Effects of radiofrequency radiation exposure on blood-brain barrier permeability in male and female rats

During the last several decades, numerous studies have been performed aiming at the question of whether or not exposure to radiofrequency radiation (RFR) influences the permeability of the blood-brain barrier (BBB). The objective of this study was to investigate the effect of RFR on the permeability of BBB in male and female Wistar albino rats. Right brain, left brain, cerebellum, and total brain were analyzed separately in the study. Rats were exposed to 0.9 and 1.8?GHz continuous-wave (CW) RFR for 20?min (at SARs of 4.26?mW/kg and 1.46?mW/kg, respectively) while under anesthesia. Control rats were sham-exposed. Disruption of BBB integrity was detected spectrophotometrically using the Evans-blue dye, which has been used as a BBB tracer and is known to be bound to serum albumin. Right brain, left brain, cerebellum, and total brain were evaluated for BBB permeability. In female rats, no albumin extravasation was found in in the brain after RFR exposure. A significant increase in albumin was found in the brains of the RF-exposed male rats when compared to sham-exposed male brains. These results suggest that exposure to 0.9 and 1.8?GHz CW RFR at levels below the international limits can affect the vascular permeability in the brain of male rats. The possible risk of RFR exposure in humans is a major concern for the society. Thus, this topic should be investigated more thoroughly in the future.     

HER2 Ile655Val and PTEN IVS4 polymorphisms in patients with breast cancer

Although HER2/PTEN pathway is commonly disrupted in cancer, association of HER2 and PTEN polymorphisms with breast cancer (BC) remains controversial. We investigated the HER2 Ile655 Val and PTEN IVS4 polymorphisms in patients with BC in Turkish population. HER2 Ile655Val (rs 1136201) and PTEN IVS4 (rs 3830675) polymorphisms were determined using polymerase chain reaction-based restriction fragment length polymorphism (PCR–RFLP) in blood samples of 118 BC patients and 118 age-matched healthy controls. We found that the frequency of the Ile/Val genotype of HER2 Ile655Val gene was significantly higher in BC patients (p < 0.009; OR: 1,983 95 % CI: 1.181—3.328). The presence of ATCTT insertion (+/+) genotype at downstream of exon 4 in intron 4 of PTEN IVS4 gene was also associated with 1.83 fold decreased risk of BC development (p < 0.033; OR: 1.83, 95 % CI: 1.11—3.03). Analysis on clinico-pathological parameters showed neither HER2 Ile655Val nor PTEN IVS4 genotypes were not associated with any of the variables (p > 0.05).In conclusion, our findings suggest that the Ile/Val genotype of HER2 and ATCTT insertion (+/+) genotype of PTEN IVS4 gene may play an important role as genetic markers for breast cancer risk, but both genes genotypes may not be useful for predicting tumor prognosis in Turkish population.     

Profound cardioprotection with timolol in a female rat model of aging-related altered left ventricular function

Increasing evidence shows a marked beneficial effect with β-blockers in heart dysfunction via scavenging reactive oxygen species. Previously we showed that chronic treatment with either timolol or propranolol possessed similar beneficial effects for heart function in male rats as age increased, whereas only timolol exerted similar benefits in female rats. Therefore, in this study, we aimed first to examine the cellular bases for age-related alterations in excitation-contraction coupling in ventricular myocytes from female rats and, second, to investigate the hypothesis that age-related changes in [Ca(2+)](i) homeostasis and receptor-mediated system can be prevented with chronic timolol treatment. Chronic timolol treatment of 3-month-old female rats abolished age-related decrease in left ventricular developed pressure and the attenuated responses to β-adrenoreceptor stimulation. It also normalized the altered parameters of [Ca(2+)](i) transients, decreased Ca(2+) loading of sarcoplasmic reticulum and increased basal [Ca(2+)](i), and decreased L-type Ca(2+) currents in 12-month-old female rats compared with the 3-month-old group. Adenylyl cyclase activity, β-adrenoreceptor affinity to its agonist, and β-adrenoreceptor density of the 12-month-old group are normalized to those of the 3-month-old group. Moreover, timolol treatment prevented dysfunction of the antioxidant system, including increased lipid peroxidation, decreased ratio of reduced glutathione to oxidized glutathione, and decreased activities of thioredoxin reductase and glucose-6-phosphate dehydrogenase, in the left ventricle of hearts from the 12-month-old group. Our data confirmed that aging-related early myocardial impairment is primarily related to a dysfunctional antioxidant system and impairment of Ca(2+) homeostasis, which can be prevented with chronic timolol treatment.     

RF hydrazine plasma modification of chitosan for antibacterial activity and nanofiber applications

Chitosan nano powders were modified using RF hydrazine plasma produced at low pressure (26.66 Pa) with 13.56 MHz frequency at a power of 100 W for 30 min. Characterization and investigation of the properties of plasma-modified chitosan (PMCh) and non-modified chitosan (Ch) were carried out using an optical monochromator, FTIR, florescence analysis, TGA, SEM, and X-ray techniques. FTIR spectra of PMCh indicated a band broadening at 3436 cm⁻¹ that confirmed increasing functional groups based on H-bonding. The number of NH₂ groups was determined from fluorescence analysis. TGA analysis shows that the moisture absorption is three times higher in the PMCh structure. Ch and PMCh in PVA solutions were used to produce nanofibers by the electrospinning method; average fiber diameters were 480 and 280 nm for Ch and PMCh, respectively. It was found that the antibacterial effect of PMCh is better than the Ch for Gram-positive strains.     

Covalent immobilization of catalase onto spacer-arm attached modified florisil: characterization and application to batch and plug-flow type reactor systems

Catalase was covalently immobilized onto florisil via glutaraldehyde (GA) and glutaraldehyde+6-amino hexanoic acid (6-AHA) (as a spacer arm). Immobilizations of catalase onto modified supports were optimized to improve the efficiency of the overall immobilization procedures. The V(max) values of catalase immobilized via glutaraldehyde (CIG) and catalase immobilized via glutaraldehyde+6-amino hexanoic acid (CIG-6-AHA) were about 0.6 and 3.4% of free catalase, respectively. The usage of 6-AHA as a spacer arm caused about 40 folds increase in catalytic efficiency of CIG-6-AHA (8.3 × 10? M?1 s?1) as compared to that of CIG (2.1 × 10? M?1 s?1). CIG and CIG-6-AHA retained 67 and 35% of their initial activities at 5 °C and 71 and 18% of their initial activities, respectively at room temperature at the end of 6 days. Operational stabilities of CIG and CIG-6-AHA were investigated in batch and plug-flow type reactors. The highest total amount of decomposed hydrogen peroxide (TAD-H?O?) was determined as 219.5 μmol for CIG-6-AHA in plug-flow type reactor.     

Lisinopril attenuates renal oxidative injury in l-NAME-induced hypertensive rats

Genetic factors related to cancer have been extensively studied and several polymorphisms have been associated to breast cancer. The FGFR4, MTHFR, and HFE genes have been associated with neoplastic diseases development. The current report outlines the analysis of the polymorphisms G388A (FGFR4), C677T (MTHFR), C282Y, and H63D (HFE) in Brazilian breast cancer patients. We studied 68 patients with invasive ductal and operable breast carcinoma and 85 women as a control group. The polymorphism frequencies in the breast cancer and control groups were analyzed, but no significant difference was observed by comparing the two groups. The presence of each polymorphism was analyzed according to the clinical features and markers already established as prognostic in the breast cancer group. The C677T, H63D, and G388A polymorphisms were not associated to histological grade, age of diagnosis, expression of HER2 receptor, or estrogen and progesterone receptor. The H63D polymorphism showed a significant association (P = 0.02) with the presence of p53 mutations, and C667T showed association to lymph node involvement (P = 0.05). Lymph node involvement, G388A polymorphism, and histological grade were independently associated to metastasis/death. Our data suggests that the polymorphisms G388A, C677T, and H63D are not useful in breast cancer diagnosis, but they may be significant additional prognostic markers related to breast cancer survival.     

The role of gender differences in beta-adrenergic receptor responsiveness of diabetic rat heart

Since the mechanisms responsible for gender differences in cardiac contractile function have not been fully elucidated, we focused to determine the effect of gender difference on β-adrenergic receptors (β-ARs) signal transduction in ventricular cardiomyocytes from insulin-dependent diabetic (streptozotocin-induced) rats. Dose-response curves of left ventricular developed pressure (LVDP) to isoproterenol (ISO) in females showed that there was only a ∼30% decrease in the maximum response without a significant shift in EC₅₀ in diabetic females. On the other hand, diabetes induced a clear rightward shift in the potency (5–10 folds) without a significant change in the maximum response in the males. In order to further determine of the underlying mechanism for this difference, we measured cAMP production and obtained dose-response curves with ISO stimulation in isolated cardiomyocytes. In diabetic females, there was no obvious change in the cAMP dose-response curve. On the other hand, there was a significant decrease in the maximum response without any apparent change in the potency of diabetic males. Our findings indicate that male and female rats are affected differently by diabetes in terms of LVDP responses to β-ARs stimulation. Also, the difference between their β-ARs induced cAMP responses may underlie this disparity.     

Combined effects of collagen type I alpha1 (COL1A1) Sp1 polymorphism and osteoporosis risk factors on bone mineral density in Turkish postmenopausal women

Identification of risk factors for osteoporosis has been essential for understanding the development of osteoporosis. The collagen type I alpha1 (COL1A1) gene is suggested to be implicated in reduced bone mineral density (BMD) in osteoporosis. In the present study, the investigation of the effects of Sp1 polymorphic variants of COL1A1 gene on BMD values, and the determination of the association between COL1A1 Sp1 gene variants and osteoporosis risk factors in the context of gene–environment interaction in Turkish postmenopausal women were aimed. For the detection of COL1A1 Sp1 polymorphism, PCR-RFLP techniques have been used. BMD for lumbar spine (L1–L4) and hip (femoral neck and total hip) was measured by DXA. This study was carried out using a sample of 254 postmenopausal women. We observed a trend decrease in BMD values in the subjects with “ss” genotype having lower BMD of lumbar spine, femoral neck and total hip than those with “SS” and “Ss” genotype, however the differences did not reach statistical significance (P > 0.05). We also found that the frequencies of the BMD under mean values at the femoral neck (57.5%) and total hip (76.2%) increased considerably in the subjects carrying “Ss/ss” genotypes in combination of having family history of osteoporosis (61.5% for femoral neck) and smoking history (90.0% for total hip). This population-based study indicates that COL1A1 Sp1 polymorphism may contribute to the development of osteoporosis in combination of osteoporosis risk factors in Turkish postmenopausal women.