Leakage of Saliva Through the Implant-Abutment Interface: In Vitro Evaluation of Three Different Implant Connections Under Unloaded and Loaded Conditions

Purpose: Bacterial leakage along the implant-abutment interface, with consequent species harboring the inner parts of two-part dental implant systems, has been reported in the literature. The aim of this in vitro study was to evaluate bacterial leakage from human saliva to the internal part of the implants along the implant-abutment interface under loaded and unloaded conditions using DNA Checkerboard. Materials and Methods: Sixty denial implants-20 each of external-hexagon, internal-hexagon, and Morse cone-connection designs-and their conical abutments were used in this study. Each group was subdivided into two groups of 10 loaded and 10 unloaded implants. The assemblies were immersed in human saliva and either (1) loaded with 500,000 cycles at 120 N (experimental group) or (2) incubated in static conditions for 7 days at 35 degrees C (unloaded control group). Results: Microorganisms were found in the internal surfaces of all types of connections. The Morse cone connection presented the lowest count of microorganisms in both the unloaded and loaded groups. Loaded implants presented with higher counts of microorganisms than unloaded implants for external- and internal-hex connections. Conclusion: Bacterial species from human saliva may penetrate along the implant-abutment interface under both unloaded and loaded conditions for all connections evaluated. Morse cone-connection implants showed the lowest counts of microorganisms for both conditions. External- and internal-hex implants showed a higher incidence of bacteria and higher bacterial counts after simulated loading. INT J ORAL MAXILLOFAC IMPLANTS 2012;27:551-560.

Influence of different shrinking temperatures and vacuum conditions on the ability of psychrotrophic Clostridium to cause 'blown pack' spoilage in chilled vacuum-packaged beef

This study determined the ability of psychrotrophic Clostridium strains isolated from vacuum-packaged beefs and abattoir environments to cause 'blown-pack' spoilage of vacuum-packaged beef stored at 2 and 15 degrees C. The influence of shrinking temperatures (83, 84 and 87 degrees C) and vacuum pressure (6 and 9 mbar) on the occurrence of such spoilage as well as the effects of simulated transportation (500 km) on the integrity of packages was determined. At 15 degrees C and 2 degrees C, twelve and six strains caused 'blown-pack' spoilage, respectively. The combination of vacuum pressure (9 mbar) combined with shrinking temperature (87 degrees C) retarded the occurrence of spoilage. The simulated transportation under the experimental conditions did not affect the integrity of packages. More studies that assess the factors that may contribute for the occurrence of 'blown-pack' spoilage should be performed to avoid the occurrence of such spoilage during its shelf-life. (C) 2012 Elsevier Ltd. All rights reserved.

Influence of different resistance exercise loading schemes on mechanical power output in work to rest ratio - equated and - nonequated conditions

Paulo CA, Roschel H, Ugrinowitsch C, Kobal R and Tricoli V. Influence of different resistance exercise loading schemes on mechanical power output in work to rest ratio-equated and -nonequated conditions. J Strength Cond Res 26(5): 1308-1312, 2012-It is well known that most sports are characterized by the performance of intermittent high-intensity actions, requiring high muscle power production within different intervals. In fact, the manipulation of the exercise to rest ratio in muscle power training programs may constitute an interesting strategy when considering the specific performance demand of a given sport modality. Thus, the aim of this study was to evaluate the influence of different schemes of rest intervals and number of repetitions per set on muscle power production in the squat exercise between exercise to rest ratio-equated and -nonequated conditions. Nineteen young males (age: 25.7 +/- 4.4 years; weight: 81.3 +/- 13.7 kg; height: 178.1 +/- 5.5 cm) were randomly submitted to 3 different resistance exercise loading schemes, as follows: short-set short-interval condition (SSSI; 12 sets of 3 repetitions with a 27.3-second interval between sets); short-set long-interval condition (SSLI; 12 sets of 3 repetitions with a 60-second interval between sets); long-set long-interval (LSLI; 6 sets of 6 repetitions with a 60-second rest interval between sets). The main finding of the present study is that the lower exercise to rest ratio protocol (SSLI) resulted in greater average power production (601.88 +/- 142.48 W) when compared with both SSSI and LSLI (581.86 +/- 113.18 W; 578 +/- 138.78 W, respectively). Additionally, both the exercise to rest ratio-equated conditions presented similar performance and metabolic results. In summary, these findings suggest that shorter rest intervals may fully restore the individual's ability to produce muscle power if a smaller exercise volume per set is performed and that lower exercise to rest ratio protocols result in greater average power production when compared with higher ratio ones.

Pathogenicity of Metarhizium anisopliae towards Rhipicephalus (Boophilus) microplus under laboratory and field conditions

Metarhizium anisopliae is one of the most studied agents of biological control of several arthropod plagues, including the cattle tick Rhipicephalus (Boophilus) microplus. Studies have been conducted to assess the fungal complex infection process towards its hosts. To accomplish that, mutant strains overexpressing or lacking assumed determinant genes for the process were constructed over the years. A fundamental experiment to demonstrate a particular gene or set of genes participation is the bioassay. The comparison of bioassays using wild and engineered strains is an essential tool to affirm a given gene is crucial in the process. Therefore, the in vitro bioassays should mimic the results obtained in tests under field conditions. In this study, tests under laboratory and filed conditions were done and a correlation analysis was performed in order to statistically validate in vitro bioassays. Tick egg laying, larvae hatching and host mortality were recorded in each experiment through 21 days, both under laboratory and field conditions. In all cases, M. anisopliae treatments were statistically different from the control treatments. A linear regression analysis was performed between the cases. Laboratory results showed a statistically significant correlation with the field conditions using the Pearson's Correlation Test (P < 0.01 host mortality - 0.969, tick egg laying - 0.977 and larvae hatching - 0.956). These results legitimize the in vitro bioassays and, therefore, constitute them as a valid tool for studying this fungus behavior, so they can be used to infer M. anisopliae response towards R. (Boophilus) microplus.

Growth potential of Salmonella spp. and Listeria monocytogenes in nine types of ready-to-eat vegetables stored at variable temperature conditions during shelf-life

Growth potential (delta) is defined as the difference between the population of a microorganism at the end of shelf-life of specific food and its initial population. The determination of 6 of Salmonella and Listeria monocytogenes in RTE vegetables can be very useful to determine likely threats to food safety. However, little is known on the behavior of these microorganisms in several RTE vegetables. Therefore, the aim of this study was to determine the delta of both pathogens in nine different types of RTE vegetables (escarole, collard green, spinach, watercress, arugula, grated carrot, green salad, and mix for yakisoba) stored at refrigeration (7 degrees C) and abuse temperature (15 degrees C). The population of aerobic microorganisms and lactic acid bacteria, including those showing antimicrobial activity has been also determined. Results indicated that L monocytogenes was able to grow (delta >= 0.5 log(10)) in more storage conditions and vegetables than Salmonella. Both microorganisms were inhibited in carrots, although a more pronounced effect has been observed against L monocytogenes. The highest 5 values were obtained when the RTE vegetables were stored 15 degrees C/6 days in collard greens (delta=3.3) and arugula (delta=3.2) (L monocytogenes) and arugula (delta=4.1) and escarole (delta=2.8) (Salmonella). In most vegetables and storage conditions studied, the counts of total aerobic microorganisms raised significantly independent of the temperature of storage (p<0.05). Counts of lactic acid bacteria were higher in vegetables partially or fully stored at abuse temperature with recovery of isolates showing antimicrobial activity. In conclusion, the results of this study show that Salmonella and L monocytogenes may grow and reach high populations in RTE vegetables depending on storage conditions and the definition of effective intervention strategies are needed to control their growth in these products. (C) 2012 Elsevier B.V. All rights reserved.

Arbitrage-Free Conditions and Hedging Strategies for Markets with Penalty Costs on Short Positions

We consider a discrete-time financial model in a general sample space with penalty costs on short positions. We consider a friction market closely related to the standard one except that withdrawals from the portfolio value proportional to short positions are made. We provide necessary and sufficient conditions for the nonexistence of arbitrages in this situation and for a self-financing strategy to replicate a contingent claim. For the finite-sample space case, this result leads to an explicit and constructive procedure for obtaining perfect hedging strategies.

Morbidity among nursing personnel and its association with working conditions and work organization

Introduction: Work organization patterns and working conditions experienced by nursing personnel in the hospital settings may be associated to increased morbidity among these health workers. Aim: To estimate the prevalence and factors associated with self-reported diseases among nursing personnel at the emergency hospital in Rio Branco/ State of Acre, Brazil. Methods: A cross-sectional study was conducted involving 272 participants who answered a questionnaire including sociodemographic characteristics, working conditions, lifestyles, work ability, and a fatigue perception scale. The self-reported diseases in the 12 months prior to data collection were considered the dependent variable. Results: A total of 85.7% of the participants reported one or more diseases in the past 12 months. Most prevalent diseases were: musculoskeletal diseases (37.1%), digestive diseases (28.7%), mental disorders (28.3%), work injuries (27.9%), and respiratory diseases (26.8%). The following significant variables remained in the final model: high work demands (OR 2.69), reported fatigue (OR 3.59), night work (OR 6.55) and being a technician or nursing assistant (OR 4.23). Conclusions: Variables related to working conditions and work organization were associated with the occurrence of reported diseases among nursing professionals. Health promotion measures at work require a comprehensive approach including the working conditions and the work organization.

The use of parthenotegenetic and IVF bovine blastocysts as a model for the creation of human embryonic stem cells under defined conditions

Clinical application of human embryonic stem cells will be possible, when cell lines are created under xeno-free and defined conditions. We aimed to establish methodologies for parthenogenetic activation, culture to blastocyst and mechanical isolation of the inner cell mass (ICM) using bovine oocytes, as a model for derivation and proliferation of human embryonic stem cells under defined xeno-free culture conditions. Cumulus-oocyte-complexes were in vitro matured and activated using Ca(2+)Ionophore and 6-DMAP or in vitro fertilized (IVF). Parthenotes and biparental embryos were cultured to blastocysts, when their ICM was mechanically isolated and placed onto a substrate of fibronectin in StemProA (R) medium. After attachment, primary colonies were left to proliferate and stained for pluripotency markers, alkaline phosphatase and Oct-4. Parthenogenesis and fertilization presented significantly different success rates (91 and 79 %, respectively) and blastocyst formation (40 and 43 %, respectively). ICMs from parthenogenetic and IVF embryos formed primary and expanded colonies at similar rates (39 % and 33 %, respectively). Six out of eight parthenogenetic colonies tested positive for alkaline phosphatase. Three colonies were analyzed for Oct-4 and they all tested positive for this pluripotency marker. Our data show that Ca2+ Ionophore, and 6-DMAP are efficient in creating large numbers of blastocysts to be employed as a model for human oocyte activation and embryo development. After mechanical isolation, parthenogetic derived ICMs showed a good rate of derivation in fibronectin and Stem-Pro forming primary and expanded colonies of putative embryonic stem cells. This methodology may be a good strategy for parthenogenetic activation of discarded human oocytes and derivation in defined conditions for future therapeutic interventions.