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Biomedical subjects

J Leary

Publications and source records attributed to J Leary.

At least 37 records · Page 2Linked to original sources

Frequent loss of heterozygosity on chromosome 18 in ovarian adenocarcinoma which does not always include the DCC locus.

Inactivation of the DCC gene on chromosome 18 owing to loss of heterozygosity is a common finding in colorectal cancer. Because both ovarian and colon cancer are features of Lynch syndrome II, which has been provisionally mapped to chromosome 18, we hypothesized that loss of heterozygosity at the DCC locus may also occur in ovarian neoplasia. Fifty-two sporadic ovarian adenocarcinoma tumours were analysed by Southern blotting for loss of heterozygosity (LOH) at six chromosome 18 loci. Overall, tumours from 31 patients (60%) showed allelic loss at one or more of these loci. A similarly high level of LOH, 66%, was found at D17S5 (17p13.3). In contrast, moderate levels of LOH, of 31%, 39% and 33%, were found at MYCL1 (1p32), D1S57 (1p) and D14S20 (14q32.33) respectively. However, analysis of partial chromosome deletions in 11 patients indicates that the smallest region of overlap appears to exclude the DCC gene but to be between the D18S5 and D18S11 loci. This suggests that another locus, as well as or apart from DCC, may be involved.

Adenocarcinoma↗

Binding of soluble CD4 proteins to human immunodeficiency virus type 1 and infected cells induces release of envelope glycoprotein gp120.

Human immunodeficiency virus (HIV) infects cells after binding of the viral envelope glycoprotein gp120 to the cell surface recognition marker CD4. gp120 is noncovalently associated with the HIV transmembrane envelope glycoprotein gp41, and this complex is believed responsible for the initial stages of HIV infection and cytopathic events in infected cells. Soluble constructs of CD4 that contain the gp120 binding site inhibit HIV infection in vitro. This is believed to occur by competitive inhibition of viral binding to cellular CD4. Here we suggest an alternative mechanism of viral inhibition by soluble CD4 proteins. We demonstrate biochemically and morphologically that following binding, the soluble CD4 proteins sT4, V1V2,DT, and V1[106] (amino acids 1-369, 1-183, and -2 to 106 of mature CD4) induced the release of gp120 from HIV-1 and HIV-1-infected cells. gp120 release was concentration-, time-, and temperature-dependent. The reaction was biphasic at 37 degrees C and did not take place at 4 degrees C, indicating that binding of soluble CD4 was not sufficient to release gp120. The appearance of free gp120 in the medium after incubation with sT4 correlated with a decrease in envelope glycoprotein spikes on virions and exposure of a previously cryptic epitope near the amino terminus of gp41 on virions and infected cells. The concentration of soluble CD4 proteins needed to induce the release of gp120 from virally infected cells also correlated with those required to inhibit HIV-mediated syncytium formation. These results suggest that soluble CD4 constructs may inactivate HIV by inducing the release of gp120. We propose that HIV envelope-mediated fusion is initiated following rearrangement and/or dissociation of gp120 from the gp120-gp41 complex upon binding to cellular CD4, thus exposing the fusion domain of gp41.

Blotting, Western↗

In-situ hybridization using biotinylated DNA probes to human papillomavirus in adenocarcinoma-in-situ and endocervical glandular dysplasia of the uterine cervix.

In-situ hybridization using biotinylated probes to human papillomavirus (HPV) DNA was performed on formalin fixed paraffin embedded tissue in 30 patients with histologically confirmed adenocarcinoma-in-situ (AIS). Thirteen of the 30 cases contained areas of endocervical glandular dysplasia (EGD) admixed with AIS. Twenty one patients showed positive staining of the AIS nuclei for HPV DNA. Ten cases (33%) were positive for HPV 16 DNA and 11 cases (37%) were positive for HPV 18 DNA. No case showed synchronous expression of HPV 16 and 18 DNA. All cases of AIS were negative for HPV 6b and 11 DNA. Four cases of EGD were positive for HPV 18 DNA and 2 cases were positive for HPV 16 DNA. Four of 6 cases of intestinal dysplasia/AIS were positive for HPV 18 DNA. Associated squamous abnormalities (HPV +/- CIN +/- SCC) were noted in 15 cases. Of these, 7 showed positive staining for HPV DNA in the squamous lesion. Moreover, 5 of these were positive in both the AIS and squamous lesion. In-situ hybridization using biotinylated DNA probes is a sensitive and safe technique readily adaptable to routine histopathology.

Adenocarcinoma↗

Social outcome.

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Activities of Daily Living↗

Demonstration of somatic rearrangements and genomic heterogeneity in human ovarian cancer by DNA fingerprinting.

A detailed study was performed in 14 patients with epithelial ovarian tumours using the satellite probes 33.15, 228S and 216S to investigate the nature of somatic changes and frequency with which clonal changes could be demonstrated during metastasis and progression. Somatic changes were evident in approximately 70% of ovarian tumours, the most common being a deletion or reduction in intensity of a band suggesting loss of heterozygosity. Additional changes that were observed included increased intensification of single bands and the appearance of novel DNA fragments. Somatic alterations were seen following digestion of DNA with methylation resistant restriction endonucleases indicating that methylation differences alone could not account for all of the somatic changes. Using DNA fingerprint analysis ovarian tumours were shown to be heterogeneous with different DNA patterns observed in different sites in five of eight patients. Generally, within an individual patient the primary and metastases appeared to share a DNA fingerprint pattern with minor variations occurring in different sites suggesting that different populations have derived from a common stem line. This study clearly demonstrates that DNA fingerprint analysis is a sensitive method to detect somatic changes in tumour DNA and for investigating the development of clonal heterogeneity in ovarian tumours.

Adenocarcinoma↗

Comparison of western blot analysis and immunocytochemical detection of P-glycoprotein in multidrug resistant cells.

A sensitive immunocytochemical technique was developed to detect a 170,000 dalton cell membrane glycoprotein (P-gp) in cell lines resistant to vincristine and vinblastine with varying degrees of resistance. P-gp was shown very clearly using the C219 monoclonal antibody and immunocytochemical detection with either antialkaline phosphate or peroxidase-antiperoxidase with silver gold intensification. There was good correlation between the results obtained with immunocytochemical detection of P-gp in single cells and Western blot analysis. The technique is easily performed and can detect P-gp in relatively small numbers of cells that Western blot analysis could miss and is suitable for clinical application.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

An evaluation of CA125, CA1 and peanut lectin immunoreactivity in epithelial ovarian neoplasms: correlation with histopathological features, prognostic variables and patient outcome.

The ability to produce monoclonal antibodies to tumour associated antigens, together with advances in immunocytochemistry, provide the potential for establishing a new functional classification of human tumours. This approach was used to investigate whether the expression of CA125, CA1 and the Thomsen-Friedenreich antigens reflected the biological behaviour of ovarian tumours and, if so, had a potential role in the clinico-pathological assessment of ovarian neoplasms. Expression of these antigens was assessed in benign, borderline and malignant ovarian epithelial tumours and attempts were made to determine if there was any correlation between immunoreactivity and tumour grade, histological subtype, FIGO Stage, tumour ploidy or patient outcome. There was no evidence that expression of these antigens had clinical significance, although it is possible that reactivity with antibody OC125 might identify patients in whom CA125 antigen levels in the sera could be used as a marker to monitor disease progress.

Antibodies↗

Variable ploidy of ovarian clear cell carcinomas. Implications for adequacy of tissue sampling.

Ten cases of clear cell (mesonephroid) adenocarcinoma of the ovary were examined for (1) variations of morphology within each tumor and its metastases, (2) ploidy of each morphologic region and (3) clinical behavior. Correlations were sought among these factors. Analysis of the ploidy in up to six morphologic regions per tumor showed variations in the ploidy in seven of the ten cases, with all seven having both diploid and nondiploid regions. The presence or absence of abnormal ploidy was not predictable based on the histomorphologic appearance of a given section. These results suggest that (1) the evaluation of a single random tissue sample may not discover aneuploidy that is present and (2) future ploidy studies on malignant tumors may require extensive tumor sampling in order to definitively exclude the presence of aneuploid populations.

Adenocarcinoma↗

Human hybrid tumor cells: observations on their production and clinical effects.

Human hybrid tumor cells have been produced by fusing cells from freshly harvested tumor specimens with cells from a cultured human tumor line, D98OR. Fusions were performed with cells from 67 tumors and continuously growing hybrid lines were obtained from 16 (24%). A successful fusion usually produced 1 or 2 hybrid lines, but four easily fusable tumors produced from 6 to 26 lines. The parent cells and hybrids were analyzed by flow cytometry. Hybrids appeared to retain a high percentage of parental deoxyribonucleic acid. Ten patients participated in a clinical study in which they received intradermal immunization with semiautologous hybrids and Corynebacterium parvum as adjuvant. The only side effect was slight local tenderness at the injection sites. No tumor regressions occurred. Skin testing with parental and hybrid cells was performed prior to and following immunization with hybrids. Delayed cutaneous hypersensitivity was often achieved for hybrids but not for autologous tumor cells.

Antigens, Neoplasm↗

Flow sorting of antigen-binding B cell subsets.

Antigen binding was used as a probe in the definition of functional B cell heterogeneity. Unprimed, anti-Thy 1 and complement-treated spleen cells were stained with fluorescent trinitrophenylated bovine serum albumin (FL-TNP-BSA). These cells were sorted, fluorescence negative from fluorescence positive, by using a multiparameter cell sorter and assayed for precursor frequency in antibody responses to TNP by limiting dilution analysis. The cells that bound FL-TNP-BSA were demonstrated to be enriched for antibody-forming precursors to the antigens TNP-lipopolysaccharide (LPS), TNP-sheep red blood cells (SRBC), and TNP- or DNP-Ficoll, whereas the fluorescence negative cells were depleted for these responses. B cells that bound FL-TNP-BSA were then sorted into populations that bound a moderate or high amount of FL-TNP-BSA. The B cells responsive to TNP-LPS and TNP-SRBC were present in both the moderate and high binding populations. In contrast, the B cells responsive to TNP- or DNP-Ficoll were present only in the cells that bound a moderate amount of FL-TNP-BSA. These experiments suggest that there is a population of B cells in adult mouse spleen that binds large amounts of antigen, and that can respond to antigen carried on LPS or SRBC but not carried on Ficoll.

Animals↗

Stress in mental health nurses: comparison of ward and community staff.

Work place stress is an increasing concern for mental health nurses. This article reports the findings of two research studies of ward and community-based staff, identifying specific stressors. Reducing staff stress levels is essential if patient care is not to suffer.

Burnout, Professional↗