Metal-enhanced Förster resonance energy transfer (ME-FRET) in anthracene/tetracene-doped crystal systems.

Anthracene tetracene-doped crystals (TA) dispersed in a thin polymer film matrix have been reported as efficient down converting systems based on Förster Resonance Energy Transfer (FRET) which occurs efficiently from donor (anthracene) to acceptor (tetracene) molecules. In this work, we demonstrate that the efficiency of this system can be further improved by a metal-enhanced FRET, which is obtained by incorporating metal nanoparticles into the polymer matrix. We report on the preparation and optical responses of polymeric transparent thin films where dodecanethiol-capped silver or gold nanoparticles are dispersed with TA in a polymethylmethacrylate (PMMA) matrix. A maximum of 11-fold and 6.5-fold enhancement was achieved with silver and gold nanoparticles, respectively. Efficiency is discussed in terms of film morphology and plasmon resonance induced effects.

A case of acute disseminated encephalomyelitis following influenza virus A-H1N1 infection.

We describe a case of acute disseminated encephalomyelitis (ADEM) occurring in a three-year old girl with influenza A (H1N1)v infection and manifesting with seizures and ataxia. The brain MRI revealed bilateral hyperintense signal changes in basal ganglia and brain stem. The patient was treated with intravenous methylprednisolone bolus followed by tapering steroids and progressively recovered without neurologic sequelae at the latest follow-up. ADEM may represent a rare postinfectious complication following novel pandemic influenza A H1N1v which should be taken into account in the differential diagnosis of associated neurologic manifestations for the specific therapeutic approach and adequate follow-up.

Experimental CC stretching phonon dispersion curves and electron phonon coupling in polyene derivatives.

We analyze the infrared and Raman spectra (both experimentally and with the aid of quantum chemical calculations) of a series of polyenals which provide us with the fortunate case of a set of polyene chains with one of the end groups consisting of a C=O group which not only does take part in the conjugation but also pulls electrons from the chain making the whole system highly polar, thus affecting the vibrational transition moments. In the following we show, for the first time, that it is possible to derive experimental phonon dispersion curves and these prove to be different for each chain length. We support our experimental findings with Density Functional Theory quantum chemical calculations which reproduce with sufficient accuracy the IR and Raman spectral pattern and at the same time help in disentangling the assignment of the fine structure observed in the experimental spectra.

A father and son with visceral leishmaniasis. A description of the pediatric case.

The paper reports a case of a 6-year-old boy affected by visceral leishmaniasis. In addition to clinical and anamnestic findings, diagnosis was made on the basis of the rapid increase in the titer of anti-Leishmania antibodies (16-fold), while the marrow smear was negative. A complete recovery was obtained using antimonial drugs.

[Phenotype expression and production of IL-2 by tonsillar and blood lymphocytes in patients with tonsil pathology]. / Espressione fenotipica e produzione di IL-2 da parte di linfociti tonsillari ed ematici in soggetti con patologia tonsillare.

In recent years several studies have attempted to investigate immunological responses in different tonsillar pathologies, including recurrent tonsillitis and focal infections. The present study was performed on ten patients who had undergone tonsillectomy for a) simple hypertrophy, b) recurrent tonsillitis and c) recurrent tonsillitis with focal manifestations. The blood (PBMNC) and tonsillar (TMNC) lymphocytes were tested separately. A subsequent investigation was performed on the PBMNC six months after surgery. The phenotypical aspects of the different subpopulations were studied using fluorescent antiserums and monoclonal antibodies. A second field of investigation concerned the in vitro blastogenesis, which was measured under spontaneous and PHA-P induced conditions. Finally, the IL-2 production was evaluated using the induced-growth capacity of an IL-2 dependent clone of a T murine cell line. The most interesting findings are presented. The phenotypical studies confirmed some peculiar aspects of the representation of tonsillar subsets. According to the hyperactivation ratio, the proliferation data proved to be higher in the tonsil than in the blood. A greater number of positive HLA-DR and IL-2 receptor cells (both antibodies being activated cell markers) was seen in the tonsil than in the blood and this, as well as the sporadic presence of spontaneous blastogenesis, suggests the possibility of an in vivo pre-activated condition. As far as the secretion of IL-2 is concerned, when compared to the peripheral blood ratio, greater production was found in the tonsil. Finally, a different production kinetic appears to be a constant result of the present study. The performed tests were unable to demonstrate any particular differences among the three different groups of pathologies.

Interleukin-2 production and interleukin-2 receptor expression in children with newly diagnosed diabetes.

In the present study, we investigated the interleukin-2 (IL-2) production and the proliferative responses by peripheral blood mononuclear cells (PBMNC) of 23 children suffering from insulin-dependent diabetes mellitus (IDDM). In addition, the presence of circulating activated T lymphocytes expressing the interleukin-2 receptor (IL-2 R) and HLA-DR antigens was evaluated. The patients were tested at hospital admittance, before starting insulin treatment. Decreased IL-2 production by phytohemagglutinin (PHA)-activated PBMNC of IDDM patients was observed when compared to normal donors. In contrast, the proliferative responses of PBMNC to PHA and Con A were in the normal range. The expression of IL-2 R on patient's lymphocytes was not different from that observed in normal donors, whereas the relative and absolute number of HLA-DR+ T cells was increased. These results confirm the presence in IDDM patients of an imbalanced cellular immune response and demonstrate that the IL-2 deficiency is already present at the diagnosis and is not correlated with insulin administration.

[Selective IgA deficiency in juvenile-onset insulin-dependent diabetes mellitus]. / Deficit selettivo di IgA nel diabete mellito insulino-dipendente ad esordio giovanile.

Variation of serum immunoglobulin (Ig) levels and increased frequency of selective IgA deficiency are frequently associated with autoimmune diseases. In insulin-dependent diabetes mellitus (I.D.D.M.) pathogenesis autoimmunity is known to play a causative role. Aim of the present study was to evaluate serum major immunoglobulin subclasses levels and frequency of IgA selective deficiency in juvenile onset I.D.D.M. IgG, IgA, IgM concentrations were determined in 191 insulin-dependent children and adolescents (100 males, 91 females; mean age 10.6 divided by 4.8 yrs; mean duration of I.D.D.M. 5.7 divided by 3.9 yrs) and in 180 age-matched healthy controls. Mean Ig levels were comparable among both group. Duration of I.D.D.M. did not affect mean serum Ig levels. Selective IgA deficiency was found in 7 on 191 diabetics: this gives a prevalence of the defect of 1:27, which is higher than in the Italian pediatric population (1:500). HLA typing evidenced 2 DR3 positive patients, 2 DR4, 1 B8-DR3 and 1 B8-DR3/DR4. The significance of selective IgA deficiency in I.D.D.M. is discussed.