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Introduction Increasing interest has recently focused on possible secular changes in the course of HIV infection.[1-7] In particular, researchers are interested in whether the calendar year of HIV seroconversion is [...]

Graphene-derived materials, such as graphene oxide (GO), have been widely explored for biomedical and biological applications, including cancer research. Despite some recent works proving that GO inhibits the migration and invasion of different cancer cells, so far most of these in vitro studies have been conducted using GO sheets dispersed in solution or as a planar film. On the contrary, little is known about cellular activities, such as cell viability, adhesion, and spreading, when cancer cells interface with GO functionalized hydrogel-based surfaces, biomechanically and structurally more similar to the tumor environment. Here, we evaluate the interactions of human breast cancer cells (MDA-MB-231) with alginate (Alg)/GO hydrogel-based substrates, and compare them with a cancer cell line from human osteosarcoma (HOS) and healthy murine fibroblasts (3T3). We observed that GO addition selectively inhibits malignant breast cancer cell adhesion efficiency and spreading area, while promotes HOS and 3T3 adhesive processes. Furthermore, we did not observe the same results over Alg substrates with GO nanosheets dispersed in the medium, without embedment into the Alg. This suggests that cancer (MDA-MB-231 and HOS) and healthy (3T3) cell adhesion efficacy does not depend on the cellular tumoral nature and it is driven by the topographical cues provided by the GO-based substrates, whose physical-mechanical characteristics better mimic those of the cell native tissue. We envision that this study can provide a rational for future design and use of graphene-based nanomaterials for cancer research by deepening the knowledge of graphene–cancer cell specific interactions.

ABSTRACTThe relationship between nevirapine plasma concentrations and the durability of both viral suppression (VS) and selection of nevirapine primary resistance mutations (PRMs) was evaluated. A nevirapine trough concentration (Ctrough) of >4,300 ng/ml was found to predict longer VS. Patients with nevirapine Ctroughs ranging from 3,100 to 4,300 ng/ml had higher probabilities of developing PRMs than those with nevirapine Ctroughs below and above this concentration interval.

In this work we investigate the influence of the use of YSZ and CeO2/YSZ as buffers in the growth of SrBi2Ta2O9 (SBT). We show that by using YSZ only the a-axis oriented Pyrochlore phase could be obtained. On the other hand a CeO2/YSZ double-buffer layer gave a c-axis oriented SBT with no amorphous SiO2 inter- diffusion layer. From the piezoelectric response. nano-meter scale ferroelectric domains could be clearly identified in polycrystalline SBT thin films. In spite that SBT is an anisotropic material with an in- plane easy axis for polarization, we observe in our films a clear ferroelectric behavior of the Capacitance versus Voltage characteristics.

Steric forces between polymer brushes and atomic force microscope tips were investigated. We studied two systems:  polystyrene (PS) grafted to silicon in cyclohexane and poly(ethylene oxide)/poly(methacrylic acid) (PEO/PMAA) diblock copolymer adsorbed with the PMAA block to aluminum oxide in aqueous medium. On approach exponentially decaying repulsive forces were observed in both systems. With a homemade heat stage we could adjust the temperature. Increasing the temperature between 19 and 53 °C led to a linear increase of the decay length for PS in cyclohexane. Also the work required to bring the tip to a certain distance increased roughly linearly with temperature. This supports the view that the repulsion is of entropic origin. At the same time this demonstrates that the temperature dependence of surface forces could be routinely measured. For PEO in water the repulsive force was not significantly affected by a change in temperature. Approaching and retracting parts of force curves measured with PS in cyclohexane were in most cases indistinguishable. In contrast, for PEO in water a significant hysteresis was observed. This might be caused by an escape of polymers underneath the tip of the atomic force microscope. When retracting the tip in some cases the stretching of individual polymers was observed in both systems. Stretching force vs distance curves could be described by a wormlike chain model with typical persistence lengths of 1 nm.

Between March 1986 and March 1994, the seroconversion to HBV associated to the seroconversion to HIV was investigated in 120 HIV seroconverters drawn from 2368 i.v. drug misusers screened for HIV, HBV and STDs. Among the 185 individuals susceptible to HIV and HBV at intake (41/120 HIV seroconverters and 144/364 HIV-negative controls), HBV seroconversion was associated with the seroconversion to HIV (p=0.006) and history of more than 3 sexual pratners per year (p=0.000). Only the history of more than 3 partners per year remained associated with the HBV seroconversion in the conditional regression. The associated seroconversion to HIV and HBV was linked to the short period of i.v. drug injections (p=0.032), history of more than 3 partners per year (p=0.000) and more than 3 i.v. drug injections per day (p=0.016). Compared to the seroconverters to HBV alone, the seroconverters to HBV and HIV were likely to have higher frequency of i.v. drug injection per day on univariate (p=0.031) and multivariate analysis (p=0.024). The seroconverters to both the viruses differed from the seroconverters to HIV alone in the year of drug debut (p=0.045), short period of i.v. drug use (p=0.048) and high frequence of injection per day (p=0.008). The multivariate analysis confirmed only the association with high frequency of injection per day (p=0.033). Higher risk of HIV seroconversion from the debut of i.v. drug use was observed in the subjects with concurrent HBV seroconversion (Log-Rank test:p=0.0008).

A prospective 19-month study of 26 human immunodeficiency virus type 1-infected patients with episodes of erythematous or pseudomembranous oral candidiasis was done to evaluate the significance of Candida albicans biotypes in patients treated with antifungal therapy. Changes in the biotype of C. albicans were frequently noted in recurrent oral candidiasis. However, no correlation was found between the various biotypes and the clinical features of oral candidiasis, the clinical stage of human immunodeficiency virus type 1 infection, or the number of CD4+ lymphocytes. On the contrary, a significant correlation appeared among clinical lesion features, CD4+ cell numbers, and time of clinical disappearance of the oral lesions. Changes in the biotype of C. albicans were observed at the end of the antifungal therapy in 17 of 26 patients who had a second appearance of oral candidiasis as well as in 10 of 14 subjects who experienced a third reappearance of oral candidiasis.

OBJECTIVE--To estimate the HIV-1 seroprevalence, behavioural risks and attitude to HIV-1 infection among lesbians. SETTING--Institute of Infectious Diseases, University of Turin, Italy. SUBJECTS--From March 1992 to May 1993, 181 lesbians were tested for HIV-1 and included in the study. METHODS--Sociodemographic details, nonsexual risks for HIV-1, sexual behaviour, STD history and attitude to HIV-1 were obtained from an anonymous, standardised, self-administered, 30-item questionnaire. Snow-ball techniques were used to recruit the largest possible number of participants. RESULTS--11 lesbians (6.1%) were found to be HIV-1 antibody positive. Of them, 10 were intravenous (i.v.) drug users. STD episodes were higher among lesbians with HIV-1 than without (p = 0.04), increasing in both groups over time. Syphilis, genital herpes and viral hepatitis were highly associated with HIV-1 (p = 0.000). In univariate analysis, i.v. drug use, bisexual behaviour, history of STDs, sex during menses and vaginal/anal manipulation were significantly linked to HIV-1 (p = 0.000). In multivariate analysis only history of i.v. drug use (p = 0.04) and bisexual behaviour (p = 0.06) remained independently associated with HIV-1. Seventy-one participants (39.3%) had already undergone AIDS testing. Only 3.5% admitted to be at risk for HIV-1 and 11% changed their sex habits after first hearing of AIDS. No lesbian had ever practised safe-sex. Television was the most important source of information on HIV-1 (84%). CONCLUSION--I.v. drug use was the most likely means of HIV-1 infecting the lesbians of Turin. The high rate of STDs and the low perceived risk to HIV-1 require programmes of STD prevention and AIDS information to be targeted at the lesbian community. [ABSTRACT FROM PUBLISHER]