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Biomedical subjects

Bing Li

Publications and source records attributed to Bing Li.

At least 91 records · Page 5Linked to original sources
PubMed2005

Electro-acupuncture improves epileptic seizures induced by kainic acid in taurine-depletion rats.

Electro-acupuncture (EA) partially inhibited epilepsy with great success. The biological basis underlying EA anti-convulsion remained uncertain, which resulted in limited application and slow improvement of acupuncture. Our previous study indicated that taurine may play an inhibitory role against epilepsy as an inhibitory amino acid in the central nervous system and EA may inhibit epilepsy via up-regulating the expression of taurine transporter to increase the release of taurine. Involvement of taurine in kainic acid (KA)-induced epilepsy and anti-convulsion of EA was further addressed on taurine deficiency animal in the present work. We instituted endogenous taurine-deficiency model by supplementation of beta-alanine (3%) in drinking water for continuous 10 days initially, injected KA into lateral cerebral ventricle to induce epileptic seizure, and performed EA treatment on DU26 "RenZhong" and K "YongQuan" acupoints by an EA apparatus (Model G6805-2) using successive waves with the frequency 64Hz and the current intensity 0.8-1.0 mA for 30 minutes in Sprague-Dawley (SD) rats. Taurine levels markedly decreased in cortex, hippocampus, striatum and cerebellum of rats after beta-alanine administration by fluore-HPLC measurement. EA alleviated epileptic activity in rats at 3.5 h time point after KA injection, whereas beta-alanine-induced taurine depletion rendered rats more susceptible to KA-induced epilepsy. Taurine transporter level increased after EA treatment. These results suggested that taurine participated in epileptogenesis and EA may be related to taurine in controlling epileptic seizure.

Animals↗
PubMed2005

[The responses of AtJ2 and AtJ3 gene expression to environmental stresses in Arabidopsis].

By using Northern analysis of the 3''terminal noncoding region of AtJ2 and AtJ3 genes obtained by PCR, it was found that AtJ2 and AtJ3 genes were constitutively expressed in Arabidopsis roots, stems, leaves, flower buds, flowers and silique. They were expressed during the whole growth phase, but the mRNA level decreased slowly with the senescing of plants. Heat shock at 37 degrees C and cold stress at 2 degrees C induced an increase in mRNA level of AtJ2 and AtJ3, but the temporal characteristics of expression of AtJ2 and AtJ3 genes demonstrated that the response of the two genes to cold stress was much slower than that to heat shock. The expression of AtJ2 and AtJ3 genes was up-regulated slightly by water stress. Salt stress had no effect on the expression of AtJ2 and AtJ3 in the experiments. These results indicate that the expression of AtJ2 and AtJ3 genes is involved in response to many environmental stresses except salt stress.

Arabidopsis↗
PubMed2005

[Association of the novel hydatidiform mole-related gene F10 with the invasiveness of trophoblastic tumor].

OBJECTIVE: To study the expressions of the novel gene F10 associated with hydatidiform mole in different trophoblastic tumors and explore the relation of F10 expression with the invasiveness of malignant trophoblastic tumor. METHODS: In situ hybridization was used to study the expression of F10 in 12 cases of hydatidiform mole, 6 cases of invasive mole, and 8 cases of choriocarcinoma. RESULTS: F10 mRNA was positive in all cases of hydatidiform mole, invasive mole, and choriocarcinoma, and the expression intensity significantly increased in the order of hydatidiform mole, invasive mole and choriocarcinoma (P<0.001). CONCLUSION: The expression of F10 gene may relate to the occurrence and invasiveness of trophoblastic tumor, with possible involvement in the invasion or malignant changes of trophoblastic cells.

Adult↗
PubMed2005

[Analysis of gene mutation in Chinese patients with Reis-Bücklers corneal dystrophy].

OBJECTIVE: To identify the mutation of the TGFBI gene in Chinese patients with Reis-Bücklers corneal dystrophy, and to study the relationship between the gene mutation and the clinical appearance. METHODS: Ten patients and 2 unaffected family members from 2 unrelated families with corneal dystrophy were studied. Molecular genetic analysis was performed on DNA extracted from peripheral leucocytes, and exons 4 and 12 of the TGFBI gene were amplified by polymerase chain reaction for direct sequencing. RESULTS: Both pedigrees showed an autosomal dominant inheritance. The clinical appearance of the cornea consisted of fine granular, subepithelial opacities which spread and become confluent with time, and resembled geographic type of Reis-Bücklers corneal dystrophy. Direct sequencing of all affected members revealed a G-to-T transition at codon 124 (CGC to CTC), producing R124L mutation of TGFBI gene. CONCLUSIONS: R124L mutation of the TGFBI gene is found in two Chinese families with Reis-Bücklers corneal dystrophy. The phenotype of Reis-Bücklers corneal dystrophy in both families belongs to the geographic type. Molecular genetic approach may be useful for the proper diagnosis of this type of corneal dystrophy.

Adolescent↗
PubMed2005

[Preliminary analysis of the 5'-flanking region of rat gamma-glutamylcysteine synthetase catalytic subunit gene].

OBJECTIVE: To analyze the characteristic of regulatory elements and corresponding transcriptional factors in the 5'-flanking region of rat gamma-glutamylcysteine synthetase (gamma-GCS) catalytic subunit (GCLC) gene. METHODS: A 1 760 bp 5'-flanking region of the rat GCLC was cloned and constructed into pGL-3 enhancer vector which includes luciferase reporter gene. Exonuclease III was used to cut the 5'-flanking region of rat GCLC gene unidirectionally into deletion mutants of different length, GCLC-Luc and its deletion mutants were used to transfect rat alveolar epithelium cells CCL-149, then the regulatory region of the gene was determined by luciferase activity assay of the transfected cells. Analysis of the transcription-factor-binding site was done using Transcription Factor Search software to indicate possible transcriptional factors. Electrophoresis mobility shift assay (EMSA) was used to determine the cis-acting elements and transcriptional factors in these regulatory regions. RESULTS: The experiment cloned the upstream regulatory sequence of rat GCLC gene and its reporter vector GCLC-Luc, as well as 11 deletion mutants of GCLC-Luc. Luciferase activity assay of the cells transfected by GCLC-Luc (-1 758/+2-Luc), mutant 1 (-1 231/+2-Luc), mutant 2 (-1 108/+2-Luc), mutant 3 (-1 087/+2-Luc), mutant 4 (-876/+2-Luc), mutant 5 (-745/+2-Luc), mutant 6 (-705/+2-Luc), mutant 8 (-613/+2-Luc), mutant 9 (-595/+2-Luc), mutant 10 (-403/+2-Luc) and mutant 11(-111/+2-Luc) were (90 012 +/- 2 445), (77 652 +/- 840), (149 927 +/- 4 915), (71 588 +/- 1 108), (99 283 +/- 2 612), (75 443 +/- 1 438), (282 772 +/- 7 046), (96 891 +/- 2 275), (148 917 +/- 5 966), (258 991 +/- 5 015) and (895 +/- 49) U, respectively. EMSA proved that activated protein-1 (AP-1) and nuclear factor-kappaB (NF-kappaB) can bind to the region of -403 to -111 bp; nuclear factor-1 (NF-1) and CCAAT/enhancer binding protein (C/EBP) can bind to the region of -705 to -613 bp; and upstream stimulatory factor (USF) can bind to the region of -745 to -705 bp. CONCLUSIONS: Two DNA regions -403 to -111 bp and -705 to -613 bp of GCLC gene, which can be bound by transcriptional factors such as NF-1, C/EBP, AP-1, and NF-kappaB on EMSA, are involved in positive gene regulation. A newly identified region -745 to -705 bp of GCLC gene, which can be bound by USF, is involved in negative gene regulation, suggesting that the interaction between E-box and USF can inhibit the expression of gamma-GCS.

5' Flanking Region↗
PubMed2005

[Expression of human-mouse chimeric antibody directed against Chikungunya virus with site-specific integration system].

AIM: To obtain CHO/dhfr(-) cells line with integrated FRT sequence in the chromosome transcription active site and to express human-mouse chimeric antibody directed against Chikungunya Virus by using the cell line. METHODS: The fusion gene of FRT and HBsAg was constructed by PCR and cloned into the MCS of pCI-neo to construct pCI-FRT-HBsAg. The pCI-FRT-HBsAg was transfected into CHO/dhfr(-) cells and cell clones with high expression of HBsAg were screened by detecting the amount of HBsAg with ELISA. A CHO cell clone with the highest expression was chosen and named as CHO/dhfr(-) FRT(+). pAFRT HFLF, a expression plasmid of chimeric antibody with RFT sequence was transfected into CHO/dhfr(-) FRT(+) cells and cell clones with high expression of the chimeric antibody were screened by increasing concentration of MTX. A CHO cell clone with high expression of the chimeric antibody was cultured in large scale and supernatant was collected from which the chimeric antibody was purified. The purified chimeric antibody was analyzed by SDS-PAGE, Western blot and IFA. RESULTS: A CHO/dhfr(-) cells line with integrated FRT sequence in the chromosome transcription active site was obtained successfully. A cell clone with yield of 5 mg/L of chimeric antibody was obtained, as compared with routine CHO cell expression system with a yield of 2 mg/L. CONCLUSION: A cell line with integrated FRT sequence in the chromosome transcription active site was obtained and with it human-mouse chimeric antibody directed against Chikungunya virus was expressed. This system lays a solid foundation which can be used for expressing antibodies and other proteins.

Amino Acid Sequence↗
PubMed2005

[The clinical feature, diagnosis and treatment of uveitis associated with juvenile chronic arthritis].

OBJECTIVE: To investigate the clinical features, diagnosis and treatment of uveitis associated with juvenile chronic arthritis (JCA). METHODS: A retrospective study was performed on the clinical data of 26 patients with uveitis associated with JCA, referred to Zhongshan Ophthalmic Center from 1996 to 2002. Taking of history, examination with slit-lamp microscope and ophthalmoscope were carefully performed in all of these patients. Laboratory tests including antinuclear antibodies, erythrocyte sedimentation rate, rheumatoid factor, C reactive protein and antistreptolysin O were used to disclose possible causes. Human leukocyte antigen B 27 and X-ray examination of sacroiliac joints and spine were carried out if necessary. Data about the treatment, visual outcome and complications were analyzed. RESULTS: Twenty-six patients, 11 males and 15 females, were included in the present studies. Age of onset of JCA and uveitis averaged 8 years and 9 years, respectively. Twenty-one patients had chronic anterior uveitis. Acute anterior uveitis and chronic panuveitis were noted in 3 and 2 patients, respectively. Twenty-two patients had bilateral uveitis, the other 4 had unilateral involvement. The ophthalmologic examination revealed that 33 of the 48 affected eyes showed mild aqueous humor flare, 24 had few cells in the anterior chamber. Complicated cataract, band keratopathy and secondary glaucoma were noted in 30, 20 and 12 eyes, respectively. The laboratory examination revealed positive antinuclear antibodies in 18 cases and rheumatoid factor positive in one case. In acute episode, patients were treated with extensive topical cycloplegic agents and corticosteroids eyedrops. In the 6 cases with severe uveitis, 3 patients were treated with cyclosporine A (5 mg.kg(-1).d(-1)) and the other 3 were treated with chlorambucil (0.1 mg.kg(-1).d(-1)). The intraocular inflammation in all of these patients was satisfactorily controlled with these treatments. Visual acuity improvement was noted in 32 affected eyes but not in the other 16 eyes which had already serious complications before the treatment. CONCLUSIONS: Uveitis associated with JCA is characterized by a chronic and recurred iridocyclitis, which usually developed within 5 year after JCA onset. Although the intraocular inflammation associated with JCA is usually white uveitis, complications such as cataract, secondary glaucoma and keratopathy occur frequently in these patients. The diagnosis is mainly based on typical clinical manifestations, the history of arthritis and positive antinuclear antibodies. Adequate application of cycloplegic agents, corticosteroids eyedrops, immunosupressives and the regular follow-up should be kept in mind in the treatment of these patients.

Adolescent↗
PubMed2005

[An experimental study on the mini pig model of obstructive sleep apnea syndrome].

A mini pig model for study of human obstructive sleep apnea syndrome (OSAS) was established by altitude hypoxia. Eight mini pigs were randomly assigned to 3 groups, named A, B, and C. They were placed in a double-roomed altitude chamber. As control, Groups A lived in Room 2 and there was an altitude of sea level in it. Groups B and C were in Room 1 and the pressure in it was 53.9 KPa with an oxygen concentration of 10.0%-11.2%. All of these mini pigs were in their rooms for 6 hours per day. Pigs in Groups B were in the room for 12 consecutive days and sacrificed on the 13th day. Pigs in Groups A and C were executed on the 23rd day. The pharyngeal CT scanning and the defermination of respiratory pressure in pharynx oralis and saturation of arterial blood oxygen were conducted in all exprimental mini pigs before they were put in chamber and before they were put to death. The pharyngeal tissues of the executed pigs were pathologically examined. CT scanning revealed there was significant (P < 0.05) increase in mini pigs' posterior pharyngeal wall (8.8 +/- 1.1 vs 6.5 +/- 0.6) and lateral pharyngeal wall (8.1 +/- 0.2 vs 6.3 +/- 0.6) on the 13th day as compared with that before they were put in chamber, and there was also significant (P < 0.05) increase (9.2 +/- 1.2 vs 6.3 +/- 0.7; 8.9 +/- 0.7 vs 6.4 +/- 0.5) on the 23rd day. There was significant (P < 0.05) reduction in diameter from left to right at the hyoid bone level (7.6 +/- 1.4 vs 9.7 +/- 1.4) and in the anteroposterior diameter at the soft palace level (3.8+/-1.1 vs 6.5 +/- 1.3) on the 13th day as compared with that before the mini pigs were put in chamber, and there was also sinificant (P < 0.05) reduction (6.4 +/- 1.6 vs 9.3 +/- 1.5; 4.3 +/- 0.9 vs 5.9 +/- 0.8) on the 23rd day. There was significant reduction (P < 0.05) in anteroposterior diameter on the posterior area of hyoid bone (3.7 +/- 0.9 vs 6.4 +/- 0.6) on the 23rd day. A significant change (P < 0.05) was observed in respiratory pressure of pharynx oralis on the 23rd day (0.0755 Mv) when compared with that before the first day (0.0658 Mv) in chamber and no significant change was seen on the 13th day. The saturation of blood oxygen decreased from 96.3% to 87.0% on the 13th day (P < 0.05) and further descended to 88.5% on the 23rd day (P < 0.05), compared with that before the first day in chamber. Pathological examination showed. In Group A, the mucosa of pharynx is covered by nonkeratinized-stratified squamous epithelium, and the layer of submucosa is thin; the muscular layer has clear striations and less fat cells among muscular fibers. In Group B, the pharyngeal epithelium is cornified and proliferated. Edema and proliferation of connective tissue occur in submucosa, and the muscular layer is thick with unclear striations; local infiltration of fat cells can be observed among muscular fibers. The pathological changes were more serious in Group C than in Group B. The results suggest that the method of intermittent altitude hypoxia could make the pharyngeal tissue of mini pig remodel and change its muscular biomechanical properties into those similar to the performance of OSAS in human. Living in altitude hypoxia for 22 days, the mini pigs became ill with OSAS, thus the expected animal model has been established in this study and could be used in further researches on OSAS in patients.

Altitude↗
PubMed2005

[Contrasting experiment of two types of MSW aerobic bioreactor landfill].

Bioreactor landfill is an emerging landfilling method, which represents the newest developing aspect of Municipal Solid Wastes (MSW) treatment. On basis of analyzing the merits and defects of present bioreactor landfilling methods, the paper improves these methods and combines organically aeration and leachate recirculation into a new reactor (called reactor A), which is contrasted with bare aerobic landfill (called reactor B). During the course of experiment, NH3, CH4, CO2, pH, temperature and electric conductivity in the two bioreactors were controlled and detected, meanwhile, COD, Fe3+, NH4(+) in the leachate were detected and analyzed. The paper researches on the wastes degradation and the COD, Fe3+ and NH4(+) removal of the two bioreactors, probes into the mechanics of wastes and leachate degradation. Finally the paper draws a conclusion that the effect of degrading wastes and leachate of bioreactor A is better than that of bioreactor B.

Bacteria, Aerobic↗
PubMed2005

[Molecular cloning and expression of the severe acute respiratory syndrome-associated coronavirus nucleocapsid protein and its clinical application].

OBJECTIVE: To clone and express nucleocapsid (N) protein of the severe acute respiratory syndrome (SARS)-associated coronavirus, and to evaluate its antigenicity and application value in the development of serological diagnostic test for SARS. METHODS: SARS-associated coronavirus N protein gene was amplified from its genomic RNA by reverse transcript nested polymerase chain reaction (RT-nested-PCR) and cloned into pBAD/Thio-TOPO prokaryotic expression vector. The recombinant N fusion protein was expressed and purified, and its antigenicity and specificity was analyzed by Western Blot, to establish the recombinant N protein-based ELISA for detection of IgG antibodies to SARS-associated coronavirus, and SARS-associated coronavirus lysates-based ELISA was compared parallelly. RESULTS: The recombinant expression vector produced high level of the N fusion protein after induction, and that protein was purified successfully by affinity chromatography and displayed higher antigenicity and specificity as compared with whole virus lysates. CONCLUSION: The recombinant SARS-associated coronavirus N protein possessed better antigenicity and specificity and could be employed to establish a new, sensitive, and specific ELISA for SARS diagnosis.

Antibodies, Viral↗
PubMed2005

A novel mutation of estrogen receptor gene detected in girls with precocious puberty.

Female precocious puberty is caused by premature activation of the hypothalamic-pituitary-gonadal axis, exposure to exogenous sex steroid hormones, and the presence of endogenous sex steroids caused by various factors. Estrogen is the final key factor to start onset of puberty. However,in some cases of precocious puberty in girls estrogen elevation could not be detected. The raised sensitivity of estrogen receptor, which may caused by ESR1 mutation or polymorphism, has been frequently mentioned for interpreting the etiology of sporadic low estrogen type cases. But no case evidence has been found in clinical practice. For the purpose of screening possible mutations in estrogen receptor gene, leukocyte genomic DNA were collected from 16 girls with precocious puberty of sporadic low estrogen,and exons of ESR1 were amplified and analysized using PCR-SSCP/silver staining method. A single strand conformation change in exon 8 was found in one of the patients (No. 14). The suspected fragment were cloned to a T vector and sequenced for analysis. Sequencing of these clones revealed that this conformation change is caused by a C to T transition. This mutation results in the replacement of arginine by cystine at position 548 of ESR1 protein. The mutation created an extra Btsl digest site and made it can be readily identified by PCR-PFLP method. Further detection using this method, and sequencing of cloned exon8 colonies from patients proved that the patient No. 14 is Arg548/Cys548 heterozagous in genotype. This mutation increased hydrophobility of the area dramatically. The position and the conservative of this residue in vertebrates suggested Arg548 may play an important role in ESR1 function. For study the role of this mutation in the onset of precocious puberty, a firefly luciferase reporter plasmid pGL3-promoter-ERE was constructed,and a pCR3. 1-hermut pisimid expressing Cys548 ER was constructed based on wild type pCR3. 1her. Co-transfection of reporter and pCR3. 1 -hermut in CMF-7 cell strain proved that Cys548 mutant can significantly increase the transcription activity over the Arg548 wild type.

Amino Acid Substitution↗
PubMed2005

[Construction of a trans-splicing ribozyme for restoring EGFP truncation mutation].

Special designed group I intron ribozymes can specifically splice objective RNA, repair the mutant gene in RNA level. The specificity of ribozyme is determined by nucleotides specific internal guide sequence (IGS) introduced to the enzyme. In this study, fragment sequence containing Tetrahymena thermophilia intron I of 26S rRNA gene was cloned and cis-splicing activity of this ribozyme was confirmed by in vitro transcription. For evaluating the trans-splicing activity of this ribozyme, a truncated mutant Green Fluorescence Protein (GFP) vector, XYQ5/XYQ10- pEGFP-C2, was constructed. This vector deleted the 3' end 564bp fragment of EGFP coding sequence, led to the lost the activity of emitting green fluorescence. Trans-splicing ribozyme plasmids ptrans-rib-CMV2 for remedy of the truncated mutant EGFP was constructed by PCR and molecular cloning techniques. This vector utilizing cloned 26S rRNA intron 1 as core enzyme; selecting T-G site at 194bp of EGFP coding sequence as splicing receptor, designed an IGS which is inversely complement to the 188-193nt of EGFP mRNA; the 195-890bp fragment of EGFP coding sequence was ligated to the 3'-end of ribozyme core. The fragment containing these components was inserted to a eukayotic expression vector pRC-CMV2. Using linearized XYQ5/XYQ10- pEGFP-C2 and ptrans-rib-CMV2 as templates, truncated EGFP mRNA and the constructed ribozyme vector were transcribed and mixed to evaluate the trans-splicing activity. Analysis of in vitro transcription products mix by RT-PCR verified the existence of wild type EGFP mRNA molecule. Co-transfection of XYQ5/XYQ10- pEGFP-C2 with ptrans-rib-CMV2 to Hela cells proved this ribozyme restored green fluorescence within cell, but the efficiency was low.

Animals↗
PubMed2005

[Functional reconstruction of hands with irreversible radial nerve injury].

OBJECTIVE: To evaluate the effect of tendon transfer on reconstructing the extension of wrist, thumb and digit after irreversible radial nerve injury. METHODS: From January 1987 to February 2005, 25 cases of irreversible radial nerve injury were treated with Riordan tendon transfer. Among them there were 19 cases of central radial nerve injury with wrist, thumb and digit extension dysfunction and 6 cases of deep branch of radial nerve injury with digit and thumb extension dysfunction. The muscle strength of wrist and digit extension ranged from grade 0 to grade I . Tendon transfer was done 4 months to 8 years after their injuries. RESULTS: Twenty-three cases were followed up for 3 to 60 months. According to the standard established by Chen Desong, 19 cases (82.6%) showed excellent and good results. Fair result was showed in 2 cases and poor result was showed in 2 cases. CONCLUSION: Riordan tendon transfer should be the first choice of treating irreversible radial nerve injury.

Adolescent↗
PubMed2004

Enhancement of synaptic plasticity through chronically reduced Ca2+ flux during uncorrelated activity.

The plasticity of synapses within neural circuits is regulated by activity, but the underlying mechanisms remain elusive. Using the dye FM1-43 to directly image presynaptic function, we found that large numbers of presynaptic terminals in hippocampal cultures have a low release probability. While these terminals were not readily modifiable, a transient but not permanent long-term reduction of network activity or Ca2+ influx could increase their modifiability. This modulation of plasticity was mediated by Ca2+ flux through NMDA and voltage-gated calcium channels and was lost within 48 hr. A more permanent enhancement of synaptic plasticity was achieved by selectively reducing the Ca2+ flux associated with uncorrelated activity via adjustment of the voltage-dependent Mg2+ block of the NMDAR. Upregulation of NR2B-containing NMDARs induced by this treatment is an important but not sole contributor to the enhancement of plasticity. Thus, quantity and quality of activity have differential effects on the intrinsic plasticity of neurons.

Animals↗
PubMed2004

Accurate determination of isthmus of lumbar pedicle: a morphometric study using reformatted computed tomographic images.

STUDY DESIGN: Lumbar pedicle isthmus, the narrowest section of pedicle, was investigated. OBJECTIVE: To determine the lumbar pedicle isthmus accurately and measure related parameters. SUMMARY OF BACKGROUND DATA: Accurate anatomic knowledge of pedicle parameters is critical for a successful transpedicular procedure. Many studies on lumbar pedicle dimensions have been conducted, yet less is known about how to obtain these data and their veracity. In fact, the narrowest section is present in the pedicle, i.e., the isthmus of the pedicle. This is the bottleneck of the pedicle; to determine and measure it could illustrate the true morphologic characteristics of the lumbar pedicle. METHODS: Ultra high-speed spiral CT scan of lumbar spine was performed in 41 patients of Chinese origin. After reformation of the original images, isthmus and transverse plane of pedicle axis were determined. Eleven dimensions of isthmus plane and three dimensions of transverse plane were calculated using software. RESULTS: Pedicle endosteal width and height in female patients who were over the age of 50 were greater than those of female patients younger than 50 years old. The isthmus endosteal width from L1 to L5 was 5.2, 6.0, 7.5, 7.5, and 8.7 mm and 4.0, 4.1, 5.4, 5.7, and 7.1 mm, respectively, in men and women. Isthmus inclination inclined to midline with less than 10 degrees above L3 but increased in L4 and 30 degrees in L5. CONCLUSIONS: An objective narrowest section, the pedicle isthmus, exists in lumbar pedicle axis. The parameters of isthmus, especially isthmus endosteal width, show the morphologic characteristics of the lumbar pedicle and are the most important data provided for transpedicular procedures. The small pedicles of female patients over the age of 50 also show certain primary osteoporosis. Isthmus inclination puts the pedicle in a more complicated space position. A better understanding of the complicated structure of the pedicle isthmus guarantees success in transpedicular procedures.

Adult↗
PubMed2004

Synthesis of Chiral beta 3-aminoxy peptides.

A series of chiral beta(3)-aminoxy acids or amides with various side chains have been synthesized via two different approaches. One is the Arndt-Eistert homologation approach, using chiral alpha-aminoxy acids as starting materials. The other approach, utilizing the enantioselective reduction of beta-keto esters catalyzed by baker's yeast or chiral Ru(II) complexes, produces chiral beta(3)-aminoxy acids with nonproteinaceous side chains. The oligomers of beta(3)-aminoxy acids can be readily prepared using EDCI/HOAt as the coupling reagent.

Amides↗
PubMed2004

Role of neuronal energy status in the regulation of adenosine 5'-monophosphate-activated protein kinase, orexigenic neuropeptides expression, and feeding behavior.

Nutrient sensing in the hypothalamus is tightly related to food intake regulation. However, the mechanisms by which the nutrient-sensing cells of the brain translate this signal of energy need into feeding behavior via regulation of neuropeptide expression are not known. To address this issue, we investigated two neuronal cell lines expressing agouti-related protein (AgRP), ex vivo hypothalamic tissues, and in vivo whole animals. Maintaining cells in a low cellular ATP concentration generated by low glucose, 2-deoxyglucose (2-DG), ATP synthesis inhibitor, and 5-aminoimidazole-4-carboxamide 1-beta-d-ribofuranoside increased phosphorylation of AMP-activated protein kinase (AMPK) and increased AgRP expression, whereas maintaining cells in high ATP status by high glucose and pyruvate supplementation in 2-DG-treated cells decreased phosphorylation of AMPK and decreased AgRP expression. Overexpression of a dominant-inhibitory mutant of AMPK significantly decreased low-glucose- or 2-DG-induced AgRP expression. Furthermore, ex vivo hypothalamus culture in high glucose concentrations decreased both expression and phosphorylation of AMPK and expression of both AgRP and neuropeptide Y, whereas pyruvate supplementation suppressed a 2-DG-induced AgRP expression. Finally, our in vivo studies clearly show that central administration of pyruvate dramatically delayed 2-DG-induced food intake. These data indicate that modulation of ATP levels in neuronal cells triggers a cascade of events via AMPK that modulate feeding behavior to restore energy status of cells.

AMP-Activated Protein Kinases↗