A Murine Model of Subarachnoid Hemorrhage

In this video publication a standardized mouse model of subarachnoid hemorrhage (SAH) is presented. Bleeding is induced by endovascular Circle of Willis perforation (CWp) and proven by intracranial pressure (ICP) monitoring. Thereby a homogenous blood distribution in subarachnoid spaces surrounding the arterial circulation and cerebellar fissures is achieved. Animal physiology is maintained by intubation, mechanical ventilation, and continuous on-line monitoring of various physiological and cardiovascular parameters: body temperature, systemic blood pressure, heart rate, and hemoglobin saturation. Thereby the cerebral perfusion pressure can be tightly monitored resulting in a less variable volume of extravasated blood. This allows a better standardization of endovascular filament perforation in mice and makes the whole model highly reproducible. Thus it is readily available for pharmacological and pathophysiological studies in wild type and genetically altered mice.     

Immune-associated biomarkers for early diagnosis of Parkinson’s disease based on hematological lncRNA–mRNA co-expression

Early stage diagnosis of Parkinson’s disease (PD) is challenging without significant motor symptoms. The identification of effective molecular biomarkers as a hematological indication of PD may help improve the diagnostic timelines and accuracy. In the present paper, we analyzed and compared the blood samples of PD and control (CTR) patients to identify the disease-related changes and determine the putative biomarkers for PD diagnosis. Based on the RNA sequencing analysis, differentially expressed genes (DEGs) were identified, and the co-expression network of DEGs was constructed using the weighted gene correlation network analysis (WGCNA). The analysis leads to the identification of 87 genes that were exclusively regulated in the PD group, whereas 66 genes were significantly increased and 21 genes were significantly decreased in contrast with the control group. The results indicate that the core lncRNA–mRNA co-expression network greatly changes the immune response in PD patients. Specifically, the results showed that Prader Willi Angelman Region RNA6 (PWAR6), LINC00861, AC83843.1, IRF family, IFIT family and calcium/calmodulin-dependent protein kinase IV (CaMK4) may play important roles in the immune system of PD. Based on the findings from the present study, future research aims at identifying novel therapeutic strategies for PD.     

Immobilization of HIV-1 TAT peptide on gold nanoparticles: A feasible approach for siRNA delivery

RNA interference is one of the prosperous approaches for cancer treatment. However, small interfering RNA (siRNA) delivery to cancer cells has been faced with various challenges restricting their clinical application over the decades. Since ROR1 is an onco-embryonic gene overexpressed in many malignancies, suppression of ROR1 by siRNA can potentially fight cancer. Herein, a delivery system for ROR1 siRNA based on HIV-1 TAT peptide-capped gold nanoparticles (GNPs) was developed to treat breast cancer. Besides, we introduced a new feasible method for conjugating the peptide to the nanoparticles. Since the GNPs have high affinity to the sulfur, the findings demonstrated the peptide successfully conjugated to the nanoparticles via Au–S bonds. As positively charged nanoparticles showed high cellular uptake, we could use a low concentration of nanoparticles led to high efficient gene transfection with negligible cytotoxicity that was confirmed by flow cytometry, confocal microscopy, gel retardation, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Following transfection, downregulation of ROR1 and its targeted gene, CCND1, induced apoptosis in cancer cells. In conclusion, the reported capped GNPs could be potentially utilized for delivering negatively charged therapeutic agents in particular genes.     

Approaching mathematical model of the immune network based DNA Strand Displacement system

One biggest obstacle in molecular programming is that there is still no direct method to compile any existed mathematical model into biochemical reaction in order to solve a computational problem. In this paper, the implementation of DNA Strand Displacement system based on nature-inspired computation is observed. By using the Immune Network Theory and Chemical Reaction Network, the compilation of DNA-based operation is defined and the formulation of its mathematical model is derived. Furthermore, the implementation on this system is compared with the conventional implementation by using silicon-based programming. From the obtained results, we can see a positive correlation between both. One possible application from this DNA-based model is for a decision making scheme of intelligent computer or molecular robot.     

Thermal manipulation during the middle incubation stage has a repressive effect on the immune organ development of Peking ducklings

Avian embryos are easily influenced by their environment during incubation. Previous studies have demonstrated that incubation temperature changes could influence muscle development and body weight, which subsequently determine the adult phenotype. The objective of this study was to investigate whether the development of immune organs in ducklings could be influenced by thermal manipulation during the middle stage of incubation. To evaluate this hypothesis, a control group was incubated under a normal temperature from E11 to E24, while the incubation temperature of the experimental group was increased by 1 °C. Our results indicated that slight changes in the incubation temperature significantly repressed the bursa of Fabricius index of the duck embryo on E25 (F1, 58=122.51, P<0.0001) and significantly repressed the spleen index of neonatal ducklings (F1, 58=74.38, P<0.0001). At 0 day posthatching (dph) and 14 dph, ducklings hatched from eggs incubated under the higher temperature had a lower percentage of globulin than the control group (F1, 10=19.97, P=0.0111; F1, 10=9.8, P=0.0352). The IFN-γ concentration of ducklings at 14 dph displayed the same trend (F1, 10=284.49, P<0.0001). These results suggested that thermal manipulation during the middle stage of incubation had a repressive effect on the development of immune organs and reduced the concentrations of serum globulin and IFN-γ. These results demonstrated that the subtle alteration of incubation temperature may weaken ducklings' immunity.     

Modification of plant bait technique for direct diagnosis for Rhizoctonia rice pathogens from Myanmar paddy field soils

A modified baiting technique was conducted for selective isolation, fungal DNA diagnosis and fungal cell lipid assay derived from Myanmar isolates of Rhizoctonia spp., causal agents of rice sheath diseases by trapping selective plant stem segments. Bait plant materials of rice, mat rush and cotton were successfully used to isolate R. solani AG1-IA, R. oryzae and R. oryzae-sativae. Moreover, the three plant materials were also effectively used to detect genomic DNA derived from all Rhizoctonia spp. obtained from Myanmar. Rice segment was the most successful materials for detection of fungal cell lipids including palmitic, stearic and linoleic acids. The results of this experiment demonstrate that bait plant materials of rice, mat rush and cotton were the best useful tools for not only direct isolation, but also fungal DNA diagnosis and cell lipid assay of Myanmar soil environmental conditions.     

Integrated control of apple pests in New Zealand

A technique is described whereby 5th‐instar larvae of the codling moth (Laspeyresia pomonella) which have finished feeding can be tagged externally with cobalt‐58 and released on apple trees, where they seek cocooning sites. Two μCi ⁵⁸Co per insect did not significantly affect larval survival in the field, or subsequent pupation, emergence, mating, and oviposition in the laboratory. Tagging was more efficient than whole‐tree scraping for the location of cocoons, and was non‐destructive of both the insects and their cocooning sites.

Relocation and observation of the tagged larvae in their cocoons permitted accurate estimation of mortality from when they left the fruit (= release) until adult emergence in the following spring. Natural mortality of larvae seeking cocooning sites was attributed mainly to insect predators, and varied significantly between trees and blocks, averaging 57% over 6 years. Avian predation by the silvereye (Zosterops lateralis) was the greatest hazard to cocooned larvae; this, too, varied significantly between blocks, and averaged 53% over the same period. Both mortalities appeared to be density‐related.     

Self-Diffusion in Electrostatically Stabilized Colloidal Suspensions Using Brownian Dynamics

Abstract

Brownian dynamics is applied to suspended colloidal particles interacting through a screened Coulombic pair potential in the dilute region where the hydrodynamics is approximated by Stokes drag. Calculated properties include the osmotic pressure, the radial distribution function, and the self-diffusion coefficient. Verification is obtained by comparing the results to independently evaluated properties. Self-diffusion coefficicents are compared to approximate theories in the literature. The self-diffusion coefficient is observed to depend strongly on the local structure but only slightly on the longer range structure.     

Incorporation of dimethoxycurcumin into charged liposomes and the formation kinetics of fractal aggregates of uncharged vectors

Abstract

Dimethoxycurcumin (DMC) is a lipophilic analog of curcumin found in Curcuma longa Linn., which is known to possess significant activity against various cancer cell lines. The purpose of this study was to develop suitable liposomal formulations in order to overcome DMC’s poor water solubility and to study the aggregation kinetic profile using the fractal analysis. DMC was incorporated into liposomal formulations composed of DPPC, DPPC:DPPG:chol (9:1:1 molar ratio) and DPPC:DODAP:chol (9:1:1 molar ratio) liposomes. Light scattering techniques were used to elucidate the physicochemical parameters of the liposomal formulations with and without DMC. The structural characteristics of the incorporated molecule were found to be crucial and promote the aggregation mechanism depending also on the liposomes’ composition. The results of our study contribute to the overall scientific efforts to prepare efficient carriers for DMC and could be a useful tool in order to study more efficiently the kinetics of the aggregation process of the liposomal carriers.     

Preparative Separation of Enantiomers Based on Functional Nucleic Acids Modified Gold Nanoparticles

The preparative‐scale separation of chiral compounds is vitally important for the pharmaceutical industry and related fields. Herein we report a simple approach for rapid preparative separation of enantiomers using functional nucleic acids modified gold nanoparticles (AuNPs). The separation of _DL‐tryptophan (_DL‐Trp) is demonstrated as an example to show the feasibility of the approach. AuNPs modified with enantioselective aptamers were added into a racemic mixture of _DL‐Trp. The aptamer‐specific enantiomer (_L‐Trp) binds to the AuNPs surface through aptamer‐_L‐Trp interaction. The separation of _DL‐Trp is then simply accomplished by centrifugation: the precipitate containing _L‐Trp bounded AuNPs is separated from the solution, while the _D‐Trp remains in the supernatant. The precipitate is then redispersed in water. The aptamer is denatured under 95 °C and a second centrifugation is then performed, resulting in the separation of AuNPs and _L‐Trp. The supernatant is finally collected to obtain pure _L‐Trp in water. The results show that the racemic mixture of _DL‐Trp is completely separated into _D‐Trp and _L‐Trp, respectively, after 5 rounds of repeated addition of fresh aptamer‐modified AuNPs to the _DL‐Trp mixture solution. Additionally, the aptamer‐modified AuNPs can be repeatedly used for at least eight times without significant loss of its binding ability because the aptamer can be easily denatured and renatured in relatively mild conditions. The proposed approach could be scaled up and extended to the separation of other enantiomers by the adoption of other enantioselective aptamers. Chirality 25:751–756, 2013. © 2013 Wiley Periodicals, Inc.