The amount of neurofilaments aggregated in the cell body is controlled by their increased sensitivity to trypsin-like proteases.

Neurofilaments are synthesised and assembled in neuronal cell bodies, transported along axons and degraded at the synapse. However, in several pathological situations they aggregate in cell bodies or axons. To investigate their turnover when separated from their normal site of degradation, we used a previously described transgenic model characterised by perikaryal retention of neurofilaments, and compared the basic features of both neurofilament synthesis and degradation with that observed in normal mice. Despite the massive perikaryal aggregates, neurofilament transcript levels were found to be unchanged, whereas the total accumulation of neurofilament proteins was markedly reduced. Neurofilaments isolated from transgenic samples are more sensitive to both trypsin and alpha-chymotrypsin mediated proteolysis. Consistent with their greater in vitro sensitivity, trypsin immunolabeling of cell bodies was stronger in transgenic mice. These results show a novel mechanism to regulate the amount of neurofilaments when they abnormally aggregate.

Double diffusion and ELISA for the detection of IgG and IgM antibodies against Micropolyspora faeni.

Fifty-eight sera of subjects with suspected farmer's lung disease (FLD) were tested by double immunodiffusion and ELISA for the detection of IgG and IgM antibodies against Micropolyspora faeni. By comparing the two methods, we obtained a high concordance of results for IgG, but not so high for IgM. ELISA is therefore a sensitive and specific test in determining antibody concentration.

Assessment of lymphocyte and phagocytic cell function in healthy volunteers undergoing short-term phenytoin administration.

The effect of short-term (2 weeks) administration of the anticonvulsant drug phenytoin on humoral and cellular immune function and phagocytic cell system activity was tested in nine healthy volunteers. No change either in the absolute or relative counts of leukocytes was found after drug treatment. Moreover, immunoglobulin serum concentration and lymphocyte subsets positive for OKT3, OKT4, OKT8, OKDRIA, OKB2, Leu 7, Leu 11a, anti-beta 2-microglobulin and antitransferrin monoclonal antibodies were not affected by phenytoin administration. A significant impairment of both polymorphonuclear neutrophil migrating activity and stimulated metabolism as measured by nitro blue tetrazolium reduction and superoxide anion generation was found after drug treatment or when phenytoin was added in vitro to the cells at concentrations lying within the anticonvulsant therapeutic range. Monocyte function was unaffected both after phenytoin administration and after direct application to the cells. The phenytoin-induced changes of polymorphonuclear neutrophil function was completely reverted within 2 weeks after drug withdrawal. The phenytoin-induced alterations of the phagocytic cell system are discussed in relation not only to the possible implications in the pathogenesis of adverse effects of anticonvulsant therapy but also to the potential therapeutic exploitation in immunologically mediated disorders.

[Serum levels of IgE in liver cirrhosis]. / Livelli sierici di IgE in corso di cirrosi epatica.

In a study of 18 subjects with liver cirrhosis, mainly of alcoholic origin, the Authors found an average increase in the serum levels of IgE, IgG, IgA, and IgM, with respect to control subjects (p less than 0.001). Nonetheless, no correlation was found in either of the cirrhotic or control groups, between serum levels of IgE and other immunoglobulins. Also, in 11 of the 18 patients with cirrhosis, a linear and direct correlation between the amount of decreased phagocytic activity in the liver (studied by hepatic scanning, using Technetium Tc 99m sulfur colloid), and the increase in serum levels of IgG (p less than 0.001) and of IgA (p less than 0.05), but not of IgE, was observed. In respect to the controls, patients with cirrhosis also showed a significant decrease in circulating T-lymphocytes OKT8+ (p less than 0.05), and a significant increase in the OKT4+/OKT8+ ratio (p less than 0.01), but no significant modification of the eosinophils and circulating T-lymphocytes OKT3+ and OKT4+. A significant correlation was present in the patients with cirrhosis, but not in the controls, between the serum levels of IgE and circulating eosinophils (p less than 0.05), and between the levels of IgM and the OKT4+/OKT8+ ratio (p less than 0.05). In the healthy control subjects, a linear, inverse correlation was present between serum IgE and circulating OKT8+ (p less than 0.05) and a direct, linear correlation was found between IgE and the OKT4+/OKT8+ ratio (p less than 0.05); both, on the other hand, were absent in the patients with cirrhosis.(ABSTRACT TRUNCATED AT 250 WORDS)

[Lymphocyte subpopulations in patients with liver cirrhosis]. / Sottopopolazioni linfocitarie in pazienti con cirrosi epatica.

We have characterized some subset of T-lymphocytes by monoclonal antibodies in 30 patients affected by hepatic cirrhosis. The OKT3 cells was significantly decreased so as OKT8. The OKT4/OKT8 ratio was significantly raised. The reduction of OKT3 was similar to that observed by other Authors. Our other results have a correlation with the alcoholic etiology of the observed disease.

[Mixed cryoglobulinemia with peripheral neuropathy in a case of HBsAg-positive chronic active hepatitis]. / Crioglobulinemia mista con neuropatia periferica in un caso di epatite cronica attiva HBsAg positiva.

We have observed a patient who developed a severe progressive peripheral neuropathy in the course of HBsAg positive chronic active hepatitis in whom high serum levels of cryoproteins was detectable, as described just once in the past. The role of HB virus in the pathogenesis of cryoglobulinemia and in the development of peripheral neuropathy was discussed.

Micropolyspora faeni antigens of three commercial extracts.

The protein composition of three commercial extracts of Micropolyspora faeni, produced in U.S.A., England and Italy has been evaluated by agarose gel electrophoresis. By crossed immunoelectrophoresis, 'tandem'-crossed immunoelectrophoresis and by a modification of this last technique, the antigenic composition and the common antigens of the extracts have been investigated. Hyperimmune rabbit serum and a pool of five human sera with precipitins to Micropolyspora faeni have been used as source of antibody. Different quantity and quality of protein content was observed in the available batches. Different antigenic composition was also observed, not directly related to the different proteins contained therein; three antigens were definitely common to all extracts and two of them represented the major antigens of each extract. Despite the total protein content, the major and common antigens were found in similar concentrations in all three products examined. Therefore, the discrepancies observed in the precipitin reactions using the three commercial Micropolyspora faeni extracts are due to differences in the minor antigen composition of the extracts.

[Allergic risk factors in wood working]. / Fattori di rischio allergico nella lavorazione del legno.

After an account on wood working schedule and on the main and most noxious chemical constituents of these materials, we consider 55 subjects working in touch with wood, on whom allergological researches have been performed through skin tests and bronchial provocation tests. The sensitivity to wood dust have been found in 10 cases (18.2%), in particular towards woods of obece, lanan, mahogany and samba. Skin tests have revealed 1 positivity to balsam of Perù and 3 to isocyanate (TDI). The bronchial provocation tests have pointed out 1 positive reaction to Mansonia's and ramin's wood and 2 to TDI. The results suggest that the respiratory manifestations due to wood's dust on subjects professionally exposed, have to be prevalently imputed to exotic woods, even if the irritant factors assume a not minor importance. It is discussed the possible role of isocyanates in this pathology.