Identification of residues in alpha-macroglobulins involved in activation of the alpha 2-macroglobulin signaling receptor

Site-directed mutagenesis of residues in the receptor binding fragment of rat alpha 1-macroglobulin identify residues 1377 and 1378 (human numbering) as crucial for interaction with the alpha 2M signaling receptor on murine macrophages. Secondary structure prediction and signaling studies with the mutant proteins suggest the alpha 2M signaling receptor binding site involves part of a loop-helix-loop motif comprised of residues 1372-1378.

Characterization of alpha 2-macroglobulin binding to human trabecular meshwork cells: presence of the alpha 2-macroglobulin signaling receptor

Direct binding of receptor-recognized alpha 2-macroglobulin (alpha 2M*) or a cloned receptor binding fragment from rat alpha 1-macroglobulin (RBF) to human trabecular meshwork cells demonstrated two classes of cell surface binding sites. One class has an apparent Kd of 5.0 nM and a receptor number of 31,800 receptors/cell. The other class has an apparent Kd of 20 pM and a receptor number of 1600 receptors/cell. Binding studies of alpha 2M* or RBF in the presence of a competitor for binding to low-density-lipoprotein receptor-related protein/alpha 2M* receptor (LRP/alpha 2MR) called receptor-associated protein (RAP) show that only the lower affinity class of binding sites is susceptible to competition with RAP. Uptake studies demonstrate specific internalization and degradation of alpha 2M* which is inhibitable by RAP. Exposure of the cells to alpha 2M* and RBF (40 nM) is associated with mean increases of 171 and 210%, respectively, in the intracellular calcium concentration, which is not inhibitable by RAP or pertussis toxin. These studies present the first characterization of alpha 2M* and RBF signaling in a primary human cell type and suggest a role for alpha 2M* in the physiology of the eye.

Selective mutations in cloned and expressed alpha-macroglobulin receptor binding fragment alter binding to either the alpha2-macroglobulin signaling receptor or the low density lipoprotein receptor-related protein/alpha2-macroglobulin receptor

alpha2-Macroglobulin (alpha2M) activated with methylamine binds to two distinct cell-surface receptors: low density-lipoprotein receptor-related protein/alpha2M receptors and alpha2M signaling receptors. Binding to lipoprotein receptor-related protein/alpha2M receptor but not alpha2M signal receptor is inhibitable by another ligand, receptor-associated protein. Direct binding studies with a recombinant receptor binding fragment (RBF) from rat alpha1M and murine macrophages demonstrate two classes of binding sites of apparent Kd = 90 pM (1500 sites/cell) and 40 nM (60,400 sites/cell). Receptor-associated protein competes with RBF for binding to the lower but not the higher affinity site. Site-directed mutation of Lys-1374 (human numbering) in RBF to Arg or Ile residues almost completely abolishes signal transduction as compared to wild-type RBF. Direct binding studies with K1374R demonstrated no significant alteration in binding to the lower affinity site; however, binding to the high affinity site is reduced by 83%. Mutation of Lys-1370 to Ala resulted in a 4-5-fold increase in the Kd for binding to the lower affinity site with no significant alteration in binding to the high affinity site or signal transduction properties. Studies demonstrate comparable internalization and degradation of wild-type RBF and K1374R; however, internalization and degradation of K1370A is negligible. These studies suggest that regions around Lys-1370 and Lys-1374 are involved in lipoprotein receptor-related protein/alpha2M receptor and alpha2M signaling receptor binding, respectively.

Altered interaction of Cis-dichlorodiammineplatinum(II)--modified alpha 2-macroglobulin (alpha 2M) with the low density lipoprotein receptor-related protein/alpha 2M receptor but not the alpha 2M signaling receptor

Receptor-recognized forms of alpha 2-macroglobulin (alpha 2M*) bind to two macrophage receptors: an endocytic receptor, the low density lipoprotein receptor-related protein/alpha 2M receptor (LRP/alpha 2MR), and a G protein-coupled receptor, the alpha 2M signaling receptor (alpha 2MSR). Binding of alpha 2M* to LRP/alpha 2MR but not alpha 2MSR is inhibited by receptor-associated protein. We now present binding characteristics of alpha 2MSR (kD approximately 50 pm; 1,530 sites/cell) using Scatchard analysis. We also demonstrate that chemical modification of alpha 2M* with cis-dichlorodiammineplatinum (cis-DDP) does not significantly alter binding to either receptor or signaling characteristics as compared with unmodified alpha 2M*. However, internalization by LRP/alpha 2MR is greatly affected. Cis-DDP-modified alpha 2M* (cis-DDP-alpha 2M*) and alpha 2M* show comparable internalization during a single round of endocytosis; however, cis-DDP modification of alpha 2M* results in a > or = 82% reduction in internalization involving receptor recycling and multiple rounds of endocytosis. Results from pH 5.0 dissociation and receptor recycling experiments suggest that the mechanism of decreased internalization of cis-DDP-alpha 2M* involves poor dissociation from the receptor in endosomes and a decrease in available surface receptors over the time of exposure to the ligand.

Split course radical radiotherapy for bladder cancer in the elderly: nonsense or commonsense? A report of 76 patients

The role of split course radical radiotherapy in bladder cancer is controversial. We have pursued such a policy in elderly patients in view of the unpredictable toxicity of radical radiotherapy in this group. Between 1987 and 1992, 76 patients were treated in this way, with 2 weeks' treatment followed by a 3-week gap. Patients were then reassessed and, if considered fit enough, a further 2 weeks of treatment was given. Fifty-three patients (mean age 78.4 years) completed treatment and 23 (mean age 78 years) received phase 1 alone. Thirty-seven of 53 patients completing treatment has a follow-up cystoscopy at 6 months. Twenty-five percent of all patients, 36% of those completing treatment, and 51% of those undergoing cystoscopy, achieved a complete response. The reasons for not completing treatment and not being followed up cystoscopically are examined. We feel that this policy has a role in selected patients whose fitness to tolerate a conventional radical course of radiotherapy is in doubt.

Referral patterns within Scotland to specialist oncology centres for patients with testicular germ cell tumours. The Scottish Radiological Society and the Scottish Standing Committee of the Royal College of Radiologists

Details of 1123 patients registered in Scotland between 1983 and 1990 for testicular cancer under the Scottish Cancer Registration Scheme were obtained and compared with registrations within the five Scottish oncology centres. Some registration discrepancies were identified. Twenty-eight cancer registrations (2.5%) were coded to the wrong site, 29 patients seen at oncology centres had no cancer registration and 14 cancer registrations had the wrong histology. Five hundred and twenty-seven patients with testicular non-seminomatous germ cell tumours (NSGCT) and 567 with testicular seminoma were identified. Referral rates to specialist oncology centres for testicular germ cell tumours were measured by period and health board area of residence. For the whole study period 92% of NSGCT and 93% of seminoma patients were referred to specialist centres for treatment. Referral rates for different health board areas of residence were not significantly different. This study shows that within Scotland the majority of patients with testicular NSGCT and seminoma are referred to specialist centres, and suggests referral rates of around 92% are underestimates. Access is not related to area of residence.

A Scottish national mortality study assessing cause of death, quality of and variation in management of patients with testicular non-seminomatous germ-cell tumours. The Scottish Radiological Society and the Scottish Standing Committee of the Royal College of Radiologists

A detailed casenote review was performed on 55 patients registered with testicular non-seminomatous germ cell tumours (NSGCT) between 1983 and 1988 under the Scottish Cancer Registration Scheme and who had died by 1992. Details of all aspects of clinical management relating to their NSGCT and death details were extracted and summarised. An assessment was made on whether the patients' management had been optimal. An analysis of 5 year survival rates by the five Scottish oncology centres demonstrated significant differences between centres (range 70.4-94.2; chi 2 = 14.46, d.f. = 4, P = 0.006). Some patients in all centres were assessed as having received suboptimal treatment, but two centres performed less well than the other three. There is a suggestion that the number of patients treated suboptimally decreases with increasing number of patients seen, but this does not reach statistical significance.

A Scottish national audit of current patterns of management for patients with testicular non-seminomatous germ-cell tumours. The Scottish Radiological Society and the Scottish Committee of the Royal College of Radiologists

A detailed casenote review was performed on all 65 patients registered with testicular non-seminomatous germ cell tumours (NSGCT) during 1989 under the Scottish Cancer Registration Scheme. Details of management at presentation and 2 years following diagnosis were recorded and analysed. In a small number of patients an unacceptable delay in diagnosis was noted. Variation was found in the frequency and type of investigations performed on patients placed on surveillance, types of chemotherapy regimens used and numbers of patients entered into trials. Three per cent of patients had a biopsy of the contralateral testis and 27% of patients defaulted from clinic attendance. Considerable variation in the management of testicular NSGCT in Scotland has been identified. The introduction of management guidelines should result in a more consistent approach to the care of these patients. Support, both financial and psychological, may reduce the unacceptable rate of default.

Radiotherapy for stages I and II testicular seminoma: results and morbidity in 238 patients

We have undertaken a retrospective analysis of 238 patients with Stages I and II seminoma of the testis treated with radiotherapy in Edinburgh between 1974 and 1989. There were five deaths from seminoma. Cause-specific survival for the whole group at 2 and 5 years was 99.2% and 98.1%, respectively. Cause-specific survival at 2 and 5 years by stage (Royal Marsden staging classification) was: Stage I, 99.5% and 98.7% and Stage II, 98.1% and 96.1%. Fourteen (5.9%) patients relapsed (one after treatment for his second testicular seminoma). Eight were given successful salvage treatment, five died of seminoma and one died of intercurrent disease. 13 (5.5%) patients developed World Health Organisation (WHO) grade 3 gastrointestinal or haematological toxicity and two developed grade 4 gastrointestinal toxicity as a result of abdominal radiotherapy. 22 patients (9.2%) developed problems ascribed to late morbidity of abdominal radiotherapy including 18 with peptic ulcer disease. Contralateral testicular tumours occurred in seven (2.9%) patients and five (2.1%) patients developed malignancies at other sites.

Radical radiotherapy for localized adenocarcinoma of the prostate. A report of 191 cases

OBJECTIVE

To assess the results of radiotherapy in the treatment of localized prostate cancer. End points for assessment were survival, local control, development of metastases, and the toxicity of therapy.

MATERIALS AND METHODS

The case notes of 191 patients who were treated with radical radiotherapy between 1982 and 1992 were reviewed. The pathology of 130 patients was reviewed by a single pathologist. A multivariate analysis was performed to identify significant prognostic factors with regard to survival and relapse.

RESULTS

One-hundred and eighty-two patients were assessable. The minimum length of follow-up was one year (median = 40 months). The actuarial cause-specific 5 and 10 year survival rates were 63% and 35% respectively. Local progression occurred in 41% of patients with 37% developing metastases. Multivariate statistical analysis demonstrated that T stage and Gleason Score were significant predictors for survival. Late complications were usually mild, with only 4% developing serious bladder toxicity.

CONCLUSION

Radical radiotherapy has a role in the curative treatment of prostate cancer. Survival is significantly related to T stage at the time of presentation, and to the Gleason Score of the tumour. Survival in this series was not as good as the best surgical series, but it is still not clear which patients should receive radiotherapy and which surgery as their primary management.

Pathogenesis of acute radiation injury to the rectum. A prospective study in patients

In a prospective investigation of the clinical and pathological effects of pelvic radiotherapy on the rectum, nine patients (age range 58-77 years) had symptoms assessed weekly during radical treatment for bladder and prostatic tumours, and at 2, 4 and 12 weeks after treatment. Stool frequency increased in all patients from a mean of 1.7 per day before treatment to 5.0 per day at 4 weeks (P < 0.05). Seven patients developed liquid stools during treatment; 6 had pain on defaecation, 8 had urgency of defaecation, all experienced tenesmus and 3 had episodes of faecal incontinence. One patient had symptoms of such severity that treatment was interrupted. Virtually all symptoms had resolved by 12 weeks after treatment. Sigmoidoscopy with biopsy of anterior and posterior rectal walls was performed before treatment began, at 2 weeks and 4 weeks during treatment, and 4 and 12 weeks after treatment. All patients during treatment had evidence of acute inflammatory damage with hyperaemic, oedematous mucosa and failure of healing of biopsy sites. Histological examination of the rectal biopsies revealed the well described characteristic mucosal changes with crypt cell damage, inflammatory cell infiltrate and loss of crypts. In 2 of 7 cases studied, pathology was still abnormal at 3 months. Radiation injury to bowel is an underemphasised cause of morbidity and further prospective studies are required to determine methods of reducing normal tissue damage and ameliorating symptoms.

Negative testicular biopsy and asynchronous bilateral testicular germ cell tumour

A case is described of a patient who was recently found to have a second primary testicular cancer 3 years after his first orchidectomy and negative contralateral testis biopsy.

Seminal fluid analysis and fine-needle aspiration cytology in the diagnosis of carcinoma in situ of the testis

Surgical biopsies and fine-needle aspirates of peri-tumoural seminiferous tubules were taken from freshly-excised orchidectomy specimens. In addition, patients with suspected germ cell tumour provided a peri-operative sample of seminal fluid. All three tissue preparations were investigated using flow cytometry, immunochemistry for placental-like alkaline phosphatase and enzymochemistry for alkaline phosphatase. Biopsy and fine-needle aspiration cytology provide the greatest diagnostic accuracy for carcinoma-in-situ using these techniques. Seminal fluid analysis did not provide a satisfactory diagnostic yield in the series of patients presented. A seminal plasma placental-like alkaline phosphatase immunoassay failed to discriminate CIS because of the high level of background germ cell alkaline phosphatase.

Sexual morbidity following radiotherapy for germ cell tumours of the testis

An anonymous questionnaire study was designed to assess sexual function after orchidectomy and radiotherapy for testicular cancer. Questionnaires were sent to: (1) 237 patients treated with orchidectomy and abdominal radiotherapy in Edinburgh from 1974 to 1988; (2) 32 patients under "surveillance" following orchidectomy alone; (3) 402 "normal" age-matched controls. All were asked questions concerning sexual function over the preceding 6 months. All the patients were also asked the same questions with reference to the first 6 months after completion of treatment. Completed questionnaires were returned from 137 (62%) radiotherapy patients, 18 (56%) surveillance patients and 121 (35%) controls. There was a significant difference between the radiotherapy patients and the controls in almost all the parameters looked at including erection, ejaculation and libido with the treated group performing less well. In addition, almost 24% of the radiotherapy patients felt disabled or disfigured by the treatment, most commonly because of the presence of only one testicle. A deterioration in sexual function was observed with increasing age. In the radiotherapy group of patients there was no difference in response between the two time periods or in any of the treatment variables. The clinical significance of these observations are unclear but together with the increasing information on other toxicities emerging following this therapy the role of radiation for early stage seminoma is being brought into question. This study also confirms the morbidity of orchidectomy. We suggest that testicular implants should be offered more widely.

Idiopathic epidural lipomatosis as a cause of pain and neurological symptoms attributed initially to radiation damage

Epidural lipomatosis is a rare condition in which overgrowth of extradural fat can lead to back pain, spinal cord compression and radiculopathy. A 51-year-old man developed back pain and reduced mobility following a standard course of radiotherapy for a Stage I seminoma. His symptoms and radiological appearances were initially attributed to radiation fibrosis. Further investigations and operative intervention revealed epidural lipomatosis. The excess lipomatous tissue was removed with complete resolution of his symptoms.

Radical radiotherapy with salvage surgery for invasive bladder cancer: results following a reduction in radiation dose

The management of invasive bladder cancer in Edinburgh, as in many other centres in the UK, has been by radical radiotherapy, with cystectomy reserved for local treatment failure or relapse. A review of the results of this policy in 1987 highlighted what was felt to be an unacceptably severe morbidity rate of 15%. The dose of radiation was therefore reduced from 55 Gy in 20 daily fractions to 52.5 Gy. Forty of 80 patients (50%) treated in this way have achieved a complete response at 6 months which is a similar response rate to that in previous reports. In addition, ten of 23 frail or elderly patients (43%) achieved a complete response with a lower dose of 50 Gy given as a split course over 7 weeks. Eighteen patients have had a salvage cystectomy, and 12 of 18 (67%) are alive and disease-free. Although follow-up is short, to date toxicity has been reduced, and our results support our decision to reduce the radiation dose.

Basaloid carcinoma of the prostate gland: histogenesis and review of the literature

The clinicopathological features of a basaloid carcinoma of the prostate gland are described in a 28-year-old man, and the management and prognosis discussed. Basaloid tumours of the prostate are very rare and only a few cases have been described in detail. Those cases which have been reported as adenoid cystic carcinoma, adenoid cystic-like carcinoma and adenoid basal cell tumour are reviewed.

Neoadjuvant chemotherapy with methotrexate and cisplatin prior to radiotherapy for invasive transitional cell carcinoma of the bladder. Assessment of feasibility and toxicity

A prospective study has been performed to assess the feasibility and toxicity of administering neoadjuvant chemotherapy with methotrexate (200 mg/m2) and cisplatin (100 mg/m2) prior to radical radiotherapy. Twenty patients with advanced transitional cell carcinoma of the bladder were assessed after each of 3 courses of chemotherapy, after radiotherapy and 6 months following treatment. Of particular concern was whether neoadjuvant chemotherapy compromised the ability to give potentially curative radical radiotherapy, delayed effective palliation of distressing urinary symptoms, or allowed local tumour progression prior to definitive treatment. It was concluded that this chemotherapy regimen was well tolerated, did not compromise the ability to give radical radiotherapy and resulted in the prompt palliation of urinary symptoms. This treatment, however, did not stop the development or progression of metastatic disease in some patients. In only 1 patient was there local progression during chemotherapy.

Surgery following chemotherapy for metastatic testicular teratoma

Twenty patients with metastatic testicular teratoma underwent surgery for residual disease after chemotherapy. Twelve patients in whom complete excision of all residual masses was possible are alive with no evidence of disease. Four patients have died of malignant teratoma, 2 have active malignant disease and 2 have inoperable residual cystic disease. Patients with malignant teratoma intermediate (MTI) primary testis tumours, and those with bulky abdominal disease at presentation, are more likely to have residual masses requiring excision. Completeness of excision appears to be the most important predictor of disease-free survival.

Low dose bleomycin with etoposide and cisplatin for metastatic testicular teratoma

Thirty-nine men with metastatic testicular teratoma were treated with a combination of bleomycin, etoposide and cisplatin (BEP). Unlike the usual regimen of these 3 agents, bleomycin and cisplatin were given on day 1 only of the cycle, with etoposide for 3 days. Thirty patients (77%) are alive and disease-free after a median follow-up of 31 months--24/25 (96%) with disease confined to lymph nodes but only 6/14 (43%) patients with lung involvement. Modified BEP chemotherapy is a well tolerated alternative to standard BEP chemotherapy for small volume nodal disease; it minimises in-patient time, hospital visits and the risk of bleomycin lung toxicity. However, omission of the weekly doses of bleomycin and shortening of the administration schedule of cisplatin and etoposide may be detrimental in patients with more extensive disease, for whom more intensive therapy may be necessary.

Fertility following cancer therapy

This article reviews the literature relating to fertility following cancer therapy. Normal fertility clearly relies on normal gonadal and normal sexual function. Consideration is given here to the possible effects of surgery, radiotherapy and chemotherapy on fertility. Surgical techniques have now been described which in selected patients may allow normal erectile and ejaculatory function in the male, where previously impotence was inevitable. Maintaining radiation doses to the testes and ovaries to a minimum will reduce the incidence of radiation-induced sterility and may allow recovery of gonadal function. It is clear that cytotoxic chemotherapy does not inevitably result in permanent sterility. Some regimens are more toxic in this respect than others, and reducing the number of courses may improve the chances of retaining fertility. Hormonal manipulations designed to protect the gonad against cytotoxic damage have thus far been unsuccessful in the clinical situation.