Carbodiimide inactivation of MMPs and effect on dentin bonding

The use of protein cross-linking agents during bonding procedures has been recently proposed to improve bond durability. This study aimed to use zymography and in situ zymography techniques to evaluate the ability of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) cross-linker to inhibit matrix metalloproteinase (MMP) activity. The hypotheses tested were that: (1) bonding procedures increase dentin gelatinolytic activity and (2) EDC pre-treatment prevents this enzymatic activity. The zymographic assay was performed on protein extracts obtained from dentin powder treated with Optibond FL or Scotchbond 1XT with or without 0.3M EDC pre-treatment. For in situ zymography, adhesive/dentin interfaces were created with the same adhesives applied to acid-etched dentin slabs pre-treated or not with EDC conditioner. Zymograms revealed increased expression of dentin endogenous MMP-2 and -9 after adhesive application, while the use of EDC as a primer inactivated dentin gelatinases. Results of in situ zymograpy showed that hybrid layers of tested adhesives exhibited intense collagenolytic activity, while almost no fluorescence signal was detected when specimens were pre-treated with EDC. The correlative analysis used in this study demonstrated that EDC could contribute to inactivate endogenous dentin MMPs within the hybrid layer created by etch-and-rinse adhesives.

Large excited state two photon absorptions in the near infrared region of surprisingly stable radical cations of (ferrocenyl)indenes

Multiphoton absorptions are important non-linear optical processes which allow us to explore excited states with low energy photons giving rise to new possibilities for photoinduced processes. Among these processes, multiphoton absorptions from excited states are particularly interesting because of the large susceptibilities characteristic of excited states. Here we explore the nonlinear transmission measurements recorded with 9 ns laser pulses at 1064 nm of the radical cations of (2-ferrocenyl)indene and of (2-ferrocenyl)-hexamethylindene, two interesting very stable molecules. The non-linear transmission data can be interpreted with a multiphoton sequence of three photon absorptions, the first being a one photon absorption related to the intramolecular charge transfer and the second a two photon absorption from the excited state created with the first process. The two photon absorption cross section is found to be several orders of magnitude larger than those usually found for two photon absorbing systems excited from the ground state.

Mesenchymal stem cells as delivery vehicle of porphyrin loaded nanoparticles: effective photoinduced in vitro killing of osteosarcoma

Mesenchymal stem cells (MSC) have the unique ability to home and engraft in tumor stroma. These features render them potentially a very useful tool as targeted delivery vehicles which can deliver therapeutic drugs to the tumor stroma. In the present study, we investigate whether fluorescent core-shell PMMA nanoparticles (FNPs) post-loaded with a photosensitizer, namely meso-tetrakis (4-sulfonatophenyl) porphyrin (TPPS) and uploaded by MSC could trigger osteosarcoma (OS) cell death in vitro upon specific photoactivation. In co-culture studies we demonstrate using laser confocal microscopy and time lapse imaging, that only after laser irradiation MSC loaded with photosensitizer-coated fluorescent NPs (TPPS@FNPs) undergo cell death and release reactive oxygen species (ROS) which are sufficient to trigger cell death of all OS cells in the culture. These results encourage further studies aimed at proving the efficacy of this novel tri-component system for PDT applications.

Endocytosis and intracellular localisation of type 1 ribosome-inactivating protein saporin-s6

Saporin-S6 is a single-chain ribosome-inactivating protein (RIP) that has low toxicity in cells and animals. When the protein is bound to a carrier that facilitates cellular uptake, the protein becomes highly and selectively toxic to the cellular target of the carrier. Thus, saporin-S6 is one of the most widely used RIPs in the preparation of immunoconjugates for anti-cancer therapy. The endocytosis of saporin-S6 by the neoplastic HeLa cells and the subsequent intracellular trafficking were investigated by confocal microscopy that utilises indirect immunofluorescence analysis and transmission electron microscopy that utilises a direct assay with gold-conjugated saporin-S6 and an indirect immunoelectron microscopy assay. Our results indicate that saporin-S6 was taken up by cells mainly through receptor-independent endocytosis. Confocal microscopy analysis showed around 30% co-localisation of saporin-S6 with the endosomal compartment and less than 10% co-localisation with the Golgi apparatus. The pathway identified by the immunofluorescence assay and transmission electron microscopy displayed a progressive accumulation of saporin-S6 in perinuclear vesicular structures. The main findings of this work are the following: i) the nuclear localisation of saporin-S6 and ii) the presence of DNA gaps resulting from abasic sites in HeLa nuclei after intoxication with saporin-S6.

Charge mapping in 3(10)-helical peptide chains by oxidation of the terminal ferrocenyl group

Two series of 3(10)-helical peptides of different lengths and rigidity, based on the strongly foldameric α-aminoisobutyric acid and containing a terminal ferrocenyl unit, have been synthesized. Oxidation-state sensitive spectroscopic tags of helical peptides, the N-H groups, allowed mapping of the charge delocalization triggered by oxidation of the terminal ferrocenyl moiety and were monitored by IR spectroelectrochemistry.

Life Expectancy of Women with Lupus Nephritis Now Approaches That of the General Population

Immunosuppressive treatment has changed the prognosis of Lupus nephritis over time, but improvement in prognosis is difficult to analyze in different historical periods, and should be better demonstrated in comparison with life expectancy of sex-and age-matched people. Long-term patient and renal survival of 90 patients diagnosed with Lupus nephritis at our center from 1968 to 2001 with a follow-up time of 14±8 years was retrospectively evaluated. Patient and kidney survival significantly increased over time. Multivariate analyses show that risks of patient and renal death decreased by 8% at each year of follow-up, and increased by more than 5 time in patients aged > 30 years at diagnosis. As only 14 patients were men, relative survival as compared to that of the sex- and age-matched general population of the Piedmont Region was calculated for the 76 women. Improvement in the survival of the cohort of women was seen at any time of follow-up: in particular, it was sharply lower in the first period (relative survival at 5,10 and 15 years = 0.784, 0.665, and 0.620, respectively) and increased in the second (relative survival at 5,10 and 15 years = 0.939, 0.921, and 0.850, respectively) nearly approaching that expected for the general population, i.e. 0.993, 0.983 and 0.967, respectively. Taken together, our data allow us to draw the conclusion that life expectancy in women with Lupus nephritis has improved over time, paralleling an improved awareness of the disease and a significant increase in steroid pulse therapy as induction/remission phase. Improvement in survival is for the first time demonstrated to cover the gap with life expectancy of the general population for women with Lupus nephritis.

Sucralfate modulates uPAR and EGFR expression in an experimental rat model of cervicitis

Sucralfate is a drug used in the treatment of gastric and duodenal ulcer; it is cytoprotective and able to increase the bioavailability of several growth factors, modulating the wound healing process. In this study we tested the possible therapeutic effect of Sucralfate in the treatment of ulcerative lesions occurring in uterine cervix; to investigate such effect we used an experimental rat model of cervicitis in which the uPAR and EGFR expression were evaluated. Cervicitis was induced in wild and ovariectomized Wistar female rats by an acetic acid-soaked tampon. The animals were divided into two main groups (4 and 7 days) and Sucralfate was administered topically until the day they were sacrificed. In order to distinguish physiological and drug-induced healing, quantitative and qualitative uPAR and EGFR expression were evaluated by using Western blot and Immunohistochemistry techniques. Western blot analysis demonstrated an increased expression of both receptors after 4 days from wounding in wild and ovariectomized animals. In particular in ovariectomized animals the expression of uPAR and EGFR increased after 4 days while it reduced following the administration of Sucralfate. In wild rats the same was observed for uPAR expression, while EGFR was different; in fact, its expression increased significantly at day 4 in the animals treated with the drug and only at day 7 in those untreated. Immunohistochemistry highlighted a noteworthy epithelial colocalization of EGFR and uPAR after 4 days in the animals treated with Sucralfate. We conclude that Sucralfate can promote the healing of ulcerative cervicitis and moreover, it reduces the normal healing time because of its modulatory property on uPAR and EGFR expression.

Immunomodulatory activity of shikimic acid and quercitin in comparison with oseltamivir (Tamiflu) in an in vitro model

The risk of an avian influenza pandemic has put oseltamivir (Tamiflu) in the spotlight and has given rise to rumors that shikimic acid (SK), which is used for the synthesis of Tamiflu, possesses therapeutic activity. This study was undertaken to determine whether SK, either alone or in combination with quercitin (QT) is able to modulate the release of IL-6 and IL-8 from peripheral blood mononuclear cells (PBMCs). The experiments were conducted comparing the properties of SK, both alone and in combination, with those of Tamiflu. The incubation of PBMCs with 100 nM Tamiflu or SK at two concentrations (10 nM; 100 nM) did not produce any change in IL-6 and IL-8 baseline levels (data expressed as incremental change vs. baseline). On the contrary, incubation with SK and QT at both concentrations (10 and 100 nM) produced a significant increase in the release of IL-8 as compared to other groups (4.19 +/- 0.82, SK-QT 10 nM; 3.83 +/- 1.17 SK-QT 100 nM, P < 0.05 vs. baseline 1.00 +/- 0.10, Tamiflu 100 nM 1.35 +/- 0.16, SK 10 nM 1.68 +/- 0.15 and SK 100 nM 1.80 +/- 0.48). The SK-QT combination also proved to be effective in the upregulation of IL-6 (3.08 +/- 0.46, SK-QT 10 nM; 3.60 +/- 0.74 SK-QT 100 nM, P < 0.05 vs. baseline 1.00 +/- 0.26). According to these findings SK alone is not able to modulate innate immunity in antiviral terms. However, the data show that the SK + QT combination, even at low doses, may be effective for the modulation of innate immunity.