Impact of tannic acid on blood pressure,oxidative stress and urinary parameters in L-NNA-induced hypertensive rats

Hypertension is a major health problem with increasing prevalence around the world. Tannic acid is water-soluble polyphenol that is present in tea, green tea, coffee, red wine, nuts, fruits and many plant foods. It has been reported to serve as an antioxidant or a pro-oxidant depending on the type of cells and its concentration. The purpose of our study was to evaluate the effect of tannic acid on systolic blood pressure, oxidative stress and some urinary parameters in the rat model of essential hypertension. Blood pressures of all rats were measured using the tail-cuff method. The nitric oxide synthase inhibitor N (omega)-nitro-L-arginine was administered orally at a dose of 0.5 g/l/day for 15 days to rats in order to create an animal model of hypertension. Tannic acid was intraperitoneally injected at a dose of 50 mg/kg for 15 days. Superoxide dismutase, catalase activity and the concentration of malondialdehyde (MDA) were determined in blood plasma and homogenates of heart, liver and kidney. In order to evaluate renal functions, urine pH, urine volume, urine creatine, uric acid, and urea nitrogen values were measured. Compared with the hypertension group, a decrease in MDA concentrations of heart tissue (p < 0.01), urea nitrogen values (p < 0.01) and urine volumes (p < 0.001) were established in hypertension + tannic acid group. There was also a decrease in blood pressure values (20th and 30th days) of this group, but there was no a statistical difference according to hypertension group. The findings of our research show the effect of tannic acid in lowering blood pressure in hypertensive rats.     

Immobilization of tyrosinase in polysiloxane/polypyrrole copolymer matrices

Immobilization of tyrosinase in conducting copolymer matrices of pyrrole functionalized polydimethylsiloxane/polypyrrole (PDMS/PPy) was achieved by electrochemical polymerization. The polysiloxane/polypyrrole/tyrosinase electrode was constructed by the entrapment of enzyme in conducting matrices during electrochemical copolymerization. Maximum reaction rate (V(max)) and Michaelis-Menten constant (K(m)) were investigated for immobilized enzyme. Enzyme electrodes were prepared in two different electrolyte/solvent systems. The effect of supporting electrolytes, p-toluene sulfonic acid and sodium dodecyl sulfate on the enzyme activity and film morphology were determined. Temperature and pH optimization, operational stability and shelf-life of enzyme electrodes were also examined. Phenolic contents of green and black tea were determined by using enzyme electrodes.     

Mechanical principles of effects of botulinum toxin on muscle length–force characteristics: An assessment by finite element modeling

Recent experiments involving muscle force measurements over a range of muscle lengths show that effects of botulinum toxin (BTX) are complex e.g., force reduction varies as a function of muscle length. We hypothesized that altered conditions of sarcomeres within active parts of partially paralyzed muscle is responsible for this effect. Using finite element modeling, the aim was to test this hypothesis and to study principles of how partial activation as a consequence of BTX affects muscle mechanics. In order to model the paralyzing effect of BTX, only 50% of the fascicles (most proximal, or middle, or most distal) of the modeled muscle were activated. For all muscle lengths, a vast majority of sarcomeres of these BTX-cases were at higher lengths than identical sarcomeres of the BTX-free muscle. Due to such “longer sarcomere effect”, activated muscle parts show an enhanced potential of active force exertion (up to 14.5%). Therefore, a muscle force reduction originating exclusively from the paralyzed muscle fiber populations, is compromised by the changes of active sarcomeres leading to a smaller net force reduction. Moreover, such “compromise to force reduction” varies as a function of muscle length and is a key determinant of muscle length dependence of force reduction caused by BTX. Due to longer sarcomere effect, muscle optimum length tends to shift to a lower muscle length. Muscle fiber–extracellular matrix interactions occurring via their mutual connections along full peripheral fiber lengths (i.e., myofascial force transmission) are central to these effects. Our results may help improving our understanding of mechanisms of how the toxin secondarily affects the muscle mechanically.     

Cell-free synthesis of cytochrome bo(3) ubiquinol oxidase in artificial membranes

Microplates for use in resource-limited laboratories should ideally not require processes that involve substantial large-scale production in order to be viable. We describe and demonstrate here an approach of using a silicone sheet with holes, conveniently cut out precisely using an inexpensive cutting plotter to correspond with regions where liquid is to be dispensed, and attaching it to a transparency to create very thin well arrays. With this, the contact angle hysteresis behavior of liquid could be harnessed to produce taller drop shapes so that the fiber probe used could read in the emitted light more effectively. Experimentation conducted revealed fluorescence measurements that were significantly more sensitive than standard microplates, notwithstanding that smaller volumes of liquid were needed. This was achieved using both the fiber optic and imaging evaluation modes. The two methods investigated, one with a lid placed and one without, showed the latter to produce marginally more sensitive readings as opposed to improved immunity from the environment with the former. These favorable measurement characteristics were found to be achievable with an estimated production cost of AU $0.40 and fabrication times of 3.5 min (96 wells) and 6.5 min (384 wells) per plate.     

Troponin and Anti-Troponin Autoantibody Levels in Patients with Ventricular Noncompaction

Ventricular hypertrabeculation/noncompaction is a morphologic and functional anomaly of myocardium characterized by prominent trabeculae accompanied by deep recessus. Dilated cardiomyopathy with left ventricular failure is observed in these patients, while the cause or pathophysiologic nature of this complication is not known. Anti-troponin antibodies are formed against circulating cardiac troponins after an acute coronary event or conditions associated with chronic myocyte necrosis, such as dilated cardiomyopathy. In present study, we aimed to investigate cardiac troponins and anti troponin autoantibodies in ventricular noncompaction/hypertrabeculation patients with/without reduced ejection fraction. A total of 50 patients with ventricular noncompaction and 23 healthy volunteers were included in this study. Noncompaction/hypertrabeculation was diagnosed with two-dimensional echocardiography using appropriate criteria. Depending on ejection fraction, patients were grouped into noncompaction with preserved EF (LVEF >50%, n = 24) and noncompaction with reduced EF (LVEF <35%, n = 26) groups. Troponin I, troponin T, anti-troponin I IgM and anti-troponin T IgM were measured with sandwich immunoassay method using a commercially available kit. Patients with noncompaction had significantly higher troponin I (28.98±9.21 ng/ml in NCNE group and 28.11±10.42 ng/ml in NCLE group), troponin T (22.17±6.97 pg/ml in NCNE group and 22.78±7.76 pg/ml in NCLE group) and antitroponin I IgM (1.92±0.43 µg/ml in NCNE group and 1.79±0.36 µg/ml in NCLE group) levels compared to control group, while antitroponin T IgM and IgG were only elevated in patients with noncompaction and reduced EF (15.81±6.52 µg/ml for IgM and 16.46±6.25 µg/ml for IgG). Elevated cardiac troponins and anti-troponin I autoantibodies were observed in patients with noncompaction preceding the decline in systolic function and could indicate ongoing myocardial damage in these patients.     

Search for microsatellite markers associated with water-stress tolerance in wheat through bulked segregant analysis

We used bulked segregant analysis (BSA) to identify microsatellite markers associated with water-stress tolerance in wheat. Two DNA pools (tolerant and sensitive) were established from the selected F₂ individuals of crosses between water-stress-tolerant and -sensitive wheat parental genotypes on the basis of the paraquat (PQ) tolerance, leaf size, and relative water content. All three traits were previously shown to be associated with water-stress tolerance on segregating F₂ progeny of the wheat crosses used in this study. Microsatellite analysis was then performed on the established DNA pools, using 35 primer pairs that included all of the chromosome group 5 (5A, 5B, 5D) markers, to detect microsatellite fragments that were present, absent, or both in the DNA pools and their parental lines. We identified one microsatellite fragment that was present in tolerant parent wheat and the tolerant bulk but absent in the sensitive parent wheat and sensitive bulk. We then followed the segregation of this marker in the tolerant F₂ individuals. Use of this marker may significantly enhance the success of selection for PQ- and water-stress-tolerant genotypes in wheat breeding programs.     

Effects of various agents on DNA fragmentation and telomerase enzyme activities in adenocarcinoma cell lines

Natural compounds such as resveratrol, tannic acid, and quercetin may help to treat cancer. Tamoxifen is a non-steroidal anti-estrogen drug widely used in the treatment of patients with estrogen receptor-positive breast cancer. The aim of the study was to compare the effects of these natural compounds and tamoxifen in colon adenocarcinoma (CaCo-2) and breast adenocarcinoma (MCF-7) cell lines, on telomerase enzyme activity, cell viability, number of cells and DNA fragmentation. In this study to determine telomerase enzyme activity was used PCR–ELISA kit. To determine cell viability and number of cells were used tripan blue stain. DNA fragmentation was determined by DNA ladder isolation kit. Tannic acid was more effective than resveratrol, with respect to reduction in telomerase activity, cell viability and cell count in breast adenocarcinoma. Tannic acid and tamoxifen was more effective than resveratrol and quercetin telomerase activity, cell viability and cell count in colon adenocarcinoma. Flavonoids such as resveratrol, tannic acid and quercetin which was studied on, has benefical effects on cancer therapy. These effects such as decreasing telomerase enzyme activity, cell viability and number of cells and inducing DNA fragmentation (apoptosis) must be studied for assist to develop new therapeutic pathways. There should be much more sudies in order to discover resveratrol, tannic acid and quercetin and other potential medicines.     

Assessment of genetic diversity of wheat genotypes by resistance gene analog-EST markers

Resistance gene analog-expressed sequence tag (RGA-EST)-based markers have been used for variety discrimination and studies of genetic diversity in wheat. Our aim is to increase the competitiveness of public wheat breeding programs through intensive use of modern selection technologies, mainly marker-assisted selection. The genetic diversity of 77 wheat nucleotide binding site (NBS)-containing RGA-ESTs was assessed. Resistant and susceptible bread wheat (Triticum aestivum) genotypes were used as sources of DNA for PCR amplifications. In our previous studies, the F? individuals derived from the combinations PI178383 x Harmankaya99, Izgi2001 x ES14, and Sonmez2001 x Aytin98 were evaluated for yellow rust resistance at both seedling and adult stages to identify DNA markers. We have now examined the genetic variability among the resistant and susceptible Turkish wheat cultivars for yellow rust disease and the mean genetic distance between the cultivars. The highest similarity was 0.500 between Harmankaya99 and Sonmez2001. The lowest similarity was 0.286 between Aytin98, PI178383 and Aytin98, ES14. A relatively high level (49.5%) of polymorphism was observed with 77 RGA-EST primers across the six wheat genotypes, despite the fact that all of them were local cultivars from geographically close locations. RGA-EST sequences were compared by BlastX algorithms for amino acid sequences to determine the polymorphic categories among the combinations. BlastX analyses of six RGA-ESTs that gave polymorphic patterns for all combinations were NBS-LRR class RGA, NB-ARC domain containing protein, NBS-type resistance protein RGC5, NBS-LRR-S/ TPK stem rust resistance protein, and putative MLA1 proteins, while 38 RGA-EST gave a monomorphic pattern.