[Biochemical diagnosis of insulinoma: correlations between blood glucose, blood insulin and the titer of plasma non-esterified fatty acids during fasting and during various diagnostic tests]

The difficulty of clinical and biochemical diagnosis of insulinoma lies in the extreme variability of both clinical symptoms and glycaemia/insulinaemia levels, so that neither parameter is a totally reliable diagnostic indicator. The possibility of introducing a third parameter, the non-esterified fatty acid (FFA) level, to enhance the reliability of insulinoma diagnosis was therefore investigated. The behaviour of glucose, insulin and plasmatic FFA levels and the correlation of the three parameters were studied in 4 patients whose suspected insulinomas were later surgically confirmed. The tests applied were as follows: 24 hour fast followed by endovenous glucose, oral glucose administration, tolbutamide stimulus test, adrenaline and glucagon tests. The results revealed anomalies in insulinaemia and glycaemia behaviour such as have already, in part, been described in organic hyperinsulinism, e.g. the discrepancy between insulin and glucose levels after prolonged fasting. It was also clear that the parameters examined still leave much room for uncertainly in the biochemical diagnosis of insulinomas. Numerous anomalies were also observed in the behaviour of plasmatic FFA. For example lipid mobilisation was often reduced in conditions that normally stimulate it (fasting, the administration of catecholamines). Equally the prolonged blockage of lipid mobilisation was encountered in the presence of factors that normally reduce lipolysis (endovenous glucose). On the basis of these results it is suggested that a combined assessment of glucose and plasmatic FFA levels may be a more sensitive diagnostic indicator of insulinoma than the insulin/glucose ratio commonly reported in the literature. The mechanism behind the lipid mobilisation anomalies of insulinomas is also discussed in the light of its apparent connection with the glucose/insulin interaction characteristic of the condition.

[A case of scleroderma with sclerodermic renal crisis and association with the Vogt-Koyanagi-Harada syndrome]

We report a case of scleroderma with "scleroderma renal crisis", (arterial hypertension, high plasma renin levels and impaired renal function) associated with a Vogt-Koyanagi-Harada syndrome which includes neurological, ophthalmic and cutaneous symptoms. This case is interesting not only because both syndromes are rare and have not previously been reported in association, but because it suggests a pathogenetic relationship between two autoimmune diseases.

[Biological screening of immuno-mediated marrow insufficiency by means of the CFU-GM assay]

We studied in agar growth behaviour of bone marrow granulocyte-macrophage progenitor cells (CFU-GM) in 16 patients with marrow failure in order to discriminate patients with cells inhibiting granulopoiesis both in bone marrow and peripheral blood. Our experimental design was based on: a) agar culture of bone marrow cells before and after treatment with antilymphocyte globulin (AGL); b) agar co-culture of marrow cells with autologous lymphocytes from peripheral blood. ALG treatment of marrow cells determined CFU-GM growth increase in 4 out of 10 patients; in the same patients co-culture with autologous lymphocytes showed a significant inhibition of CFU-GM growth. The growth enhancement induced by ALG treatment "in vitro" associated with growth inhibition in the coculture suggests the existence of a lymphocyte population suppressing the granulopoiesis both in bone marrow and peripheral blood. With this work we propose an experimental model in order to discriminate marrow failure based on cell-mediated suppression of CFU-GM growth in patient susceptible of immunosuppressive therapy with ALG.

[Evaluation of the distribution spectrum of bone marrow granulocyte-CFU and its prognostic significance in dysmyelopoietic syndromes]

We have studied bone marrow CFU-GM growth behaviour in 13 patients with Dysmyelopoietic Syndrome by means of the analytical scoring at two sequential times of aggregates. In this way we have distinguished aggregates according to their size, in clusters or colonies and grouped them according to their "in vitro" appearance time, transformation from cluster to colony, "in vitro" survival time and "in vitro" degeneration time. This statement of the study allow us to map CFU-GM subtypes in a percentage distribution related to the total growth of CFU-GM. Comparisons between absolute number of growth of different CFU-GM subtypes in DS vs Normal subjects show both significant and not significant differences, while comparisons between percentages of growth in DS vs Normal subjects did not show significant differences. With this work we suggest an outline for the study and the interpretation of CFU-GM growth patterns in the haematological disorders at risk of evolution in acute nonlymphocytic leukemia.

[Evaluation of the distribution spectrum of bone marrow granulocyte-CFU and its prognostic significance in smouldering leukemia]

We have studied bone marrow CFU-GM growth behaviour in agar in 7 patients with smouldering Leukemia (SL) in order to test prognostic value of CFU-GM assay to identify patients at high risk of progression to acute nonlymphocytic leukemia (AnLL). By means of the criterion of "topographic scoring at two sequential times", we have estimated bone marrow CFU-GM percentage distribution spectrum, a parameter independent of aggregate absolute number. Basing on our growth data, we have distinguished SL with low colony growth and SL with high cluster growth without colonies. If evaluated quantitatively, these data are not correlated with clinical evolution; if evaluated qualitatively, as percentage distribution spectrum, they are correlated with rapid progression to AnLL. With this work we show that bone marrow CFU-GM distribution spectrum is a suitable parameter to study the disorder of granulocytic line in SL.

[In vitro effect of culture fluids from neoplastic tissues on platelet aggregation. I. Human tumors of the gastrointestinal tract]

The effects on platelet function of culture media from 7 human tumours of the gastroenteric tract have been studied on platelet rich plasma obtained from 28 apparently normal subjects. Platelet aggregation was investigated according to Born's method. Some of the culture media showed an aggregating activity on platelets, while others did not; after dialysis, however, also the last ones aggregated platelets. Furthermore all the media both before and after dialysis were able to increase the platelet response to low doses of ADP (3 microM), and these effects were inhibited by Aspirin (0,1 mM). These results suggest that the tumours investigated release stimulating activities on platelet function and that these interactions can be inhibited pharmacologically.

[In vitro effect of culture fluids from neoplastic tissues on platelet aggregation. II. Experimental tumors]

We have investigated the effects on platelet function of culture media from 2 sublines of a benzopyrene-induced murine sarcoma (mFS6). Platelet aggregation was investigated according to Born's method. The cell line with greater "in vivo" invasiveness showed higher aggregating activity and higher increase on ADP-induced aggregation; these effects were inhibited by the preincubation of platelets with Aspirin (0,1 mM). These results suggest the role of platelets in metastasis formation; the possibility to inhibit pharmacologically the interactions between platelets and tumour cells could have important implications from both speculative and practical viewpoints.