Prevention of Contrast-Induced Acute Kidney Injury: Is Simple Oral Hydration Similar To Intravenous? A Systematic Review of the Evidence

Background

Pre-procedural intravenous fluid administration is an effective prophylaxis measure for contrast-induced acute kidney injury. For logistical ease, the oral route is an alternative to the intravenous. The objective of this study was to compare the efficacy of the oral to the intravenous route in prevention of contrast-induced acute kidney injury.

Study Design

A systematic review and meta-analysis of randomised trials with a stratified analysis and metaregression. Databases included MEDLINE (1950 to November 23 2011), EMBASE (1947 to week 47 2011), Cochrane CENTRAL (3^rd quarter 2011). Two reviewers identified relevant trials and abstracted data.

Settings and Population

Trials including patients undergoing a contrast enhanced procedure.

Selection Criteria

Randomised controlled trial; adult (>18 years) population; comparison of oral versus intravenous volume expansion.

Intervention

Oral route of volume expansion compared to the intravenous route.

Outcomes

Any measure of acute kidney injury, need for renal replacement therapy, hospitalization and death.

Results

Six trials including 513 patients met inclusion criteria. The summary odds ratio was 1.19 (95% CI 0.46, 3.10, p = 0.73) suggesting no difference between the two routes of volume expansion. There was significant heterogeneity (Cochran’s Q = 11.65, p = 0.04; I² = 57). In the stratified analysis, inclusion of the five studies with a prespecified oral volume expansion protocol resulted in a shift towards oral volume expansion (OR 0.75, 95% CI 0.37, 1.50, p = 0.42) and also resolved the heterogeneity (Q = 3.19, P = 0.53; I² = 0).

Limitations

Small number of studies identified; lack of hard clinical outcomes.

Conclusion

The oral route may be as effective as the intravenous route for volume expansion for contrast-induced acute kidney injury prevention. Adequately powered trials with hard endpoints should be done given the potential advantages of oral (e.g. reduced patient burden and cost) over intravenous volume expansion.     

Isolation and characterization of a heparin with high anticoagulant activity from Anomalocardia brasiliana

The isolation, some structural features, physicochemical properties and pharmacological activities of a heparin from Anomalocardia brasiliana are reported. It is shown that the mollusc heparin is very similar to those present in mammalian tissues with regard to chemical composition, physicochemical properties, pharmacological activities and susceptibility to heparinase and heparitinase II from Flavobacterium heparinum, as well as to the types of products formed by the action of these enzymes. Three significant quantitative differences were observed for the mollusc heparin when compared with the ones from mammalian origin, namely, a higher degree of binding with antithrombin III (45%), higher molecular weight (27-43 kDa) and higher anticoagulant activity (320 I.U./mg). The possible biological role of heparin is discussed in view of the present findings.     

Roles for osteocalcin in proliferation and differentiation of spermatogonial cells cocultured with somatic cells

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Linear and nonlinear relationships between neuronal activity, oxygen metabolism, and hemodynamic responses

We investigated the relationship between neuronal activity, oxygen metabolism, and hemodynamic responses in rat somatosensory cortex with simultaneous optical intrinsic signal imaging and spectroscopy, laser Doppler flowmetry, and local field potential recordings. Changes in cerebral oxygen consumption increased linearly with synaptic activity but with a threshold effect consistent with the existence of a tissue oxygen buffer. Modeling analysis demonstrated that the coupling between neuronal activity and hemodynamic response magnitude may appear linear over a narrow range but incorporates nonlinear effects that are better described by a threshold or power law relationship. These results indicate that caution is required in the interpretation of perfusion-based indicators of brain activity, such as functional magnetic resonance imaging (fMRI), and may help to refine quantitative models of neurovascular coupling.     

Preparation,Optimization, and Characterization of SERS Sensor Substrates Based on Two-Dimensional Structures of Gold Colloid

Generally, the immobilization of two-dimensional nanoparticles in immersion procedures is time-consuming (over 24 h). In this paper, we report a very effective and simple method to fabricate two-dimensional gold nanoparticle patterns over large areas with high regularity for surface-enhanced Raman scattering (SERS). We achieved a highly sensitive SERS colloid surface by optimizing temperature and immersion time. The surfaces were characterized by X-ray photoelectron spectroscopy, UV–Vis, atomic force microscopy, and scanning electron microscopy. The SERS activity of surfaces was compared by using two techniques: “dip” and “dip and dry” in an aqueous solution of 10⁻⁶ M crystal violet. The influence of the morphology of the surface was investigated with both the dip and dip and dry techniques.     

Methodological improvements of pyrosequencing technology

Pyrosequencing technology is a rather novel DNA sequencing method based on the sequencing-by-synthesis principle. This bioluminometric, real-time DNA sequencing technique employs a cascade of four enzymatic reactions producing sequence peak signals. The method has been proven highly suitable for single nucleotide polymorphism analysis and sequencing of short stretches of DNA. Although the pyrosequencing procedure is relatively straightforward, users may face challenges due to varying parameters in PCR and sequencing primer design, sample preparation and nucleotide dispensation; such challenges are labor and cost intensive. In this study, these issues have been addressed to increase signal quality and assure sequence accuracy.     

Human amniotic epithelial cells inhibit activation and pro-inflammatory cytokines production of naive CD4+ T cells from women with unexplained recurrent spontaneous abortion

Unexplained recurrent spontaneous abortion (URSA) has been assumed to be caused by a defect in maternal immunological tolerance to the fetus. Human amniotic epithelial cells (hAECs) have stem cell-like features and the ability to modulate the innate and adoptive immune responses. This study aimed to investigate whether hAECs have immunomodulatory effects on naive CD4+ T cells from URSA patients. hAECs were obtained from 15 healthy pregnant women and phenotypic profile of hAECs was determined by flow cytometry. Naive CD4+ T cells were isolated from 25 URSA patients using an immunomagnetic separation method. Naive T cells were stimulated with anti-CD3/anti-CD28 antibodies and co-cultured with different numbers of hAECs for 3 and 6 days. Immunomodulatory effect of hAECs on activation of stimulated T cell was assessed by flow cytometry and Enzyme-linked immunoasorbent assay (ELISA). The hAECs effect on pro-inflammatory cytokines production of activated T cells was also measured by ELISA. Our results indicated that hAECs significantly inhibited the activation of naive T cells in a dose-dependent manner (p?<?0.0001–0.05). They significantly reduced the production of transforming growth factor-beta1 (TGF-β1) of stimulated CD4+T cells (p?<?0.0001–0.05). Moreover, hAECs had potent immunomodulatory effects on the production of interferon-gamma (IFN-γ) and interleukin-17A (IL-17A) of activated T cells (p?<?0.0001–0.01). These findings suggest that hAECs may be a suitable cell source to modulate abnormal immune responses in women with URSA.     

A relationship between the inhibition of heparan sulfate and chondroitin sulfate synthesis and the inhibition of molting by selenate in the hemipteran Rhodnius prolixus

The insect Rhodnius prolixus synthesizes heparan sulfate and chondroitin sulfate after a blood meal containing [35S]-inorganic sulfate. A 40 to 80% inhibition of heparan sulfate synthesis was obtained when the meal was supplemented with 10(-5) and 10(-4) M sodium selenate respectively. Likewise an inhibition of the molting in the order of 30 to 60% was observed when the insects were fed with blood containing 10(-5) and 10(-4) M selenate respectively. The insects after a subsequent meal without selenate molted normally. Except for the inhibition of the ecdysis no gross physiological or morphological changes could be observed in the insects. Based on these and other findings the possible role of sulfated glycosaminoglycans in the control of cell growth is discussed.     

The effects of testosterone, 5α-dihydrotestosterone, 3α-androstanediol,and 3β-androstanediol on the maturation of rabbit epididymal spermatozoa in organ culture

Summary The fertilizing ability of spermatozoa from epididymal tubules maintained in organ cultures from 1 to 7 days was assessed after artificial insemination into receptive does. It was found that spermatozoa from the distal corpus which were already capable of fertilizing eggs prior to the cultures retain this ability for 1 day without addition of hormone and for 3–4 days when testosterone (0.5 g/ml) or 5-dihydrotestosterone (0.5 g/ml) is added to the culture medium. Spermatozoa from the proximal corpus which were not capable of fertilizing eggs prior to the cultures remain so after 1 day in cultures without addition of hormone. Testosterone, 5-dihydrotestosterone, 3-androstanediol, or 3-androstanediol was added to cultures of proximal corpus at a concentration of 0.5 g/ml. Only with 5-DHT is the mean percentage of fertilization significantly higher than the percentage obtained without addition of hormone. Insulin does not potentiate the effect of 5-DHT on sperm fertilizing ability. Epithelial growth factor is ineffective. Spermatozoa from the caput epididymidis kept in cultures for 1 to 4 days remain infertile. The results are discussed in light of the morphological findings presented in the preceding communication and in relation to the physiological requirement for sperm maturation in the epididymis.