Electronic Structure Modulation Via Iron-Incorporated NiO to Boost Urea Oxidation/Oxygen Evolution Reaction

The urea-assisted water splitting not only enables a reduction in energy consumption during hydrogen production but also addresses the issue of environmental pollution caused by urea. Doping heterogeneous atoms in Ni-based electrocatalysts is considered an efficient means for regulating the electronic structure of Ni sites in catalytic processes. However, the current methodologies for synthesizing heteroatom-doped Ni-based electrocatalysts exhibit certain limitations, including intricate experimental procedures, prolonged reaction durations, and low product yield. Herein, Fe-doped NiO electrocatalysts were successfully synthesized using a rapid and facile solution combustion method, enabling the synthesis of 1.1107 g within a mere 5 min. The incorporation of iron atoms facilitates the modulation of the electronic environment around Ni atoms, generating a substantial decrease in the Gibbs free energy of intermediate species for the Fe-NiO catalyst. This modification promotes efficient cleavage of C-N bonds and consequently enhances the catalytic performance of UOR. Benefiting from the tunability of the electronic environment around the active sites and its efficient electron transfer, Fe-NiO electrocatalysts only needs 1.334 V to achieve 50 mA cm-2 during UOR. Moreover, Fe-NiO catalysts were integrated into a dual electrode urea electrolytic system, requiring only 1.43 V of cell voltage at 10 mA cm-2.

[The feasibility analysis of multi-slice spiral CT features of gastric stromal tumors in predicting pathological National Institutes of Health risk classification]

Objective: To investigate the feasibility of multi-slice spiral CT(MSCT) imaging features of gastric stromal tumor (GST) in predicting pathological NIH risk classification, providing imaging basis for patients with GST before treatment. Methods: The clinical and CT imaging data of 504 patients(506 GST lesions), 259males and 245 females, aged from 13 to 85(60±11) years, with GST confirmed by surgery and pathology collected in the Zhongshan Hospital Affiliated to Fudan University and the Affiliated TCM Hospital of Southwest Medical University. According to pathological NIH risk classification, 506 lesions were divided into low risk group (very low and low risk degree, 277 lesions) and high risk group (medium and high risk degree, 229 lesions).Clinical data and imaging characteristics were compared between two groups. Multivariate logistic regression analysis was performed to screen out independent risk factors for statistically significant imaging indicators. Receiver operating curve (ROC) was used to evaluate the predictive value of tumor length for risk classification. Resulst: Between low risk group and high risk group,there were significant differences in gender(male/female:131/146 vs 129/100), gastrointestinal bleeding(present/absent:39/238 vs 59/170), morphology(regular/Irregular:218/59 vs 95/134), calcification(present/absent:36/241 vs 53/176), degree of necrosis(0°/Ⅰ°/Ⅱ°/Ⅲ°:197/61/16/3 vs 58/98/32/41), ulceration(present/absent:32/245 vs 94/135), growth pattern(endophytic/exophytic/mixed:102/105/70 vs 44/98/87), tumor location(fundus/cardia/body/angle/antrum:98/7/135/12/25 vs 98/6/114/5/6), feeding artery(present/absent:32/245 vs 104/125), vascular enhancement(present/absent:19/258 vs 88/141), effusion of around the disease(present/absent:0/277 vs 13/216), positive sign of fat around the disease(present/absent:0/277 vs 30/199),maximum long diameter[2.82(2.04,3.80) cm vs 5.93(4.06,8.29) cm] and short diameter [2.31(1.60,2.88) cm vs 4.40(3.21,6.37) cm]of tumor(all P<0.05).The maximum long diameter of tumor (OR=2.08,95%CI:1.35-3.20) and ulceration positive(OR=2.01,95%CI:1.03-3.92) were independent risk factors of risk classification(all P<0.05).Gastric antrum was used as the reference for tumor location, gastric fundus(OR=7.77,95%CI:2.00-30.24) and gastric body(OR=3.93,95%CI:1.03-15.01) were independent risk factors of risk classification(all P<0.05).The area under curve(AUC) of the maximum long diameter of tumor for predicting risk classification was 0.87, and the optimal critical value, sensitivity and specificity were 4.98cm, 62.9% and 95.3% respectively. Conclusions: MSCT image features of GST had certain characteristics. MSCT has certain predictive value for pathological NIH risk classification of GST, which can provide certain imaging basis for patients before treatment.

[The clinical effect and imaging features of accordion maneuver in promoting bone healing at the docking site after tibial transport under ultrasonic monitoring]

Objective: To explore the imaging features and clinical effect of accordion maneuver in promoting the bone healing at the docking site after tibial transport under ultrasonic monitoring. Methods: Retrospective analysis was conducted on the clinical data of 16 patients with tibial bone transport who were admitted to the Department of Orthopedics, the second Hospital of Shanxi Medical University from May 2018 to October 2019. All the patients were treated with accordion maneuver to promote bone healing at the docking site under ultrasound monitoring. There were 14 males and 2 females, aged (45.3±14.3) years (range: 6 to 61 years). Before tibial bone transport, the length of the tibial defect of 16 patients was (6.0±2.6) cm (range: 2.0 to 12.1 cm). The operation steps of accordion maneuver were as follows: pressurization for 2 weeks, suspension for 12 days, distraction for 2 weeks, retraction for 2 weeks, and then stop the operation to consolidate the bone mineralization. During accordion treatment, ultrasound was used to monitor the size of hematoma, Adler grade of blood flow signal and the changes of new callus in and around the docking site. X-ray was performed to monitor bone healing at the docking site. Pearson correlation coefficient was used to analyze the correlation between the size of hematoma, the resistance index of blood flow signal and the bone healing time of the docking site. Paley healing criterion was used to evaluate the bone healing and functional recovery of the patients. Results: During accordion maneuver, ultrasound examination showed that the Adler grade of blood flow signals around the docking site increased gradually before retraction and then decreased gradually, but the degree of callus mineralization continued to increase gradually. After 2 weeks of pressure on the docking site, hematoma was observed in 14 patients by ultrasound examination. X-ray showed that all docking sites had bony healing, with the healing time of (30.8±4.9) weeks (range: 23 to 40 weeks).The size of the hematoma was negatively correlated with the healing time of the docking site (r=-0.819,P<0.01). No hematoma was found in 2 patients, and after continuous observation for 20 weeks, there was still no obvious callus connection at the docking site. After bone cortical removal, ultrasound examination showed hematoma formed at the docking site. Accordion maneuver was continued, and the docking site healed at 30 and 32 weeks after surgery, respectively. There was a negative linear correlation between hematoma size at 2 weeks of compression and the blood flow resistance index at 2 weeks of retraction in 16 patients (r=-0.801, P<0.01). The patients were followed-up for (14.5±3.2) months (range: 10.6 to 20.2 months). At the last follow-up, 12 patients were evaluated as excellent and 4 were evaluated as good by Paley healing criteria. Conclusion: The distraction and compression stress applied in accordion maneuver can promote bone healing at the docking site, and ultrasound can monitor early signs of bone healing at the docking site to help determine the tendency of bone healing.

The FOXD3/miR-214/MED19 axis suppresses tumour growth and metastasis in human colorectal cancer

Background:

MiR-214 is aberrantly regulated in several tumours, but its underlying mechanisms in colorectal cancer (CRC) metastasis remain largely unknown. This study aimed to demonstrate the function and potential mechanism of miR-214 in regulating invasion and metastasis of CRC.

Methods:

The transcription factor and targets of miR-214 were predicted by bioinformatics and validated using ChIP and dual-luciferase reporter assay. DNA methylation status was explored using bisulphite sequencing PCR. The in vitro and in vivo function of miR-214 in CRC was evaluated using MTT, plate colony formation, Matrigel invasion and animal models. Real-time PCR or western blotting was performed to detect FOXD3, miR-214 and MED19 expressions in CRC cells and clinical specimens.

Results:

MiR-214 was downregulated in CRC and was significantly correlated with lymphatic metastasis. Downregulation of miR-214 might due to promoter hypermethylation in CRC. FOXD3 was validated as a transcription factor of miR-214 by ChIP assay. Dual-luciferase assay identified MED19 as a target of miR-214 in CRC. In vitro and in vivo experiments showed that miR-214 mediated the inhibiting effect of FOXD3 on proliferation, invasion and metastasis by targeting MED19. Spearman's correlation analysis showed a positive correlation between FOXD3 and miR-214, and negative correlations between FOXD3 and MED19, miR-214 and MED19 in CRC cells and clinical specimens.

Conclusions:

FOXD3/miR-214/MED19 axis is important for the regulation of growth, invasion and metastasis of CRC. Targeting the miR-214-mediated axis might be helpful for the treatment of CRC.

[Current diagnosis and treatment of pseudoaneurysms of the internal carotid artery in postirradiated nasopharyngeal carcinoma]

Nasopharyngeal carcinoma is one of the most common of head and neck malignant tumors in southern region of China. Till date radiotherapy is considered as the first choice of treatment this disease.Although the rate of occurrence of pseudoaneurysms of the internal carotid artery in post radiation treatment of nasopharyngeal carcinoma is low, it is also a hot topic in department of otolaryngology and doctors because of its dangerous and lifethreatening emergencies.In order to improve the level of diagnosis and treatment of the disease, diagnosis, risk, treatment, prognosis and prevention are current summarized in this report.

[Effect of mouse nerve growth factor on cognitive impairment in whole brain irradiation rats]

OBJECTIVE

To investigate the positive effects of mouse nerve growth factor(mNGF) on cognitive impairment in whole brain irradiation rats.

METHODS

Fifty-five male Sprague-Dawley rats were randomly divided into normal control group, mNGF treated group, saline treated group.mNGF treated group and saline treated group were cranial irradiated at a single dose of 12 Gy by X-ray.30 days after radiation each group were treated with correspondent drugs.60 days after radiation, Morris water maze experiment, EB leakage of the brain, and expressions of neuN, vWF, ZO-1 in hippocampus by immunofluorescence, and expressions of neuN, vWF, ZO-1, VEGF and GFAP in hippocampus by Western blot were tested and analyzed.

RESULTS

The escape latencies: normal control group< mNGF treated group< saline treated group; the numbers of crossing hidden platform in these 3 groups were 3.00± 1.08, 1.50± 1.08, 0.38± 0.48 times (P<0.01). EB leakage of these 3 groups were 0.14±0.14, 0.66±0.20 and 1.36±0.27 μg/g (P<0.05). In immunofluorescence, expressions of neuN, vWF and ZO-1: normal control group> mNGF treated group> saline treated group.In Western blot, expressions of neuN, vWF and ZO-1: normal control group> mNGF treated group> saline treated group, yet the expressions of VEGF and GFAP: normal control group< mNGF treated group< saline treated group.

CONCLUSION

mNGF ameliorates cognitive impairment after whole brain irradiation.

Investigation of the ASR family in foxtail millet and the role of ASR1 in drought/oxidative stress tolerance

KEY MESSAGE

Six foxtail millet ASR genes were regulated by various stress-related signals. Overexpression of ASR1 increased drought and oxidative tolerance by controlling ROS homeostasis and regulating oxidation-related genes in tobacco plants. Abscisic acid stress ripening (ASR) proteins with ABA/WDS domains constituted a class of plant-specific transcription factors, playing important roles in plant development, growth and abiotic stress responses. However, only a few ASRs genes have been characterized in crop plants and none was reported so far in foxtail millet (Setaria italic), an important drought-tolerant crop and model bioenergy grain crop. In the present study, we identified six foxtail millet ASR genes. Gene structure, protein alignments and phylogenetic relationships were analyzed. Transcript expression patterns of ASR genes revealed that ASRs might play important roles in stress-related signaling and abiotic stress responses in diverse tissues in foxtail millet. Subcellular localization assays showed that SiASR1 localized in the nucleus. Overexpression of SiASR1 in tobacco remarkably increased tolerance to drought and oxidative stresses, as determined through developmental and physiological analyses of germination rate, root growth, survival rate, relative water content, ion leakage, chlorophyll content and antioxidant enzyme activities. Furthermore, expression of SiASR1 modulated the transcript levels of oxidation-related genes, including NtSOD, NtAPX, NtCAT, NtRbohA and NtRbohB, under drought and oxidative stress conditions. These results provide a foundation for evolutionary and functional characterization of the ASR gene family in foxtail millet.

MicroRNA-206 functions as a tumor suppressor in colorectal cancer by targeting FMNL2

BACKGROUND

Colorectal cancer (CRC) is one of the most common cancers in the world. MicroRNAs play important roles in the progression of CRC. This study aimed to investigate the role of miR-206 and its novel mechanism in the invasion and metastasis of CRC.

METHODOLOGY

Real-time RT-PCR or Western blotting was used to detect the expressions of miR-206, FMNL2 and c-MET in CRC cell lines and tissues. Luciferase reporter assays were conducted to detect the associations between miR-206 and 3'UTRs of FMNL2 and c-MET. A series of loss-of-function and gain-of-function assays were performed to evaluate the effect of miR-206 on the proliferation, invasion and metastasis of CRC cells.

RESULTS

miR-206 was significantly down-regulated in CRC tissues and correlated closely with differentiation, lymphatic metastasis and serosal invasion. miR-206 suppressed CRC cell proliferation by arresting CRC cells in the G1/G0 phase and accelerating apoptosis. miR-206 also inhibited cell invasion and lung metastasis in CRC cells. Mechanically, FMNL2 and c-MET were identified as direct targets of miR-206. And FMNL2 rescued the suppression of miR-206 in the proliferation and invasion of CRC cells.

CONCLUSIONS

This study revealed functional and mechanistic links between miR-206 and oncogene FMNL2 and c-MET in the progression of CRC. miR-206 functioned as a tumor suppressor in the progression of CRC by targeting FMNL2 and c-MET. Restoration of miR-206 expression may represent a promising therapeutic approach for targeting malignant CRC.

The soybean GmDi19-5 interacts with GmLEA3.1 and increases sensitivity of transgenic plants to abiotic stresses

Drought-induced (Di19) proteins played important roles in plant growth, development, and abiotic stress responses. In the present study, a total of seven Di19 genes were identified in soybean. Each soybean Di19 gene showed specific responses to salt, drought, oxidative, and ABA stresses based on expression profiles. With a relatively higher transcript level among Di19 members under four stress treatments, GmDi19-5 was selected for detailed analysis. Inhibitor assays revealed that ABA inhibitor (Fluridone) or H2O2 inhibitor (DMTU) was involved in the drought- or salt-induced transcription of GmDi19-5. The GUS activity driven by the GmDi19-5 promoter was induced by salt, PEG, ABA, and MV treatments and tended to be accumulated in the vascular bundles and young leaves. A subcellular localization assay showed that GmDi19-5 protein localized in the nucleus. Further investigation showed that GmDi19-5 protein was involved in the interaction with GmLEA3.1. Overexpression of GmDi19-5 increased sensitivity of transgenic Arabidopsis plants to salt, drought, oxidative, and ABA stresses and regulated expression of several ABA/stress-associated genes. This present investigation showed that GmDi19-5 functioned as a negative factor under abiotic stresses and was involved in ABA and SOS signaling pathway by altering transcription of stress-associated genes.

Anticancer effect of icaritin on human lung cancer cells through inducing S phase cell cycle arrest and apoptosis

Icaritin, a prenylflavonoid derivative from Epimedium Genus, has been shown to exhibit many pharmacological and biological activities. However, the function and the underlying mechanisms of icaritin in human non-small cell lung cancer have not been fully elucidated. The purpose of this study was to investigate the anticancer effects of icaritin on A549 cells and explore the underlying molecular mechanism. The cell viability after icaritin treatment was tested by MTT assay. The cell cycle distribution, apoptosis and reactive oxygen species (ROS) levels were analyzed by flow cytometry. The mRNA and protein expression levels of the genes involved in proliferation and apoptosis were respectively detected by RT-PCR and Western blotting. The results demonstrated that icaritin induced cell cycle arrest at S phase, and down-regulated the expression levels of S regulatory proteins such as Cyclin A and CDK2. Icaritin also induced cell apoptosis characterized by positive Hoechst 33258 staining, accumulation of the Annexin V-positive cells, increased ROS level and alteration in Bcl-2 family proteins expression. Moreover, icaritin induced sustained phosphorylation of ERK and p38 MAPK. These findings suggested that icaritin might be a new potent inhibitor by inducing S phase arrest and apoptosis in human lung carcinoma A549 cells.

Fucoidan induces G1 phase arrest and apoptosis through caspases-dependent pathway and ROS induction in human breast cancer MCF-7 cells

Fucoidan is an active component of seaweed, which inhibits proliferation and induces apoptosis of several tumor cells while the detailed mechanisms underlying this process are still not clear. In this study, the effect of Fucoidan on the proliferation and apoptosis of human breast cancer MCF-7 cells and the molecular mechanism of Fucoidan action were investigated. Viable cell number of MCF-7 cells was decreased by Fucoidan treatment in a dose-dependent manner as measured by MTT assay. Fucoidan treatment resulted in G1 phase arrest of MCF-7 cells as revealed by flow cytometry, which was associated with the decrease in the gene expression of cyclin D1 and CDK-4. Annexin V/PI staining results showed that the number of apoptotic cells was associated with regulation of cytochrome C, caspase-8, Bax and Bcl-2 at transcriptional and translational levels. Both morphologic observation and Hoechst 33258 assay results confirmed the pro-apoptotic effect of Fucoidan. Meanwhile, the ROS production was also increased by Fucoidan treatment, which suggested that Fucoidan induced oxidative damage in MCF-7 cells. The results of present study demonstrated that Fucoidan could induce G1 phase arrest and apoptosis in MCF-7 cells through regulating the cell cycle and apoptosis-related genes or proteins expression, and ROS generation is also involved in these processes.

Germacrone induces apoptosis in human hepatoma HepG2 cells through inhibition of the JAK2/STAT3 signalling pathway

Previous studies have shown that STAT3 plays a vital role in the genesis and progression of cancer. In this study, we investigated the relationship between the JAK2/STAT3 signalling pathway and germacrone-induced apoptosis in HepG2 cells. HepG2 cells were incubated with germacrone for 24 h, the protein expression of p-STAT3, STAT3, p-JAK2 and JAK2 was detected by Western Blotting, and RT-PCR was used to determine the expression of STAT3, p53, Bcl-2 and Bax at transcriptional levels. Besides that, HepG2 cells were pre-treated with AG490 or IL-6 for 2 h, and then incubated with germacrone for 24 h. The expression of p-JAK2, JAK2, p-STAT3, STAT3, p53, Bax and Bcl-2 was detected by Western blotting. The activity of HepG2 cells was tested by MTT assay. The apoptosis of HepG2 cells and levels of reactive oxygen species (ROS) were flow cytometrically measured. The results showed that germacrone exposure decreased p-STAT3 and p-JAK2 and regulated expression of p53 and Bcl-2 family members at the same time. Moreover, IL-6 enhanced the activation of the JAK2/STAT3 signalling pathway and therefore attenuated the germacrone-induced apoptosis. Suppression of JAK2/STAT3 signalling pathway by AG490, an inhibitor of JAK2, resulted in apoptosis and an increase in ROS in response to germacrone exposure. We therefore conclude that germacrone induces apoptosis through the JAK2/STAT3 signalling pathway.

Isolation and characterization of an endosperm-specific promoter from wheat (Triticum aestivum L.)

Genes coding for avenin-like proteins (ALP) represent a new family of wheat storage protein genes. To find a wheat endosperm-specific promoter, a 1644-bp fragment upstream of the ALP type-B gene (GenBank accession number JN622144) was isolated. The important promoter elements of the ALP type-B gene were ascertained through sequence analysis which revealed that this fragment contains the TATA and CAAT boxes, which are important elements in gene expression. A prolamin box containing an endosperm motif and a GCN4-like motif (GLM) is present at about 300 bp upstream of the translation start site. The promoter sequence has two ESP-like elements and one of them is followed by an RY motif with the nucleotides CATG overlapping. The RY motif is considered the core functional sequence in a promoter. In an attempt to confirm the promoter activity, a series of 5'-deletions of the promoter were fused with the beta-glucuronidase (GUS) gene, and the constructs were stably introduced into tobacco plants. GUS staining confirmed that the AVL type-B promoter is an endosperm-specific promoter in tobacco seeds. Quantitative analysis of GUS expression in transgenic plants showed that even the shortest 5'-deletion, i.e. a 290-bp promoter sequence within the prolamin box, was sufficient to drive GUS expression in the endosperm. The highest expression level was found in transgenic plants containing the 5'-deletion vector construct pALP-8. This suggests that the ESP-like element overlapping with the RY motif may play a crucial role in the regulatory function of the promoter.

A novel role for Arabidopsis CBL1 in affecting plant responses to glucose and gibberellin during germination and seedling development

Glucose and phytohormones such as abscisic acid (ABA), ethylene, and gibberellin (GA) coordinately regulate germination and seedling development. However, there is still inadequate evidence to link their molecular roles in affecting plant responses. Calcium acts as a second messenger in a diverse range of signal transduction pathways. As calcium sensors unique to plants, calcineurin B-like (CBL) proteins are well known to modulate abiotic stress responses. In this study, it was found that CBL1 was induced by glucose in Arabidopsis. Loss-of-function mutant cbl1 exhibited hypersensitivity to glucose and paclobutrazol, a GA biosynthetic inhibitor. Several sugar-responsive and GA biosynthetic gene expressions were altered in the cbl1 mutant. CBL1 protein physically interacted with AKINβ1, the regulatory β subunit of the SnRK1 complex which has a central role in sugar signaling. Our results indicate a novel role for CBL1 in modulating responses to glucose and GA signals.

Overexpression of soybean GmCBL1 enhances abiotic stress tolerance and promotes hypocotyl elongation in Arabidopsis

Although extensive studies and remarkable progress have been made with Arabidopsis calcineurin B-like proteins (CBLs), knowledge of their functions in other plant species is still limited. Here we isolated gene GmCBL1 from soybean, a homolog of AtCBL1 in Arabidopsis. GmCBL1 was differentially induced by multiple abiotic stress and plant hormones, and its transcripts were abundant in seedlings and mature roots. We over-expressed GmCBL1 in Arabidopsis and found that it enhanced tolerances to both high salt and drought stresses in the transgenic plants. Overexpression of GmCBL1 also promoted hypocotyl elongation under light conditions. GmCBL1 may regulate stress tolerance through activation of stress-related genes, and may control hypocotyl development by altering the expression of gibberellin biosynthesis-related genes. This study identifies a putative soybean CBL gene that functions in both stress tolerance and light-dependent hypocotyl development.

Mechanism of polyamine toxicity in cultured cardiac myocytes

The goal of this study was to investigate the mechanism of polyamine-mediated injury to the cardiac myocytes isolated from neonatal rat hearts. The myocytes, cultured in Dulbecco's minimal essential medium-1% foetal calf serum (FBS), were exposed to spermidine or spermine. The toxicity to myocytes was determined by (a) increased release of creatine kinase (CPK) into the media and (b) decline in cell viability or functional activity. Spermidine, above 10 mum, increased the release of CPK into media, decreased cell viability and decreased the functional activity of the myocytes. The FBS exhibited polyamine oxidase activity and semicarbazide-sensitive amine oxidase activity. Aminoguanidine, MDL72,527 or semicarbazide, are the inhibitors of amine oxidases, polyamine oxidase (PAO) and semicarbazide-sensitive amine oxidase (SSAO), respectively. The addition of these inhibitors to the medium protected the myocytes from spermidine toxicity. To determine whether myocyte PAO is involved in polyamine toxicity, we used horse serum that contained high SSAO activity and negligible PAO activity. The myocyte extracts had negligible SSAO activity but high PAO activity. When myocytes were cultured in horse serum in lieu of FBS, spermine caused toxicity at above 100 mum. In horse serum, MDL72,527 and semicarbazide protected the myocytes from spermine toxicity. These observations show that extracellular amine oxidases and myocyte PAO are significant in mediation of polyamine toxicity.

[Effects of electroacupuncture on the apoptosis of brain tissue cells and the expression of Caspase-3 in the rats with cerebral-cardiac syndrome]

OBJECTIVE

To observe the effects of electroacupuncture (EA) on the apoptosis of brain tissue cells and the expression of Caspase-3 in the rats with cerebral-cardiac syndrome (CCS).

METHODS

A total of 70 healthy SD rats were selected. Ten was randomly recruited as the sham-operation group, and the rest were used for CCS model preparation. Thirty successfully modeled rats were divided into the model group, the EA group, and the non-EA group, 10 in each group. The model was prepared using injecting collagenase + heparin into the caudate nucleus. Equal volume of 0.9% sodium chloride injection was injected to rats' caudate nucleus in the sham-operation group. EA was started on the 1st day of modeling. Shuigou (GV26), Fengfu (GV16), Neiguan (PC6), and Xinshu (BL15) were needled in the EA group. Four points in the hips were needled in the non-EA group. The EA needling lasted for 20 min each time, once daily, for 3 successive times. No EA was administered to the sham-operation group or the model group. The apoptosis of brain tissue around the hematoma and the expression of Caspase-3 were detected using TUNEL and immunochemical assay.

RESULTS

TUNEL cells could be occasionally seen with fewer Caspase-3 expression in the sham-operation group. More TUNEL positive cells appeared in the tissue around the hematoma of the model group with a large amount of Caspase-3 expression. The TUNEL positive cells and Caspase-3 expression were obviously less in the EA group than in the model group and the non-EA group (P < 0.01).

CONCLUSIONS

EA could inhibit the apoptosis of brain tissue cells in CCS rats. Its mechanisms might be associated with down-regulating the Caspase-3 expression of the brain tissue around the hematoma.

Polymorphic microsatellite loci from two enriched genomic libraries for the genetic analysis of the miiuy croaker, Miichthys miiuy (Sciaenidae)

Twelve polymorphic microsatellites from the (AG)(13) and (CA)(13) enriched genomic libraries of Miichthys miiuy were isolated and characterized in a test population; the number of alleles ranged from two to nine. The observed and expected heterozygosities ranged from 0.1923 to 1.0000 and from 0.2633 to 0.8337, respectively. Three loci deviated from Hardy-Weinberg equilibrium, and linkage disequilibrium between five pairs of loci was significant. These polymorphic microsatellite loci can be used for genetic diversity analysis and molecular-assisted breeding of M. miiuy.

[Determination of 8 trace elements in mantle muscle and cuttlebone of Sepiella maindroni by ICP-MS using microwave digestion for sample preparation]

An inductively coupled plasma mass spectrometry (ICP-MS) for determination of the contents of 8 trace elements in mantle muscle and cuttlebone of Sepiella maindroni after microwave digestion of the sample has been developed. Satisfactory linearity of working curves for the 8 elements was obtained, giving all their correlation coefficients over 0.997 3. The precision of measurement ranges from 2.4% to 8.7% in terms of relative standard deviation. The recoveries and the limits of detection are in the range of 96.5%-106.3% and 0.002-0.032 microg x L(-1), respectively. It was indicated that the proposed method had the advantages of simplicity, speediness and sensitivity. The results showed that the mantle muscle and cuttlebone of Sepiella maindroni contained rich trace elements Zn and Cu, but the contents of Cd and As are higher than the limits of Chinese Pharmacopoeia, Green Trade Standard for Importing and Exporting Medicinal Plant and Preparation and U.S. Food and Drug Standard. Furthermore, our study provides new scientific foundation for the quality control, culture, general application, resource utilization and exporting of Sepiella maindroni.

Design of tandem genes cluster and expression vector for biosynthesis of soybean isoflavones

A tandem gene cluster CHS-CHI-IFS (rIFS) for secondary metabolites of plant isoflavones was constructed by using the chalcone synthase (CHS), chalcone isomerase (CHI), and isoflavone synthase (IFS) (GenBank accession numbers EU526827, EU526829, EU526830) in a single recombination event with the pET22b vector. The resulting expression vector pET-rIFS was heterogeneously expressed. The highlights of the vector include ease of handling, high efficiency and universal application among diverse plant species. To the best of our knowledge, this is the first attempt at developing a novel method of constructing tandem gene cluster for future research involving secondary metabolism of isoflavones and isoflavones engineering.

[Application of enzyme-labeled probe in testing of transgenic plant]

Used alkaline-phosphatase-labeled DNA as a probe to examine the expression of foreign UidA gene in transgenic plants. Alkaline phosphatase coupled with polyethyleneimine (PEI) using P-benzoquine as the cross-linking reagent was covalently linked to single-stranded DNA via glutraldehyde. Such DNA-enzyme complexes were used as a probe for dot hybridization and Southern blot. After hybridization and incubation with a substrate solution, results can be observed directly in three to six hours and the results showed that it was a sensitive, specific, rapid, safe and economical probe. Dot hybridization analysis showed that the UidA gene was transformed into the target plants and southern blot showed that there were at least 5 copies of UidA gene in transgenic plants.

A mutant α-amylase with only part of the catalytic domain and its structural implication

A truncated mutant alpha-amylase, Xa-S2, was obtained from Xanthomonas campestris wild type alpha-amylases (Xa-WT) through random mutagenesis that contained 167 amino acid residues (approx 65% shorter than that of Xa-WT). Secondary structure prediction implied that Xa-S2, would be unable to form the whole (beta/alpha)(8)-barrel catalytic domain and did not have the three conserved catalytic residues of wild type alpha-amylase, but it still displays the starch-hydrolyzing activity. Xa-S2 was prepared, characterized and compared to the recombinant wild-type enzymes. The K (m) for starch was 32 mg/ml; activity was optimal at pH 6.2 and 30 degrees C. In contrast, the K (m) for starch of Xa-WT was 8 mg/ml and optimal enzyme activity was at pH 6.0-6.2 and 45-50 degrees C. Our results suggested that Xa-S2 is a new amylase with a minimal catalytic domain for hydrolyzing substrates with of alpha-1,4-glucosidic bonds.

[Inheritance of the foreign gene 1Ax1 in transgenic wheat (Triticum aestivum L.) with gene cassettes lacking vector backbone sequences]

Transformation with gene minimal expression cassettes without vector backbone sequence is a new transformation technique. In the current research, the inheritance of the foreign 1Ax1 gene cassettes were analyzed in transgenic plants recovered with gene cassettes lacking vector backbone sequences. The results showed that linear 1Ax1 gene cassettes were stably expressed and separated at the rate of 3 to 1 in the seeds of T1 generation. It suggested the functional copies of 1Ax1 gene cassettes were integrated in one sites, abiding by Mendelian genetic law. It revealed firstly the feasibility of the transformation technique with gene cassettes, and proved the inheritance of transgene cassettes in subsequent generations.

In vitro mutagenesis of Xanthomonas campestris alpha-amylase gene by partially replacing deoxythymidine triphosphate with 5-bromo-2'-deoxyuridine-5'-triphosphate using a PCR technique

Three mutants of the wild type alpha-amylase gene from Xanthomonas campestris pv. campestris 8004 were obtained using a PCR technique in which deoxythymidine triphosphate (dTTP) was partially replaced by 5-bromo-2'-deoxyuridine-5'-triphosphate (BrdUTP), at an optimal dTTP:BrdUTP ratio of 1000:1. Of thre three mutants that were obtained and which were sequenced, one mutant with 40 times higher activity than the wild type alpha-amylase gene product was obtained by using primary PCR products as a template for a second PCR reaction.

Fertile transgenic plants obtained from tritordeum inflorescences by tissue electroporation

 Tissue electroporation was applied to a member of the Triticeae family, namely tritordeum (Hordeum chilense Roem.×Triticum turgidum L. Conv. durum), for the generation of fertile transgenic plants. Two transgenic plants were recovered following the treatment of 361 explants of immature inflorescences (although they were subsequently found to result from the same transformation event). The expression of both inserted marker genes (uidA and bar) was confirmed using standard assays, while transgene integration was confirmed using PCR and Southern hybridization analyses. Integration pattern, segregation ratio and the inheritance of transgene expression in T₁ progeny were consistent for the presence of a single transgene locus containing five to ten plasmid insertions. Although this procedure has been applied to other cereal species, stable transformation of the Triticeae using tissue electroporation has not previously been reported.

Attenuation of isoproterenol-mediated myocardial injury in rat by an inhibitor of polyamine synthesis

OBJECTIVE

Ornithine decarboxylase (ODC) is an initial rate-limiting enzyme in the synthesis of polyamines (putrescine, spermidine, and spermine) that play a role in cell growth and differentiation. Recent studies have shown that spermidine and spermine cause injury to a variety of cells including myocytes in vitro. In this investigation, we used alpha-difluoromethylornithine (DFMO), a specific and irreversible inhibitor of ODC activity and polyamine synthesis to test the hypothesis that polyamines contribute to myocardial injury in rat.

METHODS

Male Sprague Dawley rats were treated with (i) saline (0.2 ml/day, s.c.), (ii) isoproterenol (ISO) (5 mg/kg/day for 8 days, s.c.) to produce necrotizing myocardial injury, or with (iii) DFMO + ISO. DFMO was started 2 days before the initiation of ISO and both ISO and DFMO were continued until the end of the experimental period. Myocardial injury was assessed by determining the increased release of creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) into the plasma, and by morphometric analysis of the lesion area in heart sections stained with Gomori trichrome.

RESULTS

ISO induced the release of CPK and LDH by 6 hr and 24 hr, respectively, and produced subendocardial necrosis, which was both acute and resolving following 8 days of ISO. DFMO treatment inhibited ISO-induced increases in (i) ODC activity and putrescine and spermidine levels in heart, (ii) CPK and LDH activity in plasma, and (iii) the area of subendocardial lesions.

CONCLUSIONS

These observations suggest that polyamines are one of the intracellular factors that contribute to ISO-mediated cardiac injury in the rat.

Differential induction of polyamine oxidase activity in liver and heart of iron-overloaded rats

The present study was undertaken to investigate the effect of iron dextran treatment on polyamine oxidase (PAO) activity, iron accumulation, and lipid peroxidation in livers and hearts of rats. PAO catalyzes oxidative deamination of polyamines, the cellular aliphatic cations. This reaction produces highly toxic hydrogen peroxide, 3-acetamidopropanal, and precursors of higher polyamines. The rats were given iron dextran daily for 7 d. In iron-dextran-treated rats, a marked increase in the hepatic level of iron was associated with enhanced lipid peroxidation and increased PAO activity. Though iron accumulation and lipid peroxidation in the iron-treated rats increased significantly in the heart, PAO activity remained unchanged. The paraffin sections of livers stained with Perls iron stain showed the presence of iron in macrophages and hepatocytes. The sections of hearts showed iron deposits only in macrophages, while myocytes showed no iron staining. These results show that although iron dextran treatment results in accumulation of iron in both liver and heart, it induces PAO activity only in liver. The significance of increased PAO activity in lipid peroxidation and fibrosis in iron-mediated injury is discussed.

RAS gene mutations in Chinese leukaemia patients and members of a family with high incidence of leukaemia

We investigated mutations of N-RAS and K-RAS by using polymerase chain reaction (PCR)-oligonucleotide hybridization techniques in 40 cases of Chinese leukaemia patients and 17 presently healthy members of a family with high incidence of acute myeloid leukaemia. The results showed only two patients carried the mutation in codon 12 of N-RAS. Strikingly, however, in both cases the malignancies involved lymphoid lineage. There was no hereditary RAS mutation in the members of the remarkable family.