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Biomedical subjects

R Roncaglia

Publications and source records attributed to R Roncaglia.

29 records · Page 2Linked to original sources

[Prolonged preservation of venous allografts for vascular access in hemodialysis].

The technique of deep-freezing in liquid nitrogen of stripped saphenous veins permitted their long-term preservation, and the subsequent creation of a "bank" of venous allografts, used for arteriovenous internal shunts for hemodialysis. Histological, histochemical and immunological tests, and first clinical results have been favorable.

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Differential effects of c-myb and c-fes antisense oligodeoxynucleotides on granulocytic differentiation of human myeloid leukemia HL60 cells.

To gain some insight into the role of c-myb and c-fes in myeloid differentiation, the authors have analyzed the ability of HL60 cells to differentiate in response to several different inducers after inhibition of c-myb and c-fes function. This function has been inhibited almost completely by using deoxynucleotides complementary to two 18-nucleotide sequences of c-myb and c-fes encoding mRNA. After 5 days in culture, in several separate experiments with different oligomer preparations, more than 90% growth inhibition was observed in c-myb antisense-treated HL60 cells. At this time, independent of the differentiation inducer used, c-myb antisense-treated HL60 cells differentiate only along the monocytic pathway, whereas in sense oligomer-treated cultures, retinoic acid and dimethyl sulfoxide induced granulocytic differentiation. No perturbation of the HL60 cell growth was observed after 5 days of treatment with antisense c-fes oligomer. However, induction to granulocytic differentiation by retinoic acid and dimethyl sulfoxide resulted in progressive cell death, whereas monocytic differentiation by other differentiation inducers was only marginally affected. These results suggest that granulocytic, unlike monocytic, differentiation requires c-myb-conditioned proliferation and the activity of the protein encoded by c-fes.

Cell Cycle↗

[Gastrointestinal helminths of wild ruminants: observations on the chamois (Rupicapra rupicapra L.) in the Val Belviso reserve].

The results obtained in a survey on the gastrointestinal helminths of 32 chamois of the Riserva of Valbelviso on the Alpi Orobie are reported. All the animals were infested: the species identified with more frequence were O. circumcinta, M. marshalli, N. filicollis. Of great significance was the diffusion of N. filicollis, compared with other species of this genus, typical of the wild ruminants; Oe. radiatum, never previously observed in chamois, was also found. These results show that the promiscuity of wild and domestic ruminants in the pasture could interfere with the natural focality of the respective gastrointestinal nematodes.

Animals↗

Absence of rejection in cryopreserved saphenous vein allografts for hemodialysis.

Since November 1987, a total of 16 dialysis patients in the authors' Center, received a cryopreserved saphenous vein allograft (CSVA) as "third choice" vascular access. ABO and HLA-A-B compatibilities were determined but not considered. Saphenous veins were cryopreserved in liquid nitrogen for variable periods (1-6 mo), so that there was the opportunity to choose the most suitable in dimension. In February, 1989, a total of 13 patients retained a well-functioning access site, whereas three had died from causes unrelated to CSVA. Because rejection of venous allografts still is debated among angiologists, recipient T lymphocyte subsets (CD3-CD4-CD8 and CD4/8) were examined, as were lymphocytotoxic antibodies, before and on days 15 and 30 after implantation. No evidence of immunologic activation was found. Moreover, in 10 of 16 patients the surgeons subcutaneously implanted a fragment of CSVA, and an immunohistochemical study was carried out using an alkaline phosphatase-antialkaline phosphatase (APAAP) technique and a panel of monoclonal antibodies. Minimal infiltration of the outer layer of adventitia was found, mainly caused by monocyte macrophages (Leu M3+) with few T lymphocytes (CD3+). The authors conclude that rejection is not a major cause of failure in CSVA in dialysis patients.

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