Effects of systemic prostaglandin E1 on splanchnic and peripheral haemodynamics in control subjects and in patients with cirrhosis

Metabolomic Study of Urine from Workers Exposed to Low Concentrations of Benzene by UHPLC-ESI-QToF-MS Reveals Potential Biomarkers Associated with Oxidative Stress and Genotoxicity

Benzene is a human carcinogen whose exposure to concentrations below 1 ppm (3.19 mg·m^-3) is associated with myelotoxic effects. The determination of biomarkers such as trans-trans muconic acid (AttM) and S-phenylmercapturic acid (SPMA) show exposure without reflecting the toxic effects of benzene. For this reason, in this study, the urinary metabolome of individuals exposed to low concentrations of benzene was investigated, with the aim of understanding the biological response to exposure to this xenobiotic and identifying metabolites correlated with the toxic effects induced by it. Ultra-efficient liquid chromatography coupled to a quadrupole-time-of-flight mass spectrometer (UHPLC-ESI-Q-ToF-MS) was used to identify metabolites in the urine of environmentally (n = 28) and occupationally exposed (n = 32) to benzene (mean of 22.1 μg·m^-3 and 31.8 μg·m^-3, respectively). Non-targeted metabolomics analysis by PLS-DA revealed nine urinary metabolites discriminating between groups and statistically correlated with oxidative damage (MDA, thiol) and genetic material (chromosomal aberrations) induced by the hydrocarbon. The analysis of metabolic pathways revealed important alterations in lipid metabolism. These results point to the involvement of alterations in lipid metabolism in the mechanisms of cytotoxic and genotoxic action of benzene. Furthermore, this study proves the potential of metabolomics to provide relevant information to understand the biological response to exposure to xenobiotics and identify early effect biomarkers.

The role of age in determining the effects of lipo-PGE1 infusion on immediate arterial maximal flow velocity in patients with diabetes undergoing free flap surgery for lower extremity reconstruction: A prospective observational study

BACKGROUND

Diabetes mellitus may have a negative effect on free flap perfusion in patients undergoing reconstructive surgery. Little is known of the effects of lipo-prostaglandin E1 (lipo-PGE1) on flap blood flow in diabetes. This study investigated the effects of lipo-PGE1 on maximal blood flow velocity of the free flap arterial pedicle in patients with diabetes.

METHODS

This prospective observational study assessed maximal blood flow velocity in the arterial pedicle before and 30 min after infusion of 0.4 μg/h lipo-PGE1 in 40 patients with diabetes who received a free flap for lower extremity reconstruction. Multivariate logistic regression analysis was performed to determine whether age, hemoglobin A1c concentration, duration of diabetes, and flap type were significantly associated with increased maximal blood flow velocity after lipo-PGE1 infusion or not.

RESULTS

The maximal blood flow velocity of the free flap did not differ significantly before and 30 min after lipo-PGE1 infusion. Multivariate logistic regression analysis showed that age <65 years was the only independent factor associated with increased maximal blood flow velocity after lipo-PGE1 infusion (odds ratio = 5.344; p = 0.022).

CONCLUSION

Assessments of all patients with diabetes undergoing free flap surgery, when age was not taken into consideration, found that lipo-PGE1 did not significantly increase the maximal blood flow velocity of the free flap arterial pedicle. However, when age was taken into consideration, lipo-PGE1 increased blood flow velocity in patients <65 years old, suggesting that age influences the effect of lipo-PGE1 on the blood flow velocity.

Lipo-prostaglandin E1 increases immediate arterial maximal flow velocity of free flap in patients undergoing reconstructive surgery

BACKGROUND

In free flap surgery, the maintenance of proper blood flow after anastomosis of flap pedicle vessels is important. Lipo-prostaglandin E1 (lipo-PGE1) has been empirically administered to prevent blood flow insufficiency in a free flap reconstruction. We tested our hypothesis that lipo-PGE1 administration increases the arterial inflow of free flap. We also evaluated lipo-PGE1-related haemodynamic changes and complications.

METHODS

Thirty-seven patients who underwent free flap reconstruction were analysed. Lipo-PGE1 was administered 10 minutes after the vascular anastomosis of the free flap. The maximal blood flow velocity was measured at the free flap pedicle artery before and 30 minutes after lipo-PGE1 administration using duplex ultrasonography. The primary outcome was the difference in the maximal blood flow velocity before and 30 minutes after lipo-PGE1 administration. The arterial blood pressure, heart rate, cardiac output, stroke volume variation, and pulse pressure variation were measured simultaneously. Lipo-PGE1-related complications such as hypotension, bradycardia, hypothermia, facial flushing, diarrhoea, apnoea, and seizure were also investigated.

RESULTS

The maximal blood flow velocity was significantly increased at 30 minutes after lipo-PGE1 administration compared to the level before lipo-PGE1 administration (mean (standard deviation): 26.3 (8.7) cm/s vs 22.5 (8.0) cm/s, P = 0.002). The haemodynamic variables were not significantly different before and 30 minutes after lipo-PGE1 administration. No lipo-PGE1-related complications occurred.

CONCLUSIONS

Lipo-PGE1 significantly increases the maximal blood flow velocity without complications in patients undergoing free flap reconstruction and may be an effective and safe method of maintaining adequate blood flow in these cases.

Difference between renal and splenic resistive index as a novel criterion in Doppler evaluation of renal artery stenosis

Detection of renal artery stenosis (RAS) using Doppler is difficult to evaluate, particularly under conditions such as bilateral RAS or difficultly accessible renal arteries (RA). The objective of the present study was to assess the utility of splenic arterial compared to renal flow as an additional parameter in the Doppler evaluation of RAS. The difference between the resistive indices (RI) determined in renal and splenic parenchymal arteries (ΔRI_K-S ) was evaluated in 181 hypertensive subjects without any evidence of RAS. Subsequently 47 RA in 24 patients with suspected RAS were angiographically assessed. A ΔRI_K-S of 0.055 (median) was determined in the population without any evidence of RAS similar to RA with angiographically excluded stenosis (ΔRI_K-S 0.068). In contrast, in angiographic proven RAS, ΔRI_K-S was significantly lower (-0.050; P < .005). The assessment of the ΔRI_K-S , proved to be an easily feasible parameter, which improves the diagnostic accuracy in the detection of RAS.