Biomedical subjects
Publications and source records attributed to P Lo Presti.
We show how entanglement can be used to improve the estimation of an unknown transformation. Using entanglement is always of benefit in improving either the precision or the stability of the measurement. Examples relevant for applications are illustrated, for either qubits or continuous variables.
Quantum operations describe any state change allowed in quantum mechanics, including the evolution of an open system or the state change due to a measurement. We present a general method based on quantum tomography for measuring experimentally the matrix elements of an arbitrary quantum operation. As input the method needs only a single entangled state. The feasibility of the technique for the electromagnetic field is shown, and the experimental setup is illustrated based on homodyne tomography of a twin beam.
A primitive neuroectodermal tumor (PNET) presented as a cerebral hemispheric mass in a 33-year-old man. Bone marrow metastases were discovered 11 months later. A cell line (CHP707m) was derived from these metastases. In culture, the cells showed features of neuronal differentiation, forming short neurites and synthesizing low-molecular-weight neurofilament protein. Northern blotting showed the tumor cells express nerve growth factor (NGF) receptor messenger RNA, and fluorescence-activated cell-sorting demonstrated NGF receptors on the cell surface. Western blotting showed CHP707m NGF receptors are truncated. The receptors are functional; they bind iodine 125-labeled mouse NGF with an affinity of 1.6 x 10(-9) M, and short-term treatment with NGF induces expression by the tumor cells of the proto-oncogene, c-fos. Although CHP707m is the first central nervous system PNET cell line proven to express NGF receptors, immunohistological survey of tissue sections prepared from human central nervous system PNETs showed that 13 of 35 contained NGF receptor-positive tumor cells. Thus, more than one-third of such tumors might be responsive to the effects of NGF.
Peripheral blood lymphocytes (PBL) from 43 patients with histologically confirmed ovarian carcinoma were stimulated in mixed lymphocyte-tumor culture (MLTC) with purified autologous tumor cells. Positive results, assessed as lymphocyte proliferation, were observed in 21 cases (48.8%). Lymphoid cells associated with ascitic fluid or infiltrating solid masses were in general less reactive than PBL as only 3/11 cases had positive MLTC. Tumor cells isolated from peritoneal effusions showed no significant difference in stimulatory potential as compared to the primary tumor. These results suggest that in an appreciable proportion of ovarian carcinoma patients (approximately 50%), lymphocytes have the potential to react to autologous tumor cells. Comprehension of the immunological mechanisms of antitumor resistance may have direct practical relevance for more effective treatment of neoplasms.
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