Embryogenesis,plant regeneration and cardiac glycoside determination in Digitalis ferruginea subsp. ferruginea L

The present study reports, for the first time, an efficient in vitro plant regeneration protocol for Digitalis ferruginea subsp. ferruginea L. (rusty foxglove). We have used different concentrations of gibberellic acid (GA₃) on Murashige and Skoog (MS) medium to assess the germination frequency of seeds. High frequency of germination was achieved on MS medium with 1.0 mg l^?1 GA₃. 6-Benzylaminopurine (BAP) combined with α-naphtaleneacetic acid (NAA) or 2, 4-dichlorophenoxy acetic acid (2, 4-D) in the induction MS medium induced both somatic embryogensis and shoot organogenesis. The highest percentage of callus growth (85 %) was obtained when hypocotyl explants were cultured on MS medium containing 0.5 mg l^?1 2, 4-D plus 1.0 mg l^?1 BAP. The maximum mean number of somatic embryos (7.3 ± 1.3 embryos) or shoots (12.0 ± 1.1 shoots) per callus was obtained when medium contained 0.25 mg l^?1 NAA plus 1.0 mg l^?1 BAP or 0.5 mg l^?1 NAA plus 2.0 mg l^?1 BAP. The regenerated shoots easily rooted on MS medium. Higher amounts of lanatoside C [13.2 ± 0.5 mg 100 g^?1 dry weight (dw)] and digoxin (2.93 ± 0.31 mg 100 g^?1 dw) accumulation were obtained when shoots were obtained by indirect regeneration. We also investigated derivatives of cardenolides, i.e., digitoxigenin (730 ± 180 mg 100 g^?1 dw), gitoxigenin (50 ± 20 mg 100 g^?1 dw) and digoxigenin (490 ± 170 mg 100 g^?1 dw) from natural samples.     

Use of Rep‐PCR for Genetic Diversity Analyses in Fusarium culmorum

Fusarium culmorum is a pathogen of economically important grain crops. In this work, Rep‐PCR was used to identify genetic diversity in F. culmorum isolates which have been collected from wheat fields in Turkey. Reproducible genomic fingerprints were amplified in each strain by PCRs of prokaryotic repetitive extragenic palindromic (REP), enterobacterial repetitive intergenic consensus (ERIC) and BOX sequences. Totally 104 molecular markers were evaluated and similarity comparisons were shown as a dendrogram. The average genetic diversity was 52.3% ranging from 15.8% to 88.7% according to the Rep‐PCR data. Cluster analysis showed agreement with the distance of sampling locations. The highest genetic similarity (84.2%) was determined between two F. culmorum isolates (F1 and F2) originated from the same agro‐ecological region. Our results showed that Rep‐PCR is convenient and rapid for genetic diversity analyses and strain differentiation in F. culmorum.     

Neuroprotective effects of Caffeic acid phenethyl ester on experimental traumatic brain injury in rats

The aim of this study was to evaluate the therapeutic efficacy of caffeic acid phenethyl ester (CAPE) with an experimental traumatic brain injury (TBI) model in rats. Twenty-four adult male Sprague–Dawley rats were randomly divided into three groups of 8 rats each: control, TBI, and TBI + CAPE treatment. In TBI and TBI + CAPE treatment groups, a cranial impact was delivered to the skull from a height of 7 cm at a point just in front of the coronal suture and over the right hemisphere. Rats were sacrificed at 4 h after the onset of injury. Brain tissues were removed for biochemical and histopathological investigation. To date, no biochemical and histopathological changes of neurodegeneration in the frontal cortex after TBI in rats by CAPE treatment have been reported. The TBI significantly increased tissue malondialdehyde (MDA) levels, and significantly decreased tissue superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities, but not tissue catalase (CAT) activity, when compared with controls. The administration of a single dose of CAPE (10 μmol/kg) 15 min after the trauma has shown protective effect via decreasing significantly the elevated MDA levels and also significantly increasing the reduced antioxidant enzyme (SOD and GPx) activities, except CAT activity. In the TBI group, severe degenerative changes, shrunken cytoplasma and extensively dark picnotic nuclei in neurons, as well as vacuolization indicating tissue edema formation. The morphology of neurons in the CAPE treatment group was well protected. The number of neurons in the trauma alone group was significantly less than that of both the control and TBI +CAPE treatment groups. The caspase 3 immunopositivity was increased in degenerating neurons of the traumatic brain tissue. Treatment of CAPE markedly reduced the immunoreactivity of degenerating neurons. TBI caused severe degenerative changes, shrunken cytoplasma, severely dilated cisternae of endoplasmic reticulum, markedly swollen mitochondria with degenerated cristae and nuclear membrane breakdown with chromatin disorganization in neurons of the frontal cortex. In conclusion, the CAPE treatment might be beneficial in preventing trauma-induced oxidative brain tissue damage, thus showing potential for clinical implications. We believe that further preclinical research into the utility of CAPE may indicate its usefulness as a potential treatment on neurodegeneration after TBI in rats.     

An efficient in vitro regeneration system for Lythrum salicaria

This report describes an efficient plant regeneration system for the medicinal plant Lythrum salicaria via direct adventitious shoot development from leaf and stem explants. Leaf explants were much more responsive to regeneration than stem segments. Of the hormonal combinations tested, those involving thidiazuron (TDZ; 0.1, 0.3 or 0.5 mg dm⁻³) were more effective than the combinations of other hormones and 0.1 mg dm-3 TDZ combined with either indole-3-acetic acid (IAA) or indole-3-butyric acid (IBA) was the most productive. Rooting was readily achieved when multiple shoots were singled out and cultured on medium containing different auxins. IAA was the most effective on root development in terms of both the number of roots per shoot and the frequency of rooted shoots. More than 90 % of the regenerants survived after hardening for four weeks at gradually decreased air humidity.     

Tuning Optical Discs for Plasmonic Applications

We present simple physical and chemical procedures that allow tuning and modification of the topography of gratings present in optical storage discs into geometries optimal for grating coupled plasmon resonance excitation. After proper metal coating, the tuned surfaces exhibit sharp plasmon resonances that can be excited at wavelengths ranging from 260 nm to over 2.7 μm with relatively high quality factors. As an immediate exemplary application, use of such optimized gratings in aqueous medium for refractive index measurement is demonstrated.     

Apoptotic rate and metallothionein levels in the tissues of cadmium-and copper-exposed rats

It is well known that cadmium (Cd) has toxic and carcinogenic effects in rodents and humans, but the effects of Cd on apoptosis are still not clear. Although some studies have shown that Cd has apoptotic potential, other studies have shown that Cd can be antiapoptotic. Parameters such as sensitivity of the exposed organism or cells and the exposure conditions should be important in delineating the effect of Cd on apoptosis. In the present study, we aimed to determine the apoptotic index (AI) of Sprague-Dawley rat tissues that are loaded at a lower Cd concentration than the critical concentration (50 microg/g) for its toxic effects. Metallothionein (MT) levels of tissues were also determined and the experiments repeated with copper (Cu)-exposed rats. We detected decreases in the apoptotic index in liver and lung tissues of Cd-exposed groups accompanied with an increase in MT levels. Also, decreases of AI were detected in the liver tissues of Cu-exposed groups. These findings indicate that Cd can suppress apoptosis in vivo. The possible role of MT expression on the suppression of apoptosis and the importance of free-Cd ion concentration on switching antiapoptotic effects to proapoptotic effects are also discussed.     

Hexokinase cellular trafficking in ischemia–reperfusion and ischemic preconditioning is altered in type I diabetic heart

Diabetes mellitus (DM) has been reported to alter the cardiac response to ischemia–reperfusion (IR). In addition, cardioprotection induced by ischemic preconditioning (IPC) is often impaired in diabetes. We have previously shown that the subcellular localisation of the glycolytic enzyme hexokinase (HK) is causally related to IR injury and IPC protective potential. Especially the binding of HK to mitochondria and prevention of HK solubilisation (HK detachment from mitochondria) during ischemia confers cardioprotection. It is unknown whether diabetes affects HK localisation during IR and IPC as compared to non-diabetes. In this study we hypothesize that DM alters cellular trafficking of hexokinase in response to IR and IPC, possibly explaining the altered response to IR and IPC in diabetic heart. Control (CON) and type I diabetic (DM) rat hearts (65 mg/kg streptozotocin, 4 weeks) were isolated and perfused in Langendorff-mode and subjected to 35 min I and 30 min R with or without IPC (3 times 5 min I). Cytosolic and mitochondrial fractions were obtained at (1) baseline, i.e. after IPC but before I, (2) 35 min I, (3) 5 min R and (4) 30 min R. DM improved rate-pressure product recovery (RPP; 71 ± 10 % baseline (DM) versus 9 ± 1 % baseline (CON) and decreased contracture (end-diastolic pressure: 24 ± 8 mmHg (DM) vs 77 ± 4 mmHg (CON)) after IR as compared to control, and was associated with prevention of HK solubilisation at 35 min I. IPC improved cardiac function in CON but not in DM hearts. IPC in CON prevented HK solubilisation at 35 min I and at 5 min R, with a trend for increased mitochondrial HK. In contrast, the non-effective IPC in DM was associated with solubilisation of HK and decreased mitochondrial HK at early reperfusion and a reciprocal behaviour at late reperfusion. We conclude that type I DM significantly altered cellular HK translocation patterns in the heart in response to IR and IPC, possibly explaining altered response to IR and IPC in diabetes.     

Phase Resetting Curves Allow for Simple and Accurate Prediction of Robust N:1 Phase Locking for Strongly Coupled Neural Oscillators

Existence and stability criteria for harmonic locking modes were derived for two reciprocally pulse coupled oscillators based on their first and second order phase resetting curves. Our theoretical methods are general in the sense that no assumptions about the strength of coupling, type of synaptic coupling, and model are made. These methods were then tested using two reciprocally inhibitory Wang and Buzsáki model neurons. The existence of bands of 2:1, 3:1, 4:1, and 5:1 phase locking in the relative frequency parameter space was predicted correctly, as was the phase of the slow neuron's spike within the cycle of the fast neuron in which it occurred. For weak coupling the bands are very narrow, but strong coupling broadens the bands. The predictions of the pulse coupled method agreed with weak coupling methods in the weak coupling regime, but extended predictability into the strong coupling regime. We show that our prediction method generalizes to pairs of neural oscillators coupled through excitatory synapses, and to networks of multiple oscillatory neurons. The main limitation of the method is the central assumption that the effect of each input dies out before the next input is received.