Prospective study of early bereavement on psychological and behavioural cardiac risk factors.

BACKGROUND: Increasing evidence supports the role of emotional stress in the onset of cardiovascular disease. Although bereavement is a major emotional stress with both acute and more long-term features, the mechanism of its association with cardiovascular risk is not well understood, in particular because of limited studies of acute bereavement. The aim of the study was to identify psychological and behavioural changes in acute bereavement and potential modifiers of these changes. METHODS: Bereaved (n= 62) and non-bereaved individuals (n= 50) were evaluated within 2 weeks and at 6 months following loss using the Centre for Epidemiologic Studies -- Depression, Spielberger State Anxiety and Anger, Social Support Questionnaire and changes in appetite, cigarette and alcohol consumption, cortisol and lipids. RESULTS: Compared with non-bereaved, acutely bereaved had increased symptoms of depression (26.7 +/- 1.7 vs 5.9 +/- 0.7, P < 0.001), anxiety (47.4 +/- 2.0 vs 28.2 +/- 1.4, P < 0.001) and anger (median 16.0 vs 15.0, P < 0.001). Greater depressive symptoms were associated with being unprepared for the death, decreased sleep duration and younger age. Acutely, bereaved slept less than non-bereaved (5.8 +/- 0.2 vs 7.2 +/- 0.2 h, P < 0.001). Reduced sleep time was associated with increased anger and depression and decreased satisfaction with social support. Compared with the non-bereaved, the acutely bereaved had higher cortisol (median 306 vs 266, P= 0.003), reduced appetite (P < 0.001) and lower total cholesterol (median 4.9 vs 5.4, P= 0.006) and low-density lipoprotein (median 2.4 vs 2.9, P < 0.001). CONCLUSION: These results offer insight into the psychological, behavioural and physical changes that may contribute to cardiovascular risk in bereavement.

Variations in the relative amounts of biotin-containing enzymes present in both tumorigenic and non-tumorigenic hybrid cells and other cell lines.

The observation that radioactively labelled streptavidin binds to several biotin-containing enzymes in mammalian cells has led to the finding that there is considerable variation in the proportion of these enzymes present (namely beta-methyl crotonyl CoA; propionyl CoA; pyruvate and acetyl CoA, carboxylases). This is particularly striking when certain tumorigenic and non-tumorigenic hybrid cells are compared. It is found that there is a consistently higher proportion of pyruvate carboxylase in the tumorigenic hybrid cells. However, not all tumorigenic cell lines show this same characteristic and reasons for this are discussed. It is also shown that whilst the proportions of the four enzymes are apparently constant for a given cell type, there is a substantial degree of clonal variation and this is particularly so in tumorigenic cells in vitro. However, the more tumorigenic cells in a given population do show a higher proportion of pyruvate carboxylase. Also a range of cells derived from lymphoid tissue has been compared with normal human lymphocytes and considerable differences are again observed. The significance of these findings is considered in relation to other phenotypic properties of hybrid cells.

Detection of the urinary 'PUM' polymorphism by the tumour-binding monoclonal antibodies Ca1, Ca2, Ca3, HMFG1, and HMFG2.

A series of human urinary mucin-like glycoproteins, previously detected using lectins to stain gels after electrophoresis, and showing genetic polymorphism (Karlsson et al., 1983) can also be detected using the tumour-binding monoclonal antibodies, Ca1, Ca2, Ca3, HMFG1, and HMFG2. The evidence from immunoprecipitation and immunoadsorbant chromatography experiments is that the epitopes recognized by these antibodies are carried on the same molecules as the lectin-binding determinants. The discovery that the antibodies bind specifically to a family of molecules which show genetic polymorphism provides a powerful new tool for the analysis of the material expressed aberrantly in cancer.

The breast tumour-associated epithelial mucins and the peanut lectin binding urinary mucins are coded by a single highly polymorphic gene locus 'PUM'.

A family of mucin-type glycoproteins, present in human urine, is coded by a single highly polymorphic gene locus PUM. We have previously shown that these glycoproteins carry epitopes recognized by a series of monoclonal antibodies, many of which were raised to the human milk-fat globule membrane, and which bind to a wide variety of carcinomas and certain normal epithelia. Here we show that in the normal human mammary gland, and in breast cancers the epitopes are present on the same family of molecules as that found in urine. Thus the genetically determined variation at the PUM locus accounts for much of the electrophoretic heterogeneity of the mucin-type glycoproteins present in breast cancer and serum from breast cancer patients that has been reported previously. Knowledge of this normal inherited polymorphism is essential to the interpretation of possible changes to these molecules in malignancy.

Immunoreactive determinants of CA 125 in women with endometriosis.

Among 10 patients with endometriosis CA 125 was increased (greater than 35 U/ml) in endometriotic cyst fluid in all the patients, but only two had increased serum concentrations. Gel electrophoresis of serum, endometriotic cyst fluid, and endometriotic tissue resolved the CA 125 immunoreactive fragments from the three sources into bands of similar electrophoretic mobilities. Electrophoresis under reducing and non-reducing conditions showed immunoreactive fragments of apparent masses of 55,000 and 140,000 daltons, respectively. Analysis under reducing conditions did not result in loss of activity. CA 125 antigen is thought to be a high molecular weight glycoprotein complex. As far as is known, this is the first report describing lower molecular weight immunoreactive determinants of CA 125.

Cystic fibrosis: a detailed analysis of fibroblast membrane glycoproteins.

The binding properties of two lectins, concanavalin A and wheatgerm agglutinin to membrane glycoproteins extracted from cystic fibrosis fibroblasts have been examined. No differences were found between the binding patterns of either of these lectins to cystic fibrosis and normal fibroblast glycoproteins. The amount of concanavalin A binding to a glycoprotein of approximate Mr 150 000 has been shown to be related to the population doubling time of a cell culture at the time of analysis.

Characterization of biotinylated proteins in mammalian cells using 125I-streptavidin.

The presence of biotinylated proteins in detergent extracts of cells is demonstrated using 125I-streptavidin. Four components with apparent molecular masses (Mr) ranging from 70 to 220 kDa have been detected. These probably represent the biotinylated subunits of the carboxylase enzymes. The proportions of the four components were found to vary from cell type to cell type and also the Mr varied from species to species.

Integrated systems to reduce length of stay for knee and hip joint replacement surgeries.

To reduce length of stay while maintaining quality of care, St. Joseph's Hospital, Hamilton, ON implemented a care path with three discharge options. Two of these discharge options were early discharge to integrated community services. Patients meeting early discharge criteria are discharged home five days post-operatively with follow-up by home care nursing and physiotherapy. Otherwise, patients are discharged on day four to a multi-disciplinary rehabilitation unit at a separate facility. Patients requiring acute medical services for complications or co-morbidity stay in the acute care hospital. A prospective cohort evaluation showed no difference in complications and similar functional outcomes for the three discharge options.

A glycoprotein rapidly labelled with [14C]glucose present in a murine melanoma cell line.

If a murine melanoma cell line PG19 is metabolically labelled with [14C]glucose for a short time, one particular membrane component incorporates more radioactivity than the rest. This is a glycoprotein of about Mr 100,000, which is not preferentially labelled in non-malignant variants of the melanoma or in suppressed hybrid cells formed between PG19 and mouse fibroblasts.

The behaviour of heterogeneous nuclear ribonucleic acid in partially and completely denaturing conditions.

It is shown that the heterogeneous nuclear RNA (HnRNA) synthesized in the presence of actinomycin and at low and high temperatures sediments in low-ionic-strength sucrose gradients between the rRNA components, similar to the unmethylated RNA synthesized under ;step-down' conditions. If the ionic strength is increased then the HnRNA sediments more rapidly than 28S rRNA, with a large proportion about the 45S precursor rRNA position. Initially this was thought to be due to aggregation of the HnRNA; however, centrifugation and electrophoresis in completely denaturing conditions suggest that the molecular weight of this species of RNA is very large The experiments reveal that HnRNA is conformationally unstable relative to the nucleolar RNA and that the slower sedimentation rate of HnRNA in 5mm-EDTA-Tris base-sucrose gradients reflects the greater expansion of the HnRNA relative to the nucleolar RNA. The implications of this finding are discussed.

Studies on the surface properties of hybrid cells. III. A membrane glycoprotein found on the surface of a wide range of malignant cells.

We report here the presence of a glycoprotein of apparent molecular mass 90000 daltons on the surface of membranes of malignant cells, which is absent or very much reduced on the surface of non-malignant cells. This glycoprotein is rich in sialic acid and appears to be sensitive to the concentration of cAMP under certain conditions. Analysis of the labelled sugars present in the glycoproteins of cells metabolically labelled with [14C]glucosamine suggests that all the enzymes necessary for the conversion of the tracer precursor into the sugars normally found to be labelled are present in both the malignant and the non-malignant cells.

Studies on the surface properties of hybrid cells. I. Sialyl-transferase activity in homogenates of malignant and non-malignant cells.

We report here a method for the assay of the sialyl-transferase activity in crude homogenates of a wide range of cell lines growing in tissue culture. Our results indicate that particulate preparations from both malignant and non-malignant cells show a Km of 0.25 mM towards CMP-sialic acid in the presence of an excess of glycoprotein acceptor. There appear to be increased amounts of the enzyme associated with the preparations from malignant sources which are reflected in an increase in the apparent Vmax of these. The elevated level of sialyl-transferase activity seen in the malignant cell populations is, paradoxically, associated with a decrease in the amount of bound sialic acid associated with both the whole cell homogenate preparations and the surface of these cells.

Studies on the surface properties of hybrid cells. II. Sialyl-transferase activity on the surface of malignant and non-malignant cells.

A measurable surface activity of sialyl-transferase is demonstrated by a number of different methods to exist on the plasma membranes of both malignant and non-malignant cells. The amount of enzyme present on the surface of malignant cells is found to be higher than that on the non-malignant ones in a wide range of malignant and non-malignant cell lines. It is proposed that the difference in apparent activity results in part from the presence of incomplete glycoproteins in the surface membranes of the malignant cells and in part from an increased rate of membrane synthesis in these cells.

The suppression of malignancy by terminal differentiation: evidence from hybrids between tumour cells and keratinocytes.

When malignant human cells are crossed with diploid human keratinocytes, malignancy, as defined by progressive growth in vivo, is suppressed so long as the hybrid cells continue to produce involucrin, a protein that characterizes terminal differentiation in the keratinocyte. When, on continued cultivation in vitro, the cells lose the ability to produce involucrin, they reacquire the ability to grow progressively in the animal.

The origin of the polydispersity in sedimentation patterns of rapidly labelled nuclear ribonucleic acid.

1. A study was made of the sedimentation properties of purified preparations of the rapidly labelled RNA in the nucleus and the cytoplasm of the HeLa cell. The sedimentation of the rapidly labelled nuclear RNA was very sensitive to changes in ionic strength and bivalent cation concentration. Under the conditions usually used in sucrose-density-gradient centrifugation the rapidly labelled nuclear RNA showed extreme polydispersity, and much of it sedimented more rapidly than the 28s RNA. At low ionic strength and after removal of Mg(2+), however, the rapidly labelled nuclear RNA sedimented as a single peak at about 16s. The conversion of the polydisperse material into the 16s form did not involve degradation of the RNA, since the effect could be reversed by increasing the ionic strength of the solution. 2. The cytoplasm did not contain any RNA that showed polydisperse sedimentation under the usual conditions of sucrose-density-gradient centrifugation, or that had the same sensitivity as the rapidly labelled nuclear RNA to changes in ionic strength. All the radioactivity in the cytoplasmic RNA sedimented with the 28s, 16s and 4s components over a wide range of physical conditions, but these components did contain a labelled fraction with some of the features of the rapidly labelled nuclear RNA on columns of methylated albumin on kieselguhr. 3. In both nucleus and cytoplasm the RNA detected by ultraviolet absorption could also be converted into a 16s form by removal of bivalent cations at low ionic strength; this effect was again, within certain limits, reversible. The nuclear RNA as a whole was more susceptible to changes in ionic strength than the cytoplasmic RNA. 4. It thus appears that all the RNA in the cell, except the 4s RNA, can be prepared, without degradation, as a single peak sedimenting at about 16s. The relationship of these various 16s components to each other is discussed.

Some further information about the abnormal membrane glycoprotein associated with malignancy.

The abnormal membrane glycoprotein that we previously found to be associated with malignancy in a wide range of different tumours is present in the cell membrane as a dimer and appears to have a specific binding site for glucose.

The apparent inducibility of tumour marker glycoproteins in a melanoma cell line selected for growth in low levels of glucose.

It has been reported previously that malignancy in hybrid cells is associated with changes in two glycoproteins of molecular mass 90,000 and 100,000. In the current paper the characteristics of a clonal derivation of a murine melanoma cell line (PG19G-), selected for growth in low levels of glucose, are described. The cells had considerably reduced amounts of the 90 K and 100 K glycoproteins as judged by lectin affinity-labelling. When the level of glucose in the medium is raised the two glycoproteins become detectable after a few hours. This inducibility is specific for D-glucose and D-mannose at concentrations in excess of 300 mg/l and is inhibited by cytochalasin B but not by cytochalasin A. The 90 K glycoprotein differs from the 100 K in that its level varies with the glucose concentration even in the parent cell line PG19 and in other tumour lines. This is not the case for the 100 K glycoprotein, the synthesis and/or glycosylation of these two glycoproteins are, therefore, governed by separate control mechanisms. The relationship of the glucose-sensitive proteins to the glucose transporter is discussed.

Further characterization of the antigen defined by the monoclonal antibody M27.

Using immunoblotting techniques, the antigen that binds the monoclonal antibody M27 has been clearly defined in terms of apparent molecular mass and distribution. In reducing conditions it has an apparent mass of 178K (K = 10(3) Mr) and is present in the cytoplasm and membranes of all mammalian tissue culture cells so far examined. It is absent from lines derived from avian, piscine and amphibian sources. It is also absent from foetal liver of both rat and mouse, but subsequently appears after cultivation in vitro. Similarly, it can be detected on rat lymphocytes only after mitogenic stimulation. However, it is found on both hepatoma and lymphoma cells in vitro, and on in vivo tumours from murine sources. It thus appears to be associated with cell proliferation.