Search PubMed⌕ Search

Biomedical subjects

G Biasi

Publications and source records attributed to G Biasi.

At least 73 records · Page 4Linked to original sources
PubMed1981

[Current indications for lumbar ganglionectomy. Analysis of a series of cases].

Data concerning a personal surgical series covering the last 10 years have been collected as far as cases regarded lumbar gangliectomy. The operative indication and incidence of this type of operation, performed for sclerotic obliterating arteriopathy of the lower extremities, out of total admissions and out of total direct reconstructive surgery operations, are analysed. Postoperative and long-term results of this type of surgery are then discussed. The data collected confirm the indication for lumbar gangliectomy alone or in association with other revascularization procedures in an albeit small number of patients, represented essentially by high risk cases or patients with extremely peripheral lesions.

Arterial Occlusive Diseases↗
PubMed1981

Leukemia-cell rejection due to T-region encoded antigens.

The role of H-2- and T-region products in determining allogeneic cell rejection was evaluated in H-2 congenic and recombinant mice by transplanting A1ATH and A6ATL leukemia cell lines induced in A.TH and A.TL strains, respectively, by Moloney murine leukemia virus.--In K- or D-region incompatible hosts transplant failure was observed, while in I + T-region incompatible hosts either rejection or prolonged survival was seen. In mice preimmunized with spleen cells from I- and/or T-region incompatible donors, leukemia cells were rejected by mice immune only to T-region products, and accepted by mice immune only to I-region products.--Cell-mediated cytotoxicity studies confirmed in vivo results. Secondary CTLs specifically directed against I-region products did not lyse the A1ATH and A6ATL cells, and secondary CTLs from A.TH and A.TL mice sensitized against A6ATL and A1ATH cells respectively exerted a lytic action specific for T-region products, while no activity was observed against I determinants.--The data suggest that tumor-transplant rejection may also be governed by histocompatibility antigens encoded in the T region.

Animals↗
PubMed1981

T lymphocyte tolerance and early appearance of virus-induced cell surface antigens in Moloney-murine leukemia virus neonatally injected mice.

Regression of Moloney-murine sarcoma virus- (M-MSV) induced sarcomas in normal adult mice is accompanied by generation of virus-specific cytotoxic T lymphocytes (CTL). However, when neonatal mice that were injected with Moloney-murine leukemia virus (M-MuLV carrier) were subsequently challenged as adults with M-MSV, the sarcomas did not regress nor did they generate CTL. This failure to produce CTL cannot be ascribed to nonspecific immunodepressive effects or to suppressor cell generation since M-MuLV carrier mice exhibit normal reactivity after allogeneic cell stimulation. Moreover, addition of M-MuLV-infected cells as the third party to cultures does not reduce activity of CTL from M-MSV immune mice. Since M-MSV and M-MuLV possess common antigens, the observed unresponsiveness was considered in relationship to induction of a T lymphocyte tolerance, which may follow introduction of foreign antigens at an early stage of development. In fact, it was observed that as early as 10 days after injection, thymus, lymph node, and spleen from M-MuLV carrier mice express virus-induced cell-surface antigens that not only are targets for M-MSV-immune CTL, but also induce in vitro a strong specific cytotoxic response. In addition, a cold target inhibition assay disclosed that the same antigens are shared by both M-MuLV infected and leukemia cells, even though they are less expressed on the surface of the former. The finding that the cytotoxicity of alloreactive lymphocytes from M-MuLV carrier mice is reduced after preincubation with M-MSV immune CTL confirms that virus infection does not bring about functional inactivation of lymphocytes. Finally, it was observed that virus antigen presence on lymphocytes from M-MuLV neonatally injected mice is closely related to subsequent leukemia development.

Animals↗
PubMed1980

[Our experience with treatment of aneurysms of the thoracic aorta].

From 1964 to 1977, 64 patients affected by aneurysm of the thoracic aorta were surgically treated at the 2nd Surgical Department of the University of Milan (Head: Prof. E. Malan). 25 patients had a true aneurysm and 34 a dissecting aneurysm. The various surgical techniques are discussed. The mortality rate and postoperative results are presented.

Aortic Dissection↗
PubMed1980

[25 years of experience in the treatment of Raynaud's disease and Raynaud-like syndromes].

Reference is made to a series of 620 cases of Raynaud's phenomenon observed at the University of Milan between 1951 and 1977. The following parameters are analysed: sex, age, aetiology (where known), incidence of involvement of the four limbs, presence or otherwise of a complete sign, percentage of trophic lesions, arteriographic picture, lab examinations performed. 534 thoracic sympathectomies were performed in 464 patients with Raynaud or Raynaud-like forms. The results are described.

Adult↗
PubMed1979

Lack of T-cell mediated cytotoxicity in M-MSV system depending on H-2 haplotypes.

The H-2 restriction phenomenon was evaluated with regard to the immune response to Moloney sarcoma virus (M-MSV)-induced tumours in the mouse. Using an in vitro 51Cr release assay the lytic activity of lymphocytes from M-MSV immune strains of mice, including several H-2 recombinant strains, was determined on leukaemic cell lines originally induced in mice of different strains by neonatal infection with Moloney leukaemia virus. In analogy with other experimental models, it was observed that a compatibility between effector and target cells at the K and/or D regions is generally necessary and sufficient to obtain the cytotoxic effect. However, for the H-2d and H-2b haplotypes, identity at the K or D region respectively was not sufficient for lysis to occur. Attempts to demonstrate that this lack of activity might be associated with the absence of H-2 linked Ir responder genes, were not successful.

Animals↗
PubMed1978

The role of H-2 and H-2-like determinants in syngeneic and allogeneic cytostasis.

Specific sensitization against H-2 determinants was affected by immunizing allogeneic mice with spleen and lymph node cells in H-2 congenic combinations. Lymph nodes from the sensitized and non-sensitized mice were respectively cultured together with H-2 syngeneic tumour cell lines. The growth and viability of the tumour cells was subsequently measured by the amount of radiothymidine incorporation. If the tumour cells incorporated less isotope when cultured with the immune cells than with the normal cells this was termed 'cytostasis'. To identify the H-2 genes controlling the sensitization phase in the cytostasis assay, we studied the effect on different transplantable tumour target cells of lymphoid cells from mice sensitized against different congenic spleen cells. The results suggest that the cytostasis assay can can measure an in vitro specific response to H-2-incompatible sensitizing antigens, and that I--B incompatibility, together with K and/or D, is essential to produce effectors. Furthermore, H-2 allogeneic sensitization could induce cytostasis even against tumour cells syngeneic for the H-2 halotype of the responder strain. The implications of these findings are discussed.

Animals↗
PubMed1978

Secondary in vitro generation of cytolytic T-lymphocytes (CTL's) in the murine sarcoma virus system. Virus-specific CTL induction across the H-2 barrier.

Following in vitro stimulation of murine sarcoma virus Moloney isolate (M-MuSV)-immune spleen cells with syngeneic antigenically related Moloney leukemia cells, highly efficient cytotoxic T-lymphocytes (CTL's) were generated. The cytotoxic effect was directed only against H-2-compatible target cells bearing M-MuSV tumor-associated antigens (TAA). However, in a cold target competition assay a weak but detectable capacity to block CTL activity was also obtained when allogeneic Moloney leukemia cells were added. Moreover, when M-MuSV-immune spleen cells from mice inoculated with virus 14 days previously were stimulated by allogeneic Moloney leukemia cells, a strong cytotoxic effect toward syngeneic and allogeneic tumor cells bearing M-MuSV TAA was elicited.

Animals↗
PubMed1977

[The SITAR Project. A new approach to diagnosis and surgical indication in arteriopathic patients].

The extreme variations with which atherosclerotic disease presents as regards progression index, arterial bed localization frequency, malignity and invasiveness in different ages and often as regards different anatomopathological aspects characterizing the formation and course of the primary lesion, mean that there are still many unknowns in the aetiopathogenesis, diagnosis and operative indications for this disease. Such problems are more and more important to the vascular surgeon who, with the development of atherosclerotic disease, sees the long-term results of his arterial reconstructive surgery compromised. The vascular surgeon is therefore directly involved with his colleagues in the internal medicine and pharmacological departments in problems connected with the pathogenesis of arteriosclerosis, and indeed he contributes to setting new constraints on the choice of prosthetic materials, for use in cases of bridge-work, and in the creation of new surfaces by means of thrombendarteriectomy. On the basis of such considerations, the IInd Surgical Clinic of Milan University began, in 1975, a study whose end purpose was the drafting of a clinical card designed for data computerization. Compiled by the surgeon, it is intended essentially for vascular surgeons. However, as it is personally considered that by the very nature of the disease, the atherosclerosis approach must be interdisciplinary, it also concerns physicians in the internal medicine, pharmacological and dietological departments.

Arterial Occlusive Diseases↗
PubMed1977

Inhibitory effect of YC8 leukaemia cell line on in vitro lymphocyte reactivity.

Mitomycin-treated transplantable Moloney virus-induced lymphatic leukaemia cells (YC8) not only failed to stimulate normal allogeneic lymphocytes in one-way mixed leucocyte culture (MLC) but also exerted a strong inhibitory effect on the proliferative response of normal lymphocytes, in MLC and after stimulation by mitogens. Potentially inhibitory factors which could be released in the culture fluids by the YC8 cells were not found, but a YC8-derived adherent cell subpopulation was identified as being responsible for the in vitro suppression.

Animals↗
PubMed1976

Generation of cytotoxic cells in absence of blastogenesis by mouse leukemic cells in mixed cultures.

Primary virus-induced murine leukemias and transplantable leukemic cell lines, originally induced by virus, chemical or physical agents, failed to stimulate normal spleen cells differing at the H-2 complex or at Mls locus in the one-way mixed leukocyte culture. Lack of stimulation seems at least partially due to a nonspecific inhibitory effect since in a "three-party" culture system the leukemic cells interfered with the mixed leukocyte reaction (MLR) of normal allogeneic cells. Characterization of the leukemic cell populations used, according to their T or B cell origin, disclosed that in most cases T cell markers were present. Also, no Ia antigens were detected on leukemic cells. Furthermore, using a 51Cr release assay, leukemic cells could sensitize allogeneic normal lymphocytes to kill specifically normal as well as leukemic targets, even when no MLR was detected in parallel cultures.

Animals↗