The Effect of Single-dose Intravenous Dexamethasone on Postoperative Pain and Postoperative Nausea and Vomiting in Patients Undergoing Surgery under Spinal Anesthesia: A Double-blind Randomized Clinical Study.

BACKGROUND: The use of neuraxial anesthesia has dramatically increased. Acute postoperative pain is an undesirable outcome that can delay functional recovery for patients undergoing surgery. Nausea and vomiting in the postoperative period occurs in 20%-30% of the patients and together are the second-most common complaint reported (pain is the most common). Efficacy of glucocorticoids for reducing pain and inflammation after surgery is being explored. Glucocorticoids are strong anti-inflammatory agents, which can be used for a short-time postoperative pain control in various surgeries. Dexamethasone is a glucocorticoid with little mineralocorticoid effect commonly used perioperatively to reduce postoperative nausea and vomiting (PONV) and has a beneficial role in postoperative analgesia. Dexamethasone has also an antiemetic effect, in addition to its anti-inflammatory and analgesic effects. AIM: The main purpose of this study is to evaluate the effect of administration of single-dose intravenous (i.v.) dexamethasone on postoperative pain and PONV in patients undergoing surgery under spinal anesthesia. SETTINGS AND DESIGN: A double-blind randomized clinical study was performed in our institute between November 2014 and October 2015 after obtaining clearance from the ethical committee. MATERIALS AND METHODS: A double-blind randomized clinical study was performed on 60 patients posted for surgery under spinal anesthesia. Patients were randomly assigned into two groups: A (study: 2 ml [8 mg] dexamethasone) and B (control: 2 ml saline). In both the groups, variables such as mean arterial blood pressure (MAP), heart rate (HR), respiratory rate, severity of pain (based on visual analog scale), and other symptoms such as nausea and vomiting were recorded at different time points during the first 24 h after surgery. Statistical methods using Student t-test (two-tailed, independent) and Fischer's exact test were used for analyzing the data. RESULTS: Between-group comparisons indicated significant differences in terms of severity of postoperative pain and PONV (P < 0.001), MAP (P = 0.063), and HR (P = 0.071), which in the study group were lower than the control group. CONCLUSION: i.v. dexamethasone is efficient in reducing postoperative pain, requirement of rescue analgesia on the first postoperative day, and incidence of PONV with no significant changes in vital signs.

In situ characterisation of the aqueous gold colloid interface using CO as a surface probe: IR spectroscopic studies.

Fourier transform infrared (FTIR) spectra are presented of CO gas-treated protected gold colloids prepared from hydrazinium hydrate reduction of an Au(III) precursor which reproducibly feature a weak, shortlived peak at ca. 2169 cm(-1). When the gold colloid was treated with 99% isotopically enriched (13)CO gas, the IR peak shifted to a frequency of 2114 cm(-1) which indicated that it represented a simple gold monocarbonyl species. The value of 2169 cm(-1) for the CO stretching frequency suggests the peak represents CO physisorbed on oxidised gold atoms on the colloid surface. The peak is not observed when the concentration of the colloidally dispersed gold is reduced either by use of lower starting salt concentrations or by aggregation. It is also not observed when solutions of the protecting agent or reducing agent or the dispersion medium (water) or even the starting Au(III) salts are CO-treated individually. This confirms that the spectral feature is uniquely associated with colloidally dispersed gold. In general, the work has shown that the surfaces of Au colloids in situ have partially oxidised Au character which is of interest in systems where supported nanoparticulate gold derived from colloid preparations are considered for low temperature oxidation catalysts for CO.

Epigenetic regulation of ABCG2 gene is associated with susceptibility to xenobiotic exposure.

A highly conserved defence mechanism has evolved to protect cells from oxidative stress and xenobiotic exposure. A network of coupled xenobiotic metabolizing enzymatic reactions (XMEs) converts free oxidative radicals to less damaging metabolites, while efflux pumps remove toxins and XME derivatives from the cell. These mechanisms have been well studied in the contexts of hypoxia and Multidrug Resistance (MDR). Exposure of ruminants to fungal toxins leads to hepatotoxicosis and subsequent skin eczema (FE) depending upon toxic burden. Using toxin challenge in sheep we have investigated the potential for epigenetic regulation in cellular responses to xenobiotic exposure with a focus on the efflux protein ABCG2 which functions in Phase III of the defence mechanism. We show that 'resistance' to FE disease is positively associated with ABCG2 expression, and inversely correlated with DNA methylation state at CpG sites in the regulatory region of the ABCG2 gene. The analytical sensitivity provided by the Sequenom EpiTyper MS platform allows resolution of individual CpG sites varying significantly with disease progression, informing fine mapping of relevant transcription factor bindings which underpin this epigenetic response. Our findings indicate that epigenetic mechanisms are important to xenobiotic responses, suggest useful diagnostic markers and raise potential opportunities for disease remediation. This article is part of a Special Section entitled: Understanding genome regulation and genetic diversity by mass spectrometry.

Normal development following chromatin transfer correlates with donor cell initial epigenetic state.

If the full potential of chromatin transfer (CT) technology is to be realized for both animal production and biomedical applications it is imperative that the efficiency of the reprogramming process be improved, and the potential for deleterious development be eliminated. Generation of the first cloned animals from adult somatic cells demonstrated that development is substantially an epigenetic process (Wilmut I, Schnieke AE, McWhir J, Kind AJ, Campbell KH, 1997. Viable offspring derived from fetal and adult mammalian cells. Nature. 385(6619): 810-813.). In this study, we provide preliminary evidence that the epigenetic state of the donor cell, may be valuable in assessing potential cloning success. We have measured key indicators of cellular epigenetic state in both serially derived cell populations of the same genetic origin, but differing in epigenomic status, and in a distinct cohort of donor cell populations with diverse genetic origins and epigenomic status. Specifically, the relative abundance of particular histone modifications in donor populations prior to manipulation has been correlated with the measurable variance in reprogramming efficiencies observed following CT, as defined by the number of resulting live births and healthy progeny, and the concomitant incidence of deleterious growth measures (notably the appearance of large offspring syndrome (LOS)). Thus, we suggest that the likely outcome and relative success of cloning may be predictable based on the expression of discriminating histone marks present in the donor cell population before CT. This approach may provide the basis of a prognostic signature for the future evaluation and risk assessment of putative donor cells prior to CT, and thus increase future cloning success and alleviate the incidence of abnormal development.