Aggregation of the amyloid precursor protein within degenerating neurons and dystrophic neurites in Alzheimer's disease

Using a monoclonal antibody raised against purified, native, human protease nexin-2/amyloid precursor protein, which recognizes an amino terminal epitope on the amyloid precursor protein and detects all major isoforms of amyloid precursor protein, we examined the localization of the amyloid precursor protein within Alzheimer's and aged control brains. Very light cytoplasmic neuronal amyloid precursor protein staining but no neuritic staining was visible in control brains. In the Alzheimer's brain, we detected numerous amyloid precursor protein-immunopositive neurons with moderate to strong staining in select regions. Many neurons also contained varying levels of discrete granular, intracellular accumulations of amyloid precursor protein, and a few pyramidal neurons in particular appeared completely filled with amyloid precursor protein granules. "Ghost"-like deposits of amyloid precursor protein granules arranged in pyramidal, plaque-like shapes were identified. We detected long, amyloid precursor protein-immunopositive neurites surrounding and entering plaques. Many contained swollen varicosities along their length or ended in bulbous tips. Amyloid precursor protein immunoreactivity in the Alzheimer's brain was primarily present as granular deposits (plaques). The amyloid precursor protein granules do not appear to co-localize within either astrocytes or microglia, as evidenced by double-labeling immunohistochemistry with anti-glial fibrillary acidic protein and anti-leukocyte common antigen antibodies or Rinucus cummunicus agglutin lectin. Amyloid precursor protein could occasionally be detected in blood vessels in Alzheimer's brains. The predominantly neuronal and neuritic localization of amyloid precursor protein immunoreactivity indicates a neuronal source for much of the amyloid precursor protein observed in Alzheimer's disease pathology, and suggests a time-course of plaque development beginning with neuronal amyloid precursor protein accumulation, then deposition into the extracellular space, subsequent processing by astrocytes or microglia, and resulting in beta-amyloid peptide accumulation in plaques.

Combined radiation therapy, mitomycin C, and 5-fluorouracil for locally recurrent rectal carcinoma: results of a pilot study

Twenty-two patients underwent combined radiation therapy (XRT), mitomycin C (MMC), and 5-fluorouracil (5FU) for rectal carcinoma, locally recurrent following either abdominoperineal or anterior resections. All patients presented with symptomatic unresectable pelvic cancer. The protocol XRT doses were 45-50 Gy/20/4-6 weeks. Chemotherapy consisted of MMC 10 mg/m2 on day 1, and 5FU 15 mg/kg/day on days 1, 2, and 3 of XRT, both given by intravenous bolus injection. Only 2 of 22 patients remained NED at 5 years following treatment. All but four patients eventually experienced progression of pelvic disease. Ten of 22 patients were unable to complete the treatment protocol because of excessive acute hematological and gastrointestinal toxicity. Five patients developed neutropenic sepsis, one of whom died. Combined XRT, MMC, and 5FU as used in this study had no apparent advantage over XRT alone in terms of pelvic disease or survival, and produced significant toxicity.

Results of external beam irradiation for rectal carcinomas locally recurrent after local excision or electrocoagulation

The outcome of 42 patients who developed locally recurrent rectal carcinoma after initial local excision or electrocoagulation was presented. Five patients received combined surgery and radiotherapy (XRT). The remaining 37 patients were managed by XRT alone. The overall 5 year actuarial survival and local control rates were 21 and 22%, respectively. For patients who received XRT alone, the 5 year actuarial survival and local control rates were 20 and 15%, respectively. The corresponding figures were 35 and 40% for patients who received a total XRT dose of 50 Gy or more. One patient who underwent combined treatment developed rectal and bladder incontinence requiring surgery. For patients with rectal recurrence after initial conservative surgery, XRT is an alternative to abdominoperineal resection if major surgical resection is contraindicated.

Epidermoid anal cancer: treatment by radiation alone or by radiation and 5-fluorouracil with and without mitomycin C

One hundred ninety-two patients with primary epidermoid cancer of the anal canal were treated by a series of prospectively designed, sequential non-randomized protocols of radiation alone (RT), radiation with concurrent 5-Fluorouracil and Mitomycin C (FUMIR), or radiation with concurrent 5-Fluorouracil only (FUR). The 5-year cause-specific survival rates were 69% overall, 68% RT, 76% FUMIR, 64% FUR. The primary tumor was controlled by radiation with or without chemotherapy in 68% (130/191) overall, 56% (32/57) by RT, 86% (59/69) by FUMIR, 60% (39/65) by FUR. The results with FUMIR were significantly better than with either RT alone or FUR, and except in tumors up to 2 cm in size, this superiority was found in all T stages. Regional lymph node metastases were controlled in 33 of 38 (87%) overall. The finding of clinically detectable regional lymph node metastases at presentation did not affect survival significantly in any treatment group. Anorectal function was preserved in 88% of the patients in whom the primary tumor was controlled, and in 64% overall. The delivery of 5FU and MMC concurrently with uninterrupted radical irradiation, 50 Gy in 20 fractions in 4 weeks, produced severe acute and late normal tissue morbidity. Split course treatment, and reduction of the daily fractional dose to 2 Gy, diminished the severity of normal tissue damage. Omission of Mitomycin C reduced acute hematological toxicity, but was associated with a decreased primary tumor control rate. The most effective treatment protocols as measured by survival rates, primary anal tumor control rates, and the likelihood of conservation of anorectal function included the administration of both Mitomycin C and 5-Fluorouracil concurrently with radiation therapy.

Adult paratesticular sarcomas: a review of 21 cases

We reviewed 21 patients more than 16 years old who were seen with a diagnosis of paratesticular sarcoma from 1958 to 1987. Of the patients 14 presented with primary disease and 7 with recurrent disease. The survival of the primarily treated patients was 58% at 5 years, calculated by the product limit method. Of the 14 patients with primary disease 13 had grade 3/4 or 4/4 sarcoma and 13 of 14 underwent initial radical orchiectomy. In addition, 6 of the 14 patients underwent an adjuvant operation or radiotherapy to the groin, or groin and scrotum, and none had local relapse. Some patients also had chemotherapy. Three patients underwent adjuvant retroperitoneal node dissection and 2 had microscopically positive nodes. All 3 patients remain without relapse. Six patients had relapse: 2 locally, 2 in the retroperitoneal nodes and 2 with distant metastases. Only 1 patient (with scrotal recurrence) was salvaged. Of the 7 patients referred with recurrent disease none was salvaged. In this series there is a 2 of 14 (14%) risk of local failure and a 4 of 14 (28%) risk of retroperitoneal relapse after radical orchiectomy. Since salvage has not proved successful, patients with rhabdomyosarcoma, intermediate or high grade malignant fibrous histiocytoma, or fibrosarcoma should be considered for adjuvant retroperitoneal node dissection. All patients should undergo adjuvant dissection or irradiation of the ipsilateral pelvic and groin nodes, and scrotum.

Bladder cancer: long-term follow-up results of patients treated with radical radiation

Carcinoma of the bladder is commonly treated for cure with external beam radiation. Whilst short-term results are associated with a good chance of disease control there is little information about the long-term results of such therapy. We present a retrospective review of the Princess Margaret Hospital experience in treating transitional cell carcinoma of the bladder and emphasis on the long-term follow-up of patients treated with radiotherapy (XRT). Between 1972 and 1980, 355 patients were treated with a radical course of external beam radiation. The overall survival was 20% at 10 years and the cause-specific survival was 32%. Radiation treatment resulted in a long-term bladder preservation in at least 25% of patients. The majority of long-term survivors without evidence of relapse were patients with T1 (solitary tumours), T2 and T3a tumours. This subgroup represents patients with disease favourable for treatment with radiation. Factors affecting response to the XRT and survival included T stage and tumour bulk. Radiation complications were frequent and were usually associated with local disease recurrence.

Anal cancer

Combined modality treatment with radiation, chemotherapy, and conservative surgery controls most epidermoid cancers of the anal canal and advanced squamous cell cancers of the perianal skin. Anorectal function is preserved in about 70% of patients or more. Five-year survival rates are similar to those previously obtained with radical surgery or radical radiation therapy. The cytotoxic drugs 5-Fluorouracil and Mitomycin C are frequently given concurrently with radiation, but other effective regimens have also been described. The mechanisms of interaction of radiation and cytotoxic drugs in the treatment of anal cancer are not known.

Induction of basic fibroblast growth factor in Alzheimer's disease pathology

Alzheimer's disease (AD) and its hallmark, plaques, may be due to an imbalance of trophic support. It has been suggested that plaque biogenesis may involve a growth factor which induces sprouting of neurites to form plaques. Thus, we studied the distribution of basic fibroblast growth factor (bFGF), in the hippocampus from AD brain and in rodent brain after entorhinal ablation. Both cases have a partial deafferentation of the hippocampus. The strongest bFGF immunoreactivity in AD was shown in plaques of the dentate gyrus. Rodent brains showed a lesion-induced increase of bFGF in the dentate gyrus, primarily localized to astrocytes. Our results indicate that bFGF may serve an important biological function in plaques and possibly attract neurites.

Anal carcinoma

Although epidermoid cancer of the anus is an uncommon tumor, it has served well as a model for several disciplines within oncology. Advances in understanding the epidemiology and the definitive therapeutic role of combined radiation therapy and chemotherapy for anal tumors have encouraged many investigators to study similar applications in the more common epithelial malignancies. In this monograph, the anatomy of the anal area is reviewed emphasizing the differences in natural history and prognosis between anal margin and anal canal cancers. Treatment does not depend on the specific histologic variant of the epidermoid tumors which arise in this region. The roles of viruses, of immunodeficiency syndromes, and of a history of benign anal disease and trauma in the etiology and epidemiology of this tumor are discussed. Current staging will be critically reviewed stressing that invasive (pathologic) staging by surgery is not indicated, but noninvasive staging has definite limitations. Small superficial tumors may be definitively treated with either limited surgery or radiation. While regional treatments such as surgery and radiation offer cure to between 45% and 60% of nonselected patients, initial treatment with combination radiation and chemotherapy produces cure rates between 65% and 85% for similar groups of patients. The rationale for combined modality therapy is presented and recommendations for therapy by stage of the cancer are made. Finally, we present questions that remain for future research in the clinic and laboratory regarding epidermoid tumors of the anus.

Whose utilities for decision analysis?

The goal of this study was to examine sources of variation in the utilities assigned to health states. The authors selected a common clinical problem, carcinoma of the rectum, and examined the utilities assigned to colostomy, a common outcome of treatment for that disease. After preparing and validating a description of colostomy and its effects on patients' lives, utilities for the state were obtained from five groups of individuals. These comprised two groups of patients who received treatment for rectal cancer, a group of physicians and surgeons specializing in the treatment of this disease, and two groups of healthy subjects, none of whom were health professionals. Of the patients who had been treated for rectal cancer, one group had been treated surgically with the formation of colostomies and the other had been treated with radiotherapy and none had a colostomy. Utilities for colostomy were elicited using the standard gamble, category rating, and a treatment choice questionnaire. The groups differed substantially in the utilities assigned to colostomy. In general, patients with colostomies and physicians assigned significantly higher utilities than did patients who did not themselves have a colostomy. The clinical significance of these differences was examined in a simplified clinical decision problem that compared surgery (with colostomy) and radiotherapy (without colostomy) as primary treatment. The expected clinical value of these treatment alternatives was substantially influenced by the differences observed in utilities for colostomy. These results emphasize the importance of patient utilities in clinical decision making and the need to gain greater understanding of the factors that influence the utilities that patients assign to health states.

Complications and functional results after limb-salvage surgery and radiotherapy for difficult mesenchymal neoplasms: a prospective analysis

Wide resection with adjuvant radiotherapy is generally accepted as the optimal treatment for patients with extremity soft-tissue sarcomas. However, there is a subset of patients with "difficult" tumours who sustain such marked loss of function from limb-salvage procedures that amputation might offer a superior functional alternative. To evaluate this issue, the authors prospectively designated 19 of 52 patients registered in Toronto's Princess Margaret Hospital Prospective Sarcoma Database in 1986 as "difficult" cases, on the basis of tumour size and anatomical location. Complications and functional results of wide resection and adjuvant radiotherapy were documented. The most frequent complication was related to wound healing (8 of 19 patients). Functional analysis at 1 year follow-up demonstrated that all 19 patients had results superior to those that would be expected with amputation.

The role of surgery in the treatment of squamous cell carcinoma of the nasal vestibule

A retrospective analysis of 61 patients who were treated for squamous cell carcinoma of the nasal vestibule is presented. The general policy was to treat these carcinomas with radiation therapy, in view of the perception that this leads to a more acceptable cosmetic result. The primary nasal carcinoma was treated by surgery in five patients and by radiation in 56 patients. Surgical salvage of recurrent carcinoma in the nasal vestibule was performed without complications in 12 patients and resulted in local control in seven. Regional node metastases present at the time of diagnosis in two patients were not controlled by combined radiation and surgery. Late-developing regional node metastases were successfully managed by node dissection in three of four patients. The policy of initial treatment of the primary tumor by radiation, reserving surgery for the management of residual or metastatic cancer, resulted in good control rates and cosmesis.

The place of radiation therapy in the treatment of squamous cell carcinoma of the nasal vestibule. A review

Radiation therapy and limited resection give equally good results in early squamous cell carcinomas of the nasal vestibule, each producing local control rates of 90% or more. For more extensive disease, primary radiation therapy with surgery reserved for residual or recurrent carcinoma is recommended in view of the significant cosmetic defects which generally follow major resection. Small and superficial lesions can be treated by external beam therapy or interstitial implants. Large or infiltrative lesions are best managed by external beam therapy. Serious late morbidity following irradiation is uncommon and has been reported in fewer than 5% of patients. Regional nodal metastases are diagnosed at the time of first presentation in about 5% of patients and signal a very poor prognosis. However, the data available do not support elective treatment of clinically uninvolved regional nodes. Fewer than 5% of patients manifest late nodal metastases when the primary tumor area remains free of recurrence, and most of these metastases can be controlled by neck dissection and/or irradiation.

Current management of epidermoid carcinoma of the anal canal

Treatment with a combination of radiation therapy and chemotherapy currently allows about 80 per cent of patients with epidermoid carcinomas of the anal canal to retain anorectal function, with about a 70 per cent likelihood of cure at 5 years. In these programs, radical surgery is reserved for the management of residual cancer or of radiation- or chemotherapy-induced anorectal toxicity. Several different schedules of combined modality therapy are in use, but an important common element in most schedules appears to be the concurrent administration of radiation and 5-fluorouracil. The improvement in local control rates with combined radiation and chemotherapy, as compared to most series treated by either radical radiation or radical surgery, has not been matched by a marked improvement in survival rates, and the risk of distant metastases does not appear to have been altered by these combinations. The success of the combinations in improving local control has allowed the indications for local excision to be defined more narrowly, and should reduce the risks of local recurrence associated with conservative surgery.

Radiotherapy of Kaposi's sarcoma

Between 1958 and 1983, 91 patients with Kaposi's sarcoma were referred to the Princess Margaret Hospital. Eight patients received no specific therapy immediately following their first assessment. Twenty-seven patients were treated by local field radiotherapy, of whom 17 entered complete remission and 6 have remained relapse-free. Fifty-six patients received extended field radiotherapy, usually a single fraction of 8 Gy megavoltage gamma-ray or photon therapy; 38 achieved completed remission, and 24 have remained relapse-free for a median duration of 3 years. The actuarial relapse-free survival for patients treated by local versus extended field radiotherapy significantly favors the extended field technique although the rates of relapse after complete remission has been achieved appear similar. Immunosuppression was present in 12 patients prior to the diagnosis of Kaposi's sarcoma; these patients had a similar response rate to radiation therapy to those who were not known to be immunosuppressed. A rationale for management, and radiation technique and dose are discussed. It is concluded that radiotherapy is an effective treatment for most forms of Kaposi's sarcoma.

External irradiation for squamous cell carcinoma of the nasal vestibule

A retrospective analysis of 56 patients who underwent primary external irradiation for squamous cell carcinoma of the nasal vestibule between 1958 and 1983 is presented. The overall 5 year actuarial survival and cause specific survival rates were 64 and 87%, respectively. The 5-year local relapse-free rate after primary irradiation was 80%. Prognostic factors which lowered the local control rate after irradiation included a primary tumor size of 2 cm or more, or involvement of the skin of the ala nasi, columella, lip, cartilage, or bone. Local control was improved in patients who received a tumor dose equivalent to, or greater than, 5500 cGy/25 fractions/5 weeks. Only two patients in whom the primary tumor was controlled developed regional nodal metastases, and elective regional nodal irradiation is not recommended. Four patients (9%) developed significant late morbidity after irradiation. External irradiation is effective treatment for squamous cell carcinoma of the nasal vestibule, and produces high local control and cure rates and good cosmetic results.

A pilot study of mitomycin-C/5-fluorouracil infusion combined with split course radiation therapy for carcinomas of the larynx and hypopharynx

Fifty-seven patients with advanced squamous carcinoma of the larynx and hypopharynx were entered on a pilot study of initial therapy using split course radiation therapy combined with simultaneous chemotherapy using mitomycin-C and 5-fluorouracil. The treatment was well tolerated with 90% of patients completing their planned radiation treatment. Seventy percent of this group completed their planned chemotherapy. Significant hematological toxicity was not observed. Survival and loco regional control at one and two years of follow-up were considered at least comparable to that achieved with conventional single-course radical radiation therapy as primary treatment. Based on these results a randomized trial of this radiation-chemotherapy regimen compared to radiation therapy alone as initial therapy is in progress.

Ewing's sarcoma: a trial of adjuvant chemotherapy and sequential half-body irradiation

The results of a pilot study using adjuvant chemotherapy and sequential half-body irradiation (HBI) for nonmetastatic Ewing's sarcoma are presented. Seventeen patients received Cyclophosphamide, Vincristine, and Adriamycin (8 cycles), followed by sequential radiation treatment of the upper (500 cGy) and lower (600 cGy) half body. Survival at 3 years was 49%. These results are contrasted with those for 18 concurrently treated patients who received standard adjuvant therapy. Overall 5-year survival and relapse-free survival for these 35 consecutive patients was 61 and 53%. The pilot protocol was given on an out-patient basis with limited and acceptable acute toxicology. Further study is necessary to determine the value of the pilot protocol.