Aim: Clone and characterize of the 5′- flanking region of the nitrate reductase (NR) gene derived from Dunaliella salina(D. salina). Methods : The genomic DNA from D. salina was respectively digested with BamHI, EcoRI, HindIII, Pst I, Sal I and Xba I. A genomic walking cassette was ligated to the ends of the digested DNA fragments, and then genomic walking libraries comprising BL, EL, HL, PL, SL and XL were constsucted. The 5′- flanking region of the NR gene from genomic walking libraries of D. salina was amplified by LA-PCR. The DNA sequences were analyzed with the software - Promoter Predictions. Isolated 5′-flanking regions fused to the GUS gene were tested for transient expression in the alga. Results: A single specific PCR product of about 1200bp in length from the HL library was generated. Also, several conserved motifs, such as CAAT-box, GAGA-box were found, which are related to regulation of transcription, and the putative binding sites of transcriptional factors such as EBP, EFII, NF-E1 and LV. BLAST showed that the DNA sequences shared high homology with 5′-upstream region of the NR gene from Dunaliella viridis. The isolated 5′-flanking regions were able to strongly drive GUS reporter gene expression, suggesting that it contains the promoter elements necessary for the transcription of the NR gene. The expression pattern of the GUS gene and the NR gene were similar, both ware induced by nitrate and repressed by ammonium. Conclusion: The cloned 5′- flanking sequences of NR gene derived from D. salina might be a specific promoter with the ability to“switch on or off” an expression of the heterologous gene in transgenic D. salina.

Objective To observe the influence of coal burning fluorosis on learning and memory ability in rats and reveal its possible mechanisms. Methods Healthy 48 SD rats were divided into control, low-fluoride and high-fluoride group. All rats in fluoride exposed groups were fed with the eom polluted by drying processes with burning coal containing high level of fluoride obtained from the endemic fluorosis area to produce the animal model of fluorosis. The experiment period were 3,6 mouths, respectively. The ability of leaning and memory was measured by Morris test and cholinesterase activity detected by photometric method at 3 or 6 month after experiment, respectively. Results Fluoride contents signifieantlly influenced the escape latency, the numbers of crossing the platforms and the time of staying the platforms(the value of F was 29.29,6.47,6.50, respectively, P<0.01).In addition, the numbers of crossing the platforms and the time of staying the platforms were influenced by the exposed time(the value of F was 16.11,45.59, P<0.01). Furthermore, the fluoride contents and the exposed time had an interaction between the numbers of crossing the platforms and the time of staying the platforms (the value of F was 4.67,5.68, P<0.05 or<0.01). Three months after the experiment, the mean values of escape latency [(14.71± 4.85)s] of rats in highly fluoride exposed group were significantly prolonged as compared with controls [(9.28±4.22)s]; 6 month after the experiment, the mean values of escape latency[(12.42±8.03)s, (17.48± 8.05)s] of rats in both groups exposed to fluoride were significantly prolonged as compared to controls [(7.04± 3.29)s, P<0.05]. The decreased numbers of crossing the platforms[(1.62±0.87)number] and the declined time of staying the platforms[(16.70±5.02)s] were found in the rats exposed to high fluoride as compared to controls [(3.53±1.67 )number, (23.33±5.35)s, P<0.05]. The fluoride contents obviously influenced the activities of acetylcholinesterase and butylcolinesterase (the value of F was 12.83,13.27, P<0.01). On the other hand, the times of breeding also influnced the activities of butylcolinesterase (the value of F was 16.26, P<0.01). In 3 months of the experiment, the activities of butylcolinesterase [(0.55±0.12)kU/g] in low fluoride exposed group were significantly decreased in comparison with controls[(0.73±0.10)kU/g, P<0.05]. The activities of acetylcholinesterase[(0.62±0.42)kU/g] and butylcolioesterase[(0.58±0.10)kU/g] in high fluoride group were significantly decreased as compared to eontrois[(1.41±0.52), (0.73±0.10)kU/g, P<0.05]. The correlation analysis showed that there was a negative correlation between the cholinesterase and the escape latency(r=-0.68, P< 0.01), and a positive correlation between the cholinesterase and the time of staying the platforms(r=0.57, P< 0.01). Conclusions The ability of learning and memory in rats with coal buring fluorosis was decreased, which might be connected to the decreased activity of cholinesterase in a dose-effect correlation.

The genome of a new SV40 strain(SV-IMB)isolated from a rhesus monkey was completely sequenced and compared with other isolates.The results showed that the whole genome contains 5246bp,and the average identity of SV-IMB was 98.1% as compared to other SV40 isolates.Its regulatory region is composed of a complete enhancer and a defective enhancer.Amino acid changes occurred to some extent in both the large T antigen (T-Ag) and VP1 region.The findings demonstrate that the SV-IMB is a new SV40 isolate.

Objective To investigate the expression of extraeellular signal-regulated protein kinase (ERK1/2)pathway in rat brains with fluorosis and the effects of fluoride on learning and memory of the rats,and to reveal the mechanisms of damaged nervous system resulted from the toxicity of the ion.Methods Seventy-two SD rats were divided into 3 groups and 24 rats were in each group.Three groups were fed respectively with different concentrations of fluoride(NaF)for 6 months to establish rat models with fluorosis.Controls were fed with tap water (NaF＜0.5 mg/L):lower and higher concentration group were fed with water containing NaF(5,50 ms/L).Animals are sacrificed after 6 months of treatment with fluoride and the dissected brains were kept for analysis.The protein levels of ERK1/2 in rat brains were detected by Western-blotting and the mRNA level by RT-PCR. The spatial learning and memorizing ability was measured by Morris water maze test. Results The ERK1/2 protein in control group,lower and higher concentration group was 0.944±0.10,1.253±0.02,1.953±0.07,the differece being statistieally sighificant between any two groups (P ＜ 0.05). The phospho-ERKl/2 protein in control group,lower and higher concentration group was 0.73±0.08,0.77±0.07,1.28±0.11,the differece being statistieally sighificant between any two groups(P ＜ 0.05);the activation rate of phospho-ERK1/2 in lower and higher concentration group [(68.4± 3.8)%,(64.1±3.2)%] was decreased compared to control group[ (82.3±10.7)%],the differece being significant(P ＜ 0.05). In the navigation trial,longer escape latencies of lower concentration group on the second, the third,the fifth and the sixth day were observed[ (46.0±8.0),(24.0±2.7),(8.9±5.3),(7.4±4.1 )s] compared to the control[ (39.3±6.9),(19.1±9.1 ),(8.3±3.4),(4.8±2.7)s],the differece being significant (P ＜ 0.05 or ＜ 0.01 );the similar results were also observed in the higher concentration group[ (36.9±16.8),(37.7±12.9), (19.7±7.6),(12.2±5.7 )s],and the escape latencies of the higher concentration group on the third,the fifth and the sixth day were longer than that in lower concentration group. In the probe test,the rats took more time to reach the first cross in lower and higher concentration group[(1.17±0.75),(4.18±1.10)s] than control group[ (5.89± 0.56 ) s ],the differece being significant (P ＜ 0.05 or ＜ 0.01 ) ;stayed shorter [ ( 17.05±4.25 ),(18.20±4.57 ) s ] than control [(25.37±5.65 )s ] in platform area (P ＜ 0.01 );the activation rates of ERK1/2 were directly correlated with the time taken to reach the first cross platform located in the probe test(r = 0.364,P ＜ 0.05) and the activation rates were also directly correlated with the escape latencies on the sixth day(r = 0.497,P ＜ 0.05). Conclusion Long-term exposure of excessive fluoride induces the change of expression and activating rate of the ERK1/2 in rat brains,leading to the decreased capacity of learning and memory.

Objective To analyze the ultrasonic features of thyroid microcarcinoma (TMC) and the causes of misdiagnosis. Methods The ultrasonic features including shape, margin, echogenecity, microcalcification, vascularity and lymphadenopathy were analyzed retrospectively in 26 pathologically-proven TMC patients. Results In 26 cases, 11 cases were diagnosed correctly before operation (11/26, 42.31%), 12 cases were misdiagnosed (12/26, 46.15%) as adenoma or benign nodule, and 3 cases were missed diagnosed (3/26, 11.54%). Among the 23 cases detected on ultrasound, 21 cases were solid and hypoechoic (21/23, 91.30%);19 cases were ill-defined (19/23, 82.61%);12 cases were taller than wide in shape (12/23, 52.17%); 14 cases had microcalcification (14/23, 60.87%); 7 cases showed central or peripheral blood flow signals (7/23,30.43%) with arterial resistance index>0.70 in 3 lesions and<0.70 in 4 lesions. Conclusions Several ultrasonographic features are helpful in identiifcation of TMC, including hypo/iso-echogenecity, ill-deifned margin, taller-than-wide shape, microcalciifcation, arterial signals with high resistance index, and abnormal lymphadenopathy. Moreover, for cases with multiple lesions, to the potential co-existence of benign and malignant lesions should be considered.

OBJECTIVECongenital esophageal stenosis owing to tracheobronchial remnants (TBR) is a rare condition. This study was conducted to understand the clinical features of TBR.

METHODThe data of the four cases with TBR admitted to our hospital and 76 patients identified from the literature were reviewed. The clinical manifestation, X-ray, endoscopy, biopsy and treatment were studied retrospectively.

RESULTOf the total of 80 cases, 45 were male, 33 were female, and for 2 cases the gender was unknown. Symptoms of dysphagia and regurgitation developed at the age of 1-day to 12-month. Definitive treatment was carried out at the age of 1-month to 16-year. Twenty-seven patients had associated anomalies with esophageal atresia being the most prevalent. X-ray esophagography showed segmental stenosis at the distal third of the esophagus in all patients except three. An abrupt narrow segment at the lower esophagus with marked proximal dilatation was found in 32 cases. Esophagography of 12 cases showed distal esophageal stenosis with tapered narrowing. Esophagography of 20 cases showed flask-shaped shadow of distal esophageal stenosis and one patient showed linear projection of barium at the level of stenosis. Endoscopy found almost complete obstruction of the lower esophageal lumen without signs of the esophagitis or reflux. Esophagoscopic dilatation of the stenosis was attempted in 24 cases, but was ineffective, and 3 patients suffered esophageal perforation. Seventy-nine patients underwent resection of the stenotic segment. Histologic examination of the resected specimen showed cartilage, mucus glands, resembling bronchal tissue. Post-operative complication included anastomotic stenosis, anastomotic leakage, hiatal hernia, and gastroesophageal reflux.

CONCLUSIONTBR should be suspected in patients who present with a typical history of dysphagia after ingestion of solid food. Esophagography and esophagoscopy are the essential means for diagnosis. TBR should be different from achalasia and should be diagnosed by biopsy. Operation is the only choice of treatment.

Anastomosis, Surgical ; Barium Sulfate ; Biopsy ; Child, Preschool ; Choristoma ; complications ; Dilatation ; Esophageal Atresia ; complications ; Esophageal Perforation ; etiology ; Esophageal Stenosis ; congenital ; diagnosis ; pathology ; surgery ; Esophagoscopy ; Female ; Follow-Up Studies ; Humans ; Infant ; Male ; Postoperative Complications ; epidemiology ; Retrospective Studies ; Tracheoesophageal Fistula ; etiology

OBJECTIVETo explore the operative skills and effect of unilateral pedicle screw combined with contralateral percutaneous transfacet screws fixation in treating degenerative low lumbar disease.

METHODSFrom January 2009 to December 2011,22 patients with degenerative low lumbar disease were treated with transforaminal lumbar interbody fusion, during the operations, unilateral pedicle screw and contralateral percutaneous transfacet screw fixation were performed. There were 16 males and 6 females, aged from 32 to 71 years old with an average of (51.1 ± 10.6) years, including single segment in 20 cases and two segments in 2 cases. Clinical effects were evaluated according to visual analogue score (VAS) and Oswestry Disability Index (ODI).

RESULTSAll patients were followed up from 1 to 2.5 years with an average of 18 months. One case complicated with leakage of cerebrospinal fluid after operation and 1 case with lower limb pain of decompression-side on the 3rd day after operation. Twenty-two patients got bony fusion. There were no instability and evidence of instrument failure during follow-up. The VAS and ODI score decreased from preoperative 8.24 ± 0.72, 36.72 ± 6.84 respectively to 3.18 ± 0.66, 4.36 ± 1.12 at the final follow-up (P < 0.05).

CONCLUSIONUnilateral pedicle screw combined with contralateral percutaneous transfacet screw fixation is safe and feasible surgical technique in treating low lumbar degenerative disease. It has advantages of little trauma, rigid fixation, high fusion rate, and less complication. etc.

Adult ; Aged ; Biomechanical Phenomena ; Female ; Humans ; Intervertebral Disc Degeneration ; physiopathology ; surgery ; Lumbar Vertebrae ; surgery ; Male ; Middle Aged ; Pedicle Screws ; Spinal Fusion ; methods

RT-PCR amplification of ginseng ?-amyrin synthase gene was successfully performed based on the total RNAs extracted from ginseng hairy roots induced by Agrobacterium rhizogenes A4 using a modified guanidine isothiocyanate-method. Sequence analysis of this gene revealed that its sequence was consistent with the sequence of a previously reported ginseng ?-amyrin synthase gene (GenBank No. AB009030). This gene was inserted into pMD-119T simple vector and transformed into E.coli DH5?. Furthermore antisense plant expression vector of this gene was constructed using the pBI121 vector, laying foundation for studies on antisense regulation of ginseng ?-amyrin synthase gene.

Objective To investigate the changes of oxidative stress level in brain tissues and serum, and learning and memory in rats with oxidative stress level in nerve damage in chronic fluorosis. Methods The rats were randomly divided into 3 groups according to the body weight, eight rats in each group, i.e., control group, drinking water containing less than 0.5 mg/L of fluoride; lower fluoride exposure group, drinking water containing 5 mg/L of fluoride; higher fluoride exposure group, drinking water containing 50 mg/L of fluoride. The animals were examined six months after initiating the experiment. The total antioxidant capacity (T-AOC) and malondialdehyde (MDA), as well as learning and memory, were measured. Results Escape latency in higher fluoride exposed group[ (14.37±3.48)s] was significantly higher than that of controls[ (5.84±1.87)s] and exposed te lower fluoride [ (7.18±1.42)s], the difference being statistically signifieant(P<0.05). As compared with controls[ (2.17±0.11)× 103 U/L , (0.79±0.11)×103 U/g Pr] ,the rats exposed to higher fluoride and lower fluoride exhibited lower levels of T-AOC [(1.37±0.27)×103 U/L,(0.24±0.06)×103 U/g Prand (1.20±0.14) x 103 U/L,(0.41 ~ 0.10)×103 U/g Pr], the difference being statistically signifieant(P<0.05). As compared with controls[ (2.34±0.16) mmoL/L, (2.97±0.11)mmol/g Pr] and low fluoride exposed group[ (2.68±0.33)mmoL/L, (3.38±0.21)mmol/g Pr], higher level of MDA were observed in higher fluoride exposed group[ (3.72±0.59)retool/L, (4.01±0.21)mmol/g Pr], the difference being statistically significant(P<0.05). Conclusion The results indicated that higher amount of fluoride induced an increased level of oxidation, which might result in the decreased capacity of intelligence of rats with fluorosis.

OBJECTIVETo construct T vectors based on Xcm I recognition site and optimize the PCR fragments for its ligation.

METHODSWe firstly cloned the human histone H4 cDNA containing one Xcm I recognition site at both its 5' and 3' end into pCDNA 3.0 vector and then generated T vector with pCDNA 3.0 backbone by cutting the recombinant plasmid with Xcm I. To increase the ligation efficiency, the primers were firstly phosphorylated before DNA fragments amplification and then the PCR products were treated with Taq DNA polymerase and dATP after PCR amplification. Two DNA fragments with the length of 312 bp and 1 329 bp were ligated to it and the ligation mixture was transformed into E. coli DH5α competent cells and the positive rates of the transformants were evaluated by PCR and DNA agarose gel electrophoresis.

RESULTSOur results showed that the T vector produced by our method could ligate to the target DNA fragments with high efficiency. Besides, the phosphorylation state of the primers used for PCR amplification is also an important factor determining the cloning efficiency. What's more, as for longer DNA fragments, retreatment with Taq DNA polymerase and dATP after PCR amplification and purification could improve the ligation efficiency significantly.

CONCLUSIONOur protocol may overcome the dependence on blue/white screening to get positive clones and provide a potent way to generate T vectors and ligate them to the target PCR fragment.

Cloning, Molecular ; DNA, Complementary ; genetics ; Escherichia coli ; genetics ; Genetic Vectors ; Histones ; genetics ; Humans ; Polymerase Chain Reaction ; methods