Oxidative stress-associated hypertension in surgically induced brain injury patients: effects of β-blocker and angiotensin-converting enzyme inhibitor

The effects of two different dietary regimens during exercise on outcome of experimental acute kidney injury

BACKGROUND

Acute kidney injury (AKI) is a syndrome characterized by rapid loss of excretory function of kidney. Both exercise and some diets have been shown to increase silent information regulator (SIRT1) expression leading to reduction of kidney injury. In this study, the effect of two different diets during exercise on kidney function, oxidative stress, inflammation and also SIRT1 in AKI was investigated.

MATERIALS AND METHODS

A number of rats were randomly divided into four groups; control without exercise, control with exercise, exercise + calorie restriction (CR), and exercise + time restriction (TR). Each group was divided into two subgroups of without AKI and with AKI (six rats in each group). Endurance exercise and diets were implemented before AKI. Serum urea and creatinine, urinary albumin, kidney malondialdehyde (MDA), total antioxidant capacity (TAC), transforming growth factor (TGF-β1), and SIRT1 levels, glomerular filtration rate (GFR) and relative kidney weight were measured before and 24 h after AKI induction.

RESULTS

After induction of kidney injury, serum urea and creatinine, urinary albumin, kidney MDA and TGF-β1 levels increased in rats with both previous exercise and no previous exercise, while GFR, and kidney TAC and SIRT1 levels significantly decreased. These changes after AKI were less in the group with previous exercise than in the group that had no exercise (p <0.001). The TR diet during exercise caused a less increase in serum urea (p <0.01) and creatinine (p <0.01), and urinary albumin (p <0.001) levels after the injury compared to the just exercise group. Also, both CR and TR diets during exercise caused less change in MDA (p <0.001) and TAC (p <0.05, p <0.001, respectively) levels compared to just exercise group.

CONCLUSIONS

The results showed that exercise alone had no effect on preventing function impairment of kidney, oxidative stress, inflammation and also SIRT1 alteration following AKI, although these indexes were less among those with exercise than those without exercise. However, when the CR and TR diets were implemented during exercise, strong renoprotective effects appeared, and the protective effect of TR diet was greater.

Lipid Peroxidation and Antioxidant Consumption as Early Markers of Neurosurgery-Related Brain Injury in Children

BACKGROUND AND AIMS

Lipid peroxidation represents a marker of secondary brain injury both in traumatic and in non-traumatic conditions-as in major neurosurgical procedures-eventually leading to brain edema amplification and further brain damage. Malondialdehyde (MDA), a lipid peroxidation marker, and ascorbate, a marker of antioxidant status, can represent early indicators of this process within the cerebrospinal fluid (CSF). We hypothesized that changes in cerebral lipid peroxidation can be measured ex vivo following neurosurgery in children.

METHODS

Thirty-six children (M:F = 19/17, median age 32.9 months; IQR 17.6-74.6) undergoing neurosurgery for brain tumor removal were admitted to the pediatric intensive care unit (PICU) in the postoperative period with an indwelling intraventricular catheter for intracranial pressure monitoring and CSF drainage. Plasma and CSF samples were obtained for serial measurement of MDA, ascorbate, and cytokines.

RESULTS

An early brain-limited increase in lipid peroxidation was measured, with a significant increase from baseline of MDA in CSF (p = 0.007) but not in plasma. In parallel, ascorbate in CSF decreased (p = 0.05). Systemic inflammatory response following brain surgery was evidenced by plasma IL-6/IL-8 increase (p 0.0022 and 0.0106, respectively). No correlation was found between oxidative response and tumor site or histology (according to World Health Organization grading). Similarly, lipid peroxidation was unrelated to the length of surgery (mean 321 ± 73 min), or intraoperative blood loss (mean 20.9 ± 16.8% of preoperative volemia, 44% given hemotransfusions). Median PICU stay was 3.5 days (IQL range 2-5.5 d.), and postoperative ventilation need was 24 h (IQL range 20-61.5 h). The elevation in postoperative MDA in CSF compared with preoperative values correlated significantly with postoperative ventilation need (P = 0.05, r² 0168), while no difference in PICU stay was recorded.

CONCLUSIONS

Our results indicate that lipid peroxidation increases consistently following brain surgery, and it is accompanied by a decrease in antioxidant defences; intraventricular catheterization offers a unique chance of oxidative process monitoring. Further studies are needed to evaluate whether monitoring post-neurosurgical oxidative stress in CSF is of prognostic utility.

Beta-blockers and Traumatic Brain Injury: A Systematic Review, Meta-analysis, and Eastern Association for the Surgery of Trauma Guideline

OBJECTIVE

To determine if beta-(β)-blockers improve outcomes after acute traumatic brain injury (TBI).

BACKGROUND

There have been no new inpatient pharmacologic therapies to improve TBI outcomes in a half-century. Treatment of TBI patients with β-blockers offers a potentially beneficial approach.

METHODS

Using MEDLINE, EMBASE, and CENTRAL databases, eligible articles for our systematic review and meta-analysis (PROSPERO CRD42016048547) included adult (age ≥ 16 years) blunt trauma patients admitted with TBI. The exposure of interest was β-blocker administration initiated during the hospitalization. Outcomes were mortality, functional measures, quality of life, cardiopulmonary morbidity (e.g., hypotension, bradycardia, bronchospasm, and/or congestive heart failure). Data were analyzed using a random-effects model, and represented by pooled odds ratio (OR) with 95% confidence intervals (CI) and statistical heterogeneity (I).

RESULTS

Data were extracted from 9 included studies encompassing 2005 unique TBI patients with β-blocker treatment and 6240 unique controls. Exposure to β-blockers after TBI was associated with a reduction of in-hospital mortality (pooled OR 0.39, 95% CI: 0.27-0.56; I = 65%, P < 0.00001). None of the included studies examined functional outcome or quality of life measures, and cardiopulmonary adverse events were rarely reported. No clear evidence of reporting bias was identified.

CONCLUSIONS

In adults with acute TBI, observational studies reveal a significant mortality advantage with β-blockers; however, quality of evidence is very low. We conditionally recommend the use of in-hospital β-blockers. However, we recommend further high-quality trials to answer questions about the mechanisms of action, effectiveness on subgroups, dose-response, length of therapy, functional outcome, and quality of life after β-blocker use for TBI.

Effects of exercise and lifestyle intervention on oxidative stress in chronic kidney disease

OBJECTIVES

Determine the effects of a 12-month exercise and lifestyle intervention program on changes in plasma biomarkers of oxidative stress in pre-dialysis chronic kidney disease (CKD) patients.

METHODS

A total of 136 stage 3-4 CKD patients were randomized to receive standard nephrological care with (N = 72) or without (N = 64) a lifestyle and exercise intervention for 12 months. Plasma total F₂-isoprostanes (IsoP), glutathione peroxidase (GPX) activity, total antioxidant capacity (TAC), anthropometric and biochemical data were collected at baseline and at 12 months.

RESULTS

There were no significant differences between groups at baseline. There were no significant differences in changes for standard care and lifestyle intervention, respectively, in IsoP (p = 0.88), GPX (p = 0.87), or TAC (p = 0.56). Patients identified as having high IsoP at baseline (>250 pg/mL) had a greater decrease in IsoP with lifestyle intervention compared to standard care; however, the difference was not statistically significant (p = 0.06). There was no difference in the change in kidney function (eGFR) between standard care and lifestyle intervention (p = 0.33).

DISCUSSION

Exercise and lifestyle modification in stage 3-4 CKD did not produce changes in systemic biomarkers of oxidative stress over a 12-month period, but patients with high IsoP may benefit most from the addition of intervention to standard care.

Cancer Salivary Biomarkers for Tumours Distant to the Oral Cavity

The analysis of saliva as a diagnostic approach for systemic diseases was proposed just two decades ago, but recently great interest in the field has emerged because of its revolutionary potential as a liquid biopsy and its usefulness as a non-invasive sampling method. Multiple molecules isolated in saliva have been proposed as cancer biomarkers for diagnosis, prognosis, drug monitoring and pharmacogenetic studies. In this review, we focus on the current status of the salivary diagnostic biomarkers for different cancers distant to the oral cavity, noting their potential use in the clinic and their applicability in personalising cancer therapies.

Role of Oxidative and Nitrosative Stress in Pathophysiology of Toxic Epidermal Necrolysis and Stevens Johnson Syndrome-A Pilot Study

Background:

Oxidative and nitrosative stress caused by drug metabolism may be a trigger for keratinocyte apoptosis in the epidermis seen in toxic epidermal necrolysis (TEN) and Stevens Johnson syndrome (SJS).

Aims:

To estimate oxidative damage in the serum and to examine the role of nitric oxide in mediating epidermal damage in patients with TEN and SJS.

Materials and Methods:

A prospective study was conducted among TEN and SJS patients and controls in a tertiary care center between January 2006 and February 2010. Patients with a maculopapular drug rash without detachment of skin constituted the control group 1 (drug exposed). Patients without a drug rash constituted the control group 2 (drug unexposed). The serum values of protein carbonyls, malondialdehyde, conjugated diene and nitrates were measured. Two-group comparison with the non-parametric Mann–Whitney U test was used. Significance of differences if any was established using Pearson's Chi-square test.

Results:

Ten patients in the SJS-TEN group (study group), 8 patients in control group 1 and 7 patients in control group 2 were included. More than one drug was implicated in 4/10 patients in group 1 and 3/8 patients in group 2. SCORTEN of 0, 1 and 3 at admission were seen in 2, 6 and 2 patients, respectively. The serum values of protein carbonyls, malondialdehyde, conjugated diene and nitrates were not significantly increased in the study group when compared to the controls.

Conclusions:

There was no elevation of oxidative stress markers in patients with TEN and SJS as compared to the control population.

Effect of amlodipine, lisinopril and allopurinol on acetaminophen-induced hepatotoxicity in rats

Background

Exposure to chemotherapeutic agents such as acetaminophen may lead to serious liver injury. Calcium deregulation, angiotensin II production and xanthine oxidase activity are suggested to play mechanistic roles in such injury.

Objective

This study evaluates the possible protective effects of the calcium channel blocker amlodipine, the angiotensin converting enzyme inhibitor lisinopril, and the xanthine oxidase inhibitor allopurinol against experimental acetaminophen-induced hepatotoxicity, aiming to understand its underlying hepatotoxic mechanisms.

Material and methods

Animals were allocated into a normal control group, a acetaminophen hepatotoxicity control group (receiving a single oral dose of acetaminophen; 750 mg/kg/day), and four treatment groups receive N-acetylcysteine (300 mg/kg/day; a reference standard), amlodipine (10 mg/kg/day), lisinopril (20 mg/kg/day) and allopurinol (50 mg/kg/day) orally for 14 consecutive days prior to acetaminophen administration. Evaluation of hepatotoxicity was performed by the assessment of hepatocyte integrity markers (serum transaminases), oxidative stress markers (hepatic malondialdehyde, glutathione and catalase), and inflammatory markers (hepatic myeloperoxidase and nitrate/nitrite), in addition to a histopathological study.

Results

Rats pre-treated with amlodipine, lisinopril or allopurinol showed significantly lower serum transaminases, significantly lower hepatic malondialdehyde, myeloperoxidase and nitrate/nitrite, as well as significantly higher hepatic glutathione and catalase levels, compared with acetaminophen control rats. Serum transaminases were normalized in the lisinopril treatment group, while hepatic myeloperoxidase was normalized in the all treatment groups. Histopathological evaluation strongly supported the results of biochemical estimations.

Conclusion

Amlodipine, lisinopril or allopurinol can protect against acetaminophen-induced hepatotoxicity, showing mechanistic roles of calcium channels, angiotensin converting enzyme and xanthine oxidase enzyme in the pathogenesis of hepatotoxicity induced by acetaminophen.

Measurement of free radicals using electron paramagnetic resonance spectroscopy during open aorto-iliac arterial reconstruction

BACKGROUND

Aortic cross-clamping during abdominal aortic aneurysm (AAA) open repair leads to development of ischemia-reperfusion injury. Electron paramagnetic resonance spectroscopy (EPR) spin-trapping is a valuable method of direct measurement of free radicals. The objective of the study was to evaluate the results of EPR as a direct method of free radical measurement and degree of inflammatory response in open operative treatment of patients with AAA and aorto-iliac occlusive disease (AIOD).

MATERIAL/METHODS

The study was performed on a group of 32 patients with AAA and 25 patients with AIOD scheduled for open repair. Peripheral venous blood for EPR spectroscopy and for SOD, GPx, ox-LDL, Il-6, TNF-alfa, CRP, and HO-1 were harvested. Selected parameters were established accordingly to specified EPR and immunohistochemical methods and analyzed between groups by Mann-Whitney U test and Wilcoxon matched-pairs signed-ranks test with Bonferroni correction.

RESULTS

Free radicals level was correlated with the time of the aortic cross-clamping after the reperfusion of he first and second leg in AAA (r=0.7; r=0.47). ox-LDL in AAA decreased 5 min after reperfusion of the first leg (32.99 U/L, range: 14.09-77.12) and 5 min after reperfusion of the second leg (26.75 U/L, range: 11.56-82.12) and 24 h after the operation (25.85 U/L, range: 14.29-49.70). HO-1 concentration increased to above the level before intervention 24 h after surgery. The activities of GPx and SOD decreased 5 min after the first-leg reperfusion in AAA. Twenty-four hours after surgery, inflammatory markers increased in AAA to CRP was 14.76 ml/l (0.23-38.55), IL-6 was 141.22 pg/ml (84.3-591.03), TNF-alfa was 6.82 pg/ml (1.76-80.01) and AIOD: CRP was 18.44 mg/l (2.56-33.14), IL-6: 184.1 pg/ml (128.46-448.03), TNF-alfa was 7.74 pg/ml (1.74-74.74).

CONCLUSIONS

EPR spin-trapping demonstrates temporarily elevated level of free radicals in early phase of reperfusion, leading to decrease antioxidants in AAA. Elevated free radical levels decreased 24 h after surgery due to various endogenous antioxidants and therapies.