Human T cells in cord blood: abnormalities in IA antigens induction by phytohemagglutinin and in autologous mixed lymphocyte reactions.

About 25% of human T cells isolated from cord blood acquired la antigens, following stimulation with phytohemagglutinin (PHA) for 72 hr. This percentage is markedly lower than that found in PHA-activated T-cell populations (PHA-T cells) isolated from peripheral blood of adults. The low expression of la antigens by human T cells from cord blood does not reflect abnormalities in the sensitivity to PHA stimulation and/or in the kinetics of induction of la antigens. PHA-T cells from cord blood display a low stimulatory activity in autologous mixed lymphocyte reactions (MLR). The defect does not reflect a nonspecific abnormality in the stimulatory activity of PHA-T cells from cord blood, since the latter do not differ from PHA-T cells from adults in their ability to stimulate allogeneic T cells from adults. Furthermore the defect does not reflect a nonspecific abnormality in the proliferative response of T cells from cord blood, since the latter display a normal proliferative response to PHA-T cells from adults. The defect in the proliferative response is not restricted to the autologous MLR with PHA-T cells, since it was found also in autologous MLR with non-T cells as stimulators. Correlation of the temporal evolution of the abnormalities of human T cells with the maturation of the immune system may contribute to our understanding of the role of la antigens in cell-cell interactions and of the biological significance of abnormalities of autologous MLR.

[Fractures with loss of substance of the middle and upper third of the face: nosographic classification, surgical indications and the prevention of meningeal infections with the new antibiotic, cefuroxime]. / Le fratture con perdita di sostanza del terzo medio e superiore della faccia: inquadramento nosografico, indicazioni chirurgiche, profilassi dell infezioni meningee con il nuova antibiotico cefuroxim.

Reference is made to considerable personal experience acquired in the treatment of craniofacial fractures, particularly those affecting the upper third of the face. An account is given of the anatomical and surgical features of the naso-ethmoid-frontal and temporo-orbito-sphenoid areas--now recognised as within the domain of maxillofacial surgery--and their symptomatologies. Particular attention is directed to the question of liquorrhoea and the possibility of ascendent infections of the meninges. Reduction is favoured with respect to the former, since forward and upward repositioning often leads to the regression of ethmoidal liquorrhoea. Exclusion of the frontal sinus is regarded as a "categorical imperative" as far as meningeal infection is concerned, and support is also given for its prevention with antibiotics. A personal preference is expressed for cefuroxim, a new antibiotic with particular potency and marked diffusibility within the cerebrospinal fluid.