Elevated ribonuclease activity in the thymus and white blood cells of genetically cancer prone mice.

Ribonuclease activity in cell-free thymus homogenates was elevated for five strains of mice genetically predisposed toward leukemia or reticulum cell neoplasms (AKR, C58, PL, RF, and SJL). Such increased activity was directed against polyuridylic acid and was observed in 8-wk old mice, well before the onset of neoplastic transformation. Similarly, white blood cell ribonuclease activity was elevated in mice of the strains AKR, C2H/He, PL and RF. Statistical analysis indicated that such elevated activity in these strains related to their high incidence of spontaneous neoplastic disease. Elevated ribonuclease activity thus represents a new biochemical marker relating to the genetic propensity of some strains of mice to die prematurely of spontaneous neoplasia.

The dependence of successful immunotherapy on adequate tumor burden as shown by the treatment of AKR leukemia with poly A-poly U.

The therapeutic efficacy of polyadenlyic-polyuridylic acid (poly A-poly U) on the transplantable AKR leukemia varied with the dose of tumor cells implanted. The greater the number of AKR tumor cells injected into 8-week-old AKR mice free of clinical evidence of cancer, the greater the effect of poly A-poly U in mediating host immunologic control of the tumor. Poly A-poly U was either ineffective or could enhance tumor growth when smaller doses of tumor cells were transferred. The efficacy of an immune adjuvant depended on a tumor burden affording optimum host responsiveness. This does not necessarily arise in the host bearing minimal tumor burden.

A proper sequence for the treatment of B16 melanoma: chemotherapy, surgery, and immunotherapy.

The therapeutic effectiveness of surgery, chemotherapy, and immunotherapy alone and in combination were studied in the B16 melanoma model. The sequence of chemotherapy and immunotherapy as adjuvants to surgery proved important: Chemotherapy was significantly better when given before surgery; immunotherapy was more effective when delivered after surgery. The most effective therapeutic regimen was a combination of all three modalities: a single course of chemotherapy preceding surgery followed by immunotherapy.

A white blood cell RNase assay for the possible monitoring of malignancy.

The RNase activity observed in the sera of leukemic guinea pigs was compared to that observed in white blood cell (WBC) lysates of the same animals. The WBC-associated RNase activity directed against polyuridylic acid decreased with the progression of neoplastic disease, though serum RNase activity remained unchanged. With certain forms of cancer, therefore, variations in cell RNase may be more sensitive markers than changes in serum RNase for the evaluation of the progression or regression of disease.

Abnormal profile of human nucleolytic activity as a test for cancer.

Serum samples from patients with various malignancies including acute nonlymphocytic leukemia (ANLL), brain tumor (BT), Hodgkin's disease (HD), and non Hodgkin's lymphoma (NHL) were evaluated for nucleolytic activity against six synthetic polynucleotides: polyadenylic acid, polyuridylic acid, polycytidylic acid, polyguanylic acid, polyadenylic-polyuridylic acid, and polyguanylic-polycytidylic acid; The enzyme activity was determined spectrophotometrically by following the degradation of substrate to acid-soluble nucleotides. Most patients had elevated serum RNase activity at the 95% confidence level when compared to 30 controls. Included in this group were 67% of patients with ANLL, 46% of patients with BT, 73% of patients with HD, and 67% of patients with NHL. These data confirmed the earlier suggestion that elevated serum nuclease activity is found in patients with neoplastic disease. However, whether or not a serum was identified as abnormal depended on the substrate used in the assay; this underscored the need to test samples against a variety of polynucleotides. Alterations in serum nucleolytic activity represent an important marker of neoplastic disease and can serve as the basis for a useful clinical screening device.

Alterations in ribonuclease activities in the plasma, spleen, and thymus of tumor-bearing mice.

Six transplantable murine tumor models were evaluated for changes in RNase activity. This study was conducted with spleen and thymus homogenates, as well as with plasma collected from tumor-bearing mice. Nuclease activity directed against the synthetic substrates, polyadenylic acid, polyuridylic acid, and polycytidylic acid, was measured and the data obtained for tumor-bearing animals were compared to their normal counterparts. Elevated activity against polyuridylic acid was observed in the plasma of all tumor-bearing mice. Although not as all inclusive, RNase levels in both the spleen and thymus were generally altered as well. The observance of unilateral changes in nuclease activity directed against the synthetic substrates demonstrated that, in most cases, two or more enzymes were being detected. The assay may have some eventual value in the monitoring of cancer

Enhancement of spontaneous C3H/HeJ mammary tumorigenesis by long-term polyadenylic-polyuridylic acid therapy.

Female C3H/HeJ mice received weekly s.c. injections of 2 mg polyadenylic-polyuridylic acid. Therapy was initiated at either 2 or 9 months of age. In both cases, poly-adenylic-polyuridylic acid-treated animals developed the spontaneous mammary carcinoma associated with this strain more rapidly. Because the opposite result was formerly observed for AKR spontaneous leukemia, the data indicate the polyadenylic-polyuridylic acid has no generalized antineoplastic effect upon spontaneous tumors genetically associated with specific murine strains.

The age-dependent efficacy of polyadenylic-polyuridylic acid therapy upon the development of spontaneous leukemia in AKR mice.

The synthetic double-stranded polynucleotide, polyadenylic-polyuridylic acid, has been shown to increase the long-term survival of AKR mice. In order to determine whether this effect was age dependent, polyadenylic-polyuridylic acid was administered to AKR mice starting at 2, 4, 6, or 8 months of age. The best therapeutic effect was achieved when polyadenylic-polyuridylic acid treatments were begun at 2 months of age, and there was no beneficial effect when begun at 8 months of age.

Application of laser cytometry to the analysis of immunologically induced in vitro lymphocyte responsiveness.

This study defines an assay (laser analysis) that is a significant advance in our ability to quantitate and analyze immunologically induced in vitro lymphocyte responsiveness. Laser analysis is demonstrated to parallel radionucleotide incorporation (3H-thymidine) in terms of kinetic pattern, dose response characteristics, and statistical accuracy while exeeding radionucleotide incorporation in sensitivity. Direct quantitation of lymphocyte responsiveness, in terms of cellular proliferation, disclosed that substantial numbers of small lymphocytes were produced during in vitro stimulation with mitogen (concanavalin A) or antigen (streptokinase-streptodornase) in addition to the expected increase in lymphoblasts. The magnitude of this "total cellular response" (lymphocytes plus lymphoblasts) was found to be similar for antigen and mitogen stimulation, a finding not suggested by routine radionucleotide incorporation or morphological assays.

Effects of broad-spectrum antimycobacterial therapy on chronic pulmonary sarcoidosis.

BACKGROUND: Sarcoidosis is an idiopathic, granulomatous disease for which molecular and immunologic studies have shown an association between it and mycobacterial antigens. Microbial antigens can reduce expression of the tyrosine kinase Lck, which has been associated with sarcoidosis severity. Here we investigate the efficacy of Concomitant Levofloxacin, Ethambutol, Azithromycin, and Rifampin (the CLEAR regimen) for treatment of chronic, pulmonary sarcoidosis. METHODS: Fifteen chronic, pulmonary sarcoidosis patients with forced vital capacities (FVC) between 45-80% of predicted were enrolled in this open-label trial. The primary efficacy endpoint was change in absolute FVC from baseline to completion of therapy. Secondary endpoints were change in functional capacity measured by Six Minute Walk Distance (6MWD) and quality of life assessment measured by St. George's Respiratory Questionnaire (SGRQ). RESULTS: Of 15 patients enrolled, 11 completed 4 weeks of therapy, and 8 completed 8 weeks of therapy. The CLEAR regimen was associated with an increase in FVC of 0.23 liters at 4 weeks and 0.42 liters at 8 weeks (P=0.0098 and 0.016, respectively). The 6MWD increased by 87 meters from baseline to 8 weeks (p=0.0078). The mean score of the validated SGRQ was improved at 8 weeks over baseline (p=0.023). Normalized expression of Lck and NF-κB was observed in those with clinical improvement. CONCLUSIONS: The CLEAR regimen is associated with improved absolute FVC, as well as increased functional capacity and quality-of-life in selected chronic pulmonary sarcoidosis patients. Larger, randomized, controlled trials are needed to confirm these findings and to identify patients most likely to benefit from therapy. ClinicalTrials.gov number NCT01169038.