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The conformational properties of AT1 antagonist valsartan have been analyzed both in solution and at the binding site of the receptor. Low energy conformations of valsartan in solution were explored by NMR spectroscopy and molecular modeling studies. The NMR results showed the existence of two distinct and almost isoenergetic conformations for valsartan (cis:trans ratio around the amide bond ∼40:60) that coalesce at the temperature range of 55-60 °C in agreement with previous in solution conformational analysis study (Fang et al. Magn. Reson. Chem. 2007, 45, 929-936). Quantum mechanics and ONIOM calculations revealed that the bulky valsartan substituents actually contribute to stabilization of the transition state for interconversion. In silico docking and Molecular Dynamic studies were applied to study binding of valsartan at the AT1 receptor site models, explicitly solvated and embedded in lipid bilayers and solvent molecules. These studies revealed that the majority of docked poses adopted a trans (major) conformation. Of paramount and maybe biological importance are the MD simulations results which showed that the two acidic groups of valsartan are bridged through LYS199 enabling it for multiple hydrogen bond interactions. In a lipid bilayer environment these interactions are enhanced, designating the important role of lipid bilayers for the better binding of valsartan and its stabilization at the active site

This prospective study assessed the Surgical Site Infection (SSI) rates in General Surgery and the microorganisms isolated. From January 2000 to October 2000, 898 patients were enrolled and electively operated in a General Surgery Clinic in Athens, Greece. Pre-coded questionnaires were used. The diagnosis and surveillance of SSIs was made by the surgeon-investigator who interviewed the patients. Patients were monitored during hospitalization and post-discharge for 30 days. Overall, 402 patients underwent a clean and 496 patients underwent a clean-contaminated operation. A total of 17 SSIs (4.2%) were observed in clean and 64 SSIs (12.9%) in clean-contaminated operations. Microorganisms were isolated in 36 of 65 (55%) of cases that microbiological evaluation was performed. Staphylococcus aureus was the commonest microorganism isolated, followed by Escherichia coli and Pseudomonas aeruginosa. SSI rates were higher than expected and most SSIs, 43 of 81 (53.1%), were diagnosed post-operatively. Post-discharge surveillance of SSIs remains a critical issue. Health care professionals, especially surgeons, should participate in surveillance networks and be aware of the results so to take appropriate action.

Objectives: To evaluate the adherence of general surgeons to guidelines for antimicrobial prophylaxis. This study was held from January 2000 until October 2000 in a General Surgery Clinic in a hospital in Athens, Greece. Methods: Eight hundred and ninety-eight patients were enrolled and operated on electively. Questionnaires concerning demographic data, health status, type of surgery (clean and clean-contaminated) and parameters of antibiotic prophylaxis (antibiotic choice, route, dose, timing of first dose, timing of operative redosing and duration of prophylaxis) were completed. Results: Of the patients, 44.8% underwent a clean surgical operation and 55.2% underwent a clean-contaminated surgical operation. Inguinal hernia repair and laparoscopic cholecystectomy were the commonest operations in each category. Second-generation cephalosporins were the most frequently prescribed antibiotics, in 67%. Although, only 78.5% of procedures required prophylaxis, it was administered in 97.5%, so it was not justified and inappropriately administered in 19%. It was revealed that 100% of patients received antibiotic prophylaxis on time. The choice of antimicrobial agent was appropriate in 70% and the duration of prophylaxis was optimal in 36.3%. The overall compliance rate of surgeons with guidelines for antibiotic prophylaxis was 36.3%. Conclusions: Adherence to separate aspects of guidelines for surgical prophylaxis has to be improved. The duration of antibiotic prophylaxis was the main parameter of interest. Interventions have to be made about the development, distribution and adoption of adequate guidelines in collaboration with surgeons. © The Author 2007. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.

In this paper the development and flight testing of flapping-wing propelled, radio-controlled micro air vehicles are described. The vehicles consist of a fixed-wing and a pair of flapping wings immediately downstream of the fixed-wing which flap in counterphase to provide a mechanically and aerodynamically balanced platform and increased efficiency. The models weigh as little as 13 grams, with a 27 cm span and 18 cm length and will fly for about 20 minutes on a 135 mAh Li-Poly battery. Stable flight at speeds between 2 and 5 m/s has been demonstrated, and the models are essentially stall-proof while under power due to the flow-entrainment effect of the flapping-wing pair.

Glucocorticoid induced osteoporosis has been associated with high doses and it has been partially attributed to decreased absorption and to increased calcium excretion. The present study examined the effect of low but effective doses of methylprednisolone (MP) on calcium balance and on skeleton in rats. Total duration of the experiment 29 days. Thirty-one male Wistar rats (MP group) were injected with 4mg/kg body weight MP sc at the Ist, 11th and 20th day of the experiment and 28 rats (C group) were used as matched controls. The Ist, 11th and 20th day of the experiment rats were placed in individual metabolic cages for three days. Food and water consumption were measured at the 2nd and 3rd days after each injection; urine and faeces were collected at the same days for calcium estimation. Calcium intake and excretion after each injection was significantly lower in the MP group as compared to controls. A statistically significant positive correlation between calcium consumption and calcium excretion was found in both groups resulting in a negative final balance. Rats were killed the 29th day. Adrenal weight was statistically significant lower in MP group (p<0.001). Morphometric properties were evaluated for the right femur. No significant difference was found between the two groups. Mineral and calcium content was slightly increased in the MP group. According to these results, it seems that methylprednisolone while effective on HPA axis did not have any effect on calcium absorption and on bone calcium deposition in rats. (C) 1997, Editrice Kurtis.