Clinical and Radiographic Outcomes of Modified Posterior Atlantoaxial Temporary Fixation with Preservation of Semispinalis Cervicis: A Comparative Study

STUDY DESIGN

Retrospective study.

OBJECTIVE

Current studies suggested that the posterior cervical deep muscles should be preserved during the atlantoaxial posterior approach. This study aimed to modify the conventional temporary posterior fixation by preserving the semispinalis cervicis and to evaluate the radiographic and clinical outcomes compared with the conventional technique.

METHODS

Applied anatomical and imaging study were assessed prior to the clinical studies. Thirty patients with odontoid fracture were enrolled. 12 patients underwent modified operation with preservation of semispinalis cervicis (Group P-SSC), and 18 patients underwent conventional approach with detachment of the semispinalis cervicis (Group D-SSC) as controls. Clinical and radiological assessments were evaluated postoperatively, including activities of daily living (ADL), axial symptom scoring system (Ass), cervical range of motion (ROM), and the average atrophy rate of muscles.

RESULTS

All patients experienced fracture healed within 10 months after temporary fixation. At early follow-up, ADL accompanying extension and flexion were significantly different between the two groups. The Ass scores in the Group P-SSC were constantly higher than that in Group D-SSC. Flexion-Extension ROM in Group P-SSC was significantly larger than that of Group D-SSC. The average atrophy rate at the C3 and C5 level in Group P-SSC was 7.62±3.38% and 7.55±3.89%, repectivcly, while 15.67±5.97% and 8.56±4.76% in Group D-SSC, respectively. Significant differences in the atrophy rate were found between groups at C3 level.

CONCLUSIONS

Compared with the conventional technique, the modified surgical technique with preservation of semispinalis cervicis was effective in improving axial symptoms, decreasing the atrophy rate of muscles, and increasing the cervical ROM.

Injectable, In Situ Self-cross-linking, Self-healing Poly(l-glutamic acid)/Polyethylene Glycol Hydrogels for Cartilage Tissue Engineering

Injectable hydrogels have drawn much attention in the field of tissue engineering because of advantages such as simple operation, strong plasticity, and good biocompatibility and biodegradability. Herein, we propose the novel design of injectable hydrogels via a Schiff base cross-linking reaction between adipic dihydrazide (ADH)-modified poly(l-glutamic acid) (PLGA-ADH) and benzaldehyde-terminated poly(ethylene glycol) (PEG-CHO). The effects of the mass fraction and the molar ratio of -CHO/-NH₂ on the gelation time, mechanical properties, equilibrium swelling, and in vitro degradation of the hydrogels were examined. The PLGA/PEG hydrogels cross-linked by dynamic Schiff base linkages exhibited good self-healing ability. Additionally, the PLGA/PEG hydrogels had good biocompatibility with bone marrow-derived mesenchymal stem cells (BMSCs) and could effectively support BMSC proliferation and deposition of glycosaminoglycans and upregulate the expression of cartilage-specific genes. In a rat cartilage defect model, PLGA/PEG hydrogels significantly promoted new cartilage formation. The results suggest the prospect of the PLGA/PEG hydrogels in cartilage tissue engineering.

Injectable macro-porous chitosan/polyethylene glycol-silicotungstic acid double-network hydrogels based on "smashed gels recombination" strategy for cartilage tissue engineering

The lack of interconnected macro-porous structure of most injectable hydrogels lead to poor cell and tissue infiltration. Herein, we present the fabrication of injectable macro-porous hydrogels based on "smashed gels recombination" strategy. Chitosan/polyethylene glycol-silicotungstic acid (CS/PEG-SiW) double-network hydrogels were prepared via dual dynamic interactions. The bulk CS/PEG-SiW hydrogels were then smashed into micro-hydrogels with average sizes ranging from 47.6 to 63.8 μm by mechanical fragmentation. The CS/PEG-SiW micro-hydrogels could be continuously injected and rapidly recombined into a stable porous hydrogel based on the dual dynamic interactions between micro-hydrogels. The average pore size of the recombined porous CS/PEG-SiW hydrogels ranged from 52 to 184 μm. The storage modulus, compress modulus and maximum compressive strain of the recombined porous CS/PEG-SiW_1.0 hydrogels reached about 47.2 %, 28.2 % and 127.6 % of the values for their corresponding bulk hydrogels, respectively. The recombined porous hydrogels were cytocompatible and could effectively support proliferation and chondrogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). In a rat cartilage defect model, recombined porous CS/PEG-SiW hydrogels could promote cartilage regeneration. Hematoxylin and eosin (H&E), Safranin-O/Fast green and immunohistochemical staining confirmed the accumulation of glycosaminoglycans (GAG) and type II collagen (Col II) in regenerated cartilage.

Plant functional traits shape growth rate for xerophytic shrubs

Trade-offs exist for xerophytic shrubs between functional traits, involving in water loss and assimilate accumulation, can contribute to its survival and growth rate regulation in arid environments. However, growth analysis based on plant functional traits has been focused on the study of herbs and woody species. It is still unclear how the functional traits of xerophytic shrubs regulate their growth rate. In this study, we selectedeight xerophytic shrubs as samples to analyze the regulation process of the functional traits of shrubs on growth rate. Plants were cultivated for three years, and three harvests (every one year) were carried out. Factors explaining between-species differences in relative growth rate (RGR) varied, depending on whether different ages were considered. The results showed that RGR was positively correlated with net assimilation rate, but there was a significant negative correlation with leaf area ration (LAR), specific leaf area (SLA), and leaf biomass ratio in the age 1. However, in the age 2, RGR showed a significant positive correlation with the morphological traits (i.e., leaf area ration and specific leaf area), but not with physiological traits (i.e., net assimilation rate) and leaf biomass allocation. Our results suggested that the fluctuation of environmental factors affects the regulation path of the plant functional traits on RGR of xerophytic shrubs. However, the analysis of causality model showed that no matter in which age, net assimilation rate and leaf area ration principally drive the variation in RGR among xerophytic shrubs.

Treatment of thoracolumbar fractures by temporary posterior instrumentation with selective fusion schemes

OBJECTIVE

This retrospective study investigated the clinical and radiographic outcomes following temporary transpedicular posterior instrumentation between two cohorts of patients with thoracolumbar fractures (TLF) who underwent selective or bi-segments intervertebral articular process fusion.

METHODS

Patients with TLF who underwent the temporary posterior fixation with selective fusion (Group SF), or bi-segments fusion (Group BF) were studied. Superior intervertebral articular process and interlaminar fusion were performed in Group SF, whereas in Group BF, the patients underwent bi-segments fusion in both superior and inferior articular processes, as well as interlaminar fusion. We measured the distal and proximal intervertebral mobility, regional kyphotic angle, and vertebral height before and after surgery in both groups. Greenough Low-Back Outcome Score was used to assess the clinical outcomes.

RESULTS

Sixty-five patients with TLF from T12 to L2 fractures were enrolled in the study period: 33 patients in the Group SF and 32 patients in the Group BF. All the patients experienced fracture healing (mean follow-up time: 19.7 months). The mean postoperative functional outcomes were 65.0 ± 2.0 points for the Low-Back Outcome Score in the Group SF and 65.2 ± 1.8 for the Group BF. A progressive regional kyphotic angle was observed with time regardless of fusion but was not significantly different between the two groups. There was a statistical difference between unfused inferior proximal adjacent and inferior distal adjacent segment regardless of fracture segments.

CONCLUSIONS

The strategy of selective fusion is reported to be useful for the treatment of patients with TLF. The motion in the un-fused and adjacent segment could be better regained after instrumentation removal in the selective fusion group.

LEVEL OF EVIDENCE

Level 3.

Mussel-Inspired Bisphosphonated Injectable Nanocomposite Hydrogels with Adhesive, Self-Healing, and Osteogenic Properties for Bone Regeneration

Injectable hydrogels have received much attention because of the advantages of simulation of the natural extracellular matrix, microinvasive implantation, and filling and repairing of complex shape defects. Yet, for bone repair, the current injectable hydrogels have shown significant limitations such as the lack of tissue adhesion, deficiency of self-healing ability, and absence of osteogenic activity. Herein, a strategy to construct mussel-inspired bisphosphonated injectable nanocomposite hydrogels with adhesive, self-healing, and osteogenic properties is developed. The nano-hydroxyapatite/poly(l-glutamic acid)-dextran (nHA/PLGA-Dex) dually cross-linked (DC) injectable hydrogels are fabricated via Schiff base cross-linking and noncovalent nHA-BP chelation. The chelation between bisphosphonate ligands (alendronate sodium, BP) and nHA favors the uniform dispersion of the latter. Moreover, multiple adhesion ligands based on catechol motifs, BP, and aldehyde groups endow the hydrogels with good tissue adhesion. The hydrogels possess excellent biocompatibility and the introduction of BP and nHA both can effectively promote viability, proliferation, migration, and osteogenesis differentiation of MC3T3-E1 cells. The incorporation of BP groups and HA nanoparticles could also facilitate the angiogenic property of endothelial cells. The nHA/PLGA-Dex DC hydrogels exhibited considerable biocompatibility despite the presence of a certain degree of inflammatory response in the early stage. The successful healing of a rat cranial defect further proves the bone regeneration ability of nHA/PLGA-Dex DC injectable hydrogels. The developed tissue adhesive osteogenic injectable nHA/PLGA-Dex hydrogels show significant potential for bone regeneration application.

Knockdown of long non-coding RNA VIM-AS1 inhibits glioma cell proliferation and migration, and increases the cell apoptosis via modulation of WEE1 targeted by miR-105-5p

OBJECTIVE

Glioma including glioblastoma is the main type of primary brain tumors worldwide. LncRNAs have participated in glioma formation. This study aims to investigate the underlying mechanism for VIM-AS1/miR-105-5p/WEE1 signaling in glioma.

PATIENTS AND METHODS

The clinical tumors and adjacent tissues were collected from 24 patients with glioma in the Shang Luo Central Hospital. Then, the clinical samples were subjected to hematoxylin-eosin staining (H&E). VIM-AS1, miR-105-5p, and WEE1 levels were measured using real-time PCR. The protein levels of WEE1, Cyclin A1, PCNA, N-cadherin, Vimentin, and Bcl-2, E-cadherin, and Bax were analyzed using Western blot. The overall survival of glioma patients was evaluated using the Kaplan-Meier analysis. The interaction between VIM-AS1 and miR-105-5p was determined using RIP assay and Dual-Luciferase reporter assay, and the binding between miR-105-5p and WEE1 was also detected by Dual-Luciferase reporter assay. Cell proliferation, colony formation, cell cycle, apoptosis, and migration were confirmed using CCK-8, colony formation assay, flow cytometry, and transwell assay, respectively.

RESULTS

VIM-AS1 was elevated in cancer tissues, and high level of VIM-AS1 was positively correlated with poor overall survival. Then, VIM-AS1 could bind to and downregulate miR-105-5p. Furthermore, the knockdown of VIM-AS1 significantly suppressed tumor growth in vivo. The knockdown of VIM-AS1/overexpression of miR-105-5p inhibited glioma cell growth, colony formation, and migration, and enhanced the cell apoptosis by inhibiting expression of Cyclin A1, PCNA, Vimentin, N-cadherin, and Bcl-2, and by increasing the expression of Bax and E-cadherin. Interestingly, the overexpression of VIM-AS1 reversed the tumor-suppressing role of miR-105-5p in glioma cells. Besides, the expression of WEE1 was synergistically regulated by VIM-AS1 and miR-105-5p. Consequently, VIM-AS1 promoted glioma progression via upregulating WEE1 or downregulating miR-105-5p.

CONCLUSIONS

VIM-AS1/miR-105-5p/WEE1 signaling may be a promising target for glioma treatment.

[The reference intervals of thyroid functional indicators in pregnant population in Xi'an]

To establish reference intervals for thyroid functional indicators in early (T1), mid-term (T2), and late stage (T3) pregnancy in a population of women in Northwestern China. A cross-sectional study was conducted on 620 pregnant women. Subjects were recruited through a questionnaire where apparently healthy women were selected. Serum thyroid stimulating hormone (TSH3), total triiodothyronine (TT3), total thyroid hormone (TT4), free triiodothyronine (FT3), and free thyroid hormone (FT4) were detected using the Beckman Unicel DXI 800 automatic chemiluminescence analyzer (the third-generation TSH detection reagent for TSH3),and the reference intervals of different gestation periods were established. The results showed that the reference intervals of TSH3 in T1, T2, and T3 were 0.05-4.59, 0.61-6.01, and 0.63-4.78 mIU/L, respectively; TT3 were 1.62-2.97 nmol/L, 1.59-2.95 nmol/L, and 1.45-2.70 nmol/L, respectively; TT4 were 95.49-185.00 nmol/L, 92.70-181.54 nmol/L, and 77.93-155.09 nmol/L, respectively; FT3 were 3.18-5.22 pmol/L, 2.78-4.67 pmol/L, and 2.51-4.18 pmol/L, respectively; and FT4 were 7.72-12.97 pmol/L, 6.90-1.09 pmol/L, and 5.63-9.85 pmol/L, respectively. All thyroid function indexes had statistically significant differences between the three stages of pregnancy (TSH:H=30.879,P<0.01;FT3:H =153.827,P<0.01;FT4:H =229.967,P<0.01;TT3:H =36.484,P<0.01;TT4:H =58.531,P<0.01). 20 independent samples were collected to verify the reference intervals of TSH, FT3, FT4, TT3 and TT4 for three trimesters of pregnancy, and all of them passed.

[Radial artery thrombosis in optical coherence tomography guided transradial coronary angiography and percutaneous coronary intervention in acute coronary syndrome patients and its risk factors analysis]

Objective: To observe the radial artery thrombosis (RAT) during transradial coronary angiography (CAG) and/or percutaneous coronary intervention (PCI) by optical coherence tomography (OCT), and to investigate the risk factors of RAT during the CAG and/or PCI. Methods: In this retrospective study, we consecutively reviewed the radial artery OCT examination results of the patients who underwent OCT guided transradial CAG and/or PCI for acute coronary syndrome in heart center of Beijing Luhe hospital, Capital Medical University from October 2017 to July 2018. The incidence of RAT was observed. The patients were divided into the RAT group and non-RAT group, clinical data were collected and compared. Moreover, the types and distributions of thrombus in radial artery as well as the acute radial artery injuries under OCT were observed. Univariate analysis followed by multivariate analysis were performed to identify potential risk factors. The radial artery patency and ischemic symptoms of the involved limb were followed up at the 24-hour and the 1-month after procedure. Results: A total of 107 patients were included, the age was (58.1±12.5), and 78.5% were male (n=84). The incidence of RAT was 26.2% (n=28, 95%CI 17.9%-34.5%), and the main type of thrombus was white thrombus (n=15, 53.6%). The commonest position of RAT was the proximal portion of radial artery (n=17, 60.7%). The median thrombus volume was 0.05(0.03, 0.38) mm3, and the median thrombus score was 6.5 (3.3, 13.8). In univariate analysis, the frequency of acute radial artery injury and use of bivalirudin were significantly higher and the procedure time was significantly longer in RAT group than those in non-RAT group (all P<0.05). Multivariate regression analysis showed that the radial artery acute injury (OR=5.82, 95%CI: 2.09-16.20, P=0.001) and the procedure time (OR=1.04, 95%CI: 1.01-1.06, P=0.006) were independent risk factors of RAT. Rate of radial artery occlusion at 24 hours follow-up was similar between RAT and non-RAT group (7.14%(2/28), vs. 10.13%(8/79), P=1.000). None of the patients complicated severe ischemic symptom of the operative limb. Conclusions: RAT is a high frequency access complication during transradial coronary intervention. This phenomenon can be accurately observed by OCT. Acute radial artery injury and prolonged procedure time are risk factors of RAT during transradial coronary intervention.

Effect of phosphorus efficiency on elemental stoichiometry of two shrubs

Phosphorus (P) is an important nutrient that can restrict plant growth. However, the influence of P deficiency on elemental homeostasis and application of the growth rate hypothesis in higher plants remain to be assessed. Two shrubs, Zygophyllum xanthoxylum and Nitraria tangutorum, were used as experiment material and subjected to five P addition treatments: 0, 17.5, 35.0, 52.5 and 70.0 mg P·kg^-1 soil. The biomass and relative growth rate of Z. xanthoxylum did not change with altered P supply. There was no significant difference in P concentration among the treatments for Z. xanthoxylum, but N. tangutorum showed an upward trend. The P stoichiometric homeostasis of Z. xanthoxylum was higher than that of N. tangutorum. For Z. xanthoxylum, available P in the rhizosphere improved significantly under extreme P deficiency conditions, and P concentrations in all treatments were lower than in N. tangutorum, showing that Z. xanthoxylum had stronger P absorption and P utilization capacity. No relationships between growth rate and C:N:P ratios were found in Z. xanthoxylum. The strong P efficiency, and high and stable dry matter accumulation, are likely contributors in maintaining stoichiometric homeostasis. In addition, the relatively high biomass accumulation and high P utilization efficiency for Z. xanthoxylum does not support the growth rate hypothesis for this species.

Sensitivity of resonance properties of all-dielectric multilayers driven by statistical fluctuations

In photonics and emerging fields of quantum and topological materials, increasing demands are placed upon the state and control of electromagnetic fields. Dielectric multilayer materials may be designed and optimized to possess extremely sharp spectral and angular photonic resonances allowing for the creation of fields orders of magnitude larger than the exciting field. With enhancements of 10⁴ and higher, the extreme nature of these resonances places high constraints on the statistical properties of the physical and optical characteristics of the materials. To what extent the spectral and angular shifts occur as a result of fluctuations in the refractive indices and morphologies of the involved low-loss subdomains have not been considered previously. Here, we present how parameter variations such as those caused by fluctuations in deposition rate, yielding bias, random and compensated errors, may affect the resonance properties of low-loss all-dielectric stacks.

Responses of leaf C:N:P stoichiometry to water supply in the desert shrub Zygophyllum xanthoxylum

Based on the elemental composition of major biochemical molecules associated with different biological functions, the 'growth rate hypothesis' proposed that organisms with a higher growth rate would be coupled to lower C:N, especially lower C:P and N:P ratios. However, the applicability of the growth rate hypothesis for plants is unclear, especially for shrubs growing under different water supply. We performed an experiment with eight soil moisture levels (soil water content: 4%, 6%, 8%, 13%, 18%, 23%, 26% and 28%) to evaluate the effects of water availability on leaf C:N:P stoichiometry in the shrub Zygophyllum xanthoxylum. We found that leaves grew slowly and favored accumulation of P over C and N under both high and low water supply. Thus, leaf C:P and N:P ratios were unimodally related to soil water content, in parallel with individual leaf area and mass. As a result, there were significant positive correlations between leaf C:P and N:P with leaf growth (u). Our result that slower-growing leaves had lower C:P and N:P ratios does not support the growth rate hypothesis, which predicted a negative association of N:P ratio with growth rate, but it is consistent with recent theoretical derivations of growth-stoichiometry relations in plants, where N:P ratio is predicted to increase with increasing growth for very low growth rates, suggesting leaf growth limitation by C and N rather than P for drought and water saturation.

Exposure to electromagnetic fields aboard high-speed electric multiple unit trains

High-speed electric multiple unit (EMU) trains generate high-frequency electric fields, low-frequency magnetic fields, and high-frequency wideband electromagnetic emissions when running. Potential human health concerns arise because the electromagnetic disturbances are transmitted mainly into the car body from windows, and from there to passengers and train staff. The transmission amount and amplitude distribution characteristics that dominate electromagnetic field emission need to be studied, and the exposure level of electromagnetic field emission to humans should be measured. We conducted a series of tests of the on board electromagnetic field distribution on several high-speed railway lines. While results showed that exposure was within permitted levels, the possibility of long-term health effects should be investigated.

Wettability modified nanoporous ceramic membrane for simultaneous residual heat and condensate recovery

Recovery of both latent heat and condensate from boiler flue gas is significant for improving boiler efficiency and water conservation. The condensation experiments are carried out to investigate the simultaneous heat and mass transfer across the nanoporous ceramic membranes (NPCMs) which are treated to be hydrophilic and hydrophobic surfaces using the semicontinuous supercritical reactions. The effects of typical parameters including coolant flow rate, vapor/nitrogen gas mixture temperature, water vapor volume fraction and transmembrane pressure on heat and mass transfer performance are studied. The experimental results show that the hydrophilic NPCM exhibits higher performances of condensation heat transfer and condensate recovery. However, the hydrophobic modification results in remarkable degradation of heat and condensate recovery from the mixture. Molecular dynamics simulations are conducted to establish a hydrophilic/hydrophobic nanopore/water liquid system, and the infiltration characteristics of the single hydrophilic/hydrophobic nanopore is revealed.

The effect of surface wettability on water vapor condensation in nanoscale

The effect of surface wettability on condensation heat transfer in a nanochannel is studied with the molecular dynamics simulations. Different from the conventional size, the results show that the filmwise mode leads to more efficient heat transfer than the dropwise mode, which is attributed to a lower interfacial thermal resistance between the hydrophilic surface and the condensed water compared with the hydrophobic case. The observed temperature jump at the solid-liquid surface confirms that the hydrophilic properties of the solid surface can suppress the interfacial thermal resistance and improve the condensation heat transfer performance effectively.

Transcriptome comparison between inactivated and activated ovaries of the honey bee Apis mellifera L

Ovarian activity not only influences fertility, but is also involved with the regulation of division of labour between reproductive and behavioural castes of female honey bees. In order to identify candidate genes associated with ovarian activity, we compared the gene expression patterns between inactivated and activated ovaries of queens and workers by means of high-throughput RNA-sequencing technology. A total of 1615 differentially expressed genes (DEGs) was detected between ovaries of virgin and mated queens, and more than 5300 DEGs were detected between inactivated and activated worker ovaries. Intersection analysis of DEGs amongst five libraries revealed that a similar set of genes (824) participated in the ovary activation of both queens and workers. A large number of these DEGs were predominantly related to cellular, cell and cell part, binding, biological regulation and metabolic processes. In addition, over 1000 DEGs were linked to more than 230 components of Kyoto Encyclopedia of Genes and Genomes pathways, including 25 signalling pathways. The reliability of the RNA-sequencing results was confirmed by means of quantitative real-time PCR. Our results provide new insights into the molecular mechanisms involved in ovary activation and reproductive division of labour.

Effects of perilla extract on productive performance, serum values and hepatic expression of lipid-related genes in Shaoxing ducks

1. The aim of this study was to identify the effect of perilla extract, a source of polyunsaturated fatty acids, on lipid metabolism and expression of lipid-related genes in livers of Shaoxing ducks. 2. Two hundred and forty 28-week-old laying ducks received a commercial diet with perilla extract added at 0 (control) or 200 mg/kg of feed. 3. Ducks fed on a diet with perilla extract had increased laying rates compared with control ducks. 4. Serum concentrations of triglycerides were reduced by perilla extract, while high-density lipoprotein cholesterol and total serum cholesterol increased. 5. The expression of genes involved in hepatic lipogenesis, sterol regulatory element-binding protein-1, acetyl CoA carboxylase, stearoyl CoA desaturase, fatty acid synthase, apolipoprotein B, and apolipoprotein very low density lipoprotein, were decreased in the perilla group. 6. The mRNA expression of peroxisome proliferators-activated receptor alpha and acyl-coenzyme A oxidase was enhanced following treatment with perilla extract, and a similar tendency was observed in the expression of liver fatty acid-binding protein. 7. The results show that a diet with 200 mg/kg perilla extract regulated fat metabolism of Shaoxing ducks by improving egg laying, altering serum lipid profiles, stimulating lipid catabolic gene expression and inhibiting lipogenic gene expression in the liver.

Mesenchymal stroma cells improve hyperglycemia and insulin deficiency in the diabetic porcine pancreatic microenvironment

BACKGROUND

Stem cell differentiation is controlled by extracellular cues from the environment and by intrinsic genetic programs within the stem cell. The present study aimed to explore whether mesenchymal stromal cells (MSC) could improve hyperglycemia and insulin production in the diabetic microenvironment.

METHODS

We transplanted male porcine bone marrow-derived EGFP-expressing MSC directly into female diabetic porcine pancreas by multi-point injection. Enzyme-linked immunosorbent assay (ELISA) and fluorescent immunohistochemistry were used to analyze recipients' sera and pancreas tissues for assessment of the therapeutic effect.

RESULTS

Blood glucose levels decreased gradually in MSC-treated recipients from 15 days after the transplantation compared with untreated diabetic controls (15.94+/-0.31 mmol/L versus 16.66+/-0.11 mmol/L; P=0.01). Blood insulin increased and glucagons decreased notably in recipients from 2 weeks post-transplantation compared with untreated diabetic controls (0.049+/-0.004 microg/L versus 0.037+/-0.02 microg/L and 392.9+/-20.3 ng/L versus 433.1+/-27.6 ng/L). Hematoxylin and eosin (HE)-stained sections demonstrated that the number of islets from each section was markedly increased in recipients compared with that of diabetic controls (10.9+/-2.2 versus 4.6+/-1.4; P<0.05) and similar to that of normal controls (10.9+/-2.2 versus 12.6+/-2.6; P>0.05). The newly formed islets were smaller than normal islets (47.2+/-19.6 microm versus 119.6+/-27.7 microm; P<0.05). Analysis of pancreatic sections for EGFP in recipients indicated that the transplanted MSC survived within the pancreas. Insulin immunoreactivity of pancreatic islets showed that the newly formed islets expressed insulin.

DISCUSSION

MSC could improve diabetes upon pancreatic microenvironment without obvious immune rejections. This has theoretical and clinical applications.

Mesenchymal stem cells contribute to insulin-producing cells upon microenvironmental manipulation in vitro

BACKGROUND

Extracellular microenvironment and intrinsic genetic programs determine the fate of stem cells. We observed whether mesenchymal stem cells (MSCs) contributed to insulin-producing cells in a manipulated microenvironment.

METHODS

We delivered pancreatic pieces into Niobium-Coated Dynamatrix to construct a simulated pancreatic microenvironment, upon which soluble cytokine exchange and direct cell-cell contact between MSCs and pancreatic cells could occur. Bone marrow-derived MSCs were cultured upon the microenvironment. Differentiated isletlike cells were observed under an inverted microscope. Insulin in supernates was measurement by enzyme-linked immunosorbent assay. Insulin and c-peptide expression were verified by fluorescent immunocytochemistry and fluorescence in situ hybridization. Apoptosis of isletlike masses in high-glucose DMEM was detected by FACS.

RESULTS

After 3 to 4 weeks in culture, typical isletlike masses were observed. Insulin secreted by differentiated cells (414.47+/-30.30 mIU/L) was much greater than that of undifferentiated cells (4.89+/-1.01 mIU/L; P<.05). Insulin and c-peptide expression were positive both in protein and mRNA levels. The transdifferentiated isletlike mass did not undergo apoptosis after another 3 weeks of culture in high-glucose DMEM.

CONCLUSION

This simulated injury microenvironment without induction guided MSCs to functional isletlike cells hopefully to replace beta cells.

[Effects of activin and follistatin on FSH receptor mRNA expression of cultured Shao duck granulosa cells]

The aim of this study was to investigate the action of activin and follistatin either alone or in combination on FSH receptor mRNA expression. The results showed that activin alone increased FSH receptor mRNA level in the presence or absence of FSH in cultured granulosa cells, and the stimulating effect of activin on FSH receptor level was dose-dependent. This effect of activin was inhibited by FSP treatment which alone had no effect on FSH receptor expression. From the results, it can be concluded that activin and follistatin both exert autocrine actions on granulosa cells, and the two factors, possibly by regulating FSH receptor expression, may play important roles in follicular development.

[Expression pattern of mRNA for follistatin and inhibin/activin beta B-subunit during follicular and testicular development in duck]

Follistatin and inhibin/activin were closely related glycoprotein hormones. The quantitative competitive RT-PCR was used to investigate the expression of follistatin and inhibin/activin beta B-subunit mRNA in the developing ovarian follicles, immature and mature testes. The results revealed all samples showed the expression of mRNA for the two proteins, and the expression is more abundantly in the small follicles than in the large preovulatory follicles. Competitive RT-PCR revealed that the expression of follistatin is the highest in small yellow follicles (SYF), the mean relative content for the F1, F2, F3, F4, F5, F6-8, LWF (large white follicle), TI(immature testes), and TM(mature testes) was 0.011 +/- 0.004, 0.019 +/- 0.006, 0.021 +/- 0.009, 0.028 +/- 0.007, 0.075 +/- 0.023, 0.15 +/- 0.072, 0.29 +/- 0.068, 0.037 +/- 0.011, and 0.012 +/- 0.004, respectively, compared to a mean relative content of 1.00 for the SYF. The highest level of inhibin/activin beta B mRNA was also found in the SYF, the mean relative content for the F1, F2, F3, F4, F5, F6-8, LWF, TI, and TM was 0.009 +/- 0.003, 0.013 +/- 0.005, 0.019 +/- 0.007, 0.023 +/- 0.006, 0.29 +/- 0.084, 0.84 +/- 0.093, 0.031 +/- 0.008, 0.38 +/- 0.072, and 0.046 +/- 0.013, respectively, compared to a mean relative content of 1.00 for the SYF. Our data suggested that the expression pattern of mRNA for follistatin and inhibin/activin beta B-subunit was quite similar during follicular and testicular development. The great co-expression of mRNA for the two proteins in small follicles indicated that activin B(beta B-beta B) availability was tightly regulated by follistatin, and the two proteins might both play important roles in early follicular development.

[Studies of genetic diversity of Zhejiang native chicken breeds]

A total of 539 bases of mitochondrial DNA D-loop region of five native chicken breeds of Zhejiang province and the white leghorn chicken (as the control) were sequenced by DNA sequencing technique, and the phylogenetic trees of the chicken breeds were constructed. The results showed that 24 variation sites i.e. 4.45% sequence divergence were detected among the 30 DNA sequences, and the six breeds belonged to two different maternal lineage, one included Xianju chicken and White Leghorn chicken which had the same maternal origin, the other included Lingkun chicken, Baiyiner chicken, Wugu chicken and Xiaoshan chicken which had the same matriarchic ancestor. Among the latter lineage, Lingkun chicken, Baiyiner chicken and Wugu chicken had a closer relationship to each other than to Xiaoshan chicken.

[cDNA cloning and mRNA expression pattern in follicles of the mature inhibin alpha subunit from Xianju chicken]

The mature region of Xianju chicken inhibin alpha-subunit was amplified from the total RNA of follicle granulosa cells by RT-PCR using the primer pair designed according to the reported cDNA sequence of chicken inhibin alpha-subunit, and this fragment of alpha-subunit was cloned and sequenced subsequently. The results revealed that the mature alpha-subunit of Xianju chicken was a fragment of 113 amino acids containing one glycosylation site and seven cysteine residues. It was approximately 98% and 61.4%-68.7% identical in nucleotide sequence, 97.3% and 64.6%-69% similar in deduced amino acid sequence, respectively, in the mature region to the chicken and mammalian inhibin alpha-subunit cDNA clone. As for the mature chicken inhibin alpha-subunit, the number of potential glycosylation site and cysteine residues was the same, and their corresponding positions in the amino acid sequences were almost identical as compared to chicken and mammalian inhibin alpha-subunit, which indicated that the inhibin alpha-subunit was highly conserved among different species, implying an important role of inhibin alpha-subunit in various animals. The quantitative analysis of competitive RT-PCR for inhibin alpha-subunit revealed that the expression of alpha-subunit decreased with further follicle maturity from SYF to F1 follicle. The highest level of inhibin alpha-subunit mRNA was found in the SYF and F6-8 follicles, which indicated that inhibin alpha-subunit played an important role during the course of follicular recruitment, selection and dominance.

[Expression of inhibin alpha and inhibin/activin beta A subunits in the developing follicles of the duck]

The very sensitive quantitative competitive reverse transcription-polymerase chain reaction (RT-PCR) was used to investigate the expression of mRNA for the inhibin alpha and inhibin/activin beta A subunit in the developing ovarian follicles of the duck. The results indicated all follicles showed the expression of mRNA for the inhibin alpha and inhibin/activin beta A. The inhibin alpha subunit mRNA is expressed more abundantly than the beta A subunit in the large preovulatory follicles. Competitive RT-PCR revealed that the expression of inhibin alpha subunit is the highest in small yellow follicles (SYF), the mean relative content for the F1, F2, F3, F4/5 and LWF (large white follicle) was 0.26 +/- 0.05, 0.28 +/- 0.07, 0.57 +/- 0.12, 0.98 +/- 0.09 and 0.026 +/- 0.006, respectively, compared to a mean relative content of 1.00 for the SYF. The highest level of inhibin/activin beta A mRNA was found in the F1 follicle, the mean relative content for the F2, F3, F4/5, SYF and LWF was 0.218 +/- 0.09, 0.111 +/- 0.03, 0.058 +/- 0.011, 0.053 +/- 0.013 and 0.005 +/- 0.002, respectively, compared to a mean relative content of 1.00 for the F1 follicle. Our data suggest that the expression of the alpha subunit is reduced with follicular development whereas beta A subunit expression is dramatically enhanced, which indicates the expression of inhibin alpha and inhibin/activin beta A subunit is differentially regulated during follicular development. In addition, the highest level of beta A mRNA in F1 follicle indicates the production of dimeric inhibin and/or activin primarily occurred in the largest F1 follicle.

[Studies of the origin of Chinese domestic fowls]

A total of 539 bases fragment of mitochondrial DNA D-loop region of six domestic chicken breeds (30 individuals) were sequenced and compared to that of red junglefowl, grey junglefowl, green junglefowl and Lafayette's junglefowl issued in GenBank, and the phylogenetic trees for the chickens constructed based on the D-loop sequences. The results indicated that the four species of genus Gallus had great differences between each other, the G. g. domesticus was the next of kin to red junglefowl in Thailand and its adjacent regions, and near of kin to red junglefowl in Indonesian, Lafayette's junglefowl, grey junglefowl and green junglefowl one by one in proper order, suggesting that the red junglefowl in Thailand and its neighbour areas sufficed as the matriarchic ancestor of Chinese domestic fowls. It was also discovered that the two subspecies of Thailand i.e. G. g. gallus and G. g. spadiceus should belong to one subspecies because of their far lower differentiation compared to that among the domestic breeds.

The first stereoselective total synthesis of quinine

The first entirely stereoselective total synthesis of (-)-quinine is reported.

A new subdivision of mammalian neostriatum with functional implications to learning and memory

A new subdivision with distinctive morphological and functional attributes has been identified at the caudomedial margin of the neostriatum and surrounding the rostrolateral border of the globus pallidus in the brains of the rat, cat, monkey, and human. The subdivision is termed marginal division (MrD) based on its location. It is readily distinguishable from the rest of striatum by consisting of spindle-shaped neurons, special connections, and intensely expressed immunoreactivities of many neuropeptides and some monoamines in the fibers, terminals, and neuronal somata. Three-dimensional reconstruction from Nissl-stained sections of the rat brain revealed that the MrD is a flat, pan-shaped zone between the neostriatum and globus pallidus. Functional neuronal connections were delineated by chemical-induced c-Fos expression between the MrD and hippocampus, amygdala, as well as the basal nucleus of Meynert. In rats with chemical lesions of bilateral MrD, learning and memory functions were severely impaired as demonstrated by double blind Y-maze test. Our results thus suggested that the MrD is a distinct part and a universal structure in the neostriatum of the mammalian brain and might play an important role in the mechanism of learning and memory.