Observation of breather-like states in a single Josephson cell

We present experimental observation of broken-symmetry states in a superconducting loop with three Josephson junctions. These states are generic for discrete breathers in Josephson ladders. The existence region of the breather-like states is found to be in good accordance with the theoretical expectations. We observed three different resonant states in the current-voltage characteristics of the broken-symmetry state, as predicted by theory. The experimental dependence of the resonances on the external magnetic field is studied in detail.Comment: 7 pages, 8 figure

Identification, purification, and partial characterization of a factor from rabbit serum that inhibits prolactin secretion by pituitary cells cultured in vitro

A biological factor that inhibited prolactin secretion by pituitary cells cultured in vitro was identified, purified, and partially characterized from normal rabbit serum. This biological factor was also found to potentiate dopamine-mediated aortic contraction using rabbit aortic strips in vitro. Following SDS-PAGE, this factor displayed an apparent Mr of 17 kDa, which is different from the Mr of most known endogenous factors having an inhibiting activity on pituitary prolactin secretion, suggesting that this may be a yet-to-be identified novel molecule

Stimulation of guinea pig isolated atria by aflatoxins

Acute effects of aflatoxins (AF), and in particular cardiac actions, have not been examined as much as chronic toxicity. Thus, in the present study we evaluated the effects of specific AF on isolated guinea pig atria. Isoprenaline (ISO, 4 x 10(-9)), AFB(1) (3 x 10(-6) and 6 x 10(-5) M) and AFG(1) (3 x 10(-6) and 6 x 10(-6) M) contracted the isolated guinea pig atria, leaving the preparation hyperresponsive to ISO. These properties of AF are of interest as they could be responsible of certain cardiotoxic effects described in the literature. (C) 2000 Elsevier Science Ltd. All rights reserved

DRUG SENSITIVITY OF DIFFERENT TUMOR LESIONS FROM THE SAME PATIENT EVALUATED BY A SHORT-TERM ASSAY

A short-term antimetabolic assay, which considers the interference with [3H]thymidine incorporation as an indicator of drug effect, has been used to comparatively assess the chemosensitivity of different tumor lesions from the same patient. The analysis was performed on primary tumors and their synchronous metastases from 67 patients with breast, ovarian, gastrointestinal and germ cell testicular tumors. A remarkable difference in sensitivity to cytostatic drugs was observed between the two lesions. In contrast, a strong association in chemosensitivity (81.7% agreement rate; p less than 0.01) was observed between two synchronous metastases from 17 patients with breast, ovarian, germ cell testicular tumors or malignant melanoma. In addition, the predictive relevance of the antimetabolic assay on clinical response to chemotherapy was analyzed in relation to the type of tumor lesion tested in vitro in a retrospective correlative study on 57 patients with advanced ovarian and germ cell testicular tumors. The objective clinical response was significantly correlated to the in vitro sensitivity of metastases (83.7% agreement rate; p less than 0.01), but not to that of the primary tumor

Biological markers as indicators of pathological response to primary chemotherapy in oral-cavity cancers

The predictive role in terms of pathological response and prognostic role of biomarkers such as GST-\u3c0, p53, bcl-2 and bax expression, immuno- histochemically detected, and of the S-phase cell fraction, autoradiographically determined as thymidine labeling index (TLI), were investigated within a prospective randomized phase III clinical trial on squamous-cell carcinoma of the oral cavity, including surgery or primary chemotherapy (PCT), which foresaw the prospective determination of biological markers. Pathological response was defined as the achievement after PCT of a pathological complete remission or the presence of microresidual disease. The study was performed on tumors obtained from a series of 100 previously untreated patients with resectable T2-4N0-2M0 carcinoma. All biomarkers were unrelated, except for an inverse relation between TLI and GST-\u3c0 and a direct relation between bcl-2 and bax expression. In patients treated with surgery alone, 3-year disease-free survival (DFS) appeared to be weakly, but not significantly, related only to GST-\u3c0 and p53 expression. In patients treated with PCT, pathological response and DFS were independent of p53 expression and cell proliferation. Conversely, low GST-\u3c0 and bax expression were indicative of pathological response but lost relevance as predictors of DFS, whereas absence of bcl-2 was associated with high probability of 3-year DFS in the overall series as well as in non-responding patients. Within this latter sub-set, all patients with bcl-2-positive tumors relapsed within I year of surgery, whereas a 60% probability of 3-year DFS was observed for patients with bcl-2-negative tumors (p - 0.02). This interim analysis appears to indicate that some biofunctional markers can provide information on pathological response to PCT and could help in understanding treatment efficacy at a cellular level

The clinical predictivity of biomarkers of stage III-IV epithelial ovarian cancer in a prospective randomized treatment protocol

BACKGROUND: The aim of this study was to define the clinical relevance of functional biomarkers, prospectively assessed in a randomized clinical protocol, in patients with Stage III-IV epithelial ovarian cancer. The protocol compared cisplatin with polychemotherapy that included cisplatin and cyclophosphamide. METHODS: In a subset of 168 patients with invasive epithelial ovarian cancer cell proliferation was determined by the 3H-thymidine labeling index, DNA ploidy was assessed by flow cytometry, and the expression of p53, bcl-2, and glutathione S-transferase-pi (GST-pi) was evaluated by immunohistochemistry using the antibodies PAb1801, anti-bcl-2, and GST-pi, respectively. RESULTS: Cell proliferation, DNA ploidy, and the expression of p53, bcl-2, and GST-pi were generally unrelated to one another and unrelated to clinicopathologic features, except for an association between DNA ploidy and the rate of cell proliferation. All biologic variables except bcl-2 were slightly related to tumor grade. DNA ploidy emerged as a predictor of clinical complete response and 3-year overall survival, regardless of treatment type or residual disease. Conversely, except for a favorable outcome for patients with tumors not expressing bcl-2 who were treated with cisplatin, no definitive patterns of predictivity for short term or long term clinical outcomes were observed for the other biomarkers studied. CONCLUSIONS: DNA ploidy appears to be the most clinically relevant biomarker for epithelial ovarian cancer. More information is needed to understand the role of the other markers studied in this tumor type