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Aim : To evaluate clinical, biological and immunological features of patients with increased duodenal intraepithelial lymphocytes (IELs), and its relation to Helicobacter pylori (HP) and coeliac disease (CD). Methods : We have studied all patients accrued over a 4-year period with increased duodenal IELs. Those patients were recalled for biological and immunological evaluation and a second endoscopy. Results : Twenty-three from a total of 639 patients were identified and 17 of them were included in the study. The median duodenal IEL count was 59 per 100 epithelial cells. Twelve (71%) patients were HP+; eight of them received HP eradication. At the second endoscopy the duodenal IEL count was significantly lower 2 months after HP eradication (73 versus 28), while the IEL count was unchanged in those patients seronegative for HP (n = 5) or those in whom it was not eradicated (n = 4) (55 versus 55). No patient had coeliac antibodies, four expressed HLA-DQ2, lower than in the general population, and the prevalence of CD was 2% (12/639 patients). Conclusion : In some cases an increased duodenal IEL count may be due to an inappropriate host response to HP. HP screening and eradication should be considered before recommending a gluten-free diet.

Aims: Lymphoproliferative disorders (LPDs) are a severe complication in primary immunodeficiency and post-transplant patients. In primary immunodeficiency patients, LPDs are not well-known and, thus, we tried to evaluate their distinctive features and to determine prognostic factors predictive of clinical outcome by comparison with LPDs in post-transplant children. Methods and results: Clinical records and histopathology of 18 LPDs occurring in primary immunodeficieny children were compared with those of 10 LPDs in post-transplant children, together with results of in-situ hybridization for the detection of Epstein–Barr virus (EBV)-RNA and molecular biological techniques. LPDs were frequently extranodal, EBV-associated, and were more commonly pleomorphic in primary immunodeficiency than in post-transplant patients. A low T-cell count and abnormal T-cell function indicated bad prognosis in both groups. Polymorphic LPDs (PLPDs) were most frequent (n = 19), whereas lymphomas were rare (n = 7), and pseudo-tumoral lymphoid hyperplasias (n = 2) were observed only in primary immunodeficiency. Comparative p53/bcl-2 staining revealed a p53 overexpression in lymphomas compared with PLPDs; CD20/CD79a showed a similar staining in lymphomas, whereas PLPD expressed mainly CD20. TCR and IgH rearrangements did not help in distinguishing PLPDs from lymphomas, but detection of IgH clonality by Southern blot indicated poor prognosis, whereas oligoclonality by Southern blot regardless of PCR clonality and especially a polyclonal profile by Southern blot and PCR indicated a relatively good prognosis. Conclusions: This study documents the pleomorphism of LPDs in primary immunodeficiency compared to post-transplant children, even if some LPDs are similar in both groups (PLPDs). No criteria are useful enough to ascertain the diagnosis of malignancy in this series. Some molecular biological criteria help to predict the clinical outcome which, nevertheless, seems to depend more on the degree of immunosuppression and on T-lymphocyte presence and function.

Aims We recently showed that refractory sprue is distinct from coeliac disease, the former being characterized by abnormal intraepithelial T-lymphocytes expressing a cytoplasmic CD3 chain (CD3c), lacking CD3 and CD8 surface expression, and showing TCRγ gene rearrangements. To take advantage of the abnormal phenotype of CD3c + CD8 − intraepithelial lymphocytes (IEL) in refractory sprue we developed a simple method to distinguish coeliac disease from refractory sprue. Methods and results Comparative immunohistochemical studies using anti-CD3 and anti-CD8 antibodies were applied on paraffin-embedded and frozen biopsy specimens in refractory sprue (n = 6), coeliac disease (n = 10), healthy controls (n = 5) and suspected refractory sprue (n = 6). Comparable results were obtained on fixed and frozen biopsy specimens. In four of the six patients with suspected refractory sprue, abnormal CD3c + CD8 − IEL and TCRγ gene rearrangements were found, as in refractory sprue; the remaining two patients had normal (CD3 + CD8 +) IEL and no TCRγ gene rearrangements. Both patients had coeliac disease, as one failed to comply with a gluten-free diet, while the other was a slow responder. Conclusion This simplified immunostaining method using anti-CD3 and anti-CD8 antibodies on paraffin sections can distinguish active coeliac disease from refractory sprue and should prove useful in clinical practice.

Some interesting aspects of the forces acting between macroscopic objects (spheres and plates) immersed in solution are discussed. These include attractive forces between like-charged objects in primitive model electrolyte solutions, van der Waals forces in molecular solvents, and strong attractive interactions related to cavitation or separation-induced evaporation of liquids between inert or solvophobic walls.

A molecular dynamics (MD) calculation has been carried out for a model of solid methane at a state condition close to the triple point. We have used systems of 32 and 108 molecules interacting via atom–atom potentials. Equilibrium properties such as the configurational energy, pressure, and specific heat have been evaluated and compared where possible with experimental data. The simulated static structure factor has been analyzed assuming that rotational and translational motion can be decoupled and that the rotational structure factor can be developed as a power series in Kubic harmonics. This description is shown to yield a reasonably faithful representation of the structure in the plastic phase. The dynamical structure factor S(Q,ω) has been calculated for selected values of the momentum transfer h/Q. These results have been used to estimate the velocity of sound and hence the elastic constants. The overall agreement of the dynamical properties with experiment is not particularly good, indicating the need for a more refined intermolecular potential.

Small aliphatic alcohols have been found to localize at dilute micelles rather than remain dispersed in water when surfactants are added, even at low concentrations. Evidence for this was obtained from the effects of added micelles on proton NMR spin-lattice relaxations induced by the microenvironment with and without paramagnetic ions. Use was made of the double pulse inversion-recovery technique (..pi..-t-..pi../2 sequence). These alcohols are among the most water-soluble organic compounds known, so their localization indicates how strongly all nonionic molecules are forced from water's structure. By comparison with benzene it is suggested that the alcohols locate at the micelle surface. It was not possible to evaluate the actual degree of localization but it must be very substantial. The most striking effect was that paramagnetic Mn/sup 2 +/-induced relaxations were greatly enhanced be negatively charged micelles and weakly reduced by positive micelles. This is consistent with Mn/sup 2 +/ being attracted into or repelled from the micelle's double layer and is due to magnetic dipolar coupling of the localized proton with the electronic spin of the paramagnetic ion.