Isotope-release cytotoxicity assay with the use of indium-111: advantage over chromium-51 in long-term assays.

The adaptation of indium-111-oxine (also known as 8-hydroxyquinoline) (111In Ox) chelate for long-term (18-48 hr) isotope-release assays of cell-mediated cytotoxicity (CMC) and its advantages over the use of 51 Cr are described. Labeling of DBA/2 P815 mastocytoma cells with 111InOx resulted in the incorporation of as many as a million counts per minute in 10(5) cells with no reduction in cell viability. 111InOx labeled both mouse and human tumor cells. 111InOx, like 51Cr, primarily labeled cytoplasmic constituents; up to 80% of the label existed in a releasable form. 111InOx was quantitatively released from labeled P815 in response to specifically sensitized C57BL/6 lymphocytes. The high labelling efficiency of 111InOx offered a significant advantage over 51Cr in 18- to 48-hour assays for CMC by reducing the counting error and thus making the assay more precise. Because of its higher labeling efficiency, 111InOx can be used in microcytotoxicity assays. 111InOx has the added advantage of a lower spontaneous release in culture than 51Cr. This feature of 111InOx also makes the calculation of specific isotope release more accurate than that achieved with 51Cr in long-term cytotoxic assays.

Brain metastases in patients with renal cell carcinoma: prognosis and treatment.

Thirty-four patients with renal cell carcinoma and brain metastases were reviewed to define important prognostic factors and treatment results. The following covariates were analyzed to determine their influence on survival: disease-free interval, serum calcium, number of central nervous system (CNS) metastases, weight loss, performance score, age, radiation therapy, surgery, and surgery plus radiation. The mean survival for all patients was 7.0 months (range, seven days to 32 months). The patients with a good performance score of 0-2 survived significantly longer (mean survival, 10.2 months) than those with a poor performance score of 3-4 (mean survival, 2.8 months; p = 0.0019). Surgery was associated with significantly improved survival (mean survival, 13.8 months versus mean survival, 4.2 months; p = 0.014). However, all the surgical patients were from the good performance score group, suggesting patient selection. Radiation was associated with an improved mean survival of 8.6 months versus 3.2 months. Performance score is a significant prognostic factor. Furthermore, the data support treatment with radiation therapy for patients with multiple CNS metastases and surgery followed by postoperative radiation therapy for patients with single CNS metastases.

Membrane type 1-matrix metalloproteinase (MT1-MMP) and MMP-2 immunolocalization in human prostate: change in cellular localization associated with high-grade prostatic intraepithelial neoplasia.

Membrane type 1-matrix metalloproteinase (MT1-MMP) is a known activator of latent MMP-2 (pro-MMP-2), and increased MMP-2 expression has been associated with tumor aggressiveness in prostate cancer. However, expression of MT1-MMP in human prostate tissue has not been described. We investigated the expression and immunolocalization of MT1-MMP and MMP-2 in the epithelial components of benign prostate epithelium, high-grade prostatic intraepithelial neoplasia (HGPIN), and prostate cancer. Tissue sections from the peripheral zone of 50 prostates (radical prostatectomy specimens) were chosen based on their containing benign glands, HGPIN, and prostate cancer glands. All 50 sections were immunostained for MT1-MMP and MMP-2 and were evaluated for staining pattern, uniformity, and intensity. Western blotting and gelatin zymography were done to confirm expression of MT1-MMP and activity of MMP-2, respectively. Comparisons were made between benign epithelium, HGPIN, and cancer. In benign glands, basal cells (BCs) uniformly stained intensely for MT1-MMP, whereas secretory cells (SCs) were rarely positive (P < 0.0001). Conversely in HGPIN, SCs showed consistent cytoplasmic staining (P < 0.0001). In cancer cells, staining was heterogeneous and varied from no staining to very intense staining in select glands. MMP-2 in normal tissue stained both BCs and the apical region of SCs, whereas in HGPIN, staining was observed in the SC in a predominantly cytoplasmic pattern. Similar to MT1-MMP, staining in cancer tissue for MMP-2 was heterogeneous; however, there was a significant association between the pattern of MMP-2 and MT1-MMP staining within the epithelial components of the cancer glands in individual specimens (P < 0.001). Finally, MMP-2 and MT1-MMP were confirmed to be expressed in the prostate tissues by gelatin zymography and Western blotting. In conclusion, we found that consistent changes in localization and intracellular distribution of MMP-2 and MT1-MMP were associated with the transition from benign prostate epithelium to HGPIN, suggesting that regulation of these enzymes is altered during the earliest stages of prostate cancer.

Distinct regions of thyroglobulin control the proliferation and suppression of thyroid-specific lymphocytes in obese strain chickens.

The effect of thyroglobulin (Tg)iodination on the proliferation and suppression of thyroid-specific lymphocytes was examined in vivo in the obese strain (OS) and Cornell strain chicken models of autoimmune thyroiditis. Spleen cells from OS chickens were able to transfer disease to Cornell strain recipients. The ability to transfer disease was markedly reduced if the donors were raised on an iodine-depleting regimen. This deficiency was corrected by immunization of donor chickens with iodinated Tg. Immunization with low iodine Tg was ineffective. Neonatal tolerance induction with either iodinated or low iodine Tg reduced thyroiditis in 2-week-old OS chickens. Spleen cells from these tolerized chickens transferred to 4-day-old OS chickens were less thyroiditogenic. These results indicate that thyroid autoreactive cells are responsive to iodinated Tg, but not to low iodine Tg. Both of the Tg preparations, however, can induce tolerance to the disease. We conclude that distinct regions of the Tg molecule regulate the proliferation and suppression of thyroid-reactive lymphocytes, respectively. Only the former is dependent on the iodination of Tg. These results emphasize the importance of Tg as a self-antigen and provide one mechanism by which iodine may induce autoimmune thyroiditis.

Phase II evaluation of 1-(2-chloroethyl)-3-(2,6-dioxo-(piperidyl)-1 nitrosourea (PCNU)(NSC-95466) in patients with advanced carcinoma of the lung.

Sixty-one assessable patients with advanced small cell and non-small cell carcinoma of the lung were given PCNU on an intermittent every 6-week schedule. Starting doses ranged from 75 mg/m2 for poor-risk patients to 100 mg/m2 for good-risk patients, depending on the bone marrow, liver, and renal status. Six partial responses (two small cell carcinoma, two adenocarcinoma, two large cell carcinoma) of short duration were documented. The major toxic effects were thrombocytopenia (35%) and leukopenia (16%). PCNU does not appear to have sufficient antitumor activity to warrant further investigation in advanced lung cancer.

Serum levels of immunoreactive thymosin alpha 1 and thymosin beta 4 in large cohorts of healthy adults.

Enzyme linked immunosorbent assays were used to measure serum levels of immunoreactive thymosin alpha 1 and thymosin beta 4 in 681 healthy adults (range 18 yr-101 yr). Immunoreactive thymosin alpha 1 was found to occur at a geometric mean of 540 pg/ml with a range from 252 to 1158 pg/ml. There were no differences in the levels when analyzed according to race, sex or age. Immunoreactive thymosin beta 4 was measured at a geometric mean of 12.6 ng/ml with a range from 6.9 to 23.0 ng/ml. There were no differences in the levels when analyzed according to race or sex, however, there was a slight upward trend with increasing age. This data may be useful as a reference when monitoring clinical studies, determining the kinetics of drug metabolism and distinguishing patient groups with elevated levels of either of these peptides.

The incidence and significance of thromboembolic complications in patients with high-grade gliomas.

Coagulation system abnormalities in patients with malignancy ranges from asymptomatic laboratory abnormalities to overt clinical manifestations. To determine the incidence and significance of clinically manifest thromboembolic phenomena in patients with high-grade gliomas, the records were analyzed of 77 patients that presented between January 1985 and June 1988. Fifteen patients (19%) had clinically manifest deep venous thrombosis and/or pulmonary emboli during the course of their disease. All these patients were ambulatory before and at the time of diagnosis of the event. The thromboembolic episodes occurred at the time of initial management of the primary tumor while there was documented clinical improvement in the functional status of the patient or at the time of progression of the disease. One patient died as a result of a pulmonary embolism; in two others, an embolism was a significant contributor to the patient's death. Anticoagulation resulted in complications in two of eight patients treated. Thromboembolic events occur with high frequency in patients with high-grade gliomas and contribute to the high morbidity and mortality seen in these patients. The optimum approach to screening and the treatment of these events has not been determined.

Oral etoposide in the treatment of hormone-refractory prostate cancer.

BACKGROUND: Hormone-refractory prostate cancer generally remains a chemotherapy-resistant tumor and therefore warrants the continued evaluation of promising agents. METHODS: Twenty-two eligible patients with hormone-refractory prostate cancer were treated with oral etoposide at a dosage of 50 mg/m2/day for 21 days in a 28-day cycle. Response was evaluated using standard solid tumor response criteria. RESULTS: There were two partial responses of 6 and 14 months' duration, respectively. Two patients had disease stabilization, one for 6 months and one for 12 months. Median survival was 31 weeks, with an overall 1-year survival of 30%. Reversible alopecia and myelosuppression were the primary toxicities noted. CONCLUSIONS: Single-agent oral etoposide has minimal activity in patients with hormone-refractory prostate cancer.

Vesicourethral anastomosis biopsy after radical prostatectomy: predictive value of prostate-specific antigen and pathologic stage.

OBJECTIVES: To assess the role of clinical parameters and pathologic stage in predicting a positive vesicourethral anastomosis (VUA) biopsy in patients with a rising prostate-specific antigen (PSA) level after radical prostatectomy. METHODS: Forty-five patients were referred for a rising PSA level after radical prostatectomy. Transrectal ultrasound evaluation included visualization of the VUA and VUA quadrant biopsies. The rate of positive biopsies (per core and per patient) was correlated with race, PSA level, and the radical prostatectomy pathologic stage. RESULTS: Overall, 53% of patients had a positive biopsy. In multivariate analysis, the dominant independent and synergistic clinical parameters determining positive biopsy rates were a PSA greater than 1 ng/mL at the time of biopsy and the pathologic stage (P = 0.04 and P = 0.02, respectively). Using a PSA cutoff point of 1.0 ng/mL, those patients with organ-confined disease and a PSA of 1.0 ng/mL or less showed no positive cancer cores (low-risk group). Conversely, 89% of patients with extraprostatic extension and a PSA greater than 1.0 ng/mL had a positive biopsy (P <0.01) (high-risk group). Patients with organ-confined disease and a PSA greater than 1.0 ng/mL or extraprostatic extension and a PSA 1.0 ng/mL or less (intermediate-risk group) had a significantly higher chance of having residual cancer than the low-risk group (P <0.025). CONCLUSIONS: The PSA level at the time of biopsy and the pathologic stage of the radical prostatectomy specimen were the strongest determinants of a positive biopsy. A combination of PSA and pathologic stage is useful for decisions regarding VUA biopsy. Patients with organ-confined disease and a PSA of 1.0 ng/mL or less do not appear to benefit from a VUA biopsy, and patients with extraprostatic extension and a PSA greater than 1.0 ng/mL have such a high probability (89%) of local recurrence at the VUA that biopsy may be unnecessary. It appears that VUA biopsy can be restricted to those patients with an intermediate risk (organ-confined disease with PSA greater than 1 ng/mL or extraprostatic extension with a PSA less than 1 ng/mL).

Dose-response and dose-survival advantage for high versus low-dose cisplatin combined with vinblastine and bleomycin in disseminated testicular cancer. A Southwest Oncology Group study.

One-hundred fourteen patients with advanced testicular cancer were randomized to treatment consisting of either high-dose (120 mg/m2, monthly) or low-dose (15 mg/m2, daily X 5 monthly) cisplatin, both combined with vinblastine and bleomycin. There were 60 (53%) complete remissions and 42 partial remissions for an overall response rate of 90%. An additional 11 patients, 4 with carcinoma and 7 with mature teratoma, following surgical cytoreduction, were rendered free of disease. There was a significantly higher complete response rate for high dose induction chemotherapy, 63%, when compared with low dose, 43% (P = 0.03). A survival advantage was also observed for patients receiving high-dose therapy (P = 0.009). For the subgroup of patients with maximal disease and embryonal +/- teratoma +/- seminoma histology there was a clear advantage in favor of high-dose over low-dose therapy both in complete response rate and survival (P = 0.03). There have been only four relapses, all occurring within 1 year of study entry. While there has been a higher frequency of leukopenia, renal, neuromuscular, and mucosal toxicity with high-dose therapy, thus far no irreversible toxicity leading to functional impairment has been seen. The authors have demonstrated a clear-cut relationship for dose of therapy, not only with response and survival, but with the increased potential for cure as well.

Thymosin treatment of chronic hepatitis B: a placebo-controlled pilot trial.

Chronic hepatitis B is a severe and frequently progressive disease. We assessed the safety and efficacy of thymosin fraction 5 and thymosin-alpha 1 in a prospective, placebo-controlled trial in 12 patients with chronic hepatitis B. All patients had histological and biochemical evidence of active liver disease for at least 6 mo before treatment and were positive for serum hepatitis B virus DNA and HBsAg. Seven patients received thymosin fraction 5 or thymosin-alpha 1 and five patients received placebo twice weekly for 6 mo. By the conclusion of the study (1 yr), serum aminotransferase levels had improved significantly in thymosin-treated patients, but not in the placebo group. Six (86%) of the thymosin treated patients and one (20%) patient given placebo cleared hepatitis B virus DNA from serum (p less than 0.04, Fisher's exact test). After treatment, replicative forms of hepatitis B virus DNA were present in the liver specimens of four of five placebo-treated patients but in only one of seven thymosin-treated patients (p less than 0.04, Fisher's exact test). Response to thymosin therapy was associated with significant improvements in peripheral blood lymphocyte and CD3 and CD4 counts and in in vitro production of interferon-gamma over initial values. No significant side effects were observed in patients given thymosin or in placebo-treated patients. Clinical, biochemical and serological improvement in patients responding to thymosin were sustained during 26 +/- 3 mo of follow-up. The results of this pilot trial suggest that thymosin therapy promotes disease remission and cessation of hepatitis B virus replication in patients with chronic viral infection.

Thymosin alpha1 treatment of chronic hepatitis B: results of a phase III multicentre, randomized, double-blind and placebo-controlled study.

Previous clinical trials have suggested that thymosin alpha1 (Talpha1), an immunomodulatory peptide, may be effective in the treatment of chronic hepatitis B (CHB). The aim of this study was to determine the efficacy of Talpha1 in a multicentre, placebo-controlled and double-blind study of 97 patients with serum hepatitis B virus (HBV) DNA- and hepatitis B e antigen (HBeAg)-positive CHB. Patients who had been hepatitis B surface antigen (HBsAg) positive for at least 12 months entered a 3-month screening period prior to randomization. Forty-nine patients received Talpha1 (1.6 mg) and 48 patients received placebo, twice weekly for 6 months, and were followed-up for an additional 6 months. At inclusion, both groups were comparable for age, gender, histological grading, and aminotransferase and HBV DNA levels. A complete response to treatment, defined as a sustained serum HBV DNA-negative status (two negative results at least 3 months apart) during the 12-month study, with negative HBV DNA and HBeAg values at month 12, was seen in seven (14%) patients given Talpha1 and in two (4%) patients treated with placebo (P = 0.084). Five (10%) patients given Talpha1 and four (8%) patients given placebo exhibited a delayed response (defined as sustained serum HBV DNA negativity achieved after the 12-month study period with negative HBV DNA and HBeAg values at the last assessment). A total of 12 (25%) patients given Talpha1 and six (13%) patients given placebo showed a sustained loss of HBV DNA with a negative HBeAg value during or following the 12-month study period (P < 0.11). These results do not confirm observations of treatment efficacy reported in other clinical studies.