Search PubMed⌕ Search

Biomedical subjects

M M Bui

Publications and source records attributed to M M Bui.

11 recordsLinked to original sources
PubMed2005

Small-cell tumors of the liver: a cytological study of 91 cases and a review of the literature.

This study was designed to consider the cytomorphological spectrum, differential diagnosis, and the role of ancillary studies in small-cell tumors of the liver. Three independent pathologists reviewed cytological slides from 91 cases of small-cell tumors of the liver. The results were compared with the findings of three recently published studies (Cytopathology 11 (2000) 262-267; Diagn Cytopathol 19 (1998) 29-32; and Acta Cytol 40 (1996) 937-947). The role of immunohistochemistry in reaching timely and specific diagnoses was also examined. The diagnostic categories included 44 cases of metastatic small-cell undifferentiated carcinoma, 15 cases of metastatic neuroendocrine carcinoma, 10 cases of metastatic adenocarcinoma, 7 cases of malignant lymphoma, 4 cases of hepatocellular carcinoma with small-cell features, 2 cases of cholangiocarcinoma, 1 case of poorly differentiated carcinoma, and 8 cases of rare tumors including granulosa cell tumor (2 cases), sarcoma (4 cases), malignant melanoma with small-cell features (1 case), and meningioma with small-cell features (1 case). Metastatic granulosa cell-tumor, metastatic melanoma, and metastatic meningioma should be included in the differential diagnoses of small-cell malignancies found in the liver.

Adenocarcinoma↗
PubMed2000

Molecular predictive factors for local recurrence and distant metastasis of breast cancer after lumpectomy with postoperative radiation therapy.

To determine the risk factors associated with the recurrence and metastasis of breast cancer after lumpectomy with postoperative radiation therapy, 112 cases were studied who had been treated during a period of 11 years at the University of Florida Health Science Center/Jacksonville. The patients were evaluated for their age, race, and clinical stage, as well as the tumor grade, stage, histological type, and node involvement. Among these cases, four (4%) recurred locally within a year of treatment; 10 (9%) cases presented with distant metastasis within three years. No obvious clinical risk factors were identified for local recurrence; however, positive-node status seemed to be associated with distant metastasis. The primary tumors of these cases were then studied using immunohistochemical staining to evaluate the potential prognostic value of tumor markers such as estrogen receptor (ER), progesterone receptor (PR), tumor suppressor gene p53, HER-2/neu oncogene, and multi-drug resistance gene (MDR). The expression of p53 was associated with all local recurrence cases as well as 50% of those who had metastasis. The expression of MDR was observed in 80% of the distant metastatic cases. This preliminary result may warrant further studies on larger number of cases to assess the predictive value of p53 and MDR in the outcome of breast cancers in patients treated with postoperative radiation therapy.

Adult↗
PubMed2000

Fluorescence in situ hybridization (FISH) for detection of HER-2/neu amplification in breast cancer: a multicenter portability study.

Amplification and/or overexpression of HER-2/neu has been shown to be both a prognostic and predictive marker in breast cancer. Recent studies have also confirmed the efficacy of Herceptin (trastuzumab) as adjuvant therapy for patients with overexpression of HER-2/neu. Therefore, it is critical that precise and reproducible assays be used in the clinical laboratory setting for determination of the HER-2/neu status in patients with breast cancer. The objective of this study was to determine the portability (reproducibility between different institutions) of the PathVysion HER-2 fluorescence in situ hybridization (FISH) assay used for detection of amplification of the HER-2/neu gene in formalin-fixed, paraffin-embedded tissue sections of invasive ductal carcinoma of the breast. Study specimens consisted of one breast tumor with a normal HER-2/neu copy number, two tumors with a low level, and one tumor with a high level of HER-2/neu amplification. The PathVysion HER-2 assay was shown to be highly reproducible on different assay days (n = 3) and between different institutions (n = 5) in the detection of amplification of the HER-2/neu gene in routinely processed clinical specimens of breast carcinoma. In addition, this study examined the feasibility of enumerating FISH signals in 20 nuclei in contrast to 60 nuclei per specimen. Although a modest increase in variation was observed when analyzing 20 compared to 60 nuclei, the mean ratios were similar. Therefore, analysis of as few as 20 nuclei with this FISH HER-2/neu assay may be sufficient for determining the amplification level of the HER-2/neu gene.

Antimetabolites, Antineoplastic↗
PubMed2000

Assessment of Her-2/neu overexpression in primary breast cancers and their metastatic lesions: an immunohistochemical study.

Since the development of novel immunotherapy using Herceptin as the first agent specifically indicated for HER-2/neu overexpression in metastatic breast cancer, there has been interest in using HercepTest as a predictor of response to such therapy. There is debate whether it is justifiable to perform HercepTest on every newly diagnosed breast cancer, since only approximately 43% of the cases will have related metastatic disease, and Herceptin is indicated only for breast cancer with metastatic disease. It may be more cost-effective to limit HercepTest to the related metastatic lesions. Therefore, it is important to assess whether the pattern of HER-21neu overexpression of metastatic breast cancer is also present in the primary lesion. HercepTest was performed on formalin-fixed, paraffin-embedded tissue sections of 56 primary breast cancers and their corresponding metastatic lesions. The protocol and scoring guidelines recommended by the manufacturer were followed. Tissue sections (5 microm) of a primary and the metastatic lesion from the same case were placed parallel on a single glass slide. The pattern and intensity of HER-2/neu overexpression (32%) in the primary and metastatic lesions were found to be nearly identical. Heterogeneity was observed in only one case. The score of primary cancer was 3+, and the metastatic lesion was 2+. Both were reported as positive. Intratumor heterogeneity (1+ to 3+) was also noted in two (4%) cases. However, the same pattern was found in both the primary and related metastatic lesions. The nearly identical HercepTest results in the primary and metastatic lesions suggest the potentiality of limiting the HercepTest to breast cancer-related metastases. Currently, any superficial and most deep-seated metastatic lesions can be easily sampled by fine needle aspiration biopsy or core biopsy, providing adequate samples for HercepTest. Eliminating unnecessary use of the HercepTest may provide a cost-effective alternative approach to the management of breast cancer patients.

Breast Neoplasms↗
PubMed1996

Paternally transmitted IDDM2 influences diabetes susceptibility despite biallelic expression of the insulin gene in human pancreas.

Whereas it is well known that the insulin gene (INS) region at 11p15.5 (IDDM2) confers susceptibility to insulin-dependent diabetes mellitus (IDDM), it is still controversial whether the parental origin of IDDM2 influences IDDM susceptibility. We have analysed the Pst I + 1127 polymorphism in 123 USA multiplex families and detected linkage only in male meioses using the affected sibpair analysis (P = 0.009). Application of the transmission/disequilibrium test (TDT) found significantly increased transmission of the IDDM-associated INS allele from fathers heterozygous for INS to their diabetic offspring (P = 0.00002), but the transmission from heterozygous mothers was not significantly different from random expectation. In non-diabetic families, the transmission from parents heterozygous for INS was not significantly different from random expectation in either paternal or maternal meioses. Maternal imprinting of the INS gene in pancreatic islets was originally considered the most favorable explanation for the observed gender-related difference. However, our study has demonstrated biallelic expression of INS in pancreatic tissues from the human fetuses and thus suggests that INS is probably not imprinted in the pancreatic islets.

Alleles↗
PubMed1995

Affected-sib-pair mapping of a novel susceptibility gene to insulin-dependent diabetes mellitus (IDDM8) on chromosome 6q25-q27.

Affected-sib-pair analyses were performed using 104 Caucasian families to map genes that predispose to insulin-dependent diabetes mellitus (IDDM). We have obtained linkage evidence for D6S446 (maximum lod score [MLS] = 2.8) and for D6S264 (MLS = 2.0) on 6q25-q27. Together with a previously reported data set, linkage can be firmly established (MLS = 3.4 for D6S264), and the disease locus has been designated IDDM8. With analysis of independent families, we confirmed linkage evidence for the previously identified IDDM3 (15q) and DDM7 (2q). We also typed additional markers in the regions containing IDDM3, IDDM4, IDDM5, and IDDM8. Preliminary linkage evidence for a novel region on chromosome 4q (D4S1566) has been found in 47 Florida families (P < .03). We also found evidence of linkage for two regions previously identified as potential linkages in the Florida subset: D3S1303 on 3q (P < .04) and D7S486 on 7q (P < .03). We could not confirm linkage with eight other regions (D1S191, D1S412, D4S1604, D8S264, D8S556, D10S193, D13S158, and D18S64) previously identified as potential linkages.

Chromosome Mapping↗
PubMed1994

Additive susceptibility to insulin-dependent diabetes conferred by HLA-DQB1 and insulin genes.

Several genomic polymorphisms at the insulin (INS) gene and its flanking regions were analyzed in 197 unrelated Caucasian patients affected by insulin-dependent diabetes (IDDM) and 159 ethnically matched, normal controls ascertained from the South-Eastern United States. We found that the frequency of homozygotes for the common variant at the insulin gene was significantly increased in the diabetic population (RR = 2.0, p < 0.005). However, the polymorphisms in the 5' and 3' regions flanking the INS were not significantly associated with IDDM. These results suggest that the IDDM susceptibility locus on chromosome 11p is located within the region extending from the 5' VNTR to the 3' end of the INS gene. We determined the HLA-DQB1 genotypes by denaturing gradient gel electrophoresis (DGGE) and/or sequence-specific primers (SSP) techniques to assess the possible interactions between INS and HLA. DQB1*0302 had the strongest predisposing effect on IDDM susceptibility (RR = 9.3) and DQB1*0602 the strongest protective effect (RR = 0.02). However, a significant predisposing effect of DQB1*0201 could be demonstrated only after removal of the effects of DQB1*0302 and DQB1*0602. Analyses of the genotypes revealed that all genotypes containing 0602 were protective and that the heterozygous genotype 0201/0302 and homozygous genotype 0302/0302 confer the highest risk (RR = 20.9 and 12.9 respectively). However, heterozygous genotypes 0302/X (X excludes 0201, 0302 and 0602) have a significantly lower predisposing risk. Similarly, there is heterogeneity in risk between predisposing 0201/0201 homozygous individuals and protective 0201/X individuals. When subjects were stratified by HLA genotypes, the relative risks conferred by INS did not vary, thus suggesting that the susceptibility effects conferred by HLA and INS are additive rather than interactive.

Base Sequence↗
PubMedDate not supplied

Lipogranuloma.

Explore the source record for details and available documents.

Adult↗
PubMedDate not supplied

Reproducibility of LSI HER-2/neu SpectrumOrange and CEP 17 SpectrumGreen Dual Color deoxyribonucleic acid probe kit. For enumeration of gene amplification in paraffin-embedded specimens: a multicenter clinical validation study.

Overexpression and/or amplification of HER-2/neu gene have been found to be prognostic and predictive in breast and other cancers. Fluorescence in situ hybridization (FISH) assay, with its sensitivity and specificity, can be a superior method of detection when its performance characteristics are demonstrated. A multicenter study was initiated to evaluate the reproducibility of the LSI HER-2/neu SpectrumOrange and CEP 17 SpectrumGreen Dual Color DNA Probe for enumeration of both the HER-2/neu gene and chromosome 17 (signals) in interphase cells. Section slides were prepared from four cell lines (H, E, R, and N) with known ratios of the HER-2/neu to CEP 17 copy numbers (approximately H = 1.10, E = 1.70, R = 4.50, N = 9.0). The study variable was the ratios of the HER-2/neu to chromosome 17 copy numbers. Reproducibility with respect to assay, site, lot, day and reader was evaluated at 3 centers. Out of 120 specimen slides, 100 percent were successfully assayed. There were no significant differences among: (1) four repeated assays of the same specimen (p = 0.99), (2) the four probe lots (p = 0.33), or (3) the four study days (p = 0.54). There was statistically significant, but not important differences among centers and between readers. The ratios of the HER-2/neu to chromosome 17 copy numbers were estimated with accuracy and precision; the mean ratios (and sd) for specimens, H, E, R, and N were 1.05 (0.06), 1.81 (0.12), 4.48 (0.28), and 8.60 (1.23), respectively. In summary, assays with the LSI HER-2/neu and CEP 17 Dual Color DNA Probe Kit, conducted at three sites by 6 different technicians, over 8 assay days, using kits from four lots, were performed with a high success rate in paraffin-embedded specimens. The signal enumeration was also accurate and precise. This study demonstrated that the results obtained by using the LSI HER-2/neu SpectrumOrange and CEP 17 SpectrumGreen Dual Color DNA Probe Kit are reliable and reproducible.

Breast Neoplasms↗
PubMedDate not supplied

Comparison of proliferation activity in breast carcinoma by flow cytometry analysis of S-phase and quantitative analysis of MIB-1.

The S-phase which assesses tumor proliferation has been considered to be an independent prognostic factor for breast carcinoma. Quantitative analysis of MIB-1 immunoreactivity is a newly recognized method of determining cellular proliferation that offers some advantages over flow cytometry when limited tumor tissue is available. However, it has been controversial whether there is a significant correlation between MIB-1 immunostaining and S-phase in defining proliferation activity in breast cancer. In order to explore the usefulness of MIB-1 as an additional proliferation parameter and a potential prognostic factor for breast cancer, we analyzed 94 cases of invasive ductal carcinoma of the breast by both flow cytometry (for S-phase and DNA ploidy) and quantitative MIB-1 immunohistochemical analysis using formalin-fixed paraffin-embedded tissue. MIB-1 staining was quantitatively analyzed by image analysis and by visual scoring. Forty-six cases were diploid by flow, while the remaining 48 cases were aneuploid tumors. T-test results indicated that S-phase means were significantly greater (p = 0.0001) in aneuploid cases (mean = 18) compared to diploid cases (mean = 7). MIB-1 means were also greater in aneuploid patients, but these differences were only marginally significant (p = 0.05). S-phase was positively correlated with MIB-1 (r = 0.36, p = 0.003 for image analysis and r = 0.34, p = 0.001 for visual scoring). ROC curve analysis indicated that MIB-1 quantitation is a good predictor of high S-phase (i.e., > 10 percent) in aneuploid cases. A MIB-1 cutoff value of 25 percent for image analysis achieved 82 percent specificity and 80 percent sensitivity for aneuploid high S-phase, while a MIB-1 cutoff value of 40 percent for visual scoring was 73 percent specific and 85 percent sensitive. However, in diploid cases, no comparable MIB-1 cutoffs could be achieved for detecting high S-phase. In summary, our study demonstrated that aneuploid breast carcinomas proliferate more aggressively than diploid tumors. Although linear correlation between MIB-1 and S-phase was weak, MIB-1 was considered to be a good predictor of high S-phase in aneuploid breast cancer patients, possibly due to a threshold effect. Image analysis and visual scoring of MIB-1 immunoreactivity appeared to be comparable in analyzing proliferative activity in breast cancer. Thus MIB-1 assessed by visual scoring may be a less expensive alternative to image analysis.

Aneuploidy↗