Study on the method of microelectrodes implantation of artificial facial nerve prosthesis in closed mouth of orbicularis oris muscle in monkeys with facial nerve paralysis / 中华口腔医学杂志

Objective@#To explore the optimal method of microelectrode implantation that can produce efficient mouth closure with microelectrode for orbicularis oris muscle (OOM) in rhesus monkeys with unilateral peripheral facial paralysis (UPFP) in order to provide basis for the research and development of artificial facial nerve prosthesis (AFNP).@*Methods@#Right lateral peripheral facial paralysis model on four healthy rhesus monkeys (two males and two femles, aged 5-6 years, weighed 2.0-3.0 kg) were prepared. AFNP electric stimulation was used to induce closed-mouth reaction of the affected OOM with a one-way rectangular pulse, 50 Hz frequency and 0.2 ms pulse width in vitro. Around the affected lateral OOM, four stimulus electrodes implantation positions were selected at the upper lip (position A), the lower lip (position B), the connection with the corner of the mouth to the ipsilateral tragus (position C), and the horizontal line of the mouth angle (position D). According to the different implantation positions of three stimulation electrodes on the stimulation side of AFNP and the results of our previous study, six groups of microelectrode implantation methods were designed. In Group A, two microelectrodes were implanted at position A and one microelectrode was implanted at position B; in Group B, one microelectrode was implanted at position A, B and C respectively; in Group C, one microelectrode was implanted at position A and two microelectrodes were implanted at position B; in Group D, one microelectrode was implanted at position A, B and D respectively; in Group E, one microelectrode was implanted at position A, C and D respectively; in Group F, one microelectrode was implanted at position B, C and D respectively. The minimum stimulating current (threshold current) required for effective mouth closure were recorded. The threshold and peak current values were compared using one-way ANOVA and LSD-t multiple comparisons.@*Results@#The microelectrodes of the AFNP stimulating side in Group E and F failed to induce a smooth mouth closure. The microelectrodes in A, B, C and D group induced smooth mouth closure. The threshold current value of OOM contraction on affected side in the Group A, B, C, and D were (1.35±0.05), (1.02±0.04), (1.40±0.04) and (1.10±0.02) mA, respectively (F=295.302, P<0.001), with the lowest value in Group B and there was significant difference between the current value in Group B and those in the other groups (all P<0.05). The peak current value of OOM contraction on affected side in the four groups were (3.95±0.02), (2.95±0.03), (3.99±0.05) and (3.51±0.01) mA, respectively (F=1 014.985, P<0.001). Group B showed the best lip-closure morphology observed with naked eyes.@*Conclusions@#When three output microelectrode of the AFNP stimulated side are separately imbedded into the upper lip, the lower lip and the connection with the corner of the mouth to the ipsilateral tragus, AFNP can sufficiently induce closed-mouth reaction. These positions are suitable as priority options microelectrodes implantation positions for the microelectrodes of the AFNP stimulated side.

Separation, purification and antioxidant activity of polysaccharide from Coprinus comatus / 生物工程学报

We compared the ways of deproteinization for crude polysaccharides of Coprinus comatus, and finally selected Sevage method as the optimal method. Two main fractions of Ccp-I-A and Ccp-I-B were obtained after DEAE-52 cellulose and Sephadex G-200 chromatography, both were white-floc, soluble in water, insoluble in absolute ethyl alcohol, acetone and other organic solvents. Additionally, Fehling reagent, CTAB, Sulphuric acid-carbazole, I-KI and FeCl₃ reaction were all negative. GC analysis showed Ccp-I-A was composed of mannitose, glucose and galactose in molar ratios of 2.03:9.52:1, whereas Ccp-I-B was composed of fucose and galactose with molar ratios of 1:5.21. Antioxidant activity test showed that Ccp-I-A and Ccp-I-B had good scavenging abilities on DPPH and ·OH. Compared to Ccp-I-B,the scavenging activity of Ccp-I-A was much stronger, and the scavenging rate could reach 72.1% and 55.3% respectively when the concentration was 300 μg/mL.

A cascade of recently discovered molecular mechanisms involved in abiotic stress tolerance of plants.

Today, agriculture is facing a tremendous threat from the climate change menace. As human survival is dependent on a constant supply of food from plants as the primary producers, we must aware of the underlying molecular mechanisms that plants have acquired as a result of molecular evolution to cope this rapidly changing environment. This understanding will help us in designing programs aimed at developing crop plant cultivars best suited to our needs of a sustainable agriculture. The field of systems biology is rapidly progressing, and new insight is coming out about the molecular mechanisms involved in abiotic stress tolerance. There is a cascade of changes in transcriptome, proteome, and metabolome of plants during these stress responses. We have tried to cover most pronounced recent developments in the field of "omics" related to abiotic stress tolerance of plants. These changes are very coordinated, and often there is crosstalk between different components of stress tolerance. The functions of various molecular entities are becoming more clear and being associated with more precise biological phenomenon.

Pistil drip following pollination: a simple in planta Agrobacterium-mediated transformation in cotton.

Transgenic cotton plants were developed by pistil drip inoculation in a solution containing Agrobacterium carrying a gene for resistance to the herbicide Basta (bar), 10% (w/v) sucrose, 0.05% (v/v) Silwet L-77 and 40 mg acetosyringone l(-1). Pistil drip during 17:00-19:00 on the first day of flowering resulted in 0.07-0.17% Basta-resistant plants/number of viable seeds generated, and stigma excision prior to pistil drip during this time period gave rise to a transformation efficiency of 0.46-0.93%, in contrast with 0.04-0.06% generated from pistil drip during 9:00-11:00 on the second day of flowering. PCR and Southern blot analysis confirmed the integration of the bar gene into the cotton genome, and a T1 and T2 generation herbicide resistance test consistently revealed expression and stable heritability of the bar gene in the two generations.

Molecular cloning and characterization of a cytosolic glutamine synthetase gene, a fiber strength-associated gene in cotton.

An expressed sequence tag encoding glutamine synthetase (GS) was identified by microarray-based hybridization using fiber mRNAs of allotetraploid Gossypium hirsutum, 7235, a super quality property germplasm line, and TM-1, a genetic standard in G. hirsutum. Northern-blot analysis verified transcript accumulation differences in 8 DPA fibers (including ovules) in the two varieties. The full-length cDNA encoding GS in 7235 was isolated and named GhGS. Sequence analysis revealed that the GhGS was similar to cytosolic GS. Southern-blot analysis showed that tetraploid cotton contained at least one copy of the A sub-genome and the D sub-genome. Genomic GhGS sequences were subsequently isolated from different varieties, TM-1, 7235 and two diploid progenitor cottons, G. herbaceum (A-genome) and G. raimondii (D-genome). Molecular mapping and single-marker analysis revealed that the GhGS was significantly correlated with fiber strength and was mapped to chromosome D7. Additionally, GS activities and total protein of the ovules and the fibers were assayed. The results showed a significantly higher GS activity in 7235 seeds compared to TM-1 seeds at 5 and 8 DPA. Also significant differences were found in total protein content and seed weight at 11 DPA. This suggested that GS promoted the seed-forming process by providing N. On the other hand, in fibers, GS activity and total protein assay indicated a lower total GS activity and longer fiber elongation period in 7235. These results suggest that the respective roles of the GS in ovules and fibers do not completely overlap.