration, and muscle glycogen utilization during prolonged exercise. Results from an initial graded maximal test were used to determine exercise intensity levels during a subsequent 1-h submaximal endurance ride on the wheelchair ergometer (60%-70% VO2 max).

Fully automated preparation of high-quality stained blood films.

A detailed description is given of the operation of Technicon's AutoSlide, which automatically produces a microscope-ready, precipitate-free, stained blood smear with superior cell distribution and good morphology. A 40-test-tube turntable carrying anticoagulated blood inputs samples at 40-second intervals. The blood films are drawn consecutively on a continuous Mylar substrate, with nylon mesh replacing the usual glass slide spreaders.

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.

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.

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.

The intrarenal distribution of tritiated para-aminohippuric acid determined by a modified technique of section freeze-dry radioautography.

Section freeze-dry radioautography has been used to examine the intrarenal distribution of a water-soluble organic acid (para-aminohippuric acid (PAH-3H)) under constant-infusion, steady-state conditions in mouse and rat kidney in vivo. The technique described here has the following advantages: (a) Sectioning and freeze-drying are accomplished in a closed cryostat at temperatures below -40 degrees C; (b) Handling of the section is facilitated by mounting of the section-to-be on adhesive-coated Saran Wrap prior to cutting; (c) Unembedded freeze-dried sections are attached to photographic film at ambient temperature in the dark room; (d) Fixation follows completion of radioautographic exposure and precedes photographic development; (e) Permanent close contact is maintained between tissue and film. Morphologic preservation compared favorably with that obtained by optimal fixation techniques, which, however, permit diffusion.