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Biomedical subjects

G Luciani

Publications and source records attributed to G Luciani.

At least 37 records · Page 2Linked to original sources

Amniotic membrane diffusion chambers: a new possibility for pancreatic islet transplantation.

In order to avoid the host foreign-body reaction which is probably responsible for the long-term failure of the artificial membrane diffusion chambers currently used for protecting the implanted islet tissue from rejection, we tested the human amniotic membrane as a possible new tool for enclosing transplanted islets of Langerhans. Bag-shaped chambers were made with human amniotic membranes and the diffusion of 125 I-Insulin out and of D-glucose into the chambers was measured. The diffusion patterns of insulin and glucose were shown to be better than those described for the best artificial membranes, the 50% diffusion being reached at min 42 for 125 I-Insulin and at min 11 for D-glucose. Moreover, it was shown that no lymphocytes diffused into the amniotic membrane chambers. These results, together with the already known characteristics of the human amniotic membrane, induce us to propose it as a suitable material for further experimental work in islet tissue transplantation.

Amnion↗

Glucocorticoid inhibitory action on the response to PHA of residual circulatory lymphocytes in renal transplant patients following immunosuppressive therapy.

The inhibitory effect of glucocorticoids on the in vitro response to phytohaemagglutinin of the residual circulating T lymphocytes in renal transplant patients during maintenance immunosuppressive therapy with glucocorticosteroids and azathioprine has been investigated. As in normal subjects, the steroid-induced inhibition of transplanted patients' lymphocyte response was inversely correlated with the mitogen concentration used. On the other hand, the response of the various lymphocyte preparations from transplanted patients appeared less inhibited by steroids than the corresponding preparations from normal subjects. The addition to the culture of the adherent cell product interleukin 1 was effective in removing to a similar extent the steroid inhibitory effect on lymphocytes from normal and transplanted subjects. Thus, the lesser inhibitory effect of glucocorticoids on transplanted patient lymphocytes could be explained by the higher percentages of monocytes present in all peripheral blood mononuclear cell preparations. These results suggest that during immunosuppressive therapy with glucocorticoids and azathioprine the residual circulating lymphocytes have a responsiveness to in vitro dexamethasone suppression similar to that of normal peripheral blood lymphocytes.

Antibodies, Monoclonal↗

Autoimmunity in ocular and generalised myasthenia gravis.

Restricted ocular myasthenia gravis (OMG) and generalised myasthenia gravis (GMG) have been shown to differ in a number of respects. In OMG, antiacetylcholine receptor, antistriational and antinuclear antibodies were rare relative to their frequency in GMG. In contrast, antithyroid antibodies and a history of thyroid disease were much more prevalent in OMG than in GMG, OMG was not associated with the female predominance seen in GMG and appeared to be relatively common in some races rather than others. It is suggested that different pathogenetic mechanisms are responsible for these two forms of MG.

Age Factors↗

Imbalances in peripheral blood T-cell subpopulations in renal transplant patients.

The distribution of T-lymphocyte subpopulations bearing receptors for the Fc portion of IgG (TG) or IgM (TM) was monitored in 22 renal allograft recipients treated with immunosuppressive therapy and in 10 uraemic patients on haemodialysis. No significant difference in the distribution of T cells and T-cell subsets was found between normal controls and haemodialysed patients. In transplanted patients, however, a significant reduction of the total T-cell percentage (P less than 0.005), of TM subset percentage (P less than 0.025) and absolute number (P less than 0.005) and of TG absolute number (P less than 0.05) was observed. Considering patients with allografts functioning for more than 1 year only, the reduction in TM cells in terms of percentage (P less than 0.0005) and absolute number (P less than 0.025) was significant, while TG subset levels did not change significantly. In patients transplanted less than 1 year previous to our study, total T cells and T-cell subsets were reduced significantly only as absolute numbers. During the 1st year we observed several increments of TM values towards normal levels, especially in the first 2 months after transplantation. During this period, TM subset levels sharply increased at acute rejection crisis and returned to previous values with rejection reversal. Our results suggest that the TM subset plays a prominent role in the mechanisms involved in the immunological response to allografts, and therefore repeated TM cell monitoring could be useful in the follow-up of renal transplant patients.

Graft Rejection↗

Study of the metabolic effects of bunitrolol (Koe 1366) in angina induced by catecholamine infusion.

In ten angina patients responding with a myocardial anaerobic metabolic pattern to isoproterenol infusion, a new beta-blocking agent, bunitrolol, was effective in normalizing the myocardial lactate extraction ratio. The correlation with lipid metabolism was also interesting because beta-blocker action reduced significantly arterial non-esterified fatty acids (NEFA) level as well as myocardial NEFA extraction. The metabolic behavior suggests the effectiveness of bunitrolol in the treatment of ischemic heart disease.

Angina Pectoris↗

A new HLA antigen apparently not controlled by the known HLA loci.

The human allogeneic serum RM3 recognizes a lymphocyte structure inherited with the HLA chromosome. Population studies show several positive associations with antigens of the HLA-A and HLA-B series. Negative association have been found with antigens of the HLA-C series. Moreover the distribution of the RM3 factor is in Hardy-Weinberg equilibrium with that of the HLA-C alleles. However, serological investigations (namely the 'lysostrip' technique) bring evidence that RM3 serum does not appear to contain antibodies directed against any of the antigens of the HLA-A, B and C series. The study of a segregant family, showing a crossing over between the HLA-A and HLA-B loci, shows that the RM3 factor segregates on the side of the HLA-A locus. In conclusion, within the limits of the serological approach used, the present study presents evidence of a new serologically defined HLA locus, different from those so far described.

Alleles↗

Antigenic determinants of the W28 molecule different from but spatially close to W28 determinant.

The existence of two allelic determinants, subtypic to W28 (named TO54 and TO55), and of an antibody cross-reacting W28 times HL-A10, is demonstrated. These new determinants have been studied by means of population and family studies and with the following serological techniques: absorption, elution, lysostrip and blocking by F(ab)-2 fragment. The results suggest that determinants TO54 and TO55 are very similar each other and are spatially close to the supertypic factor.

Adsorption↗

[Exposure to wood dust in a group of carpentry craftsmen in secondary wood processing].

In order to evaluate the risk connected with wood dust exposure in millwork on a group of 13 craft industries, 74 area dust samplings and 74 personal dust samplings were made. In personal samplings both the total portion and the respirable fraction were calculated. Area samplings showed dust levels (average, standard deviation, fiducial limit, FLS95%) under ACGIH TLV-TWA for soft wood dust: TLV-TWA for hard wood was basically reached, and OTL levels gave evidence for high risk of exceeding TLV-TWA in the medium-long term. The exposure levels by personal samplings (average, standard deviation, fiducial limit, FLS95%) were clearly over TLV-TWA, both for hard woods and, although less clear, for soft woods. OTL levels gave evidence for a frankly unacceptable exposure condition in the medium-long term. Differences between average levels of total dust exposure (2.5 mg/m3) and respirable portion (2.3 mg/m3) were not statistically significant (p > 0.05) as well as the differences among the 4 groups of companies with homogeneous product activity (p > 0.05). In consideration of toxicological peculiarity of wood dust and carcinogenicity of wood manufacture as exposure circumstances classified in group 1 by IARC, the results show the need for prevention measures to reduce workers' exposure risk, by means of environmental improvement and better work organization, technological structures, individual attitudes and personal protection.

Air Pollutants, Occupational↗