Current practices of preoperative bowel preparation among North American colorectal surgeons

In North America, the rate of infections following colorectal surgery decreased after the introduction of oral antibiotic bowel preparation against colonic microflora. Eight hundred eight board-certified colorectal surgeons were surveyed for their current bowel preparation practices before elective procedures. The 471 responders (58%) all use mechanical preparation: oral polyethylene glycol solution (70.9% of the respondents), oral sodium phosphate solution with or without bisacodyl (28.4%), and "traditional" methods of dietary restriction, cathartics, and enemas (28.4%). Most surgeons (86.5%) add oral and parenteral antibiotics to the regimen; 11.5% add only parenteral antibiotics, 1.1% add only oral antibiotics, and 0.9% add no antibiotics. Generally (77.8% of cases), oral neomycin and erythromycin or metronidazole are combined with a perioperative parenteral antibiotic. Most individuals start the preparation as outpatients the day before surgery, and the parenteral drugs are added to the regimen 1-2 hours before the procedure. The use of outpatient bowel preparation is increasing; however, patient selection is critical, and education is needed to reduce the rate of complications.     

Determination of Ozonation Rate Constants for Lincomycin and Spectinomycin

Recent occurrences of pharmaceutical antibiotics in surface water, drinking water, and wastewater systems have gained significant attention due to their potential threats to human health. This study determined the absolute second-order rate constants of ozone with two amine-based antibiotics, namely, lincomycin and spectinomycin, using the stopped-flow technique under controlled ionic strength, buffer, and temperature. Results indicate that ozone reacts quickly with the selected antibiotics, and the reaction rate significantly depends on solution pH. For lincomycin, ozone attacks its free amine group and sulfur group with absolute rate constants of 2.76 × 10⁶ M^?1·s^?1 (for neutral form) and 3.26 × 10⁵ M^?1·s^?1 (for monoprotonated form), respectively. For spectinomycin, ozone attacks two free amine groups with absolute rate constants of 1.27 × 10⁶ M^?1·s^?1 (for neutral form) and 3.30 × 10⁵ M^?1·s^?1 (for monoprotonated form), respectively. These rate constants have been corrected to zero ionic strength. Protonated amine is nonreactive toward ozone. Model prediction indicates that lincomycin and spectinomycin can be effectively transformed by ozonation processes around neutral pH.     

Enhanced Bioremediation of Fuel-Oil Contaminated Soils: Laboratory Feasibility Study

In this study, microcosm experiments were conducted to evaluate the effectiveness of (1) nutrients, hydrogen peroxide (H2O2), and cane molasses addition; (2) soil washing by biodegradable surfactant [Simple Green (SG)]; and (3) soil pretreatment by Fenton-like oxidation on the bioremediation of fuel-oil contaminated soils. The dominant native microorganisms in the fuel-oil contaminated soils after each treatment process were determined via polymerase chain reaction, denaturing gradient gel electrophoresis, and nucleotide sequence analysis. Results show that approximately 32 and 56% of total petroleum hydrocarbon (TPH) removal (initial concentration of 5,000?mg?kg?1) were observed in microcosms with the addition of nutrient and cane molasses (1,000?mg?L?1), respectively, compared to only 9% of TPH removal in live control microcosms under intrinsic conditions (without amendment) after 120 days of incubation. Addition of cane molasses would cause the increase in microbial population and thus enhance the TPH degradation rate. Results also show that approximately 61% of TPH removal was observed in microcosms with the addition of H2O2(100?mg?L?1) and nutrient after 120 days of incubation. This indicates that the addition of low concentration of H2O2(100?mg?L?1) would cause the desorption of TPH from soil particles and increase the dissolved oxygen and subsequent bioremediation efficiency in microcosms. Approximately 95 and 69% of TPH removal were observed in microcosms with SG (100?mg?L?1) and higher dose of H2O2(900?mg?L?1) addition, respectively. Moreover, significant increases in microbial populations were observed and two TPH biodegraders (Pseudomonas sp. and Shewanella sp.) might exist in microcosms with SG or H2O2 addition. This indicates that the commonly used soil remedial techniques, biodegradable surfactant flushing, and Fenton-like oxidation would improve the TPH removal efficiency and would not cause adverse effects on the following bioremediation process.     

Oral bioavailability and intestinal absorption of candesartan cilexetil: role of naringin as P-glycoprotein inhibitor

Objective: The aim of the study is to explore the pharmacokinetic behavior of candesartan solid dispersions prepared by different pharmaceutical interventions using P-gp inhibitor in rabbits to validate the effectiveness of naringin as a pharmaceutical excipient in enhancing the oral delivery of lipophilic candesartan cilexetil.

Methods: Male albino rabbits (1–1.5?kg) were orally administered pure CAN suspensions and various candesartan solid dispersions (10?mg/kg) with and without naringin (15?mg/kg) and blood samples were collected at specified time points. CAN plasma samples were measured using HPLC.

Key findings: After oral dosing of pure CAN suspension, the mean AUC0-8?h was found to be 0.14?±?0.09?μgh/ml which was increased significantly, i.e. 0.52?±?0.13?μgh/ml with freeze-dried solid dispersions in the presence of naringin (p?p?Conclusion: These results are quite stimulating for further development of a clinically useful oral formulation of candesartan cilexetil based on P-gp inhibition using naringin, a natural flavonoid as a pharmaceutical excipient.     

Long-term land application of biosolids-a case study.

Impact of long-term land application of biosolids on groundwater and soil quality of an application site, which had been operated for 8-15 years, was evaluated in this study. During and after the biosolids application, biosolids-amended soil, groundwater, and background soil samples were collected mainly for pathogen, nitrogen, phosphorus, and heavy metal analyses. Soil test data showed that there was no heavy metal accumulation in the biosolids-amended soil even after 10 years of biosolids application. Similar results were also observed from the groundwater samples in which the heavy metal concentrations in all groundwater samples were well below the maximum contamination levels of the drinking water standards. In addition, bacteriological levels of the soil and groundwater samples were close to the background level and below the permissible limits, respectively, thereby showing no pathogen contamination. However, nitrate-nitrogen contamination of the groundwater was occasionally observed probably due to an excess loading of the biosolids in the past. This problem can be alleviated by applying biosolids at agronomic rates so that no excess nitrogen is available for leaching down to the groundwater.     

In vivo evaluation of magnetite nanoparticles for use as a tumor contrast agent in MRI

Magnetite nanoparticles, coated by three different artificial polypeptides, were conjugated to an antibody specific to the carcinoembryonic antigen (CEA). To protect the particles from fast blood elimination, the coats were modified by various sugars, polyethyleneglycol, albumin, and sialoproteins, respectively. The protective effect was determined by using a specific in vitro test and by analyzing the biodistribution of the nanoparticles in nude mice grafted with CEA-tumors. In particular, a prolongation of the blood circulation time has been expected, if a natural modifier is attached to the coated nanoparticles. Although the elimination rate could hardly be decreased by any modifiers, the tumor accumulation is slightly improved by using the specific sialoprotein glycophorin B. The usefulness of nanoparticles as image contrast agents is probably limited by their microdistribution within the tumor tissue. The requirements for a contrast agent to be highly tissue specific are discussed.     

Expression of growth factors and their receptors in the postnatal rat cochlea

RT-PCR was used to assay for growth factors and receptors from seven different protein families in cochlea tissues of the juvenile rat. There was a broad representation of the growth factor families in all the cochlea tissues examined, though the organ of Corti and stria vascularis expressed a greater variety than the spiral ganglion. This broad expression suggests that a variety of known growth factors play significant roles in the development, maintenance, and repair of the inner ear. The results of this survey serve as a basis for the design of future in vitro experiments that will address the ability of growth factors to protect hair cells from damage and to evoke a repair-regeneration response by injured hair cells.