The accumulation of heavy metals in Typha latifolia L. grown in a stream carrying secondary effluent

Typha latifolia L. from aquatic plants is widely found throughout Kehli Stream (Elazig, Turkey). This study examined the uptake of some metals by T. latifolia and the transfer from roots to other plant parts. The accumulation of Mn in T. latifolia L. can be suggested as a tolerance strategy due to its transfer factor higher than 1.0. The enrichment coefficients in the leaves of T. latifolia L. were higher than 1.0 for Zn and Mn and often lower than 1.0 for other metals. Similarly, the enrichment coefficients of all metals, except for Cr, in roots of T. latifolia L. were higher than 1.0. This study demonstrated that T. latifolia L. could be considered as either a bio-indicator or a bio-accumulator for sediments and water polluted by metals.     

The Short‐Term Effect of Occupational Levels of 50 Hz Electromagnetic Field on Human Heart Rate Variability

Previous studies have indicated that there is no consensus on the effects of extremely low‐frequency electromagnetic (ELF‐EMF) exposure on the cardiovascular system. This study aimed to explore the short‐term effect of ELF‐EMF exposure on heart rate (HR) and HR variability (HRV). The sample consisted of 34 healthy males aged 18–27 years. The participants were randomly assigned to the EMF (n = 17) or the Sham group (n = 17). We employed a double‐blind repeated‐measures design consisting of three 5 min experimental periods. The chest region of each individual in the EMF group was exposed to 50 Hz, 28 μT, linear polarized, continuous EMF during the EMF exposure period. HR and HRV data were recorded continuously by using a photoplethysmography sensor. Within‐subject statistical analysis indicated a significant HR deceleration in both the EMF and Sham groups. However, the standard deviation of the NN intervals (SDNN), root mean square of successive differences (RMSSD), low‐frequency (LF), and high‐frequency (HF) powers increased only in the EMF group and remained stable in the Sham group. We also compared the same HRV indices measured during the EMF and Sham periods between the two experimental groups. The between‐subject analysis results demonstrated significantly higher SDNN, RMSSD, LF, and HF values in the EMF group than in the Sham group. The LF/HF ratio did not change significantly within and between groups. On the basis of these results, we concluded that short‐term exposure of the chest region to ELF‐EMF could potentially enhance parasympathetic predominance during the resting condition. Bioelectromagnetics. 2021;42:60–75. © 2020 Bioelectromagnetics Society.     

Evidence that NOS2 acts as a trigger and mediator of late preconditioning induced by acute systemic hypoxia

Chronic systemic hypoxia (SH) enhances myocardial ischemic tolerance in mammals. We studied the delayed cardioprotection caused by acute SH and associated signaling mechanism. Conscious adult male mice were exposed to one or two cycles of hypoxia (H; 10% O(2)) or normoxia (21% O(2)) for various durations (30 min, 2 h, 4 h) followed by 24 h of reoxygenation. Hearts were isolated 24 h later and subjected to ischemia-reperfusion in a Langendorff model. Infarct size was reduced in mice pretreated with one (H4h) or two cycles (H4hx2) of 4 h SH compared with normoxia mice (P < 0.05), which was abolished by an inducible nitric oxide synthase (NOS2) inhibitor (S-methylisothiourea, 3 mg/kg) given before SH or ischemia. H4hx2 also failed to reduce infarct size in NOS2 knockout mice. Cyclooxygenase-2 (COX-2) inhibitor (NS-398, 10 mg/kg) did not block the protection given either before H4hx2 or ischemia. A two- to three fold increase in myocardial NOS2 expression was observed in H4h, H2hx2, and H4hx2 (P < 0.05), whereas endothelial NOS (NOS3) or COX-2 remained unchanged. We conclude that acute SH induces delayed cardioprotection, which is triggered and mediated by NOS2, but not by NOS3 or COX-2.     

Assessment of DNA strand breakage by the alkaline COMET assay in dialysis patients and the role of Vitamin E supplementation

Although the role of reactive oxygen species (ROS) in chronic renal failure (CRF) is not definitely demonstrated, a consistent number of observations has provided evidence for the presence of oxidative stress in uremic patients undergoing maintenance dialysis. In order to investigate this hypothesis further and to understand the role of antioxidant supplementation, peripheral blood lymphocytes were taken from 36 dialysis patients before and after Vitamin E supplementation in a dosage of 600 mg per day (2x300 mg) for 14 weeks and examined in the alkaline Comet assay for DNA strand breakage. The results were also compared with those of 36 controls with comparable age, sex, and smoking habits, and with no history of renal disease. The DNA breakage observed in the lymphocytes of patients before Vitamin E supplementation was significantly higher than in the controls (P<0.001) but a clear protective effect of Vitamin E supplementation were observed after 14 weeks of therapy.     

The role of chemical fingerprinting: application to Ephedra

Ephedra sinica, known as Ma Huang, is one of the oldest medicinal herbs in Traditional Chinese Medicine (TCM). Preparations, namely teas, of E. sinica have been used for over 5000 years as a stimulant and as an antiasthmatic. In the West, extracts of E. sinica, E. intermedia or E. equisetina are most commonly used in dietary supplements as a stimulant and to promote weight loss. More than 50 species of Ephedra are native to both hemispheres, but the detection of ephedrine alkaloids has been limited to species in Eurasia. Currently, methods exist to quantitate the ephedrine alkaloids in extracts of plant material or dietary supplements, but the methods are not able to verify the extract is of an Ephedra species. Reverse phase high performance liquid chromatography with photodiode array detection was applied for the chemical fingerprinting of the Ephedra species. Two regions of comparison were determined in the chromatograms at 320 nm. The series of peaks between 52 and 64 min confirms an Ephedra species is being analyzed. The aforementioned peaks also could distinguish between Ephedra species from Eurasia, North America and South America. Peaks at ca. 57 and 59 min were isolated and determined to be two new compounds, 4-(2-eicosyloxycarbonyl-vinyl)-benzoic acid and 4-(2-docosyloxycarbonyl-vinyl)-benzoic acid respectively. Authentication of ground plant material as Ephedra can be achieved by this chemical fingerprinting method.     

Effect of iron supplementation on oxidative stress and antioxidant status in iron-deficiency anemia

This study was designed to measure the effect of iron supplementation on antioxidant status in iron-deficient anemia, including the time for hemoglobin normalization and at the time of filling of iron body stores. The extent of plasma lipid peroxidation was evaluated by measuring the levels of malondialdehyde and glutathione peroxidase (GSH-Px), and the activities of superoxide dismutase (SOD) and catalase in 63 patients with iron-deficiency anemia before and after 6 wk of iron supplementation and at the time when body iron stores are saturated. After 6 wk of iron supplementation, a significant decrease of oxidative stress was observed in the treated subjects relative to controls (p<0.05). No significant differences existed between treated patients at 6 wk and at the end of the study. The erythrocyte levels of catalase, SOD, and GSH-Px were significantly lower in treated patients relative to controls (p<0.05). These levels increased after 6 wk of supplementation (p<0.05) and showed no significant differences with those at the end of the study.