Sequential activation of three distinct ICE-like activities in Fas-ligated Jurkat cells

ICE family proteases have been implicated as important effectors of the apoptotic pathway, perhaps acting hierarchically in a protease cascade. Using cleavage of endogenous protease substrates as probes, three distinct tiers of ICE-like activity were observed after Fas ligation in Jurkat cells. The earliest cleavage detected (30 min) was of fodrin, and produced a 150 kDa fragment. The second phase of cleavage (50 min) involved PARP, U1-70kDa and DNA-PKcs, all substrates of the CPP32-like proteases. Lamin B cleavage was observed during the third cleavage phase (90 min). Distinct inhibition profiles obtained using a panel of peptide-based inhibitors of ICE-like proteases clearly distinguished the three different cleavage phases. These studies provide evidence for a sequence of ICE-like proteolytic activity during apoptosis. The early fodrin cleavage, producing a 150 kDa fragment, identifies an ICE-like activity proximal to CPP32 in Fas-induced Jurkat cell apoptosis.

Apopain/CPP32 cleaves proteins that are essential for cellular repair: a fundamental principle of apoptotic death

Proteolysis mediated by the interleukin 1 beta-converting enzyme (ICE) homologues is an important mechanism of the apoptotic process. The ICE homologue apopain/CPP-32/Yama (subsequently referred to as apopain) cleaves poly(ADP-ribose)polymerase (PARP) early during apoptosis. Additional apoptosis-specific protein cleavages have been observed in which the direct involvement of ICE-like proteases has been postulated. These substrates include the 70-kD protein component of the U1-ribonucleoprotein (U1-70kD), and the catalytic subunit of the DNA-dependent protein kinase (DNA-PKcs). The present studies demonstrate that U1-70kD and DNA-PKcs are excellent substrates for apopain, with cleavage occurring at sites that are highly similar to the cleavage site within PARP. The fragments generated from isolated protein substrates by apopain are identical to those observed in intact apoptotic cells, in apoptotic cell extracts, and in normal cell extracts to which apopain has been added. Like PARP, cleavage of these substrates in apoptotic cell extracts is abolished by nanomolar concentrations of Ac-DEVD-CHO and micromolar amounts of Ac-YVAD-CHO, confirming the involvement of apopain or an apopain-like activity. We propose that a central function of apopain or similar homologues in apoptosis is the cleavage of nuclear repair proteins, thereby abolishing their critical homeostatic functions.

NOD mouse diabetes: the ubiquitous mouse hsp60 is a beta-cell target antigen of autoimmune T cells

In the NOD mouse, the onset of beta-cell destruction is associated with spontaneous development of T-lymphocytes reactive to members of the 60 kDa heat shock protein (hsp60) family, including the Mycobacterial (MT) and the human (H) hsp60 molecules. Diabetes in the NOD mouse is a spontaneous tissue-specific autoimmune disease occurring without prior immunization. Therefore, it has been suggested that the anti-hsp60 T cells involved in the autoimmune diabetes of NOD mice might reflect molecular mimicry between MT-hsp60 and a beta-cell tissue specific molecule sharing similar T cell epitopes, the p277 peptide of hsp60 in particular. We cloned and expressed the mouse hsp60 cDNA from a beta-cell tumour. This mouse beta-cell hsp60 cDNA was found to be identical in sequence to the hsp60 of mouse fibroblasts. We further report that NOD spleen cells and an NOD diabetogenic T cell clone C9 responded to the recombinant mouse hsp60 and to its peptide M-p277 to the same extent as to H-hsp60 and H-p277. Splenocytes of mice of other strains did not respond to p277. Moreover, treatment of 3 month old NOD mice with the non-modified self M-p277 peptide was as efficient as H-p277, from which it differs in one amino acid, in halting progression of the disease. Thus, anti-H-p277 T cells modulating diabetes in the NOD mouse are autoreactive, and are targeted at the mouse beta-cell hsp60, which is not tissue specific. These findings raise the question of how a non-tissue specific molecule may be a target of a tissue-specific autoimmune disease.

Surface blebs on apoptotic cells are sites of enhanced procoagulant activity: implications for coagulation events and antigenic spread in systemic lupus erythematosus

The restriction of phosphatidylserine (PtdSer) to the inner surface of the plasma membrane bilayer is lost early during apoptosis. Since PtdSer is a potent surface procoagulant, and since there is an increased incidence of coagulation events in patients with systemic lupus erythematosus (SLE) who have anti-phospholipid antibodies, we addressed whether apoptotic cells are procoagulant and whether anti-phospholipid antibodies influence this. Apoptotic HeLa cells, human endothelial cells, and a murine pre-B-cell line were markedly procoagulant in a modified Russell viper venom assay. This procoagulant effect was entirely abolished by addition of the PtdSer-binding protein, annexin V, confirming that it was PtdSer-dependent. The procoagulant effect was also abolished by addition of IgG purified from the plasma of three patients with anti-phospholipid antibody syndrome, but not IgG from normal controls. Confocal microscopy of apoptotic cells stained with fluorescein-isothiocyanate-conjugated-annexin V demonstrated (Ca2+)-dependent binding to the surface of membrane blebs o apoptotic cells, but not to intracellular membranes. Recent data indicate that the surface blebs of apoptotic cells constitute an important immunogenic particle in SLE. We propose that the PtdSer exposed on the outside of these blebs can induce the production of anti-phospholipid antibodies, which might also enhance the immunogenicity of the bleb contents. When apoptosis occurs in a microenvironment in direct contact with circulating plasma, the unique procoagulant consequences of the apoptotic surface may additionally be expressed. This might explain the increased incidence of pathological intravascular coagulation events that occur in some lupus patients who have anti-phospholipid antibodies.

DNA-dependent protein kinase is one of a subset of autoantigens specifically cleaved early during apoptosis

Proteolytic cleavage of key substrates appears to be an important biochemical mechanism underlying the apoptotic process, and the centrality of interleukin 1 beta-converting enzyme (ICE)-like proteases as mediators of apoptosis has been suggested. The identification of the relevant substrates of the ICE protease family during apoptosis therefore constitutes a major challenge. Using human autoantibodies, we demonstrate here that a subset of autoantigens is specifically cleaved early during apoptosis. One of these cleaved molecules is identified as the catalytic subunit of the DNA-dependent protein kinase. The time courses of all proteolytic cleavages are identical and coincide with the onset of morphologic apoptosis. Furthermore, all cleavages share the same inhibition characteristics, which implicate an ICE-like activity(ies). We propose that cleavage of these autoantigens targets these molecules for an autoimmune response by revealing immunocryptic fragments in a proimmune apoptotic setting. Study of the immunogenicity of these fragments may yield insights into the autoimmune targeting of molecules. Moreover, the autoantibodies described will be valuable tools for the elucidation of mechanistically important proteolytic steps along the apoptotic pathway.

DNA amplification of HER-2/neu and INT-2 oncogenes in epithelial ovarian cancer

OBJECTIVE

Oncogene alterations are thought to be prognostic indices in patients with breast cancer. The present study was carried out to investigate the amplification of the HER-2/neu and INT-2 oncogenes in ovarian cancer.

METHODS

In a retrospective study of 196 patients with epithelial ovarian cancer, the amplification of the oncogenes HER-2/neu and INT-2 in the DNA of paraffin-embedded tumor cells was determined by quantitative PCR. The purpose of this study was to analyze whether the two oncogenes correlated with such predictive factors as FIGO stage, histological grade, ascites, postoperative residual tumor mass, hormone receptor content, and preoperative CA 125 serum levels. The effect of HER-2/neu and INT-2 amplification on patient survival was also studied.

RESULTS

The only correlation found in this study was between INT-2 and preoperative CA 125 levels (P = 0.03). No correlations were demonstrable between HER-2/neu (log-rank test; P = 0.67) and INT-2 (log-rank test; P = 0.75) amplifications and overall survival.

CONCLUSION

Unlike the established prognostic factors, neither HER-2/neu nor INT-2 appears to be predictive for survival in patients with ovarian cancer.

Homeopathy, other forms of alternative medicine sources of ongoing debate among physicians, patients

Amy Rosen is the 1994 winner of the Amy Chouinard Memorial Essay Contest. Named in memory of longtime CMAJ and Canadian Journal of Surgery contributor Amy Chouinard, the competition is intended to stimulate interest in medical and health-related writing among journalism students. The winning essay examines the growing public interest in homeopathic medicine and physicians' opinions of the trend.

Novel packages of viral and self-antigens are generated during apoptosis

Immune context is an essential determinant of the host response to potential autoantigens. The clustering of the autoantigens targeted in systemic lupus erythematosus within surface blebs of apoptotic cells generates high concentrations of autoantigen within discrete subcellular packages. We demonstrate here that when apoptosis is induced by Sindbis virus infection, viral antigens and autoantigens cocluster exclusively in small surface blebs of apoptotic cells. The surface of these blebs is rich in viral glycoproteins, and virions can be seen blebbing from their surface. We propose that these blebs of mixed foreign and self-origin define a novel immune context that may challenge self-tolerance.

A CD4+ T cell line-secreted factor, growth promoting for normal and leukemic B cells, identified as thioredoxin

In this study, a B cell growth stimulatory factor, constitutively secreted by a human CD4+ T cell hybridoma clone, MP6, has been purified and characterized. Serum-free 24 h culture media from MP6 cells were collected, concentrated by ultrafiltration and separated by gel chromatography. Fractions were analyzed for stimulatory activity using [3H]thymidine incorporation in normal and leukemic (B-CLL) B cells as target cells. Activity was present in a 12 kDa protein peak. Upon storage this lost activity indicating that the factor was sensitive to air oxidation, a well-known property of mammalian thioredoxins (Trxs). Treatment of the inactive fraction with dithiothreitol restored full activity. When culture medium was analyzed with a radioimmunoassay for human placenta Trx, the MP6 clone was shown to release 30-50 ng/ml per million cells during 24 h. The B cell stimulatory activity of the MP6 medium was removed by Sepharose-bound anti-human placenta Trx IgG and activity was recovered by elution from the antibodies. Furthermore, MP6 medium showed Trx activity with NADPH and Trx reductase using an insulin disulfide reduction assay. Starting from 5 l of serum-free MP6 conditioned medium, the Trx was purified approximately 100,000-fold. After gel electrophoresis banding, the material was analyzed by peptide sequencing and a full length sequence of an 104 amino acid long protein was obtained. This Trx sequence was identical to the previously published sequence of human Trx from HTLV-1 transformed T cells, adult T cell leukemia-derived factor/Trx.(ABSTRACT TRUNCATED AT 250 WORDS)

Multidisciplinary mental health teams

This study surveyed current practice amongst 91 Indian and Australian staff working within multidisciplinary mental health teams, looking at leadership skills, conflict resolution and therapeutic abilities. Length of training was associated with management skills, though these skill were more developed by psychiatric nurses and occupational therapists working in community settings. Hospital settings involved less consensual decision-making than community teams. Psychiatric nurses spent most time in clinical work, and occupational therapists were rated as less skilled in the therapeutic activities assessed than any other profession. Psychiatrists and clinical psychologists undertook most research. The activities assessed in this study could be undertaken by a team comprising psychiatrists, psychiatric nurses and social workers, with clinical psychologists employed where possible, especially for research or service evaluation.

Specific cleavage of the 70-kDa protein component of the U1 small nuclear ribonucleoprotein is a characteristic biochemical feature of apoptotic cell death

The U1 small nuclear ribonucleoprotein particle is essential for splicing of precursor mRNA, an activity that depends upon both the RNA and protein components of the U1 particle. One of the U1-specific proteins that is functionally important in this splicing reaction is the 70-kDa protein (U1-70kDa). We report here that U1-70kDa is specifically cleaved in apoptotic cells, resulting in the generation of a 40-kDa fragment. The kinetics of this cleavage coincided with the appearance of cells with apoptotic morphology in the population, and the proportion of 40-kDa fragment observed was markedly increased in apoptotic cells that had become detached from the substratum. Although the inhibitor characteristics of the activity cleaving U1-70kDa suggest that interleukin 1 beta-converting enzyme (ICE) might be responsible, the specific ICE inhibitor N-(N-acetyl-tyrosinyl-valinyl-alaninyl)-3-amino-4-oxob utanoic acid (YVAD-CHO) did not prevent cleavage, and U1-70kDa was not cleaved by purified ICE in vitro. Further study of this novel cleavage and the enzyme responsible will yield information about proteolytic events that might be central in the mechanism and control of apoptosis.

Lymphogenous metastasis in the primary carcinoma of the fallopian tube

The bad prognosis of primary Fallopian tube carcinoma (FTC) is mostly ascribed to early lymphogenous metastasis. Yet, there is a lack of information on the tumor size at which lymph node metastasis must be expected to occur. Our study was therefore designed to correlate the anatomopathologic substratum and the histologic results with the lymph node status. Data were obtained from 21 women who received primary surgery, during which additional total pelvic and para-aortic lymphadenectomy was performed as well. The "surgical" staging was compared to the final clinical staging after histologic inspection of the lymph nodes according to the FIGO classification. Lymph node metastases never occurred as long as the tumor was confined to the tube (stage I). Lymphogenous dissemination set in only after further, local expansion of the tumor, involving the ovaries, the peritoneum, or the uterus (surgical stage II); 3 of the 7 patients of surgical stage II had to be reclassified to stage III because of manifest lymph node metastases. After the onset of intra-abdominal or general metastasis (stage IV), lymph node metastases occurred significantly more often (P = 0.048). Due to the specific lymphatic drainage, lymphogenous metastasis must be expected to spread as far as to the para-aortic region even in the early stages. Highly differentiated tumors (G I) do not disseminate into the lymphatic system, not even in advanced stages, whereas anaplastic tumors (G II and III) metastasize relatively early. As soon as metastasis has occurred, prognosis of life diminishes markedly, but not significantly (49 versus 24 months, P = 0.19). Correct FTC-staging is obtained only on the basis of pelvic and para-aortic lymphadenectomy.

Assertive community treatment for the seriously mentally ill in suburban Sydney: a programme description and evaluation

Assertive and intensive community treatment for the seriously mentally ill is becoming a widely accepted approach internationally. This type of service is, however, still relatively new in Australia and New Zealand, and it has rarely been fully integrated into a comprehensive catchment area community and hospital mental health service. This paper has two aims. Firstly, it describes an innovative assertive community mental health service in suburban Sydney. This service was initially provided to 64 clients with a serious mental illness, who had previously experienced repeated hospitalisations and were unable to benefit from existing high quality services. Secondly, it presents the results of the ongoing evaluation of this service. Following the implementation of the service, the number of psychiatric bed days occupied by these clients decreased by 62%; the number of clients admitted decreased, client functioning improved and symptom severity decreased, all to a significant degree.

[Conisation in stage Ia cervix cancer]

Between 1975 and 1988, a total of 78 patients suffering from cervical cancer stage Ia were treated by conisation based on a positive smear. According to FIGO, these 78 patients consisted of 53 (67.9%) stage Ia1 and 25 (32.1%) stage Ia2 cases. Complete removal of the tumour by conisation was achieved in 51 patients. In 23 cases (29.5%) the margin of resection was reached by a carcinoma in situ, in 4 cases (5.1%) invasive carcinoma was found. Conisation was not followed by further surgery in 10/51 patients with complete tumour removal. One patient (1/23) with incomplete removal underwent surgery elsewhere. In the other 67/78 patients following hysterectomy, the pathologist diagnosed three cases of cervical cancer, 11 cases of carcinoma in situ and 53 cases (67.9%) without pathological findings. Carcinoma in situ after hysterectomy was found in only 2 cases (4.9%) with primarily free resection margins of the conus. Among the 27 patients with carcinoma in situ or invasive carcinoma reaching the conus margin, 9 cases of carcinoma in situ and 3 invasive carcinomas were diagnosed histologically after hysterectomy and one patient underwent surgery elsewhere. In this study, the value of conisation as single therapy of cervical cancer stage Ia1 and stage Ia2 with good prognosis (depth of infiltration of < 3 mm and no invasion of blood vessels) is discussed and the importance of thorough and exact histological examination is emphasised.

Primary fallopian tube carcinoma--a retrospective survey of 51 cases. Austrian Cooperative Study Group for Fallopian Tube Carcinoma

OBJECTIVE

To evaluate retrospectively the importance of invasion beyond the basement membrane on overall survival in Fallopian tube carcinoma and its influence on the necessity of postoperative adjuvant therapy (stage 0 vs. stage I).

DESIGN

In a nationwide analysis the data of 51 patients were evaluated. The participating departments provided the study center with histologic specimens. A re-staging was done according to the FIGO-classification for Fallopian tube carcinomas. Stage 0 patients received no further postoperative therapy, in stage I patients were divided in 2 groups to evaluate the impact of postoperative adjuvant therapy (chemotherapy vs. irradiation).

RESULTS

Patients of stage 0 had a significantly better prognosis than patients of stage I (p = 0.035). Stage I patients treated by irradiation showed a significantly better prognosis than patients treated by chemotherapy (p = 0.017).

CONCLUSION

Tumour penetration through the basement membrane causes prognosis to deteriorate significantly (5-year survival rate about 50% in stage I). Postoperative therapy is thus indicated with stage I disease. Irradiation seems to give better results than chemotherapy.

Autoantigens targeted in systemic lupus erythematosus are clustered in two populations of surface structures on apoptotic keratinocytes

Systemic lupus erythematosus is a multisystem autoimmune disease in which the autoantibody response targets a variety of autoantigens of diverse subcellular location. We show here that these autoantigens are clustered in two distinct populations of blebs at the surface of apoptotic cells. The population of smaller blebs contains fragmented endoplasmic reticulum (ER) and ribosomes, as well as the ribonucleoprotein, Ro. The larger blebs (apoptotic bodies) contain nucleosomal DNA, Ro, La, and the small nuclear ribonucleoproteins. These autoantigen clusters have in common their proximity to the ER and nuclear membranes, sites of increased generation of reactive oxygen species in apoptotic cells. Oxidative modification at these sites may be a mechanism that unites this diverse group of molecules together as autoantigens.

Evaluation of adjuvant therapy after surgery for primary carcinoma of the fallopian tube

OBJECTIVE

To evaluate the impact of postoperative therapy (chemotherapy vs. irradiation) on overall survival.

DESIGN

A nationwide retrospective analysis.

SETTING

Hanusch-Krankenhaus, Department of Gynaecology,

SUBJECTS

115 patients with histologically proved primary carcinoma of the Fallopian tube: 49 received six treatment cycles of a cis-platinum regimen (group I), 24 patients were treated by full irradiation using 50 Gray minimum (group II). The two groups had a similar distribution of stage I and II; in the more advanced stages chemotherapy was the predominant method of treatment.

RESULTS

The five-year survival rate was 53% for women receiving irradiation as against 27% for those given cis-platinum. If the analysis was restricted to those patients with comparable stage I and stage II lesions, the p-value (0.07) was of borderline significance. There was no advantage in adding abdominal to pelvic irradiation (P = 0.62).

CONCLUSIONS

Stage I and stage II carcinoma is probably better treated postoperatively by radiotherapy than chemotherapy. Chemotherapy may have more therapeutic potential in patients with more advanced lesions.

Microwave thermal balloon angioplasty in the atherosclerotic rabbit

We evaluated the angiographic and histologic response of the coronary vessels of the atherosclerotic rabbit to microwave thermal balloon angioplasty. Sixteen rabbits with atherosclerosis of the external iliac arteries following a high fat diet and endothelial denudation were treated with either CBA or MBA. Four weeks following angioplasty angiography was repeated, and following the death of the animals, the vessels treated were excised for histologic evaluation. In vessels with MBA with peak temperatures of 85 degrees C there was an increase in luminal diameter immediately postangioplasty, from 1.66 +/- 0.32 mm to 2.54 +/- 0.23 mm (p < 0.05). The diameter at 4 weeks (2.29 +/- 0.74 mm) remained increased compared with the preangioplasty diameter (p < 0.05). With microwave angioplasty at 70 degrees C there was an increase in luminal diameter, from 1.92 +/- 0.37 mm to 2.40 +/- 0.22 mm (p < 0.05) immediately postangioplasty. This increase in diameter was not sustained at 4 weeks (1.86 +/- 0.28 mm). In the vessels treated with CBA there was no significant increase in diameter noted either immediately postangioplasty or at 4 weeks postangioplasty. In the thermally treated vessels, histologic evaluation revealed a loss of lipid-laden cells; it also revealed the formation of a concentric hypocellular fibrotic layer. Microwave thermal balloon angioplasty at 85 degrees C results in enhancement of the immediate and delayed response to angioplasty. Modification of the proliferative response to angioplasty may be accomplished with this modality.

Hypersensitivity to latex in health care workers: report of five cases

Concern about transmission of acquired immunodeficiency syndrome and hepatitis has greatly increased the use of latex gloves. Latex allergy is a newly emerging problem with potential life-threatening sequelae among health care personnel. Patients are also at risk. We report on five cases of latex allergy in health care workers who were using latex gloves for variable lengths of time before their allergic reaction. All workers had a significant history of reactions to other allergens, including inhalants and food. Each individual had at least one systemic symptom that was directly attributed to latex exposure. Reactions to latex ranged from severe contact urticaria (all cases), bronchospasm (three cases), angioedema (two cases), and rhinorrhea (one case) to anaphylactic reactions that required immediate attention in three cases. Levels of specific IgE to latex (as measured by in vitro enzyme immunoassay) and total IgE were elevated in all five patients (total IgE > 100 kU/L). Long-term treatment included avoidance of latex, administration of antihistamines, and desensitization to other, nonlatex allergens. Health care workers should have increased awareness of latex allergy. At risk are health care workers with a history of other allergies and those with atopic dermatitis or eczema. In vitro testing may be useful, especially in persons with skin conditions such as eczema or urticaria or for persons with a history of systemic reactions to the latex allergen as reported in these five cases.