The effect of intra-wound vancomycin powder application in reducing surgical site infections after total hip arthroplasty

Post-operative total hip arthroplasty surgical wound infections are associated with substantial morbidity, mortality, and economic burden. Intra-wound vancomycin powder application may prevent infections after hip surgery. The objectives of this study is to answer the question as to whether the application of 2 gram intra-wound vancomycin powder In patients undergoing total hip arthroplasty, lead to reduced rates of postoperative surgical site infections or not? From April 2013, 125 patients had consent prior to their hip surgery. These 125 patients had total hip arthtoplasty by three different surgeons at Imam Hossein hospital. All patients received either 2 grams of IV Cefazolin one hour prior to the incision or 1 gram of IV Vancomycin one hour prior to the incision in patient with a Penicillin allergy. Near the end of the procedure, the wound was thoroughly irrigated with normal saline. for All patients befor surgical wound closure 2 gram of Vancomycin powder was poured into the wound. Postoperatively, patients continued on intravenous antibiotics for twenty-four hours. All patients underwent routine postoperative surgical care including physical therapy, routine radiographs, and routine managment of pain medications. Laboratory tests include Hb , BUN, Cr and electrolits were done before surgery and postoperatively after 48 hours and 7 days. All patients were discharged within the first 3 days after surgery and follow-up at weeks 2 and 4 and one year after surgery was performed. During the course of follow up that has ranged from one months to one year, sixteen of patients experienced surgical site infection. 10 patients were lost to follow up. No allergic reactions or adverse outcomes were reported from the use of 2 gram of Vancomycin powder prior to closure. Although intra-wound application of Vancomycin is known to minimize infections in spinal surgery little previous studies reported if Vancomycin application will reduce surgical site infection in hip surgeries. This study demonstrates that intra-wound application of Vancomycin reduces surgical site infection in total hip arthroplasty without any adverse complications

ESSAYS IN OIL PRICE SHOCKS AND MACROECONOMICS OF OIL EXPORTING COUNTRIES

The central issue that this dissertation tries to address is the relationship between oil price shocks and the macroeconomics of oil exporting countries. For all those who had a chance to live in an oil exporting countries, it is evident that oil revenue plays a major role to induce ups and downs in economy and also in politics. I tried to address this phenomenon in the first chapter in which the relationship between oil price shocks and business cycles is investigated. In the first chapter it is shown that in some oil exporting countries like Kuwait, Venezuela and Libya, the impact of oil price shock is conditional on the cycle of the economy. An oil price shock has different effect when the economy is in boom than when it is in bust. Iran is not included in the sample of countries of this chapter since exogenous radical political events like revolution, persistent war, sanction, short term civil war and so on, makes the performance of the economy too volatile to be able to fit its data with regime switching models. This approach works well when changes are smooth. Therefore, I analyzed the case of Iran in a separate chapter through the VAR and SVECM framework. This paper examines the well-known Dutch disease hypothesis for the case of Iran. The result of second chapter partially contradict the prediction of this hypothesis since it is shown that positive oil price shock has permanent positive effect on GDP which is consistent with the finding of Esfahani, Mohades and Pesaran (2009). Success of populist candidate in presidential election in Iran and Venezuela motivated the writing of the first paper. This paper explores the relationship between quality of institution and the composition of government budget. It shows that when the quality of institution is low, majority of constituency prefer direct transfer rather than public spending on necessary and productive public goods, although investment in public goods is a prerequisite for development. But when the quality of institution is high, voters choose public investment. That is the cause of the difference in the public choice of two countries: Norway and Venezuela. This is in line with the finding of the literature on political economy of oil. Therefore, all three chapters although are different in method and content but concern a central issue which is the role of oil in the economy of oil exporting countries

Two-step purification and partial characterization of an extra cellular α-amylase from Bacillus licheniformis

The aim of this study was production and partial purification of α-amylase enzyme by Bacillus licheniformis. B. Licheniformis was allowed to grow in broth culture for purpose of inducing α-amylase enzyme. Optimal conditions for amylase production by B. Licheniformis are incubation period of 120 h, temperature of 37 °C and pH 7.0. The α-amylase enzyme was purified by ion exchange chromatography on DEAE-sepharose CL-6B and sephadex G-100 gel filtration with a 19.1-fold increase in specific activity as compared to the concentrated supernatant and with a specific activity of 926.47 U/mg. The α-amylase had the highest activity at pH 7.0 and 65 °C. According to the data on native polyacrylamide gel electrophoresis, the molecular weight of the purified enzyme was 72 kDa

Polymerase Chain Reaction Assay Using the Restriction Fragment Length Polymorphism Technique in the Detection of Prosthetic Joint Infections: A Multi-Centered Study

Background: PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) techniques have been used for the diagnosis of bacteria in some infections. In this study, we aimed to evaluate the diagnostic accuracy of PCR for the diagnosis of prosthetic joint infections (PJI) and to identify isolated microorganisms, using the RFLP method. Methods: During January 2015 to January 2018, patients who were suspected of having PJI after arthroplasty surgery or were candidates for revision surgery due to loosening of implant entered the study. Patients who had 1 major criterion or 3 minor criteria for PJI based on the Philadelphia Consensus Criteria (PCC) on Periprosthetic Joint Infection were considered as cases of PJI. Both culture results and PCR findings, were cross compared with results of the PCC (as the gold standard criteria). Results: Overall, 76 samples were included in the study. Mean (standard deviation) age of patients was 66.72 ± 11.82 years. Overall, 57.9 of patients were females. Prevalence of PJI was 50 based on the PCC. Sensitivity, specificity, positive predictive value, negative predictive value, and general efficacy of PCR for detection of PJI was 97.4, 100, 100, 97.4, and 98.7, respectively. Sensitivity, specificity, positive predictive value, negative predictive value, and general efficacy of culture was 31.6, 100, 65.7, 100, and 59.4, respectively. We isolated a broad range of bacteria using PCR-RFLP including Gram-positive cocci such as Staphylococcus sp., Streptococcus sp., and Enterococcus sp., and Gram-negative bacilli such as Enterobacteriaceae sp., Pseudomonas sp. Citrobacter sp., as well as Chlamydophila pneumonia, Stenotrophomonas maltophilia, Brucella melitensis, non-gonococcal Neisseria, Kingella kingae, Bacteroides ovatus, and Proteus mirabilis from PJI patients. Conclusion: Inhere, for the first time, we showed that PCR-RFLP is a powerful tool for identifying the type of bacteria involved in PJI, and can be used for follow-up of patients suspected of PJI and those with a history of antibiotic use. PCR-RFLP may be able to substantially decrease detection time of PJI among PCR-based methods, while allowing more accurate identification of the bacteria involved. © 2018 Elsevier Inc