Improved detection of fluorescently labeled microspheres and vessel architecture with an imaging cryomicrotome

Due to spectral overlap, the number of fluorescent labels for imaging cryomicrotome detection was limited to 4. The aim of this study was to increase the separation of fluorescent labels. In the new imaging cryomicrotome, the sample is cut in slices of 40 μm. Six images are taken for each cutting plane. Correction for spectral overlap is based on linear combinations of fluorescent images. Locations of microspheres are determined by using the system point spread function. Five differently colored microspheres were injected in vivo distributed over two major coronaries, the left anterior descending and left circumflex artery. Under absence of collateral flow, microspheres outside of target perfusion territories were not found and the procedure did not generate false positive detection when spectral overlap was relevant. In silico-generated microspheres were used to test the effect of background image, transparency correction, and color separation. The percentage of microspheres undetected was 2.3 ± 0.8% in the presence and 1.5 ± 0.4% in the absence of background structures with a density of 900 microspheres per color per cm3. The image analysis method presented here, allows for an increased number of experimental conditions that can be investigated in studies of regional myocardial perfusion

From ‘Hellstrom Paradox–to anti-adenosinergic cancer immunotherapy

Cancer therapy by endogenous or adoptively transferred anti-tumor T cells is considered complementary to conventional cancer treatment by surgery, radiotherapy or chemotherapy. However, the scope of promising immunotherapeutic protocols is currently limited because tumors can create a ‘hostile–immunosuppressive microenvironment that prevents their destruction by anti-tumor T cells. There is a possibility to develop better and more effective immunotherapies by inactivating mechanisms that inhibit anti-tumor T cells in the tumor microenvironment and thereby protect cancerous tissues from immune damage. This may be now possible because of the recent demonstration that genetic deletion of immunosuppressive A2A and A2B adenosine receptors (A2AR and A2BR) or their pharmacological inactivation can prevent the inhibition of anti-tumor T cells by the hypoxic tumor microenvironment and as a result facilitate full tumor rejection [Ohta A, Gorelik E, Prasad SJ et al (2006) Proc Natl Acad Sci USA 103(35):13132–3137]. This approach is based on in vivo genetic evidence that A2AR play a critical role in the protection of normal tissues from overactive immune cells in acutely inflamed and hypoxic areas. The observations of much improved T-cell-mediated rejection of tumors in mice with inactivated A2AR strongly suggest that A2AR also protects hypoxic cancerous tissues and that A2AR should be inactivated in order to improve tumor rejection by anti-tumor T cells

Cyclosporin and tacrolimus increase plasma levels of adenosine in kidney transplanted patients

8reservedThe immunosuppressive agents, cyclosporin (CsA) and tacrolimus (FK506), display cardioprotective activities. The mechanism would consist on the inhibition of the enzyme, adenosine kinase (AK), leading to an increase in adenosine (ADO) levels. ADO, inosine (INO) and nucleotide plasma levels were measured in kidney transplant recipients before and 1, 2, 4, 6 and 8 h after the administration of CsA or FK506. After CsA and FK506 administration, ADO plasma levels significantly increased, reaching a peak level after 2 h (483 ± 124 and 429 ± 96 nm, respectively), and then progressively declined. Calculated peak values (tmax) of ADO were slightly delayed with respect to those of CsA and FK506. Treatment with rapamycin did not influence the phenomenon. The dynamic profile of plasma changes of ADO, nucleotides and INO were consistent with the inhibition of the enzyme, AK. ADO increase may be clinically relevant in terms of anti-ischaemic, tissue protecting, and immunosuppressive activities as well as in terms of nephrotoxicitymixedCapecchi, PIER LEOPOLDO; Rechichi, Serena; Lazzerini, PIETRO ENEA; Collini, A; Guideri, Francesca; Ruggieri, Giuliana; Carmellini, Mario; LAGHI PASINI, FrancoCapecchi, PIER LEOPOLDO; Rechichi, Serena; Lazzerini, PIETRO ENEA; Collini, A; Guideri, Francesca; Ruggieri, G; Carmellini, Mario; LAGHI PASINI, Franc