In vitro photomorphogenesis,plant growth regulators,melatonin content,and DNA methylation under various wavelengths of light in Phalaenopsis amabilis

Plant Cell, Tissue and Organ Culture (PCTOC) - We tested the feasibility to promote growth and shoot proliferation of Phalaenopsis through different wavelengths of LED and fluorescent. Therefore,...     

Cyclic presence and absence of conspecifics alters circadian clock phase but does not entrain the locomotor activity rhythm of the fruit fly Drosophila melanogaster

Circadian clocks use a wide range of environmental cues, including cycles of light, temperature, food, and social interactions, to fine-tune rhythms in behavior and physiology. Although social cues have been shown to influence circadian clocks of a variety of organisms including the fruit fly Drosophila melanogaster, their mechanism of action is still unclear. Here, the authors report the results of their study aimed at investigating if daily cycles of presence and absence (PA) of conspecific male visitors are able to entrain the circadian locomotor activity rhythm of male hosts living under constant darkness (DD). The results suggest that PA cycles may not be able to entrain circadian locomotor activity rhythms of Drosophila. The outcome does not change when male hosts are presented with female visitors, suggesting that PA cycles of either sex may not be effective in bringing about stable entrainment of circadian clocks in D. melanogaster. However, in hosts whose clock phase has already been set by light/dark (LD) cycles, daily PA cycles of visitors can cause measurable change in the phase of subsequent free-running rhythms, provided that their circadian clocks are labile. Thus, the findings of this study suggest that D. melanogaster males may not be using cyclic social cues as their primary zeitgeber (time cue) for entrainment of circadian clocks, although social cues are capable of altering the phase of their circadian rhythms.     

The effects of Vitamin A administration on the development of vitrified-warmed mouse blastocyst

The purpose of this study was to evaluate the development of vitrified-warmed mouse blastocysts following a period of Vitamin A administration. Four to six weeks old BALB/c mice were given an intraperitoneal injection of either 0.1 ml paraffin oil alone (control, Con) or paraffin oil containing 250IU of Vitamin A (experiment, Exp). Ten days later the mice were given second paraffin or paraffin Vitamin A injection and an injection of 10IU equine chorionic gonadotropin (eCG) followed 48 h later by 10IU human chorionic gonadotropin (hCG). Blastocysts were collected from both groups and randomly divided into non-vitrified (Con 1, Exp 1) and vitrified (Con 2, Exp 2) subgroups. Embryos in the vitrified group were exposed sequentially to two solutions (10% ethylene glycol, 10% DMSO in holding medium (HM: DMEMF(12)+10% FBS) and 20% ethylene glycol, 20% DMSO in HM) before plunging into liquid nitrogen. After warming at 37 degrees C, cryoprotectants were diluted serially with 0.25 and 0.15M sucrose solution in HM. The vitrified-warmed and the fresh embryos of the control and the experiment groups were cultured in DMEMF(12) with 10% FBS for 72 h. Although, on the first day of culture, the rate of development to the hatched blastocyst was nearly identical between the two vitrified groups (15.8% versus 13%) but after 48 h, the rate of plated embryos was statistically higher in the vitrified Vitamin A than the vitrified control group (63.1% versus 19.6%, P<0.001). After 48 h, in the non-vitrified groups, the rate of the plated embryos was also significantly higher in the Vitamin A than the control group (70.5% versus 49.3%, P<0.01). These data provided evidence that systemic administration of Vitamin A may enhance the potential development of blastocysts in culture and is capable to reduce the adverse effects of vitrification at least during the first 2 days of cultivation.     

Increase of autophagy and attenuation of apoptosis by Salvigenin promote survival of SH-SY5Y cells following treatment with H2O2

Oxidative stress is a major component of harmful cascades activated in neurodegenerative disorders. Here, we tried to elucidate the possible neuroprotective effect of Salvigenin, a natural polyphenolic compound, on oxidative stress-induced apoptosis and autophagy in human neuroblastoma SH-SY5Y cells. We measured cell viability by MTT test and found that 25?μM is the best protective concentration of Salvigenin. GSH and SOD assays suggested that Salvigenin activates antioxidant factors. At the same time, measurement of ER stress-associated proteins including calpain and caspase-12 showed the ability of Salvigenin to decrease ER stress. We found that Salvigenin could decrease the apoptotic factors. Salvigenin inhibited H₂O₂-induced caspase-3 which is a hallmark of apoptosis in addition to reducing Bax\Bcl-2 ratio by 1.45 fold. Additionally, Salvigenin increased the levels of autophagic factors. Our results showed an increase in LC3-II/LC3-I ratio, Atg7, and Atg12 in the presence of 25?μM of Salvigenin by about 1.28, 1.25, and 1.54 folds, respectively, compared to H₂O₂-treated cells. So it seems that H₂O₂ cytotoxicity mainly results from apoptosis. Besides, Salvigenin helps cells to survive by inhibiting apoptosis and enhancing autophagy that opens a new horizon for the future experiments.     

Matrix metalloproteinas-9 functional promoter polymorphism 1562C>T increased risk of early-onset coronary artery disease

The Matrix metalloproteinas-9 functional promoter polymorphism 1562C>T may be considered an important genetic determinant of early-onset coronary artery disease (ECAD). In this study, association between MMP-9 1562C>T allele with plasma MMP-9 activity, homocysteine and lipid–lipoproteins level and ECAD in Iranian subjects was investigated. This case–control study consisted of 53 ECAD patients (age < 55 years) and unrelated late-onsets CAD (age > 70 years) who angiographically had at least 50% stenosis. MMP-9 1562C>T polymorphism was detected by PCRRFLP, plasma MMP-9 activity, serum lipid and homocysteine levels were determined by gelatin gel zymography, enzyme assay and by HPLC, respectively. The presence of MMP-9 1562C>T allele was found to be associated with ECAD (OR = 3.2, P = 0.001). The ECAD patients with MMP-9 1562C>T allele had higher MMP-9 activity (P = 0.001), LDL-C (P = 0.045), TC (P = 0.02) and homocysteine (P = 0.01) levels than the LCAD subjects. MMP-9 1562C>T allele is a risk factor for ECAD. The carriers of this allele have high levels of MMP-9 activity, LDL-C, TC and homocysteine (P = 0.01), thus, are more likely to develop myocardial infarction and CAD at young age (less than 55 years).     

Reproducibility of swallow-induced cortical BOLD positive and negative fMRI activity

Functional MRI (fMRI) studies have demonstrated that a number of brain regions (cingulate, insula, prefrontal, and sensory/motor cortices) display blood oxygen level-dependent (BOLD) positive activity during swallow. Negative BOLD activations and reproducibility of these activations have not been systematically studied. The aim of our study was to investigate the reproducibility of swallow-related cortical positive and negative BOLD activity across different fMRI sessions. We studied 16 healthy volunteers utilizing an fMRI event-related analysis. Individual analysis using a general linear model was used to remove undesirable signal changes correlated with motion, white matter, and cerebrospinal fluid. The group analysis used a mixed-effects multilevel model to identify active cortical regions. The volume and magnitude of a BOLD signal within each cluster was compared between the two study sessions. All subjects showed significant clustered BOLD activity within the known areas of cortical swallowing network across both sessions. The cross-correlation coefficient of percent fMRI signal change and the number of activated voxels across both positive and negative BOLD networks were similar between the two studies (r ≥ 0.87, P < 0.0001). Swallow-associated negative BOLD activity was comparable to the well-defined "default-mode" network, and positive BOLD activity had noticeable overlap with the previously described "task-positive" network. Swallow activates two parallel cortical networks. These include a positive and a negative BOLD network, respectively, correlated and anticorrelated with swallow stimulus. Group cortical activity maps, as well as extent and amplitude of activity induced by volitional swallowing in the cortical swallowing network, are reproducible between study sessions.     

Assessment of genetic mutations in the XRCC2 coding region by high resolution melting curve analysis and the risk of differentiated thyroid carcinoma in Iran

Homologous recombination (HR) is the major pathway for repairing double strand breaks (DSBs) in eukaryotes and XRCC2 is an essential component of the HR repair machinery. To evaluate the potential role of mutations in gene repair by HR in individuals susceptible to differentiated thyroid carcinoma (DTC) we used high resolution melting (HRM) analysis, a recently introduced method for detecting mutations, to examine the entire XRCC2 coding region in an Iranian population. HRM analysis was used to screen for mutations in three XRCC2 coding regions in 50 patients and 50 controls. There was no variation in the HRM curves obtained from the analysis of exons 1 and 2 in the case and control groups. In exon 3, an Arg(188)His polymorphism (rs3218536) was detected as a new melting curve group (OR: 1.46; 95%CI: 0.432-4.969; p = 0.38) compared with the normal melting curve. We also found a new Ser(150)Arg polymorphism in exon 3 of the control group. These findings suggest that genetic variations in the XRCC2 coding region have no potential effects on susceptibility to DTC. However, further studies with larger populations are required to confirm this conclusion.