Effect of molar mass of an experimental primer on shear bond strength to dentin

A novel oligomer was synthesized in different molecular masses and used as a primer in dentin bonding. The hypothesis was that an intermediate molecular mass would optimize the conflicting needs for diffusion into etched dentin (low M(w)) and high mechanical properties (high M(w)). The initial oligomer synthesized was tert butylmethacrylate-co-maleic anhydride, which was further reacted to add hyrdoxyethyl methacrylate (HEMA) across the anhydride. The oligomer was synthesized in a series of molecular masses from approximately 800-6000 amu. The oligomer with an average M(w) of approximately 1000 amu provided the highest bond strength (16 MPa), with both lower and higher molar mass oligomers producing lower bond strengths. A polynomial model was fitted to the data with an R(2) = 0.606, while a linear model only had an R(2) = 0.534. This implies that the graph of molar mass to bond strength has a maximum in the range of molar masses examined, and that an optimum molar mass can be found between 800 and 6000 amu.     

Towards a fully-synthetic substitute of alginate: development of a new process using thermal gelation and chemical cross-linking

We have previously described a gelation process based on the occurrence of both physical and a chemical mechanisms ('tandem process'), in which a telechelic linear poly(propylene glycol)-bl-poly(ethylene glycol)-bl-poly(propylene glycol) is first thermally gelled and subsequently covalently cross-linked by the reaction of polymer end groups at the termini of the copolymer. The quick kinetics of the reverse thermal gelation and the harmless character of the Michael-type addition between two sets of terminal groups, acrylates on one set and thiols on the other, allows irreversibly cross-linked hydrogels to be obtained in a rapid and biocompatible fashion, even when gelation was conducted in direct contact with cells. This allows in principle for an application of the tandem process in cell encapsulation. In the present work, we have optimized the macromolecular architecture and functionality of the precursors for allowing the use of the tandem process in encapsulation devices designed for calcium alginate. The mechanical, diffusional and biocompatibility properties of these materials were characterized; the comparison of mass transport properties of the tandem gels with those of calcium alginate suggests a similar or even better immunoisolation effect.     

The protective role of tiopronin in cisplatin ototoxicity in Wistar rats

The purpose of this study was to evaluate cisplatin-induced ototoxicity and the protective effects of tiopronin. Twenty-four adult Wistar rats served as subjects and were divided into three groups. Eight rats receiving only saline (group A) were used as controls. Eight rats received cisplatin (2 mg/kg) injections (group B) and eight rats received cisplatin and tiopronin (300 mg/kg) (group C) for 8 consecutive days. Both ears of all animals were tested by DPOAE before treatment and on the 4th and 9th days. Seventy-two hours after the final recording session, all animals were killed, and the left cochleas were prepared for electron microscopy and analysed. DPOAE responses were significantly reduced in group B compared to controls (p<0.05). When tiopronin was added, DPOAE responses were significantly increased compared to those obtained with the administration of cisplatin alone (p<0.05). The cochleogram showed that tiopronin had a significant protective effect in the basal half and in the lower half of the middle turn. We conclude that tiopronin, a drug effective in protecting against cisplatin nephrotoxicity, is also effective in protecting against cisplatin ototoxicity.     

Anxiety and self-consciousness in patients with minor facial lacerations

BACKGROUND: Although minor facial injuries are relatively common, their psychological impact is an area neglected in the literature. For physiologically major injuries (such as facial cancers, burns and fractures), the face has been suggested to be a psychologically significant area of the body and disfigurement has been found to have numerous potential social consequences for patients. AIMS: This paper reports the findings of an inquiry that explored the psychological impact of minor facial injuries and the influence of patient and scar characteristics in relation to self-consciousness and anxiety levels. METHOD: Data were collected in 2001 in an accident and emergency unit from patients with a visible laceration over 1.5 cm that was treatable in an outpatient setting. The Derriford Appearance Scale (with general and social self-consciousness subscales) and the State-Trait Anxiety Inventory were administered to 63 patients 1 week later; data on 50 patients were also available 6 months after the injury. RESULTS: Larger scar size, living alone and aetiology of injury were significantly related to self-consciousness and anxiety levels, although gender, age, socio-economic group, location of scar, satisfaction with appearance and number of scars were not. General self-consciousness improved at 6 months but social self-consciousness and anxiety remained the same. Patient factors were not related to changes in general self-consciousness over time. CONCLUSIONS: Minor facial scars can have significant psychological impact for some people. Awareness training for health professionals, social skills training for affected patients and a patient information leaflet are recommended.     

Comprehensive decision analytical modelling in economic evaluation: a Bayesian approach

Decision analytical models are widely used in economic evaluation of health care interventions with the objective of generating valuable information to assist health policy decision-makers to allocate scarce health care resources efficiently. The whole decision modelling process can be summarised in four stages: (i) a systematic review of the relevant data (including meta-analyses), (ii) estimation of all inputs into the model (including effectiveness, transition probabilities and costs), (iii) sensitivity analysis for data and model specifications, and (iv) evaluation of the model. The aim of this paper is to demonstrate how the individual components of decision modelling, outlined above, may be addressed simultaneously in one coherent Bayesian model (sometimes known as a comprehensive decision analytical model) and evaluated using Markov Chain Monte Carlo simulation implemented in the specialist software WinBUGS. To illustrate the method described, it is applied to two illustrative examples: (1) The prophylactic use of neurominidase inhibitors for the prevention of influenza. (2) The use of taxanes for the second-line treatment of advanced breast cancer.The advantages of integrating the four stages outlined into one comprehensive decision analytical model, compared to the conventional 'two-stage' approach, are discussed.     

Pediatric influenza prevention and control

Global evaluation of influenza vaccination in children indicates that current recommendations are not followed. Most children at high risk for influenza-related complications do not receive the vaccine, and increased efforts are needed to protect them. Furthermore, vaccinating healthy infants 6-23 months of age and their close contacts should be strongly encouraged. Vaccinations are recommended for children with recurrent acute otitis media or recurrent respiratory tract infections and possibly for healthy daycare and school-age children because of the potential socioeconomic implications of influenza. Issues that need to be addressed include educating physicians and parents concerning influenza-related illness and complications, cost-effectiveness and safety of licensed vaccines, adequate vaccine supply, and availability of intranasal products.     

Dietary phylloquinone intake as a potential marker for a heart-healthy dietary pattern in the Framingham Offspring cohort

Abstract Associations were evaluated among self-reported dietary intakes of phylloquinone (vitamin K-1), lifestyle characteristics, and intermediary markers of cardiovascular disease risk in a population-based cohort of men and women. Dietary phylloquinone intakes were assessed by food frequency questionnaire in 1,338 men and 1,603 women (mean age, 54 years) participating in the Framingham Heart Study. Cross-sectional associations with lifestyle characteristics and lipid profiles, including total cholesterol, low-density lipoprotein and high-density lipoprotein cholesterol, and triglyceride concentrations, were estimated across increasing quintile categories of phylloquinone intakes. Participants in the highest quintile category of phylloquinone intake consumed more fruit, vegetables, fish, dietary fiber, and dietary supplements ( P <.001), and consumed less meat and less saturated fat ( P <.001). Higher phylloquinone intakes were also associated with lower triglyceride concentrations ( P <.001). In conclusion, a high phylloquinone intake may be a marker for an overall heart-healthy dietary pattern.     

Surgical site infection - a European perspective of incidence and economic burden

This retrospective review of reported surgical site infection (SSI) rates in Europe was undertaken to obtain an estimated scale of the problem and the associated economic burden. Preliminary literature searches revealed incomplete datasets when applying the National Nosocomial Infection Surveillance System criteria. Following an expanded literature search, studies were selected according to the number of parameters reported, from those identified as critical for accurate determination of SSI rates. Forty-eight studies were analysed. None of the reviewed studies recorded all the data necessary to enable a comparative assessment of the SSI rate to be undertaken. The estimated range from selected studies analysed varied widely from 1.5-20% - a consequence of inconsistencies in data collection methods, surveillance criteria and wide variations in the surgical procedures investigated - often unspecified. SSIs contribute greatly to the economic costs of surgical procedures - estimated range: 1.47-19.1 billion Euro dollars. The analysis suggests that the true rate of SSIs, currently unknown, is likely to have been previously under-reported. Consequently, the associated economic burden is also likely to be underestimated. A significant improvement in study design, data collection, analysis and reporting will be necessary to ensure that SSI baseline rates are more accurately assessed to enable the evaluation of future cost-effective measures.