Atomic force microscopy and photon correlation spectroscopy: two techniques for rapid characterization of liposomes.

The direct evaluation of the heterogeneity of the particle population of nanometric drug delivery systems as liposomes is difficult to achieve owing to the dimension and the carrier characteristics. The influence of the lipidic ratio and composition on the physical stability of liposomes during their storage was investigated using atomic force microscopy (AFM) and photon correlation spectroscopy (PCS). Liposomes were made by a mixture of different lipids and obtained using distinct methods of preparation. AFM images, acquired immediately after the deposition of the sample on mica surface, clearly showed the spherical shape of the lipidic vesicles. In all the 7 months of the experiment, the average sizes of the different liposomes evaluated using the two techniques were comparable. According to PCS analysis, AFM images confirmed that almost all the diversified vesicular systems tended to form aggregates during their storage; this loss of stability was strengthened by the increase of polydispersity index value. The different behaviours observed were to ascribe to the lipidic composition more than the methods of liposome preparation. In conclusion, AFM technique owing to the relative simplicity cold be useful for the technological control of size distribution profile according to the preparative factors and moreover to the batch-to-batch reproducibility.     

Epidemiological, clinical and viral determinants of the increased prevalence of high-risk human papillomavirus (HPV) infections in elderly women

BACKGROUND: Population-based studies have reported a second peak of human papillomavirus (HPV) prevalence among women > 55 years, but reasons for this U-shaped HPV prevalence curve are poorly understood. OBJECTIVES: To analyse determinants of high-risk HPV (HR-HPV) infections among postmenopausal women. STUDY DESIGN AND METHODS: A cohort of 3,187 women was stratified into three age categories: i) youngest age group < 25 years (n = 1.103); ii) women between 26-55 years (n = 2.004), and iii) women > 55 years (n = 80), analysed for epidemiological, clinical and virological determinants of their HR-HPV infections. Real-time PCR was used for HPV genotyping, analysis of viral loads for HPV16, 18/45, 31, 33/52/58, 35 and 39, and load of integrated HPV16. RESULTS: Age-standardised prevalence of HR-HPV infections showed a second peak among women > 55 years, with a perfect U-shaped curve (R2 = 0.966). The factors explaining this increased HR-HPV prevalence among older women include: i) cohort effect, ii) higher viral loads for HR-HPV types with cubic model curve (R2 = 0.714) for HPV 16, iii) distinct shift (p = 0.0001) from multiple-type infections to single HR-HPV types, iv) transition from episomal to integrated HPV16 (p = 0.009), v) higher load of integrated HPV16 (p = 0.009), and, vi) higher proportion of incident infections, higher rate of viral persistence, and lower rate of HR-HPV clearance. CONCLUSIONS: These data suggest that in women who fail to eradicate their HR-HPV infection until menopause, selection of integrated viral clone has taken place, driving the process towards progressing disease. Consequent to this, most of the HR-HPV infections in women > 55 years were associated with high-grade CIN or invasive carcinoma.     

Fullerene derivatives: an attractive tool for biological applications

The fullerene family, and especially C60, has very appealing photo-, electro-chemical and physical properties, which can be exploited in many and different biological fields. Fullerene is able to fit inside the hydrophobic cavity of HIV proteases, inhibiting the access of substrates to the catalytic site of the enzyme. It can be used as radical scavenger; in fact some water-soluble derivatives are able to reduce ROS concentrations. At the same time, if exposed to light, fullerene can produce singlet oxygen in high quantum yields. This action, together with the direct electron transfer from excited state of fullerene and DNA bases, can be used to cleave DNA. In this review we report the most recent aspects of fullerene biological applications.     

Epstein-Barr Virus–Related Post-Transplant Lymphoproliferative Disorders in Cystic Fibrosis Lung Transplant Recipients: A Case Series

Background

Solid organ transplantation is associated with a higher risk of Epstein-Barr virus (EBV)–related lymphoproliferative disease due to immunosuppressive regimen. Little evidence is currently available on post-transplant lymphoproliferative disorders (PTLDs) in the lung transplant (LuTx) setting, particularly in cystic fibrosis (CF) recipients.

Sensitivity of Ph1+ CFU-GM to human recombinant interferon α and γ alone and in combination

Summary The in vitro effect of human recombinant interferon (IFN) alone and in combination were studied on granulomonocytic colony forming units (CFU-GM) from the peripheral blood of 10 Ph1+ chronic myeloid leukemia (CML) patients and from the marrow of 5 normal or non-leukemic subjects. - and -IFN alone determined a slight inhibition on colony growth with a preferential effect on pure macrophagic colonies. At maximum concentration (10⁴ U/ml) leukemic colony inhibition was 46±34% for IFN and 43±19% for IFN. Culture growth with + IFN in combination were significantly inhibited (up to 96±4%) with a concentration-related effect. Similar results were obtained with normal CFU-GM. The synergism that was found in vitro is probably relevant for the in vivo therapeutic effects of these compounds in CML and suggest that the combination is worth testing in vivo.This work was supported by CNR, Oncology Finalized Project, contract n. 8701169.44. and n. 8600603.44. and by AIRC