Cloning and sequence analysis of zooA, a Streptococcus zooepidemicus gene encoding a bacteriocin-like inhibitory substance having a domain structure similar to that of lysostaphin.

The nucleotide sequence has been determined for zooA, a gene encoding the bacteriocin-like inhibitory substance zoocin A in Streptococcus zooepidemicus strain 4881. The zooA gene product corresponds to the 285-amino acid (aa) zoocin A pre-peptide from which a leader sequence is cleaved to form the 262-aa biologically active molecule of estimated molecular mass 27,877 Da. Expression of zooA in a Gram-negative host was shown by the extracellular release from Escherichia coli, containing cloned zooA, of a biologically active peptide having an identical range of anti-bacterial activity to that of zoocin A, purified from S. zooepidemicus strain 4881. Data base searches revealed sequences having homologies with known muralytic proteins produced by both Gram-positive and Gram-negative bacteria and indicate a 'mix and match' blending of domain-type structures, the C-terminal putative receptor-recognition region of the molecule being joined by a threonine-proline-rich linker to an N-terminal putative catalytic region having homology with several known endopeptidases, including lysostaphin.

Papillary and follicular thyroid cancer. Prognostic factors in 1,578 patients.

This report from the Canadian survey of thyroid cancer describes 1,074 patients with papillary thyroid cancer and 504 with follicular thyroid cancer followed for four to 24 years. The study groups included more patients with "advanced" disease and fewer with "early" disease than in the general population because these patients were referred to radiotherapy cancer centers, sometimes routinely, but often because referring physicians believed that certain clinical features indicated the need for additional treatment. Although this report is subject to all the problems of retrospective studies, a careful assessment of the pretreatment extent of disease combined with a long follow-up period has allowed an analysis of prognostic factors with considerable confidence. Univariate analysis of 12 possible prognostic factors (excluding treatment) demonstrated that nine of them were of statistical significance: postoperative status, age at diagnosis, extrathyroidal invasion, distant metastases, nodal involvement, differentiation, sex, tumor size, and pathologic type (in descending order of importance). Multivariate analysis was carried out using cause-specific survival rates. Independently important prognostic factors at initial treatment were age at diagnosis, extrathyroidal invasion, and degree of differentiation histologically for papillary cancers; and extrathyroidal invasion, distant metastases, primary tumor size, nodal involvement, age at diagnosis, and postoperative status for follicular cancers. The prognostic factors for tumor recurrence were quite different for the papillary and follicular cancers and ranked differently for the two groups.

Ependymomas: results of radiation treatment.

Between 1958 and 1980, 102 patients with the diagnosis of ependymoma were seen at the Princess Margaret Hospital. Eleven patients had recurrent disease or were treated elsewhere and 91 patients received radiation therapy following their primary surgical procedure. Fifty patients had cranial tumors and 41 had spinal tumors. The overall survival at five years was 60% and at 10 years was 54%. Those patients with spinal tumours did significantly better with a five year survival of 83% versus 43% for the group with cranial tumors. The other prognostic factors included tumor grade, functional status, age of the patient and interval from surgery to radiation. The most common site of relapse was at the original tumor location, but five patients did show spread through the craniospinal axis. An analysis of dose and the volume treated is made and recommendations for therapy given.

Radiotherapy for atypical or malignant intracranial meningioma.

PURPOSE: To study the natural history of intracranial atypical and malignant meningiomas, and the role of radiotherapy in the treatment of these tumors. METHODS AND MATERIALS: The records of the 59 patients who were treated at the Princess Margaret Hospital between 1966 and 1990 with histologically confirmed intracranial atypical or malignant meningiomas were retrospectively reviewed. The median age was 58 years. Twenty-four patients were referred for radiation immediately after diagnosis and the remainder after at least one recurrence. The extent of the most recent surgery prior to radiation was gross total excision in 17, subtotal excision in 35, biopsy in 3, and none or unknown in 4. Seventeen had atypical meningiomas, defined as the presence of mitoses, nuclear atypia, or necrosis. Forty-two had malignant meningiomas on the basis of brain invasion (60%) or a pathologist's designation of malignant or hemangiopericytic meningioma. All patients received megavoltage radiation to a median dose of 50 Gy. RESULTS: Disease progressed in 39 patients (66%) after radiation. Of these, 36 died of meningioma and 3 were alive after further surgery. The 5-year actuarial overall and cause-specific survivals were 28 and 34%, respectively. Age less than 58, treatment after 1975, and a radiation dose of 50 Gy or more were independently associated with higher cause-specific survival by multivariate analysis. CONCLUSIONS: Young age, modern imaging and treatment planning techniques, and a postoperative radiation dose of at least 50 Gy contribute to improved outcome in patients with atypical or malignant meningiomas. We recommend that all patients receive radiotherapy immediately after initial surgery.

Papillary and follicular thyroid cancer: impact of treatment in 1578 patients.

We report the experience from 13 Canadian radiotherapy centres concerning the treatment and outcome for 1074 papillary and 504 follicular thyroid cancer patients followed for 4-24 years. Surgical resection was carried out in almost all patients; there was no correlation between the type of operation and recurrence or survival. Treatment with external irradiation (201 patients) radioiodine (214 patients), or both (107 patients) was used more often in poor prognosis patients than in those with good prognostic factors, and was effective in reducing local recurrences and improving survival, especially in patients with microscopic residual disease postoperatively. Treatment complications were common but rarely fatal. Thyroid cancer was the cause of death in over half of the papillary cancer deaths and in two-thirds of the follicular cancer deaths.

Spinal cord ependymomas: a retrospective analysis of 59 cases.

PURPOSE: To determine the outcome of patients with primary spinal ependymoma treated with postoperative radiotherapy and to identify clinical and treatment variables predictive of outcome. METHODS AND MATERIALS: A retrospective chart review was undertaken of 59 spinal ependymoma patients referred to the Princess Margaret Hospital between 1958 and 1987. All patients were treated with radiation therapy to either the site of the primary tumor or the craniospinal axis. There were 23 female and 36 male patients with a median age of 37 years (range: 8-66 years). Median follow-up was 130 months (range: 1-371 months). Clinical variables including age, sex, length of symptoms, functional status, tumor location, and grade as well as treatment variables including extent of surgery, radiation dose and treatment volume were analyzed for influence on outcome. RESULTS: Treatment was well-tolerated with no cases of radiation myelopathy identified. Overall actuarial survival at 5 and 10 years was 83% and 75%, respectively. Eleven patients had recurrent tumor with the 9/11 having a component of their recurrence within the treatment field. Median time to recurrence was 2 years with 9 of the 11 recurrences within the first 3 years. Tumor grade was the only independent variable identified as predictive of outcome. Patients with well differentiated tumors had a 5-year cause-specific survival of 97% compared to 71% for those with intermediate or poorly differentiated tumors (p = 0.005). CONCLUSION: We conclude that postoperative irradiation for patients with spinal ependymomas is associated with a favorable outcome and that tumor grade is a major prognostic factor. Based on results of this series and a review of the literature, specific management recommendations are made for this rare tumor.

Medulloblastoma in adults.

PURPOSE: To assess the outcome and prognostic factors for adult patients with medulloblastoma managed by postoperative radiotherapy between 1958 and 1988 at the Princess Margaret Hospital. METHODS AND MATERIALS: A retrospective review was undertaken of 48 patients age 16 years or older who received radiotherapy for medulloblastoma. The median age at diagnosis was 25 years, with 36 male and 12 female patients. Sixteen tumors were confined to midline structures, and 32 were localized to a cerebellar hemisphere or involved midline and lateral structures. The desmoplastic variant was reported in 12 cases. Complete macroscopic removal was achieved in 22 patients, subtotal removal in 23, and biopsy only in 3. Forty-six patients received craniospinal radiation and 2 patients received local irradiation only. RESULTS: Median overall survival was 7.9 years, and 5- and 10-year overall survival was 62% and 41%, respectively. Significant factors for disease-free survival were M stage (M0 vs. M1-4, p = 0.0005), functional state at the time of radiotherapy (1-2 vs. 3-5, p = 0.005), and the absence or presence of hydrocephalus preoperatively (p = 0.02). Twenty-four patients developed recurrent disease, with 14 relapsing first in the posterior fossa. Subtotal removal of tumor (p = 0.04) was the only factor predictive of posterior fossa relapse. CONCLUSIONS: Patients with disease outside the posterior fossa at diagnosis, symptomatic patients (neurologic functional state 3-5) at the time of radiotherapy, and those who present with hydrocephalus have poorer disease-free survival. Gross total resection improved posterior fossa control.

Radiation therapy for pituitary adenoma: treatment outcome and prognostic factors.

PURPOSE: Radiation therapy is often an integral part of postoperative treatment in patients with nonfunctional pituitary adenomas. The Princess Margaret Hospital (PMH) experience was reviewed and analyzed to establish the role of radiation therapy in local control relative to its complications, and to see if subgroups of patients with a greater or lesser risk of recurrence postsurgery can be defined. METHODS AND MATERIALS: Records of 160 patients with nonfunctional pituitary adenoma treated between 1972 and 1986 were reviewed retrospectively. The review focused on 128 patients treated with surgery and postoperative radiation as initial therapy. The median total dose was 45 Gy. Local tumor control was defined as lack of progression or recurrence of adenoma as assessed clinically and by imaging studies. The following factors were analyzed for prognostic significance in local tumor control: age, sex, direction of tumor extension, radiation dose, and preoperative tumor size as reflected by the radiation field size. Complications including hypopituitarism and second tumors were analyzed. Hypopituitarism was defined as requirement for permanent hormone replacement therapy. RESULTS: With a median follow-up duration of 8.3 years, the 10-year actuarial local control rate was 87% for the entire 160 patients and 91% for the 128 patients given postoperative radiation as initial treatment. For the 29 patients referred for treatment of recurrent tumor, the 10-year local control rate was 78%. Prognostic factors for local control identified in univariate analysis included age (p = 0.005) and radiation field size (p = 0.0001). Older patients and those with larger tumors requiring large radiation portals were less likely to achieve durable local control. These two factors remained significant in a multivariate analysis (p < 0.005). The major complication, hypopituitarism requiring hormonal replacement with thyroxine, glucocorticoid, and sex hormone was observed to date in 65% (100 out of 155), 68% (105 out of 154), and 67% (85 out of 127) of evaluable patients, respectively. Radiation was the contributing cause of the hypopituitarism in only 23%, 16%, and 13%, respectively. There were no cases of brain necrosis or radiation damage to the optic pathways. Two patients developed a fatal in-field glioma of the brain stem at 10 and 15 years following radiation. CONCLUSION: Postoperative external beam radiation therapy is highly effective in preventing recurrence of hormonally inactive pituitary adenomas. Hypopituitarism is commonly observed, but radiation can only be incriminated as the contributing cause in approximately one-fifth of the cases. Treatment of patients at the time of recurrence gave comparable local control rates to those irradiated initially. Favorable patients (age < or = 50, with small tumors removed totally) probably can be safely observed postoperatively with radiation reserved for recurrence.

Myelopathy following hyperfractionated accelerated radiotherapy for anaplastic thyroid carcinoma.

From 1975 to 1982, 32 patients with a diagnosis of anaplastic carcinoma of the thyroid were entered into a protocol of hyperfractionated accelerated radiotherapy. The tumor dose was 30-45 Gy at 1 Gy per fraction given 4 times a day at 3-h intervals. The results were disappointing with a median survival of less than 6 months. Two patients developed radiation myelopathy at 8 and 13 months, total spinal cord dose being 39.9 and 48.3 Gy, respectively. The risk of spinal cord damage was much higher than expected. The possible radiobiological causes and clinical implications are discussed.

Role of radiation therapy in clinical hormonally-active pituitary adenomas.

BACKGROUND AND PURPOSE: The outcome following radiation therapy (RT) of hormonally-active pituitary adenomas was assessed. The purpose of this analysis was to determine the control rate after radiation, identify any prognostic factors and evaluate the late toxicity. MATERIALS AND METHODS: From 1972 to 1986, 145 patients received RT for hormonally-active pituitary adenomas. The median age was 39 years (range 15-76), with 81 males and 64 females. There were 52 patients with acromegaly, 64 with prolactinoma, and 29 with Cushing's disease. The median follow-up was 7.3 years. RT was given as primary treatment in 17 patients, after initial surgery in 65 patients, and as part of salvage therapy in 63 patients. The median total dose was 50 Gy (daily fraction: 2 Gy). Tumor control was defined as normalization of basal hormonal level and lack of progression of adenoma assessed by imaging studies. The following factors were analyzed for prognostic significance in tumor control: age, sex, tumor type, direction of tumor extension, radiation dose, and radiation field size. RESULTS: The 10-year actuarial proportion of patients with persistent elevated hormone level were 61% following RT alone, and 44% with the addition of medical management. The progression-free rate was 96% at 10 years. Of the 20 deaths, three patients died with uncontrolled pituitary adenoma and three died of treatment complications. The actuarial 10-year overall and cause-specific survival rates were 86% and 97%. The actuarial rates of radiation-induced hypopituitarism were 35%, 22% and 22% at 10 years for thyroid, glucocorticoid and gonadal functions, respectively. None of the factors examined were found to be significant predictors of tumor control. CONCLUSIONS: Post-operative external beam RT is highly effective in preventing recurrence of space-occupying effects of hormonally-active pituitary adenomas. However, long-term biochemical remission is observed only in approximately 40% of patients (at 10 years), with an additional 20% requiring medical therapy. Malignancies of the CNS can develop as an infrequent late event.

The role of surgery in the management of thyroid lymphoma.

The role of surgery in the management of patients with primary lymphoma of the thyroid gland has been addressed after review of 61 patients treated at Princess Margaret Hospital between 1958 and August 1982, 46 of whom had clinical stage I and II disease confined to the thyroid gland or lymph nodes or both above the diaphragm. Postoperative radiation therapy was used in 34 patients, radiation therapy and chemotherapy in 11 patients, and chemotherapy alone in 1 patient. Analysis of disease progression, local relapse, and distant disease recurrence indicated that postoperative residual disease bulk predicted strongly for both local and distant disease progression. Overall cause-specific survival was 59% at 5 years, with a relapse-free rate of 46% at 5 years. Of those with less than 2.5 cm of residual disease after surgery, 80% achieved lifelong local disease control compared with 40% for those with residual disease in excess of 2.5 cm after surgery. Distant relapse rates were 7% and 23% for those with less than 2.5 cm and greater than 2.5 cm after surgery, respectively. The long-term survival rate for those with disease progression during this period was approximately 10%, with a median survival expectancy of 18 months. It is suggested that those patients without an antecedent cytologically based diagnosis of lymphoma undergo biopsy and removal of operable tumor without compromise of parathyroid glands, recurrent laryngeal nerves, or appearance. Those patients with an existing cytologic diagnosis of lymphoma and bulky and/or inoperable tumor may be more effectively managed with a combined chemotherapy-radiation therapy program.

Recombinant capsular antigen (fraction 1) from Yersinia pestis induces a protective antibody response in BALB/c mice.

Yersinia pestis produces a glycoprotein capsule, the biosynthesis of which appears to be temperature dependent. The fraction I (F1) component of this capsule is specific to Y. pestis and the detection of F1 antibodies is the basis for several serological tests. We report the cloning of the F1 gene and its expression in Escherichia coli using the phagemid vector lambda ZAPII and a F1-specific monoclonal antibody. The recombinant F1 antigen had a molecular weight of 17 kDa, which proved to be identical to that of the F1 antigen produced by Y. pestis. The recombinant cells produced F1 antigen at 37 degrees C but only minimal amounts at 27 degrees C, suggesting that the genetic features affected by temperature in Y. pestis may be operating in the E. coli clone. It is not known if their similar molecular weights reflect the glycosylated nature of both proteins. F1 antigen purified from the E. coli recombinant induced a protective immune response in BALB/c mice challenged with up to 10(5) virulent Y. pestis. The resistance of immunized mice to plague infection correlated with high titers of F1 antibody. The cloned gene expresses an immunogenically competent F1 antigen suitable for use in plague serodiagnostics and vaccine development.

Failure of intragastrically administered Yersinia pestis capsular antigen to protect mice against challenge with virulent plague: suppression of fraction 1-specific antibody response.

We evaluated the Yersinia pestis capsular (fraction 1 [F1]) antigen as a potential oral immunogen in mice. We found that single doses of as much as 0.4 mg of F1, administered by intragastric (ig) intubation, were unprotective and did not stimulate production of detectable levels of specific antibody. Three weekly ig doses resulted in low serum antibody levels that also did not provide protection against challenge with virulent Y. pestis. Assays of type-specific antibody following intubation and subsequent challenge with a subcutaneous inoculation of F1 revealed that the quantity of antigen intubated and the secondary IgG2a antibody levels were inversely related, suggesting the induction of tolerance to intragastrically administered F1 antigen. Transfer of spleen cells from intubated mice to F1 immune recipients failed to demonstrate suppression of specific antibody, indicating that the immune tolerance observed in intubated mice was not due to a T suppressor cell-mediated effect. The results of this study indicate that Y. pestis F1 antigen is not likely to be an efficacious immunogen for oral vaccination of mice against plague.

Nucleotide sequence and analysis of the gene in Borrelia burgdorferi encoding the immunogenic P39 antigen.

The P39 antigen is a specific, highly conserved, and immunogenic protein of Lyme disease spirochetes, Borrelia burgdorferi sensu lato. The nucleotide sequence of the gene encoding this protein was determined and found to be the first of two tandemly arranged open reading frames located on the spirochete's chromosome. These two open reading frames were designated bmpA for the gene encoding P39 and bmpB for the gene encoding the putative protein ORF2 encoded by the second open reading frame. The nucleic acid sequence identity for the two open reading frames was 62% while their deduced amino acid sequences were 52% identical. Comparison to sequence data bases demonstrated that the deduced amino acid sequences of both P39 and ORF2 were homologous to TmpC, a putative outer or cytoplasmic membrane lipoprotein of the syphilis spirochete, Treponema pallidum.

The effects of preoperative irradiation on primary tracheal anastomosis.

Preoperative radiotherapy was used in the management of selected patients with cancer of the lung or trachea who might subsequently require segmental resection of bronchus or trachea and reconstruction by primary anastomosis. This study was designed to determine the effects of varying dosages of preoperative irradiation on anastomotic healing. Two rings were resected from the cervical trachea of 20 dogs following irradiation with varying doses of cesium. There were no important adverse effects on healing of the trachea or adjacent organs in dogs receiving up to 3,500 rads. All dogs receiving a higher dose than this developed some anastomotic stenosis, which was severe in 6 of 8 animals. Similar adverse effects were observed in 2 patients managed by preoperative radiotherapy (4,000 rads in three weeks) and tracheal resection with primary anastomosis.

Medullary thyroid cancer: analyses of survival and prognostic factors and the role of radiation therapy in local control.

Records of 73 patients with medullary thyroid cancer were reviewed to assess prognostic factors and the role of external beam radiation therapy. Patients were treated between 1954 and 1992. The median age was 49 years (range 15-85), M:F ratio 1.6:1, and the median follow-up was 7.9 years. (2.5-34.6). The primary tumor size was < 1 cm in 10%, 1-4 cm in 53%, and > 4 cm in 37%. Multifocality was noted in 32%, and 23% had metastasis at presentation. Eight patients presented with inoperable tumors, 40% had gross, and 37% microscopic residual disease postthyroidectomy. Extraglandular extension was present in 56%, and 74% had pathologically involved lymph nodes. Treatment was by total or near total thyroidectomy in 41 patients; 37 had a lymph node dissection. Forty-six patients were irradiated, the dose of radiation ranging from 20 to 75.5 Gy; median was 40 Gy, treatment time median was 28 days and the median number of fractions was 20. The overall cause specific survival (CSS) was 70% and 57% at 5 and 10 years, respectively. In a univariate analysis, the following factors predicted for lower CSS: age as a continuous variable (p = 0.003), male gender (p = 0.008), presence of distant metastasis (p < 0.0001), lymph node involvement (p = 0.03), gross residual disease (p < 0.0001), tumor size > 4 cm (p = 0.05), extraglandular invasion (p < 0.004), vascular invasion (p = 0.007), diarrhea (p < .0007), and abnormal postoperative calcitonin (p = 0.02). On multivariate analysis only two factors were significant: the presence of extraglandular invasion, and postoperative gross residual disease. There was no difference in local/regional relapse free rate between patients receiving external radiation and those that did not, but in 40 high risk patients (microscopic residual disease, extraglandular invasion, or lymph node involvement), the local/regional relapse free rate was 86% at 10 years with postoperative external beam radiation (25 patients), and 52% for those with no postoperative external radiation (p = 0.049). To optimize local/regional tumor control, we therefore continue to advise external beam radiation in patients at high risk of local/regional relapse.

Pineal and suprasellar germinomas. Results of radiation treatment.

The results of radiation treatment of 52 patients with a tumor in the pineal region or a suprasellar germinoma are analyzed. The overall 5-year survival rate was 59%. Ten patients in whom initial biopsy confirmed pineal germinoma were all alive 2 to 121 months from diagnosis, although two developed meningeal seeding at 2 and 7 months. Twelve of 15 patients 25 years old or younger with an unbiopsied tumor in the pineal region were alive 12 to 225 months after irradiation, with a 5-year survival rate of 81%. In comparison only five of 16 patients older than 25 years with a pineal region tumor survived, a 5-year survival rate of 37%. This marked age dependence in survival rates was attributed to a high proportion of germinomas in the younger patients and gliomas in the older patients.

Radiation-induced cerebellar chondrosarcoma. Case report.

The authors report a case of chondrosarcoma arising in the cerebellum 16 years after treatment of a cerebellar malignant astrocytoma by subtotal resection and irradiation. It is thought that the chondrosarcoma arising within the intracranial cavity was a probable consequence of previous ionizing radiation.

Radiation treatment for medulloblastoma. A 21-year review.

One hundred and twenty-two patients with medulloblastoma received postoperative irradiation at the Princess Margaret Hospital, Toronto, from 1958 to 1978, inclusive. The surgical procedure in these patients was total resection (44 patients), subtotal resection (66 patients), or biopsy alone (12 patients). Twenty-five patients received adjuvant chemotherapy. Overall 5- and 10-year survival rates were 56% and 43%, respectively. Improved survival rates were associated with an increased degree of resection and with posterior fossa radiation doses of 5200 rads or more. The posterior fossa was the common site of first relapse (in 56 patients, 46%). Systemic metastases at first relapse occurred in 18 of 52 patients (35%), and were associated with the use of ventriculosystemic shunts. Millipore filters did not prevent systemic relapse in shunted patients. A subset of 15 patients who received a posterior fossa dose of 5200 rads or more after a total resection had a 5-year survival rate of 77%, which remained constant to 10 years. This result is considered to be the upper limit that can be achieved by current treatment methods.

The role of external radiation in the management of papillary and follicular thyroid cancer.

Review of 137 patients with differentiated thryroid carcinoma (82 papillary and 55 follicular) demonstrates that external radiation in moderate dosage eradicates microscopic disease. Its use could lead to a decrease in surgical complications by avoiding unnecessarily radical attempts at removing all potential microscopic disease. Gross tumor also responds favorably to external radiation, but its very slow regression rate has led to the misconception that external radiation is ineffective in the treatment of these cancers. Both radioiodine and thyroid hormone play an important role in the management of differentiated thyroid cancers, but their effectiveness should not be overestimated.