Intraperitoneal Aminoguanidine Improves Sciatic Nerve Ischemia–Reperfusion Injury in Male Sprague-Dawley Rats

The present work was designed to investigate the potential protective effects of post-ischemic treatment with aminoguanidine (AG) on sciatic nerve ischemia/reperfusion (I/R) injury in rat. Seventy-two rats were divided into 12 groups (n = 6). We used ischemia model in these groups by occluding the right common iliac and femoral arteries for 3 h with a silk suture 6-0 using slipknot technique. Treatment groups (2, 4, 6, 8, 10, and 12) received 150 mg/kg AG intraperitoneally 24 h after induction of ischemia. After certain time intervals of reperfusion (2, 4, 7, 14, and 28 days), the function of the hind limb was assessed using behavioral scores based on gait, racing reflex, toe spread, pinch sensitivity, paw position, and grasp. After euthanasia, sciatic nerves were removed at the end of reperfusion times and sections were cut at 5 μm, then were stained for light microscopy studies and graded for ischemic fiber degeneration (IFD), edema, and apoptosis. Maximal behavioral deficit occurred at 7 days of reperfusion. The comparison of behavioral score pertaining to the control and AG groups revealed significant differences and showed also a better time course in recovery (P < 0.05). Other than 3 and 4 groups, the amount of edema in AG treatment groups showed significant differences compared with control groups (P < 0.05). IFD was also significantly decreased in the AG treatment groups than controls. Most importantly, I/R-induced apoptosis were improved significantly on the 4th, 7^th, and 14th days of reperfusion in AG-treated groups compared to controls. In conclusion, our findings suggest that post-ischemic administration of AG exhibits protective effect against sciatic nerve I/R injury.     

Aminoguanidine Changes Hippocampal Expression of Apoptosis-Related Genes,Improves Passive Avoidance Learning and Memory in Streptozotocin-Induced Diabetic Rats

Cognitive dysfunction occurs in patients with diabetes mellitus. The objective of this study was to examine whether bilateral intrahippocampal CA1 (intra-CA1) injection of aminoguanidine (AG) can either affect the Bcl-2 family gene expression or reduce the diabetic imposing abnormalities of passive avoidance learning (PAL) and memory. Rats were divided into five groups: control (C), control treated with normal saline (CS), control treated with AG (S-AG), diabetics (D), and diabetics treated with AG (D-AG). Diabetes mellitus was induced by a single intraperitoneal injection of streptozotocin (STZ) (50 mg/kg). AG (30 μg/rat) or vehicle was administered intra-CA1 bilaterally at the onset of hyperglycemia. PAL was assessed 7 weeks later. Animals were killed, and hippocampus was dissected following the behavioral test. The expressions of Bax, Bcl-2, and Bcl-xl mRNAs were measured using semiquantitative RT-PCR technique. The result of passive avoidance task showed that AG significantly improved the cognitive performance in diabetic rats. Moreover, AG treatment decreased the levels of Bcl-2 and Bcl-x_L expressions in diabetic group. The ratio of Bax/Bcl-2 and Bax/Bcl-x_L decreased significantly in AG-treated diabetic animals. In conclusion, initial treatment with AG by intra-CA1 micro-injection improves the impaired passive avoidance task in STZ-induced diabetic rats which may be related to the decreased Bax/Bcl-2 and Bax/Bcl-x_L ratios.     

Biodecolorization of textile azo dyes by isolated yeast from activated sludge: Issatchenkia orientalis JKS6

An ascomycetous yeast strain isolated from activated sludge could decolorize Reactive Black 5 azo dye at 200 mg l^?1 up to 90 % within 12–18 h under agitated condition. Yeast decolorization ability was investigated at different RB5 concentrations and, at higher dye concentration, 500 mg l^?1, the decolorization was found to be 98 % after 36 h incubation time. Extensive decolorization (95–99 %) was obtained in presence of five other azo dyes, Reactive Orange 16, Reactive Red 198, Direct Blue 71, Direct Yellow 12, and Direct Black 22, by isolated yeast. HPLC analysis, UV–vis spectra and colorless biomass obtained after complete decolorization showed that the decolorization occured through a biodegradation mechanism. Decolorization was occurred during the exponential growth phase which is associated to primary metabolism. Laccase production by the yeast cells was not detected. The isolated yeast was characterized according to phenotypical and molecular procedures and was closely related (99 % identity) to Issatchenkia orientalis.     

Increased Plasma YKL-40/Chitinase-3-Like-Protein-1 Is Associated with Endothelial Dysfunction in Obstructive Sleep Apnea

Purpose

Obstructive sleep apnea (OSA) is a common disorder affecting 15–24% of the adults and is associated with increased risk of hypertension and atherosclerosis. The exact mechanisms underlying hypertension in OSA are not entirely clear. YKL-40/Chitinase-3-like protein-1 is a circulating moiety with roles in injury, repair and angiogenesis that is dysregulated in atherosclerosis and a number of other diseases. We sought to determine the role of YKL-40 in endothelial dysfunction and hypertension in OSA.

Methods

We studies 23 normotensive OSA (N-OSA) and 14 hypertensive OSA (H-OSA) without diabetes and apparent cardiovascular disease. Endothelial-dependent nitric oxide-mediated vasodilatory capacity was assessed by flow-mediated vasodilation (FMD). YKL-40, vascular endothelial growth factor (VEGF) and the soluble form of VEGF receptor-1or sFlt-1 were measured in plasma using ELISA methodology.

Results

N-OSA subjects aged 49.1±2.3 years and H-OSA aged 51.3±1.9 years with BMI 36.1±1.6 and 37.6±1.9 kg/m², respectively. The apnea-hypopnea index (AHI) was 41±5 events/hr in N-OSA and 46±6 in H-OSA with comparable degree of oxygen desaturations during sleep. FMD was markedly impaired in H-OSA (8.3%±0.8) compared to N-OSA (13.2%±0.6, P<0.0001). Plasma YKL-40 was significantly elevated in H-OSA (55.2±7.9 ng/ml vs. 35.6±4.2 ng/ml in N-OSA, P = 0.02) and had an inverse relationship with FMD (r = −0.52, P = 0.013). There was a significant positive correlation between sFlt-1/VEGF, a measure of decreased VEGF availability, and YKL-40 (r = 0.42, P = 0.04).

Conclusion

The levels of plasma YKL-40 were elevated in H-OSA group and inversely correlated with the endothelial-dependent vasodilatory capacity whereas there was a positive correlation between sFlt-1/VEGF and YKL-40. These findings suggest that YKL-40 is dysregulated, in part, due to perturbation of VEGF signaling, and may contribute to endothelial dysfunction and hypertension in OSA.     

Serum Stability and Physicochemical Characterization of a Novel Amphipathic Peptide C6M1 for SiRNA Delivery

The efficient delivery of nucleic acids as therapeutic agents is a major challenge in gene therapy. Peptides have recently emerged as a novel carrier for delivery of drugs and genes. C6M1 is a designed amphipathic peptide with the ability to form stable complexes with short interfering RNA (siRNA). The peptide showed a combination of random coil and helical structure in water but mainly adopted a helical conformation in the presence of anions or siRNA. Revealed by dynamic light scattering (DLS) and microscopy techniques, the interaction of C6M1 and siRNA in water and HEPES led to complexes of ∼70 and ∼155 nm in size, respectively, but showed aggregates as large as ∼500 nm in PBS. The time-dependent aggregation of the complex in PBS was studied by DLS and fluorescence spectroscopy. At molar ratio of 15∶1, C6M1 was able to completely encapsulate siRNA; however, higher molar ratios were required to obtain stable complexes. Naked siRNA was completely degraded in 4 h in the solution of 50% serum; however C6M1 protected siRNA against serum RNase over the period of 24 h. Western blotting experiment showed ∼72% decrease in GAPDH protein level of the cells treated with C6M1-siRNA complexes while no significant knockdown was observed for the cells treated with naked siRNA.     

Critical slowing down as an early warning of transitions in episodes of bipolar disorder: A simulation study based on a computational model of circadian activity rhythms

Bipolar disorder is characterized by repeated episodes of mania and depression, and can be understood as pathological complex system behaviour involving cognitive, affective and psychomotor disturbance. Accurate prediction of episode transitions in the long-term pattern of mood changes in bipolar disorder could improve the management of the disorder by providing an objective early warning of relapse. In particular, circadian activity changes measured via actigraphy may contain clinically relevant signals of imminent systemic dysregulation. In this study, we propose a mathematical index to investigate the correlation between apparently irregular circadian activity rhythms and critical transitions in episodes of bipolar disorder. Not only does the proposed index illuminate the effects of pharmacological and psychological therapies in control over the state, but it also provides a framework to understand the dynamic (or state-dependent) control strategies. Modelling analyses using our new approach suggest that key clinical goals are minimizing side effects of mood stabilizers as well as increasing the efficiency of other therapeutic strategies.     

An architecture for a shop-floor controller using colored Petri nets

In a dynamic and flexible manufacturing environment, a shop-floor controller must be designed so that it automatically (or with minimum human intervention) and quickly responds to the changes (e.g., in part type or part routing) in the system. Such a performance may be achieved provided that the controller is simple and sufficiently general in its scope of application. In this article, we present an architecture for such a shop-floor controller. The architecture is based on colored Petri nets with ordered colored sets and structured input and output functions.     

Differences in proliferation rate between CADASIL and control vascular smooth muscle cells are related to increased TGFβ expression

Cerebral autosomal‐dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a familial fatal progressive degenerative disorder. One of the pathological hallmarks of CADASIL is a dramatic reduction of vascular smooth muscle cells (VSMCs) in cerebral arteries. Using VSMCs from the vasculature of the human umbilical cord, placenta and cerebrum of CADASIL patients, we found that CADASIL VSMCs had a lower proliferation rate compared to control VSMCs. Exposure of control VSMCs and endothelial cells (ECs) to media derived from CADASIL VSMCs lowered the proliferation rate of all cells examined. By quantitative RT‐PCR analysis, we observed increased Transforming growth factor‐β (TGFβ) gene expression in CADASIL VSMCs. Adding TGFβ‐neutralizing antibody restored the proliferation rate of CADASIL VSMCs. We assessed proliferation differences in the presence or absence of TGFβ‐neutralizing antibody in ECs co‐cultured with VSMCs. ECs co‐cultured with CADASIL VSMCs exhibited a lower proliferation rate than those co‐cultured with control VSMCs, and neutralization of TGFβ normalized the proliferation rate of ECs co‐cultured with CADASIL VSMCs. We suggest that increased TGFβ expression in CADASIL VSMCs is involved in the reduced VSMC proliferation in CADASIL and may play a role in situ in altered proliferation of neighbouring cells in the vasculature.