In-vivo and in-vitro evaluations for the effect of cyclophosphamide on the carcinogen metabolizing system of mouse-liver microsomes

The effect of the antineoplastic immunosuppressive alkylating agent cyclophosphamide (CPhA) on the modification of the carcinogen-metabolizing capacity was studied in vivo in mouse liver microsomes at different durations of treatment, from one to six consecutive days. The in vitro effect of increasing concentrations of the drug upon this enzyme system was also investigated. Following the administration of CPhA, a significant time-dependent decrease was observed in the activity of the low substrate level of the hepatic microsomal N-nitrosodimethylamine demethylase (NDMAdII). The high substrate level of the enzyme (NDMAdII) also exhibited a similar decrease which was not a subject for the treatment intervals where the greatest decrease (-60%; p<0.05) emerged at day 3 of the administration-point. The activity of the aryl hydrocarbon (benzo(alpha)pyrene) hydroxylase (AHH) revealed a significant increase at the single dose of CPhA, while at the repeated dose treatment (for 3 days) no alteration was noticed in the enzyme activity. This figure of expression in AHH was reversed to a significant inhibition at the 6 day-repeated dose, the time-point at which an almost identical effect was also observed in the hepatic content of cytochrome P450. The alterations in the metabolism of NDMA and benzo(alpha)pyrene which had been seen in the in vivo assays was further confirmed by the results of the in vitro experiment.     

Bone-tissue engineering: complex tunable structural and biological responses to injury,drug delivery,and cell-based therapies

Bone loss and failure of proper bone healing continues to be a significant medical condition in need of solutions that can be implemented successfully both in human and veterinary medicine. This is particularly true when large segmental defects are present, the bone has failed to return to normal form or function, or the healing process is extremely prolonged. Given the inherent complexity of bone tissue – its unique structural, mechanical, and compositional properties, as well as its ability to support various cells – it is difficult to find ideal candidate materials that could be used as the foundation for tissue regeneration from technological platforms. Recently, important developments have been made in the implementation of complex structures built both at the macro- and the nano-level that have been shown to positively impact bone formation and to have the ability to deliver active biological molecules (drugs, growth factors, proteins, cells) for controlled tissue regeneration and the prevention of infection. These materials are diverse, ranging from polymers to ceramics and various composites. This review presents developments in this area with a focus on the role of scaffold structure and chemistry on the biologic processes that influence bone physiology and regeneration.     

Powder Compression Properties of Paracetamol,Paracetamol Hydrochloride,and Paracetamol Cocrystals and Coformers

The objective was to study the relationship between crystal structure, particle deformation properties, and tablet-forming ability for the monoclinic form of paracetamol (PRA), 2 cocrystals and a salt crystal of PRA in addition to 2 coformers (oxalic acid and 4,4′-bipyridine). Thus, the structure–property–performance relationship was investigated. Analytical powder compression was used for determination of effective plasticity, as inferred from the Heckel yield pressure and the Frenning parameter, and the elastic deformation was determined from in-die tablet elastic recovery. The plasticity could not be linked to the crystal lattice structure as crystals containing zig-zag layers displayed similar plasticity as crystals containing slip planes. In addition, crystals containing slip planes displayed both high and low plasticity. The mechanical properties could not be linked to the tablet-forming ability as the tablet tensile strength, unexpectedly, displayed a tendency to reduce with increased plasticity. Furthermore, the elastic deformation could not explain the tablet-forming ability. It was concluded that no relationship between structure–property–performance for PRA and its cocrystals and salt could be established. Thus, it was indicated that to establish such a relationship, an improved knowledge of crystallographic structure and interparticle bonding during compaction is needed.     

The impact of clinical pharmacist and ID intervention in rationalization of antimicrobial use

What is known and objective

There is little research on the impact of implementing and monitoring antimicrobial policy in Saudi hospitals. The purpose of this study is to measure the impact of the clinical pharmacist (CP) and infectious disease consultant (ID) interventions on the use of three antimicrobials (caspofungin, imipenem, meropenem) in hospitalized patients in the King Abdullah Medical City hospital.

Methods

The study was carried out in the King Abdullah Medical City, in Mekkah, Saudi Arabia. The hospital is a tertiary center that provides CCU, CSICU, Cardiac, Hematology, ICU, Medical, Neuroscience, Oncology, and specialized surgery services. The use of three antimicrobials (caspofungin, imipenem, meropenem) was reviewed by the clinical pharmacist for four periods, pre and post implementation of policy. Relevant data were collected in four periods. In the first period, before policy implementation, data were collected retrospectively to be used as baseline status reference, and in the three remaining periods that followed data were collected prospectively, and compared to baseline data, to evaluate the role of clinical pharmacist and ID interventions in optimizing antimicrobial therapy.

Results and discussion

Caspofungin duration of therapy was not affected significantly by the intervention. Statistically significant reduction in antimicrobial therapy duration was observed in imipenem (37%) and meropenem (37%) from baseline, which indicate a better control on antimicrobial use and reduction in antimicrobial resistance.

What is new and conclusion

The impact of the clinical pharmacist and ID interventions, in reducing antimicrobial therapy duration using imipenem and meropenem, is clear from the result presented above. However, lack of restriction and follow up in the antimicrobial policy in case of negative culture makes antimicrobial use uncontrollable in these cases. Establishing good and accepted policy may help reduce consumption and total cost of therapy.     

ZnO Nanoparticles-Modified Dressings to Inhibit Wound Pathogens

Zinc oxide (ZnO) nanoparticles (NPs) have been investigated for various skin therapies in recent years. These NPs can improve the healing and modulate inflammation in the wounds, but the mechanisms involved in such changes are yet to be known. In this study, we have designed a facile ZnO nano-coated dressing with improved antimicrobial efficiency against typical wound pathogens involved in biofilm and chronic infections. ZnO NPs were obtained by hydrothermal method and characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Fourier-transform infrared spectroscopy. Antibacterial and antibiofilm effects were evaluated against laboratory and clinical isolates of significant Gram-negative (Pseudomonas aeruginosa and Escherichia coli) and Gram-positive (Staphylococcus aureus and Enterococcus faecalis) opportunistic pathogens, by quantitative methods. Our results have shown that the developed dressings have a high antibacterial efficiency after 6–24 h of contact when containing 0.6 and 0.9% ZnO NPs and this effect is similar against reference and clinical isolates. Moreover, biofilm development is significantly impaired for up to three days of contact, depending on the NPs load and microbial species. These results show that ZnO-coated dressings prevent biofilm development of main wound pathogens and represent efficient candidates for developing bioactive dressings to fight chronic wounds.