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S A Brooks

Publications and source records attributed to S A Brooks.

At least 19 recordsLinked to original sources
PubMed1996

Oligosaccharide release from frozen and paraffin-wax-embedded archival tissues.

Altered glycosylation is a feature of many solid tissue diseases such as ulcerative colitis, Crohn's disease, cancer, and connective tissue disorders. Conventionally, oligosaccharide changes have been studied by immunohistochemical techniques. We have adapted existing techniques, developed for purified protein preparations, to allow the release of intact oligosaccharides from archival tissues, so that the oligosaccharides may be structurally characterized. In our study, sections cut from paraffin-wax blocks were dewaxed and oligosaccharides were released using hydrazine and labeled with 2-aminobenzamide. Sialylated oligosaccharides were compared by passing through a GlycoSep C divinylbenzene anion exchange resin column and neutral oligosaccharides were compared by passing through a BioGel P4 column. The oligosaccharide profiles obtained from the same fresh frozen versus archival paraffin-wax-embedded, normal liver, and tumor tissues showed remarkable similarity in terms of their sialylated and neutral structures. Matrix-assisted laser desorption ionization mass spectrometry has shown that the oligosaccharides are not affected by fixation in formalin and storage in paraffin wax. The results indicate that while the proteins themselves may be denatured, oligosaccharides are not adversely affected by fixation in formalin and storage in paraffin wax. By applying these methods, oligosaccharides from archival tissues, where the natural history of the disease has been followed, may now be liberated and structurally characterized.

Animals↗
PubMed1996

Identification, purification and analysis of a 55 kDa lectin binding glycoprotein present in breast cancer tissue.

The Helix pomatia agglutinin (HPA)-binding glycoproteins from primary breast cancers and their metastases were compared with appropriate normal control tissues on Western blots. From these studies a single glycoprotein of 55 kDa was found to bind HPA in tumours but not in normal control tissues. The glycoprotein was identified by protein sequencing as being homologous to human immunoglobulin heavy chain variable region. Subsequent immunostaining showed it to be immunoglobulin subclass A. IgA1 was purified from both tumour and normal tissue by affinity chromatography. It was demonstrated that IgA1 from tumour tissue bound HPA whereas IgA1 from normal tissue did not. The oligosaccharides were cleaved from the protein backbone and the glycans from the HPA-binding glycoform of IgA1 were compared with those from normal human IgA1. IgA1 from tumour tissue appears to be associated with an HPA-binding glycan which is not present on the normal tissue-derived IgA1.

Amino Acid Sequence↗
PubMed1996

Histochemistry to detect Helix pomatia lectin binding in breast cancer: methodology makes a difference.

A number of studies have shown that altered cellular glycosylation, as detected by binding of Helix pomatia lectin to paraffin sections, is associated with metastatic disease and consequent poor patient prognosis in breast and other cancers. In a 24-year retrospective study, sections of 373 primary breast cancers were stained for binding of the lectin using two different histochemical techniques: a direct method (using peroxidase-conjugated lectin) and an indirect method (using native, unconjugated lectin). Similar percentages of cases were positive (79%) and negative (21%) for lectin binding with either technique, but there was enormous inconsistency when individual cases were examined. A total of 38/373 (10.2%) cases that were negative by the indirect method were positive by the direct method, and 37/373 (9.9%) cases that were negative by the direct method were positive by the indirect method. Life tables calculated for lectin staining vs nonstaining cases showed a very strong correlation between lectin binding and long-term survival (p < 0.0001) when staining was performed by the indirect method, but only very weak correlation with prognosis (p < 0.03, borderline significance) when the direct technique was employed. SDS-PAGE revealed that there were differences in breast cancer glycoproteins recognized by native lectin and peroxidase-conjugated lectin immobilized on Sepharose 4B affinity beads. Helix pomatia lectin binding appears to be an intriguing and potentially valuable marker of biological behavior in breast cancer. This study emphasizes the importance of selecting an appropriate immunohistochemical technique for its visualization.

Animals↗
PubMed1995

Expression of alpha-GalNAc glycoproteins by breast cancers.

The expression of complex carbohydrates recognised by Helix pomatia lectin (HPA, nominal monosaccharide binding specificity alpha-GalNAc) has been shown to predict unfavourable prognosis in breast and other cancers. It has been suggested that the prognostic significance of HPA binding may be through recognition of either Tn epitope (alpha-GalNAc-O-serine/threonine) or blood group A antigen (terminal alpha-1-->3GalNAc attached to the basic H-antigen, Fuc-alpha-1-->2-Gal-beta-1-->4(or 3) GlcNAc-->R). In this study, the expression of glycoproteins terminating in alpha-GalNAc residues was investigated immunohistochemically using HPA and two monoclonal antibodies--BRIC 66 (anti-alpha-GalNAc) and BRIC 111 (anti-Tn). In paraffin sections, 74/87 (85%) of breast cancers expressed HPA-binding ligands, while 28/87 (32%) were positive for BRIC 66 binding and 25/87 (29%) expressed Tn. Distribution of staining patterns were distinctive and different with the three markers. BRIC 66, BRIC 111 and HPA binding to glycoproteins derived from breast cancer homogenates and to blood group A and Tn positive glycoproteins in Western blots confirmed the immunohistochemistry data. The results suggest that the prognostic significance of HPA binding in breast cancer is unlikely to be simply through recognition of blood group A antigen or Tn epitope on cancer cells. Breast cancers may express a complex profile of related but distinct glycans sharing similar terminal immunodominant sugar GalNAc, which may be implicated in aggressive biological behaviour.

ABO Blood-Group System↗
PubMed1995

Lectin-binding properties of human breast cancer cell lines and human milk with particular reference to Helix pomatia agglutinin.

Several studies have shown binding of a variety of lectins to breast cancer cells in tissue sections. In particular, binding of the lectin from the Roman snail, Helix pomatia agglutinin (HPA), to breast cancer cells is linked with a poor prognosis. The molecular basis for lectin binding to metastatic breast cancers is not known. To elucidate this in a model system, lectin-binding patterns of seven human breast cancer cell lines were investigated, their cell membranes were isolated, and HPA binding was assessed. In addition, the influence of fixation and processing on lectin-binding sites was also investigated. Binding of lectins to the tumor cells was very heterogeneous between and within the different cell lines and was influenced by fixation and processing. However, some cell lines showed HPA-binding sites both in vivo and in tissue sections. Analysis of the isolated cell membrane glycoproteins from these cell lines on Western blots revealed that HPA can bind to several membrane glycoproteins. In contrast, human milk shows only one major milk glycoprotein that is HPA-positive. Therefore, a switch in glycosylation appears to be taking place during the transformation to a metastatic phenotype.

Animals↗
PubMed1995

Expression of the CD15 antigen (Lewis x) in breast cancer.

The expression of the cell adhesion molecule CD15 (also known as Lewis x) by breast cancers and by adjacent normal and benign breast epithelium was investigated in a series of 98 tumours. Immunohistochemistry was performed on paraffin sections using the anti-CD15 monoclonal mouse IgM antibody Dako-M1. Some 35% of cancers expressed CD15, as did 45% of normal and 60% of hyperplasia. No association was observed between cancer cell staining, or any epithelial staining (cancer, benign and normal), and tumour size, histological grade, nodal status, age at diagnosis or the frequency of 'events' (recurrence or death). Chi-squared tests in each case were non-significant. The pattern of CD15 expression by breast cancer was frequently associated with the leading edge of invading tumour or with the outer edge of boli of carcinoma in situ, possibly suggesting a potential role in invasiveness, and with cancer cells trapped intravascularly, possibly suggesting a role in metastasis.

Adult↗
PubMed1994

Glycosylation patterns of the human colon cancer cell line HT-29 detected by Helix pomatia agglutinin and other lectins in culture, in primary tumours and in metastases in SCID mice.

Human colonic cancer cells (HT-29, 10(7) cells/dose) were injected subcutaneously between the scapulae of 19 severe combined immunodeficient (SCID) mice. After 19 days, large tumours had developed in 18 out of the 19 animals and the mice were then killed. Metastases were detected in the lungs of 16 animals but not in other organs investigated. Surgical removal of the primary tumour in another group of five animals led to a prolonged survival and further growth of metastases in the lungs. HT-29 injection into the tail vein (n = 5) resulted in colonization of the lungs. The tumours that developed in the animals were signet cell carcinomas; these forms are not seen in HT-29 cells in culture. Glycoconjugate expression of the tumours was assessed using several lectins. In many cases the results indicated a stability of lectin-binding patterns from cell culture conditions to implantation into the SCID mice. This was true for the lectin Helix pomatia agglutinin (HPA), the binding of which is associated with a high metastatic potential in some human tumours, including colon cancer. All the primary tumours and metastases were HPA positive. This xenograft tumour model seems to be a clinically relevant system for the study of glycoconjugate expression in human colon cancer cells and their metastases.

Animals↗
PubMed1993

Markers of prognosis in breast cancer--the relationship between binding of the lectin HPA and histological grade, SPF, and ploidy.

Abnormal cellular glycosylation as demonstrated by the binding of a lectin from Helix pomatia (HPA) to paraffin-embedded sections has been shown in several studies to be associated with aggressive biological behaviour and poor long-term patient prognosis in breast cancer. This study aims to address the possibility that expression of the HPA binding ligand may be of prognostic significance through an association with increased cellular proliferation (as measured by S-phase fraction and histological grade), anaplasia (reflected in histological grade), or ploidy (DNA index). In a 24 year retrospective study, paraffin-embedded sections of 366 primary breast cancers were stained for binding of HPA. All tumours were assessed for histological grade. Flow cytometry was performed on all cases for which sufficient tumour tissue was available (358/366 cases) and S-phase fraction (SPF) and ploidy calculated. Data regarding patient age at diagnosis, nodal status, and tumour size were also recorded. Life table analyses revealed survival advantage for HPA 'non stainers' in comparison to 'stainers' (p < 0.001); for patients with tumours of low grade vs. high grade (p < 0.001); and for those with tumours of low SPF vs. high SPF (p < 0.001). No survival advantage was shown for those with diploid vs. aneuploid tumours (p = 0.17). No association was apparent between HPA binding and grade, SPF, or ploidy (Chi squared values not significant). This was confirmed by multivariate analysis in which nodal status, tumour size, and SPF were independently predictive of survival. There was no confounding effect of grade, SPF, or ploidy upon the correlation between survival and HPA binding. HPA was, however, not independently predictive owing to its strong association with nodal status. The results of this study suggest that the prognostic significance of altered glycosylation, as detected by HPA binding, is unlikely to be through an association with proliferative rate, degree of anaplasia, or cellular ploidy, but may rather be through a direct association with the presence of nodal metastases.

Breast Neoplasms↗
PubMed1992

Characterization of a novel mRNA expressed by neurons in mature brain.

In previous studies, differential hybridization screening of an activated murine T-lymphocyte cDNA library identified an interleukin 2-responsive mRNA, designated F5, expressed in lymphoid tissues and brain only. We now report characterization of a full-length clone isolated from an adult mouse brain cDNA library. Neither the nucleic acid nor amino acid sequences demonstrated similarity to reported sequences. On Southern blotting, the protein coding sequence hybridized to genomic DNA from a variety of species. On Northern blotting, F5 mRNA was expressed in adult mouse brain, spinal cord, eye, and dorsal root ganglia but not in peripheral nerve. In situ hybridization studies demonstrated prominent expression by neurons in brain. F5 mRNA expression was undetectable in embryonic rat cerebral hemisphere and low until postnatal day 21. F5 is a novel mRNA selectively expressed by proliferating lymphocytes and mature neurons.

Amino Acid Sequence↗
PubMed1991

Prediction of lymph node involvement in breast cancer by detection of altered glycosylation in the primary tumour.

Axillary lymph node metastases at the time of diagnosis of breast cancer is the most accurate predictor of long-term prognosis. However, in patients treated by conservative surgery lymph node status often remains unknown. We have investigated the relation between changes in glycosylation of primary breast cancer cells, as judged by lectin binding, and the presence of axillary lymph node metastases. In a 24-year retrospective study, paraffin-embedded sections of 373 primary breast cancers were stained for the binding of Helix pomatia lectin (HPA). There was a strong association between HPA binding and presence of lymph node metastases, but no association with tumour size, histological grade, S-phase fraction, or patient age at diagnosis. This relation was confirmed by multiple regression analysis (in both survival and relapse free survival models) in which the prognostic significance of HPA binding was lost once nodal status had been introduced into the models. Life tables calculated for lymph-node positive versus lymph-node negative and HPA staining versus non-staining patients were almost identical over 15 years of follow-up. We propose that HPA recognises a glycoprotein that is associated with metastasis (to axillary lymph nodes and elsewhere) and poor prognosis in breast cancer. HPA binding to paraffin sections of primary tumour could aid difficult treatment decisions by providing an additional assessment of staging and likely long-term patient prognosis.

Actuarial Analysis↗
PubMed1990

Reviewing reviewers.

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Book Reviews as Topic↗
PubMed1988

What price insanity?

The insanity defence in Canada is defined by the use of Section 16 of the Criminal Code. Legal sanity is determined by the application of an outdated set of rules which require only that the accused be able to determine right from wrong in the particular circumstances that appear to have applied at the time of the alleged offence. The actual application of the defence suggests that its interpretation in practice is considerably affected by factors other than the mental state of the accused. The arbitrary and ill-understood nature of these interposed factors removes any certainty that justice, or the well-being of the accused, is to be found by use of the existing law. Psychiatry should not rest content that its understanding of the determinants of human behavior is in any way accurately represented by Canada's Criminal Code.

Adult↗
PubMed1987

Predictive value of lectin binding on breast-cancer recurrence and survival.

A new approach for predicting long-term survival of breast-cancer patients is the detection of carbohydrate expression in paraffin-embedded sections of the primary tumour. The binding of a lectin (HPA), derived from the albumin gland of the Roman snail, Helix pomatia, to N-acetyl-galactosaminyl oligosaccharides appears valuable in assessing long-term prognosis. The clinical progress of 179 patients, followed-up for 15-20 years, was related to staining of paraffin sections of their primary breast cancers by HPA. All patients had had mastectomy but were not stratified by pathology or treatment. There were significant differences, in premenopausal patients, between groups with and without HPA staining in both time to first recurrence and survival time. HPA binding provides an extra tool for staging to aid decisions in early adjuvant treatment, with the advantage of being applicable to routinely fixed paraffin-embedded material.

Acetylgalactosamine↗
PubMed1987

Folie à Deux in the aged: variations in psychopathology.

The etiology of Folie à Deux remains a controversial topic; the relationship between the psychopathology exhibited by the dominant partner and that shown by the submissive one being particularly unclear. Modern etiological theories attempt to reduce the phenomena of Folie à Deux to a procrustean mould, emphasizing in particular the contribution of schizophrenic pathology to the development of the condition. A case is described which raises doubts about the general applicability of this approach.

Aged↗
PubMed1985

Dignity and death: a reply.

Some form of utilitarian approach can be discerned as underlying much current medical ethical decision-making. Criticisms of the practical effects of such an approach are not parried by asserting the fundamental strengths of utilitarianism as theory.

Aged↗
PubMed1984

Dignity and cost-effectiveness: a rejection of the utilitarian approach to death.

Utilitarianism is commonly assumed to be the most appropriate sub-structure for medical ethics. This view is challenged. It is suggested that the utilitarian approach to euthanasia works against the patient's individual advantage and is a corrupting influence in the relationship between the physician and society. Dignity for the individual patient is not easily achieved by assessing that person's worth against the yardstick of others' needs and wishes.

Attitude to Death↗