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Biomedical subjects

A A Keshgegian

Publications and source records attributed to A A Keshgegian.

At least 19 recordsLinked to original sources
PubMed2000

Lack of correlation between serum levels of E- and P-cadherin fragments and the presence of breast cancer.

Breast cancers often show reduced expression of the transmembrane cell-cell adhesion protein, E-cadherin. In addition, approximately half of breast carcinomas express P-cadherin, which correlates with poor survival. A large fragment of the E-cadherin extracellular domain can be detected in serum, and it has been proposed that an increase in serum E-cadherin can denote the presence of a tumor. In this study, we tested the possibility that serum E- or P-cadherin levels might be useful diagnostic or prognostic indicators in breast cancer. However, we found no indication that the level of serum E-cadherin correlated with the presence of breast cancer. In addition, although we successfully detected a fragment of P-cadherin in serum, we found that its level was considerably lower than that of E-cadherin and did not correlate with the presence of P-cadherin-positive breast cancer.

Breast↗
PubMed1999

P-cadherin expression in breast carcinoma indicates poor survival.

BACKGROUND: The cadherin family of cell-cell adhesion molecules and their associated proteins, the catenins, are essential to embryonic development and the maintenance of adult tissues. During development, the homotypic interaction of a particular cadherin with an identical cadherin expressed on a neighboring cell results in the sorting of cells to form distinctive tissues. Cadherins are believed to be tumor suppressors, and their altered expression and function have been associated with tumor development. METHODS: The authors examined the expression of P-cadherin, E-cadherin, and N-cadherin, and alpha-catenin and beta-catenin in 183 cases of invasive breast carcinoma by immunohistochemistry on paraffin sections using specific antibodies and a steam-based antigen retrieval method. RESULTS: P-cadherin was positive in 95 cases and negative in 88 cases of breast carcinoma. Positive P-cadherin expression in breast carcinoma showed a strong correlation with poor patient prognosis. Five years after surgery, 90% of the patients with P-cadherin negative tumors were alive in contrast to only 59% of patients with P-cadherin positive tumors. The difference in survival reached statistical significance (P = 0.0001) as early as 2 years after surgical treatment. Expression of N-cadherin, alpha-catenin, and beta-catenin did not correlate with patient survival. Multivariable statistical analyses of the data showed that expression of P-cadherin was independent of tumor size and lymph node metastases, but correlated inversely with estrogen/progesterone receptor status. In ductal carcinomas, positive P-cadherin expression correlated with a higher histologic grade. In contrast, expression of E-cadherin was low in high grade ductal carcinomas but negative tumors were uncommon. Negative or low E-cadherin expression did not correlate with poor survival. In lobular carcinomas, E-cadherin expression frequently was negative or low, and P-cadherin always was negative. CONCLUSIONS: Expression of P-cadherin in breast carcinoma is associated strongly with poor survival and constitutes an independent prognostic predictor. P-cadherin expression is a better indicator of clinical outcome than alterations in the expression of E-cadherin, N-cadherin, alpha-catenin, or beta-catenin.

Adult↗
PubMed1998

Bcl-2 oncoprotein positivity and high MIB-1 (Ki-67) proliferative rate are independent predictive markers for recurrence in prostate carcinoma.

Predicting the clinical behavior of prostate carcinoma can be difficult; one approach is to identify molecular prognostic markers. We evaluated proliferative rate (MIB-1 antibody) and expression of bcl-2, p53, and retinoblastoma (pRB) proteins, which have cell cycle-related functions, in 208 consecutive radical prostatectomy specimens. Values were correlated with histopathologic parameters (Gleason tumor score, tumor amount, capsule invasion, and involvement of surgical margins, seminal vesicles, or lymph nodes) and with recurrence-free survival (4-year median follow-up). A high MIB-1 proliferative rate was associated with all of the measured histopathologic parameters, p53 overexpression with tumor amount, and pRB expression with positive lymph nodes. pRB and p53 expression levels were not associated with differences in recurrence-free survival. A high MIB-1 proliferative rate and bcl-2 positivity were associated with increased recurrence, both considered individually, and also independently and additively when examined together and with the most predictive histopathologic factors (Gleason tumor score and seminal vesicle involvement). MIB-1 proliferative rate and bcl-2 positivity may prove to be useful markers for poor prognosis in prostate carcinoma.

Biomarkers, Tumor↗
PubMed1997

erbB-2 oncoprotein expression in breast carcinoma. Poor prognosis associated with high degree of cytoplasmic positivity using CB-11 antibody.

The relationship between immunohistochemically measured membranous expression of erbB-2 oncoprotein and prognosis in breast cancer is controversial, and the relationship between cytoplasmic positivity and prognosis has been minimally investigated. The clinical course of 300 women with infiltrating breast carcinoma, whose tumors were stained for erbB-2 oncoprotein with CB-11 monoclonal antibody, was followed for 5 to 79 months (median, 41 months). Higher numbers of cancer-related deaths were observed in patients with moderate-to-strong cytoplasmic positivity (15/60, 25%) and strong membranous positivity (9/29, 31%) than in patients with negatively stained tumors (8/53, 15%) or tumors with weaker degrees of cytoplasmic or membranous positivity (rate similar to or less than negative tumors). Relapse-free survival was also significantly shorter in patients with tumors with strong membranous positivity and moderate-to-strong cytoplasmic positivity; much of the latter relationship was due to a high number of patients who had erbB-2-positive tumors and who were never disease free. A significant association between decreased relapse-free survival and moderate-to-strong cytoplasmic (but not membranous) positivity persisted even after correction for other variables associated with poor outcome (histologic grade, tumor size, lymph node involvement, and hormone receptor status). Moderate-to-strong erbB-2 oncoprotein cytoplasmic positivity, measured with CB-11 antibody, is associated with a poor prognosis and seems to have biologic significance.

Breast Neoplasms↗
PubMed1997

Expression of P-cadherin identifies prostate-specific-antigen-negative cells in epithelial tissues of male sexual accessory organs and in prostatic carcinomas. Implications for prostate cancer biology.

Cadherins constitute a family of calcium-dependent cell-cell adhesion molecules the individual members of which are essential for the sorting of cells into tissues during development. In this study, we examined the expression of E-cadherin, N-cadherin, and P-cadherin in tissues obtained from radical prostatectomies. Epithelial cells of prostatic glands, ejaculatory ducts, and seminal vesicles expressed E-cadherin but not N-cadherin. P-cadherin was expressed in epithelial cells of the seminal vesicles and ejaculatory ducts. In the prostate it was limited to the basal cells of prostatic acini, glands with basal cell hyperplasia, and atrophic glands denuded of the luminal cells. All P-cadherin-positive cells were negative for prostatic-specific antigen. Prostatic cancers were mostly P-cadherin negative, but some tumors had P-cadherin-positive areas frequently located close to ejaculatory ducts and negative for prostatic-specific antigen. The mutually exclusive expression of P-cadherin and prostatic-specific antigen suggests that these proteins are involved in differential mechanisms of cell regulation in prostate cancer. P-cadherin may become a useful marker in the diagnosis and management of patients with prostate cancer and low levels of prostatic-specific antigen.

Animals↗
PubMed1996

Estrogen receptor-negative, progesterone receptor-positive breast carcinoma: poor clinical outcome.

OBJECTIVE: The biological significance of breast carcinomas negative (-) for estrogen receptor (ER), but positive (+) for progesterone receptor (PR) is unclear. It has been proposed that these tumors contain ER whose presence is masked in binding assays by endogenous estrogen. We analyzed the clinical outcome of 17 patients with ER-PR+ tumors. METHODS: The disease-free and overall survival of a series of 300 women with invasive breast carcinoma was followed for 7 to 79 (median 41) months. RESULTS: The recurrence rate was significantly greater in ER-PR+ tumors (8/17 [47%]) than in ER+PR+ tumors (27/177 [15%]), and it was similar to the high recurrence rate of ER-PR- tumors (21/57 [37%]). The cancer-related death rate was 3 1/2 times higher in the ER-PR+ group than in the ER+PR+ group. A significant association between ER-PR+ tumors and tumor recurrence or cancer-related death persisted even after correction for other variables associated with poor outcome (eg, tumor size and lymph node involvement). CONCLUSIONS: Estrogen receptor-negative, progesterone receptor-positive breast carcinomas are biologically different from ER+PR+ tumors and have a poor clinical outcome.

Breast Neoplasms↗
PubMed1995

ErbB-2 oncoprotein overexpression in breast carcinoma: inverse correlation with biochemically- and immunohistochemically-determined hormone receptors.

The relationship between erbB-2 oncoprotein overexpression and hormone receptors in breast cancer is controversial. Of 320 infiltrating carcinomas, 75 (23%) showed membranous positivity for erbB-2 protein using CB-11 antibody, with 31 (9.7%) strongly positive. Estrogen and progesterone receptors, determined by both biochemical and immunohistochemical assays, were negative more often in strongly erbB-2 positive tumors, or were positive at lower amounts, than in 56 tumors devoid of CB-11 staining. Strong erbB-2 positivity also correlated with lower patient age, higher histopathologic tumor grade, and higher S phase fraction, but not with tumor size, lymph node involvement, or DNA aneuploidy. Thirty-three lobular carcinomas showed strong erbB-2 positivity as frequently as the overall group (9.1%). Cytoplasmic CB-11 positivity without membrane positivity, thought not to correlate with true erbB-2 positivity, was observed in 189 (59%) tumors with a slight (1-2 +) reaction in 124 (39%) tumors and a moderate-to-strong (3-4 +) reaction in 65 (20%) tumors. Moderate-to-strong cytoplasmic positivity correlated with higher histopathologic grade and negativity for immunohistochemical, but not biochemical, hormone receptors. CB-11 cytoplasmic positivity may have biological significance.

Age Factors↗
PubMed1995

Proliferation markers in breast carcinoma. Mitotic figure count, S-phase fraction, proliferating cell nuclear antigen, Ki-67 and MIB-1.

Proliferative rate is an important prognostic marker in breast carcinoma. However, the best measurement method has not been established. This study evaluated mitotic figure counts (MFC) as mitoses per 10 high power fields (HPF) and per 1,000 cells, S-phase fraction by flow cytometry, and Ki-67, MIB-1, and proliferating cell nuclear antigen (PCNA) positivity by immunohistochemistry in 135 breast carcinomas. There was strong correlation between the two MFC methods and significant correlation between MIB-1 positivity and all proliferation markers except Ki-67. S-phase fraction showed significant correlation with all proliferation markers except PCNA. Ki-67 positivity correlated only with S-phase fraction, and PCNA positivity only with MIB-1 and mitoses per 10 HPF. High MFC was associated with other prognostic factors: high histologic tumor grade, absence of biochemical and immunohistochemical hormone receptors, and DNA aneuploidy, but not lymph node involvement or tumor size. MIB-1 positivity was also associated with these parameters, except lymph node involvement, tumor size, and DNA aneuploidy. Mitotic figure count and MIB-1 positivity were associated strongly with disease-free survival, up to 46 months. The other proliferation markers were associated with fewer prognostic factors and showed weak or absent association with disease-free survival. The best proliferation markers are mitotic figure counting (either method) or MIB-1 positivity.

Antibodies, Monoclonal↗
PubMed1994

Biochemically estrogen receptor-negative, progesterone receptor-positive breast carcinoma. Immunocytochemical hormone receptors and prognostic factors.

The significance of breast carcinomas biochemically negative (-) for estrogen receptor (ER), but positive (+) for progesterone receptor (PR), is poorly understood. It has been proposed that these tumors, more common in younger women, contain ER whose presence is masked in a biochemical binding assay by endogenous estrogen. Such tumors should be positive for ER by immunocytochemical assay. In a series of 319 tumors, 18 (5.6%) were biochemically ER-PR+. Patient age in this group (mean age, 59 years; range, 36 to 89 years) was slightly, but not significantly, lower than in patient groups with other receptor profiles. Only two (11%) of the 18 tumors were ER+ by immunocytochemical assay, not higher than the immunocytochemical ER positivity rate of seven (13%) of 62 biochemically ER-PR- tumors in the same series. Progesterone receptor was positive by immunocytochemistry in nine (50%) ER-PR+ tumors, lower than the rate in biochemically ER+PR+ tumors (158 [87%] of 181). The tumor size, histologic tumor grade, and S-phase fraction showed trends to be higher in biochemically ER-PR+ tumors than in ER+PR+ tumors. Biochemically ER-PR+ breast carcinomas are biologically different from ER+PR+ tumors.

Adult↗
PubMed1992

Pseudoexfoliative fibrillopathy in visceral organs of a patient with pseudoexfoliation syndrome.

Evidence is increasing that pseudoexfoliative material develops in widespread areas of skin and parabulbar tissues as well as intraocularly. To determine whether this process is even more diffusely distributed, ultrastructural examination was performed on visceral and ocular tissues of a patient with long-standing glaucoma found to have bilateral ocular pseudoexfoliation at autopsy. Aggregates consistent with pseudoexfoliative material were present in the lung, heart, liver, and gallbladder, in addition to the classic intraocular sites. The aggregates were in the fibrovascular septa and stroma of these organs, most frequently adjacent to elastic and oxytalan fibers. They stained positively for elastin and human amyloid P protein, like the ocular sites, in preliminary immunologic testing. Rare atypical aggregates were seen in one of the four control patients. These findings suggest that pseudoexfoliation is a systemic process involving abnormal matrix synthesis, particularly as related to elastic tissue components.

Aged↗
PubMed1992

Evaluation of a soft-handling computerized pneumatic tube specimen delivery system. Effects on analytical results and turnaround time.

A computerized pneumatic tube specimen delivery system with system-wide air cushion soft handling features was evaluated. There were no significant differences in values (largely normal) for components of a standard chemical profile or complete blood count in specimens delivered from the outpatient center or neonatal intensive care unit by pneumatic tube compared to couriers. The pneumatic tube system also did not affect values for pO2, pCO2, and pH over a wide range (pO2, 25 to 438 mmHg) in specimens sent from the operating room during cardiac surgery. The pneumatic tube system decreased the median turnaround time for potassium and hemoglobin results on specimens from the emergency department by 25%. The system evaluated is a rapid, efficient mechanism for sending specimens to the clinical laboratory that produces no significant effects on analytical results and has the ability to decrease turnaround time.

Blood Cell Count↗
PubMed1988

Determination of estrogen receptor by monoclonal antireceptor antibody in aspiration biopsy cytology from breast carcinoma.

The authors evaluated the ability of a monoclonal antibody immunoperoxidase procedure (ERICA [Estrogen Receptor Immunocytochemical Assay], information from Regulatory Affairs Department, Abbott Laboratories, North Chicago, IL) to detect estrogen receptor in aspiration biopsy cytology (ABC) specimens from breast cancer routinely taken by fine-needle aspiration during office diagnostic evaluation. Results were correlated with biochemical values determined from dextran-coated charcoal (DCC) assay on tumor tissue obtained subsequently at operation. ERICA had positive results in 32 of 41 DCC-positive cases (sensitivity, 78%) and in 5 of 17 DCC-negative cases (specificity, 71%). The semiquantitative degree of ERICA positivity correlated with the concentration of estrogen receptor by DCC. Results of both assays correlated with the histologic grade of the tumor and patient age. Estrogen receptor can be determined by immunocytochemistry in ABC specimens in a community hospital. However, the sensitivity and specificity of this procedure compared with biochemical assay, and eventual response to hormonal therapy, require further investigation.

Adult↗
PubMed1988

Creatine kinase MM isoforms in serum after cardiac surgery.

We evaluated creatine kinase (CK; EC 2.7.3.2) MM3:MM1 isoform ratios in the serum of cardiac patients immediately after cardiac surgery for the diagnosis of perioperative myocardial injury. The mean ratio was 4.8 (range, 1.4-10.7) in 22 patients who had postoperative myocardial complications and 4.6 (1.3-9.6) in 66 patients who did not. By the first postoperative day the ratio had decreased substantially in both groups of patients. The isoform ratio did not correlate with the concentration of total CK, CK-MB, total lactate dehydrogenase (LD), or the incidence of LD1:LD2 or LD5:LD2 ratio reversal. Of these measurements, CK-MB and LD concentrations differed most between the groups of patients; parallel testing of CK-MB and LD showed an optimized sensitivity and specificity of 77% and 87%, respectively. We conclude that analysis for CK-MM isoforms does not add information in the period immediately after cardiac surgery; concentrations of CK-MB and LD correlate with myocardial injury, but the sensitivity and specificity of these measurements may not be high enough for clinical utility.

Aged↗