Hybrid Molecular Dynamics for Lattice Supersymmetry

We present the first results obtained with a Hybrid Molecular Dynamics algorithm applied to an $N=1$ SU(2) Super-Yang--Mills on the lattice. We derive the Hamilton equations of motion for the system with Wilson gluinos and present preliminary results on small lattices.Comment: 8 pages, uuencoded file containing latex source and two ps figure

Improved bilinears in unquenched lattice QCD

We summarize the extent to which one can use Ward identities to non-perturbatively improve flavor singlet and non-singlet bilinears with three flavors of non-degenerate dynamical Wilson-like fermions.Comment: Lattice2003(improve) (3 pages, no figures

IL CMV NELL'AIDS: SIGNIFICATO CLINICO DI PARAMETRI VIROLOGICI

Il Cytomegalovirus \ue8 causa di patologie gravi e spesso mortali nei pazienti affetti da AIDS. Da un punto di vista diagnostico la definizione del ruolo eziologico. in una patologia in atto, di una infezione da CMV accertata in laboratorio \ue8 problematica a causa delle frequenti riattivazioni cui va incontro il Cytomegalovirus in soggetti immu- nodepressi. Nel tentativo di risolvere questo problema sono stati analizzati i dati relativi ai 56 pazienti con AIDS con patologia attribuibile ad infezione da CMV (sui circa 250 esaminati) risultati positivi all'accertamento di laboratorio nel corso del 1991 Sui leucociti polimorfonucleati di ciascun paziente si era proceduto all'esecuzione di prove di isolamento tradizionale e di evidenziazione dell'antigene p72 in fibroblasti fetali umani (56 soggetti) e alla ricerca della proteina p65 sul citocentrifugato (27 pazienti). I soggetti in esame sono stati presi in considerazione in quanto positivi ad almeno una delle prove citate. Al fine di definire l'eventuale ruolo eziologico del CMV evidenziato, si sono presi in considerazione alcuni parametri virologici quantitativi (numero di giorni necessari per la comparsa dell'effetto citopatico in coltura cellulare, numero di cellule positive per le proteine p72 o p65) che sono stati valutati in rapporto al risultato clinico del trattamento anti CMV cui sono stati sottoposti 38 pazienti studiati (36 con DHPG e 2 con Foscarnet) considerato come indicazione indiretta del ruolo causale di CMV. Parametri virologici significativi sono stati riscontrati in un numero limitato di casi. L'effetto citopatico \ue8 comparso entro 8 giorni dalla semina in 11 dei 35 campioni, la presenza degli antigeni virali \ue8 stata rilevata su pi\uf9 di 50 cellule in 3/28 e in 3/17 (non coincidenti) dei pazienti positivi rispettivamente per p72 e per p65. N\ue9 la frequenza dei positivi ai test considerati n\ue9 l'entit\ue0 della positivit\ue0 sono risultate statisticamente differenti tra pazienti migliorati e non migliorati dopo trattamento. L'insieme di questi dati induce a concludere che i parametri considerati non siano discriminanti per definire il significato eziologico di una positivit\ue0 per CMV in pazienti con AIDS con quadri clinici attribuibili a Cytomegalovirus. L'ampliamento della casistica e l'inclusione nella valutazione anche di parametri relativi allo stadio dell'infezione da HIV (staging, numero dei CD4/rnm3) potr\ue0 consentire di risolvere il problema esaminato

The effect of the Interleukin-6-174G > C promoter gene polymorphism on endothelial function in healthy volunteers.

AIMS: Atherosclerosis is a chronic inflammatory condition, manifest in its early stages by endothelial dysfunction. Interleukin-6 (IL6) plays a key role in driving this process through stimulation of acute phase protein synthesis. We have examined the effect of the IL6 gene -174G > C promoter polymorphism on endothelial function in a group of healthy subjects. METHODS: 248 adults aged 20-28 years participated. Polymerase chain reaction was performed for the -174G > C polymorphism. Brachial artery diameter was measured at rest and after forearm cuff occlusion by high-resolution ultrasound. Responses were represented as absolute flow mediated dilatation (FMDA). RESULTS: Overall there was a trend towards greater FMDA for genotype CC, P = 0.14. No effect was seen in women; however, in men, following multivariate analysis, there was a significant association between genotype and FMDA, P = 0.04. In addition, a significant detrimental effect of smoking on FMDA was only seen in males of genotype CC (P < 0.05) when compared to nonsmokers of the same genotype. CONCLUSION: IL6-174G > C promoter polymorphism influences endothelial function in healthy male subjects. The detrimental effect of smoking on endothelial function is most clearly seen in men of genotype -174 CC, suggesting a genotype-specific interaction with smoking

Regulatory T cells, immune activation and apoptosis are involved in persistently reduced CD4 counts in HIV-infected immunological non-responders

CD4 counts are persistently reduced and CD4 T lymphocytes are functionally-defective in a percentage of HIV-infected, HAART-treated patients (immunological non-responders \u2013INR-). T regulatory cells (Treg), immuneactivation and apoptosis are suggested to play a role in such CD4 count defects. The PD-1/PD-L1 and the Fas/FasL pathways elicit apoptosis of antigen-specific cells; Treg down-regulate T cell function and induce apoptosis by PD1/PD-L1 interaction. To verify possible role for these mechanisms in INR we enrolled 38 HIV-infected patients with comparable CD4 nadirs and HIV RNA 1 year. CD4 counts were >500 cells/\uf06dl in 15 patients (full responders \u2013FR-); in 23 other patients (INR) CD4 were <200 cells/\uf06dl. PBMC were stimulated with gag+env or with CMV peptides. Flow-cytometry was used to analyze intra and extracellular PD1 in CD4+ T lymphocytes as well as the expression of PD-L1, TLR2 and TLR4, and of Fas and FasL on immune cells. Treg lymphocytes (CD4+/CD25high/Foxp3+), IL-10 production, activation of caspases 8 and 9, and plasmatic LPS concentration were also examined in all patients. Results showed that in INR compared to FR patients: 1) intra-and extracellular PD1 positive CD4+ T lymphocytes, 2) Fas- and FasL-expressing CD4+T lymphocytes, 3) Treg and IL-10 production, and 4) the percentage of apoptotic cells are increased. Additionally, in INR patients CD14+/TLR2+ TLR4+ cells are augmented, plasmatic LPS concentration is higher, and CD4+ T cells are hyperactivated. These increases are seen both in gag+env- and CMV-stimulated PBMC. Notably, PD-L1 expression was comparable in CD14+ and CD19+ cells of both groups of patients. The augmented plasmatic LPS concentration detected in INR could explain immune activation and presence of higher Treg cell function. PD1/PD-L1interaction results in an increased apoptosis of antigen-specific CD4+ T lymphocytes. IL-10 is also increased in INR, this observation could explain the functional T helper impairments also seen in these patients. Apoptosis plays an important role in the defective immune reconstitution seen in INR