Dental resin composites consist of organic polymers with inorganic fillers used as bonding resins and direct filling materials in dentine adhesives and as sealing agents for inlays, crowns and ...orthodontic brackets. Despite various modifications in the formulation, the chemical composition of composite resins includes inorganic filler particles and additives, which are incorporated into a mixture of an organic resin matrix. Among them, 2‐hydroxyethylmethacrylate (HEMA) is one of the most frequently used. Several studies have attempted to clarify the mechanisms underlying HEMA cytotoxicity. Most of them support the hypothesis that this compound, once released in the oral environment, increases reactive oxygen species (ROS) production and oxidative DNA damage through double‐strand breaks evidenced by in vitro presence of micronuclei. As a consequence, the glutathione detoxifying intracellular pool forms adducts with HEMA through its cysteine motif and inflammation begins to occur: transcription of early genes of inflammation such as tumour necrosis factor α or inducible cyclooxygenase up to the secretion of prostaglandins 2. These phenomena are counteracted by N‐acetylcysteine (NAC), a nonenzymatic antioxidant, but not by vitamin E or other antioxidant. Consequently, NAC prevents HEMA‐induced apoptosis acting as a direct ROS scavenger. This minireview collects the most significant papers on HEMA and tries to make an overview of its cytotoxicity on different cell types and experimental models.
Human dental pulp stem cell (DPSC) differentiation toward the osteoblastic phenotype is enhanced when culture media are supplemented with differentiating factors, i.e. ascorbic acid, ...β-glycerophosphate and dexamethasone. Liposomes, spherical vesicles formed by a phospholipid bilayer, are frequently used as carriers for drugs, growth factors and hydrophobic molecules. The aim of this work was to speed up DPSC commitment to the osteogenic lineage by embedding differentiating factors within liposomes. Firstly, liposomes were prepared by rehydrating a phospholipidic thin film and characterised in terms of dimensions. Secondly, liposome-exposed DPSCs were characterised by their immunophenotypic profile. Levels of CD90 were significantly decreased in the presence of liposomes filled with ascorbic acid, β-glycerophosphate and dexamethasone (Lipo-Mix) with respect to normal differentiation medium (DM), while CD73 and CD29 expression were enhanced, suggesting osteogenic commitment. Additionally, an appreciable extracellular matrix deposition is detected. Thirdly, the Lipo-Mix formulation better increases alkaline phosphatase activity and levels of Collagen I secretion with respect to DM. In parallel, the new liposome formulation is capable of decreasing the release of H2O2 and of triggering a precocious antioxidant cell response, redressing the redox balance required upon mesenchymal stem cell commitment to osteogenesis. It can be therefore hypothesised that Lipo-Mix could represent a suitable tool for clinical regenerative purposes in the field of tissue engineering by speeding up DPSC osteogenic commitment, mineralised matrix deposition and remodelling.
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a major etiologic agent that causes bloody diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome (HUS). Shiga toxin (Stx) is the main ...virulence factor of EHEC responsible for the progression to HUS. Although many laboratories have made efforts to develop an effective treatment for Stx-mediated HUS, a specific therapy has not been found yet. Human consumption of bovine colostrum is known to have therapeutic effects against several gastrointestinal infections because of the peptide and proteins (including antibodies) with direct antimicrobial and endotoxin-neutralizing effects contained in this fluid. We have previously demonstrated that colostrum from Stx type 2 (Stx2)-immunized pregnant cows effectively prevents Stx2 cytotoxicity and EHEC O157:H7 pathogenicity. In this study we evaluated the preservation of the protective properties of hyperimmune colostrum against Stx2 (HIC-Stx2) after pasteurization and spray-drying processes by performing in vitro and in vivo assays. Our results showed that reconstituted HIC-Stx2 colostrum after pasteurization at 60°C for 60 min and spray-dried under optimized conditions preserved specific IgG that successfully neutralized Stx2 cytotoxicity on Vero cells. Furthermore, this pasteurized/dehydrated and reconstituted HIC-Stx2 preserved the protective capacity against EHEC infection in a weaned mice model. The consumption of hyperimmune HIC-Stx2 bovine colostrum could be effective for HUS prevention in humans as well as in EHEC control in calves. However, further studies need to be done to consider its use for controlling EHEC infections.
Aim
To investigate the inflammatory response in human gingival fibroblasts (HGFs) treated with a relatively low 2‐hydroxyethyl methacrylate (HEMA) concentration by studying reactive oxygen species ...(ROS) production, cyclooxygenase‐2 (COX‐2) and tumour necrosis factor‐alpha (TNF‐α) gene expression, and prostaglandin E2 (PGE2) release.
Methodology
Cultured HGFs were exposed to 3 mmol L−1 HEMA for 0, 24 or 96 h. ROS production was investigated by flow cytometry; TNF‐α and COX‐2 gene expression was determined by RT‐PCR, and prostaglandin E2 production was detected by an enzyme immunoassay.
Results
After 24‐ or 96‐h HEMA incubation, ROS levels were approximately eightfold and elevenfold higher than controls, whilst COX‐2 gene expression was approximately twofold or fourfold higher than controls, respectively. Twenty‐four‐hour exposure enhanced TNF‐α mRNA levels by approximately 66%, whilst after 96‐h incubation, TNF‐α gene expression was fivefold higher than controls. Ninety‐six‐hour HEMA treatment increased PGE2 concentration in the culture medium by around 17% compared with controls.
Conclusions
2‐Hydroxyethyl methacrylate treatment (3 mmol L−1) induced an inflammatory response in HGFs modulated by ROS production, as well as by the increase in TNF‐α and COX‐2 gene expression and by PGE2 release.
Ruminants are the primary reservoir of Shiga-toxin producing Escherichia coli (STEC) O157:H7 and the main source of infection for humans. The aim of this study was to assess the immunogenic ...properties of a candidate vaccine consisting on the recombinant proteins of E. coli O157:H7 IntiminC280, the carboxy-terminal fraction of Intimin γ, EspB and the fusion protein between the B subunit of Stx2 and Brucella Lumazine Synthase (BLS)(BLS-Stx2B), in Holstein Fresian calves.To accomplish this goal we vaccinated calves with two doses of different vaccine formulations: 2 antigens (IntiminC280, EspB), 3 antigens (IntiminC280, EspB, BLS-Stx2B), BLS-Stx2B alone and a control non-vaccinated group. All antigens were expressed as recombinant proteins in E. coli. Specific IgG titres increased in vaccinated calves and the inclusion of BLS-Stx2B in the formulation seems to have a stimulatory effect on the humoral response to IntiminC280 and EspB after the booster. The neutralizing activity of antibodies against these two antigens was assessed in Red Blood Cell lysis assays and adherence to Hep-2 cells as a correlate of T3SS activity. Both sera from animals vaccinated with 2 or 3 antigens inhibited both virulence properties. Serological response to Stx2 was observed in animals vaccinated only with BLS-Stx2B and with 3 antigens and neutralization of Stx2 cytotoxicity was also observed in both groups. In conclusion, immunization of calves with BLS-Stx2B, IntiminC280 and EspB elicited a potent humoral response able to neutralize Shiga toxin 2 cytotoxity and the T3SS virulence properties in vitro. These results suggest that this formulation is a good candidate vaccine to reduce STEC shedding in cattle and needs to be further assessed in vivo.
Adrenal incidentalomas, defined as masses discovered incidentally during imaging investigation of non-adrenal disorders, have become a rather common finding in clinical practice. The prevalence is ...not well characterized and varies among studies. The aim of the present study was to perform a prospective evaluation of the prevalence of adrenal incidentalomas among subjects undergoing computerized tomography (CT) scan of the chest in a screening program of lung cancer (Tic TAC study) in Piedmont, a region of Northwestern Italy. This evaluation included 520 subjects (382 males and 138 females, aged between 55-82 yr), referred to our hospital from April to December 2001. Twenty-three patients with adrenal masses were identified: 21 adrenal adenomas, 1 myelolipoma, and 1 metastasis of lung cancer. Therefore, the overall prevalence of adrenal lesions was 4.4%, and that of benign adrenal masses was 4.2%. This prevalence is higher than those found in previous CT scan series reported in the literature, probably because of the use of high-resolution CT scanning technology. Another factor that influenced our results is that subject age is skewed towards the decades characterized by a greater occurrence of adrenal masses. The outcome of this study confirms that we are presently able to identify incidentally discovered adrenal masses more often than in early years and that the prevalence of adrenal incidentalomas on CT images is approaching that of autopsy series. The present study provides a reliable estimate of the prevalence of adrenal incidentaloma with currently used CT scanners. Notwithstanding that our subjects were at increased risk of lung cancer, the rate of adrenal metastases was low. We think that the present results can be generalized even if we may disclose the lack of histological diagnosis.
Abstract The aim of this observational study was to investigate the occurrence of postoperative delirium (POD) in elderly patients undergoing urological surgery and to identify those factors ...associated with delirium. Ninety consecutive patients (81 males and 9 females; average age of 74.3 ± 0.40 years), undergoing urological surgery in University-Hospital Urological Clinic were selected. Personal, medical, cognitive and functional data, biochemical parameters, preoperative medications, conduct of surgery and anesthesia and details of hemodynamic control were collected as predictors of delirium. After surgery, the subjects were divided on the basis of delirium onset within a week observation period. Delirium was diagnosed by the Confusion Assessment Method. Delirium started the first post-operative day (2F; 6 M) and lasted 3.0 ± 0.8 days. Subjects with POD were significantly older, had a previous history of delirium, were more impaired in the instrumental activities of daily living and had poorer clock drawing test (CDT) score. Interestingly, a significantly greater number of hypotensive events were recorded during anesthesia. Age, cognitive and functional status, previous history of delirium and hypotensive episodes intrasurgery are the best predictor of POD in this setting. Our findings have implications in preventing delirium in elderly by an early and targeted evaluation.
ABSTRACT
Mycobacterium tuberculosis and Mycobacterium bovis are responsible for tuberculosis in humans and animals, respectively. Both species are closely related and belong to the Mycobacterium ...tuberculosis complex (MTC). M. tuberculosis is the most ancient species from which M. bovis and other members of the MTC evolved. The genome of M. bovis is over >99.95% identical to that of M. tuberculosis but with seven deletions ranging in size from 1 to 12.7 kb. In addition, 1200 single nucleotide mutations in coding regions distinguish M. bovis from M. tuberculosis. In the present study, we assessed 75 M. tuberculosis genomes and 23 M. bovis genomes to identify non‐synonymous mutations in 202 coding sequences of regulatory genes between both species. We identified species‐specific variants in 20 regulatory proteins and confirmed differential expression of hypoxia‐related genes between M. bovis and M. tuberculosis.
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