Deciphering the molecular effects of non-ablative Er:YAG laser treatment in an in vitro model of the non-keratinized mucous membrane

Lasers in Medical Science -     

Short‐term Effects of Social Exclusion at Work and Worries on Sleep

The present study investigated short‐term effects of daily social exclusion at work on various indicators of sleep quality and tested the mediating role of work‐related worries using a time‐based diary study with ambulatory assessments of sleep quality. Ninety full‐time employees participated in a 2‐week data collection. Multilevel analyses revealed that daily workplace social exclusion and work‐related worries were positively related to sleep fragmentation in the following night. Daily social exclusion, however, was unrelated to sleep onset latency, sleep efficiency and self‐reported sleep quality. Moreover, worries did not mediate the effect of social exclusion at work on sleep fragmentation. Theoretical and practical implications of the results are discussed. Copyright © 2012 John Wiley & Sons, Ltd.     

Combination of betulinic acid with cisplatin--different cytotoxic effects in two head and neck cancer cell lines

Betulinic acid (BetA), a new experimental cytotoxic compound that is active against human melanoma cells and neuroectodermal tumor cells, has recently been shown to be also effective against head and neck squamous carcinoma cells (HNSCC). In this study we investigated BetA in combination with cisplatin in squamous cell carcinoma cell lines of the tongue. SCC25 and SCC9 were treated with BetA and/or cisplatin. Cells were counted with an automated analyzing system. Caspase activation was determined using the M30 Cyto-Death ELISA, expression of the anti-apoptotic protein Mcl-1 by Western blot analysis. Visualization of apoptotic cells was achieved by immunohistochemistry. Synergistic cytotoxic effect and the induction of apoptosis under combined treatment was observed in SCC25 cells only after 24 or 48 h, whereas treatment of SCC25 cells for 72 h with BetA and cisplatin showed antagonism or subadditive effects. In SCC9 cells, antagonism occurred over an increase of dose and time during treatment. Furthermore, we could not demonstrate a significant alteration in the expression of the anti-apoptotic protein, Mcl-1. Our in vitro data demonstrate that BetA seems to be an unlikely candidate for combination with cisplatin in the treatment of head and neck cancer.     

Reversible and irreversible peri-implant lesions: report and etiopathogenic analysis of 7 cases

The purpose of this report is to review the aberrations in the integration process of cylindrical endosseous implants, though such aberrations are seldom observed. These issues are treated according to the following scheme: (1) infectious lesions, which consist of peri-implantitis, intraosseous infectious foci, and septic voids; (2) transitory lesions; (3) lesions related to occlusal overload; and (4) healing defects. In this report, we illustrate these categories with patient histories and discuss the clinical findings and etiopathogenies.     

Stimulating effect of implant loading on surrounding bone. Comparison of three numerical models and validation by in vivo data

A number of algorithms have been proposed to model the adaptive behavior of bone under load. However, the predictions of several models have neither been compared nor have they been systematically related to in vivo data. To this end, the stress states of loaded implant-bone interfaces were analyzed before and after osseointegration using finite element (FE) techniques. In a preliminary step, an FE mesh of a cylindrical implant encased in a cancellous core surrounded by a cortical layer was constructed, and the stresses and strains that developed at the interface were determined. The implant was loaded with 100 N vertical and 30 N lateral loads. Using this structure, the peak compressive and tensile stresses were determined. Then bone remodeling predictions were assessed using three different models: von Mises equivalent strain, strain energy density and effective stress. Finally, a systematic search of the literature was conducted to relate the numerical predictions to existing in vivo data. The FE simulations led to the following conclusions: (1) calculated compressive stresses were lower than the ultimate compressive stresses of cortical and cancellous bone. (2) Calculated tensile stresses were generally superior to experimental data on the tensile strength of the bone-implant interface. (3) With one exception, the predictions of all models were homogeneously grouped on the stimulus scales. (4) The predictions of the models as to bone gain or loss were not consistent and at times contradictory. It is hypothesized that this effect is linked to a lazy zone that is too narrow. With respect to the application of the numerical models to in vivo data, peak strains and strain energy densities were consistent with in vivo data. No in vivo data were found that supported effective stress as a stimulus.     

Longitudinal study of energy expenditure in preterm neonates <30 weeks' gestation during the first three postnatal weeks

OBJECTIVES: The objective of this study was to measure energy expenditure (EE) in a contemporary population of preterm neonates <30 weeks' gestation. STUDY DESIGN: Prospective longitudinal cohort study in 26 consecutive preterm neonates (gestational age, 27 weeks [23-29] [median, range]; birth weight, 980 g [554-1592]). EE was measured by indirect calorimetry on postnatal days 1, 3, 5, 10, and 21. Data on body weight, energy intake, and medical therapy were prospectively collected. RESULTS: EE increased from 121 +/- 25 kJ/kg per day (29 +/- 6 kcal/kg per day) (mean +/- SD) on day 1 to 222 +/- 25 kJ/kg per day (53 +/- 6 kcal/kg per day) on day 21. An energy deficit occurred only on day 1. EE was closely related to energy intake: For each additional kJ given, EE increased by 0.3 kJ (r = 0.789, P <.0001). Neonates with a birth weight <1000 g did not have a more pronounced energy deficit than the heavier neonates. EE during nasal continuous positive airway pressure in the first postnatal week was 25% lower than during spontaneous respiration. CONCLUSIONS: EE could be predicted from energy intake with acceptable accuracy in preterm neonates <30 weeks' gestation during the first 3 postnatal weeks. There was no prolonged energy deficit.     

Hypoglycaemic effect of Opuntia lindheimeri Englem in a diabetic pig model

The hypoglycaemic activity of Opuntia lindheimeri Englem. was investigated in non-diabetic (control pigs) and streptozotocin-induced diabetic pigs using an enteral (oral) route of administration. Following the administration of O. lindheimeri extract (0, 250 or 500 mg/kg body weight), blood glucose concentrations in control pigs fluctuated around initial baseline concentrations, but were not consistently affected by either the dose of O. lindheimeri or by the time following administration. In contrast, administration of O. lindheimeri extract to STZ-treated pigs resulted in both a dose- (p < 0.001) and time-dependent (p < 0.001) decrease in blood glucose concentrations. The hypoglycaemic effect of the extract was apparent within 1 h of administration, with maximal effects occurring at 4 h after administration. These results confirm the hypoglycaemic effect of O. lindheimeri extract in a diabetic pig model. In addition, given the physiological similarities of the pig to humans, this model will be of tremendous use in assessing the long-term effects of Opuntia administration on the secondary problems associated with diabetes.     

Microstructures of brazings and welds using grade 2 commercially pure titanium

PURPOSE: Microstructural analyses of commercially pure titanium (CpTi) are scarce. The present report presents the micrographs, fractographs, elemental characteristics, and hardness profiles of brazed joints and weldments using machined rods of CpTi. MATERIALS AND METHODS: CpTi rods were joined using four techniques: laser welding, electric-arc welding, electron-beam welding, and gold- and Ti-filler brazing. The specimens were then subjected to tensile and fatigue loading. After sectioning and patterning, optical micrographs of intact joints were obtained. Fractured surfaces were investigated using scanning electron microscopy (SEM). The joint's composition was determined by SEM-energy dispersive x-ray analysis. Hardness was determined at specific locations using a microindenter. RESULTS: While laser welding left the parent metal's equiaxed structure fairly intact, electric-arc welding, electron-beam welding, and brazing created a heat-affected zone in the vicinity of the joint. The extent and characteristics of the heat-affected zone depended on the amount of heat transferred to the specimens. In this respect, brazing essentially increased grain size and altered their shape. Electron-beam welding augmented this phenomenon, yielding grains that encompassed the full diameter of the joint. Electric-arc welding disrupted the granular pattern and generated highly lamellar/acicular structures. CONCLUSION: Hardness was not a good indicator of mechanical resistance, nor was the joint's structural continuity with the parent substrate. Still, acicular microstructures were characterized by a peculiar behavior in that such joints were highly resistant to tensile stresses while their fatigue strength ranged among the lowest of the joints tested.