Biomedical subjects

S Liang

Publications and source records attributed to S Liang.

At least 55 records · Page 3Linked to original sources

PubMed2000

[Tracheal transplantation].

OBJECTIVE: To treat long tracheal cancer by tracheal transplantation. METHODS: In March 17, 1999, a patient received a total laryngeal resection and a resection of 8 cm upper and middle trachea, which was replaced by a 6 cm long trachea of another donor. The donor trachea was dipped first in preservation liquid A for sterilization for 24 hours, then in preservation liquid B for over 48 hours for destructing MHC. Pedunculated greater omentum and pedunculated greater pectoral musculus supplied the blood for the donor trachea. One side of the donor was anastomosed with the lower trachea, and the other with the neck skin. RESULTS: The patient survived 300 days after operation. The auto tracheal membrane covered the donor surface; auto- and xeno trachea was well anastomose. The new trachea grew very well. CONCLUSION: Trachea transplantation is possible the best method to treat long tracheal disease if the transplantable trachea is less 5 cm.

Aged↗

PubMed2000

[Automated fluorescent analysis of STR profiling and sex determination].

Denaturing PAGE coupled with the ABI377 fluorescent automated DNA sequencer was used to test the performance and reproducibility of the automated DNA profiling systems at vWA31A, TH01, F13A01, FES, TPOX, CSF1PO and Amelogenin gene. The allele designation windows at the 7 genetic markers were established and implemented into the genotype reading software. Alleles differing in just 1 bp in length could easily be discriminated. Furthermore, the interpretation guidelines were outlined for the 7 genetic systems by investigating the relative peak areas of heterozygote peaks and relative stutter peak areas in various monoplex systems. Our results indicate that if the ratio between two peaks is equal to or higher than 0.404, a herozygote could be determined, otherwise the homozygote be made.

Alleles↗

PubMed2000

[Study on erzhi pill effects on neuro-endocrinologic-immuno network of animal of deficiency of yin].

OBJECTIVE: To investigate Erzhi Pill effect on Neuro-Endocrinologic-Immuno network of animal of deficiency of Yin. METHOD: In the experiment through the determination of hemotic cortisol, insulin, testosterone, beta-endorphin, cholesterol, weight of adrenal and thymus, ConA-induced, spleelymphocyte proliferation and activity of natural killer cells (NKC). The changes of the animals of deficiency of Yin and the effects of the Erzhi Pill were investigated. RESULT: It showed that rats of deficiency of Yin, their hemotic, cortisol, insulin, testosterone, beta-endorphin, weight of adrenal and thymus decreased, cholesterol increased and mouse of deficiency of Yin, their lymphocyte proliferation and activity of NKC dcreased, which might be modulated with Erzhi Pill. Erzhi Pill could improve hemotic cortisol, insulin, testosterone, beta-endorphin, weight of adrenal and thymus, reduce hemotic cholesterol, improve lymphocyte proliferation and activity of NKC. CONCLUSION: This principle could improve animals of deficiency of Yin regulating Neuro-Endocrinologic-Immuno network and keeping homeostais.

Animals↗

PubMed2000

[Analysis of Amomun villosum species and some adulterants of zingiberaceae by RAPD].

Different Amomum villosum Lour. species and some their adulterants of Zingiberaceae were researched using RAPD. The PCR indicates favourable differentiation of the reaction. The Amomum villosum Lour. species have the similar DNA fingerprints while it is obviously differ from adulterants. There are 12.17 percent of primers which appear polymorphism. We can identify different species according to these dissimilarity. We also construct the tree of the molecular evolution through NJ software, the hereditary distance of the graph shows different relationships between Amomum villosum Lour. species and their adulterants. The result created by software is analogous the traditional methods.

Amomum↗

PubMed2000

[Histological study of the local-regional invasion of pyriform sinus carcinoma].

OBJECTIVE: In order to offer the basis for the operation of the pyriform sinus carcinoma, the local-regional invasion patterns of the pyriform sinus carcinoma were investigated. METHODS: Twenty-six surgical specimens obtained from patients who undergone laryngopharyngectomy were subjected to a whole organ section study. RESULTS: Tumors located in the lateral wall of the pyriform sinus spread mainly towards the lateral wall of the hypopharynx. Tumors located in the inner wall of the pyriform sinus spread mainly towards the larynx and opposite side pyriform sinus, the paraglottic space and thyroid cartilage were particularly frequent invaded. It was rare of the invading of the cricoid cartilage. The invasion of the epiglottis and preepiglottic space across the midline had not been found. There were two invading routines, the paraglottic space and preepiglottic space. The invasion of the paraglottic space was through the aryepiglottic fold and the inner surface of the thyroid cartilage. The invading of the preepiglottic space was through the aryepiglottic fold and the upper part of the inner surface of the thyroid cartilage. CONCLUSIONS: The invading of the preepiglottic space was not the contraindication of the partial laryngectomy. It is practicable to preserve the laryngeal function in most of the patients while tumors located on the lateral or inner wall of the pyriform sinus. There was a tendency to the invading to the contralateral side in the inner wall of the pyriform or postcricoidarytenoid region. Attention should be paid to the submucosal spreading in the postcricoidarytenoid region.

Adult↗

PubMed1999

Age-related variation in the interstitial tissues of the cardiac conduction system; and autopsy study of 230 Han Chinese.

The amount of fatty and fibrous tissues in 230 Han Chinese who died of noncardio-vascular diseases has been studied by a semi-quantitative method and analysed by chi-square test. The results have shown some consistency. Generally, in the sino-atrial node (SAN), fibrosis and fatty influtratin appear only after 40 years of age and increase one grade with every 20 years. The atrio-ventricular node (AVN) showed fatty change after 30 years of age and fibrosis appeared after 60. In the His bundle (HB), fatty infiltration and fibrosis appear after 40 years. The left bundle branch (LBB) showed similar changes. The appearance of fibrosis in the AVN seems to be later than that reported by Lev.

Adolescent↗

PubMed1999

Emerging HIV infections with distinct subtypes of HIV-1 infection among injection drug users from geographically separate locations in Guangxi Province, China.

Heroin users from Guangxi province, a southern province of China that borders Vietnam in the south and Yunnan province in China in the west, were studied for prevalence and risk factors for HIV-1 infection. Viral env sequences from HIV-1-positive individuals were also determined for subtypes of HIV-1. The overall HIV prevalence among 227 heroin users was 40%. Most had used drugs for < or = 3 years. Sharing of injection equipment and unprotected sex were significantly associated with HIV-1 infection. Subtypes C and E HIV-1 were detected in infected heroin users and were sharply segregated in two geographic locations: only subtype C was found in a border city with Yunnan province, whereas only subtype E was found in a city bordering northern Vietnam. HIV-1 strains within each subtype were remarkably homogenous, with a mean intersubject DNA distance of 2.32% for subtype E and 1.13% for subtype C, respectively. Phylogenetic analysis of C2-V5 region of Guangxi subtype E env sequences revealed significant clustering with subtype E sequences from southern Vietnam and Cambodia. These results suggest that HIV-1 infection among heroin users in Guangxi represents two emerging epidemics initiated from distinct sources: one from Vietnam and another from Yunnan province. Factors associated with HIV-1 infection were not restricted to injection practices. Unprotected sexual behaviors are likely to increase the probability of HIV transmission beyond this high-risk population. Designing and implementing effective intervention strategies targeted toward both injection drug use and high risk sexual behavior are urgently needed to further reduce HIV-1 spread in China.

China↗

PubMed1999

Activities of constitutive promoters in Escherichia coli.

The in vivo activities of seven constitutive promoters in Escherichia coli have been determined as functions of growth rate in wild-type relA+ spoT+ strains with normal levels of guanosine tetraphosphate (ppGpp) and in ppGpp-deficient DeltarelADeltaspoT derivatives. The promoters include (i) the spc ribosomal protein operon promotor Pspc; (ii) the beta-lactamase gene promotor Pblaof plasmid pBR322; (iii) the PLpromoter of phage lambda; (iv) and (v) the replication control promoters PRNAIand PRNAIIof plasmid pBR322; and (vi) and (vii) the P1 and P2 promoters of the rrnB ribosomal RNA operon. Each strain carried an operon fusion consisting of one of the respective promoter regions linked to lacZ and recombined into the chromosome at the mal locus of a lac deletion strain. The amount of 5'-terminal lacZ mRNA and of beta-galactosidase activity expressed from these promoters were determined by standard hybridization or enzyme activity assays, respectively. In addition, DNA, RNA and protein measurements were used to obtain information about gene dosage, rRNA synthesis and translation rates. By combining lacZ mRNA hybridization data with gene dosage and rRNA synthesis data, the absolute activity of the different promoters, in transcripts/minute per promoter, was determined. In ppGpp-proficient (relA+ spoT+) strains, the respective activities of rrnB P1 and P2 increased 40 and fivefold with increasing growth rate between 0.7 and 3.0 doublings/hour. The activities of Pspc, PL, Pbla, and PRNAIincreased two- to threefold and reached a maximum at growth rates above 2.0 doublings/hour. In contrast, PRNAIIactivity decreased threefold over this range of growth rates. In ppGpp-deficient (DeltarelA DeltaspoT) bacterial strains, the activities of rrnB P1 and P2 promoters both increased about twofold between 1.6 and 3.0 doublings/hour, whereas the activities of Pspc, PL, Pbla, and PRNAI, and PRNAIIwere about constant. To explain these observations, we suggest that the cellular concentration of free RNA polymerase increases with increasing growth rate; for saturation the P1 and P2 rRNA promoters require a high RNA polymerase concentration that is approached only at the highest growth rates, whereas the other promoters are saturated at lower polymerase concentrations achieved at intermediate growth rates. In addition, the data indicate that the respective rrnB P1 and PRNAIIpromoters were under negative and positive control by ppGpp. This caused a reduced activity of rrnB P1 and an increased activity of PRNAIIduring slow growth in wild-type (relA+ spoT+) relative to ppGpp-deficient (DeltarelA DeltaspoT) bacterial strains.

Cell Division↗

PubMed1999

Expression and localisation of dynamin and syntaxin during neural development and neuromuscular synapse formation.

The expression and subcellular localisation of dynamin and syntaxin were examined during the periods of motor neuron development and neuromuscular synaptogenesis in the mouse embryo. Both dynamin and syntaxin could be detected by immunoblotting in the spinal cord at embryonic day 10 (E10; 2 days before axon outgrowth) and at all subsequent ages examined. Reverse transcription and polymerase chain reaction (RT-PCR) identified low levels of all three carboxy-terminal splicing forms of dynamin I in spinal cord from as early as E10. During the period of maturation of spinal neurons, from E10 to the first postnatal day (P0), the short carboxy-terminal splicing form of dynamin I (dynamin I*b) was up-regulated, as was dynamin III, relative to dynamin II mRNA. Syntaxin immunostaining became colocalized with the synaptic vesicle protein, SV2, at neuromuscular synapses within 12 hours of the commencement of synapse formation and throughout subsequent development. In contrast, dynamin, which is important for activity-dependent synaptic vesicle recycling and, thus, sustained neurotransmission, could not be detected at most newly formed synapses until several days after synapse formation. The delayed appearance of dynamin at the synapse, thus, heralds the neonatal development of robust synaptic transmission at the neuromuscular junction.

Animals↗

PubMed1999

Solution structure of the major alpha-amylase inhibitor of the crop plant amaranth.

alpha-Amylase inhibitor (AAI), a 32-residue miniprotein from the Mexican crop plant amaranth (Amaranthus hypochondriacus), is the smallest known alpha-amylase inhibitor and is specific for insect alpha-amylases (Chagolla-Lopez, A., Blanco-Labra, A., Patthy, A., Sanchez, R., and Pongor, S. (1994) J. Biol. Chem. 269, 23675-23680). Its disulfide topology was confirmed by Edman degradation, and its three-dimensional solution structure was determined by two-dimensional 1H NMR spectroscopy at 500 MHz. Structural constraints (consisting of 348 nuclear Overhauser effect interproton distances, 8 backbone dihedral constraints, and 9 disulfide distance constraints) were used as an input to the X-PLOR program for simulated annealing and energy minimization calculations. The final set of 10 structures had a mean pairwise root mean square deviation of 0.32 A for the backbone atoms and 1.04 A for all heavy atoms. The structure of AAI consists of a short triple-stranded beta-sheet stabilized by three disulfide bonds, forming a typical knottin or inhibitor cystine knot fold found in miniproteins, which binds various macromolecular ligands. When the first intercystine segment of AAI (sequence IPKWNR) was inserted into a homologous position of the spider toxin Huwentoxin I, the resulting chimera showed a significant inhibitory activity, suggesting that this segment takes part in enzyme binding.

Amino Acid Sequence↗

PubMed1999

[Research on the protective effect of wine against cardiovascular diseases].

Recent studies reveal that wine is rich in phytoalexin and polyphenolic compounds, which can inhibit atherosclerosis by modulating metabolism of plasma lipid and lipoprotein, preventing platelet from aggregation and relaxing cardiovascular smooth muscle, etc.. A long-term moderately intake of wine can reduce the morbidity and mortality of ischemic heart diseases.

Coronary Disease↗

PubMed1999

Assignment of the three disulfide bonds of Selenocosmia huwena lectin-I from the venom of spider Selenocosmia huwena.

The positions of the disulfide bonds of Selenocosmia huwena lectin-I (SHL-I) from the venom of the Chinese bird spider S. huwena have been determined. The existence of three disulfide bonds in the native SHL-I was proved by matrix-assisted laser desorption ionization time-of-flight mass spectroscopic analysis. To map the disulfide bonds, native SHL-I was proteolytically digested. The resulting peptides were separated by reverse phase high-performance liquid chromatography. Matrix-assisted laser desorption ionization time-of-flight mass spectroscopic analysis indicated the presence of one disulfide bond Cys7-Cys19. The partially reduced peptides by using Tris-(2-carboxyethyl)-phosphine at pH 3.0 were purified by reverse phase high-performance liquid chromatography. Four M Guanidine-HCl was found to increase the yields of partially reduced peptides prominently. The free thiols were carboxamidomethlate by iodoacetamide. The specific location of another disulfide bond Cys2-Cys14 was proved by comparing N-terminal sequencing analysis of the partially reduced and alkylated SHL-I with that of the intact peptide. Finally, the three disulfide linkage of SHL-I could be assigned as Cys2-Cys14, Cys7-Cys19, Cys13-Cys26.

Amino Acid Sequence↗

PubMed1999

Three-dimensional structure of Selenocosmia huwena lectin-I (SHL-I) from the venom of the spider Selenocosmia huwena by 2D-NMR.

The three-dimensional structure of native SHL-I, a lectin from the venom of the Chinese bird spider Selenocosmia huwena, has been determined from two-dimensional 1H NMR spectroscopy recorded at 500 and 600 MHz. The best 10 structures have NOE violation <0.3 A, dihedral violation <2 deg, and average root-mean-square differences of 0.85 + 0.06 A over backbone atoms. The structure consists of a three-stranded antiparallel beta-sheet and three turns. The three disulfide bridges and three-stranded antiparallel beta-sheet form a inhibitor cystine knot motif which is adopted by several other small proteins, such as huwentoxin-I, omega-conotoxin, and gurmarin. The C-terminal fragment from Leu28 to Trp32 adopts two sets of conformations corresponding to the cis and trans conformations of Pro31. The structure of SHL-I also has high similarity with that of the N-terminus of hevein, a lectin from rubber-tree latex.

Amino Acid Sequence↗

PubMed1999

Oxidative folding of reduced and denatured huwentoxin-I.

Huwentoxin-I, a neurotoxic peptide with 33 amino acid residues and three disulfide bonds, was used to investigate the pathway of reduction/denaturation and of oxidative folding in small proteins with multiple disulfide bonds. Titration of thiol groups, reversed-phase HPLC, 1D NMR spectroscopy, and biological activity assays were used to monitor the extent of reduction/ denaturation and renaturation of the toxin. The reduction and denaturation of huwentoxin-I resulted in a 100% loss of bioactivity as measured in a mouse phrenic nerve-diaphragm preparation. About 90% of full biological activity could be restored under optimized conditions of oxidative refolding of the reduced peptide. Several reaction conditions employing air oxidation, oxidized and reduced glutathione (GSSG and GSH), and cystine/cysteine were investigated in order to find optimal conditions for renaturation of huwentoxin-I. The best renaturation yield was achieved in 0.1 mM GSSG and 1 mM GSH at pH 8.5 and 4 degrees C over 24 hr. High concentrations of glutathione and high temperatures reduced renaturation yields. Oxidative refolding of huwentoxin-I in air requires about 6 days for maximal yields and is inhibited by EDTA.

Amino Acid Sequence↗

PubMed1999

Exploring the conformational diversity of loops on conserved frameworks.

Loops are structurally variable regions, but the secondary structural elements bracing loops are often conserved. Motifs with similar secondary structures exist in the same and different protein families. In this study, we made an all-PDB-based analysis and produced 495 motif families accessible from the Internet. Every motif family contains some variable loops spanning a common framework (a pair of secondary structures). The diversity of loops and the convergence of frameworks were examined. In addition, we also identified 119 loops with conformational changes in different PDB files. These materials can give some directions for functional loop design and flexible docking.

Computer Simulation↗

PubMed1999

The beta+-thalassemia mutation [IVS-II-5 (G-->C] creates an alternative splicing site in the second intervening sequence.

We report a beta-thalassemia mutation [IVS-II-5 (G-->C)] in a Chinese family. Recently we cloned this beta-globin gene and studied its transient expression in murine erythroleukemia (MEL) cells. Both the thalassemic and normal beta-globin genes were isolated by polymerase chain reaction and TA-vector cloning. When the cloned beta-thalassemic globin gene was introduced into MEL cells, two kinds of spliced cytoplasmic beta-globin RNAs were detected. The predominant RNA was normally spliced, while the less abundant RNA contained an insertion of the first 47 nucleotides of the second intervening sequence localized between exons 2 and 3. These results suggest that the mutation [IVS-II-5 (G-->C)] causes a beta+-thalassemia.

Adolescent↗

PubMed1999

[The analysis of pathological changes of cardiac conduction system in 54 cases of cardiac sudden deaths].

OBJECTIVE: To elucidate the exact cause of death in cases of cardiac sudden deaths. METHODS: Sampling of cardiac conduction system (CCS) designed by the research group was adopted. The CCS of 120 cases died of cardiac sudden deaths were collected for routine histological examination. RESULTS: In 54 out of 120 cases, the causes of death were attributed to lesions present in the CCS, and 85.2% of them were young adults. The peak age range was from 20 - 30. Much more in males (6.7:1). The pathological changes in CCS include: inflammation (46.2%), fatty infiltration, hypertrophic cardiomyopathy associated with CCS changes; hemorrhage, developmental anomalies, fibrosis and tumors. CONCLUSION: The pathological changes of CCS are relatively common, as the cause of sudden deaths. Which is considered to be the pathological basis of the unstable cardiac electric potentials and arrhythmia. This study recommended the necessity of routine examination on CCS in cases of sudden deaths.

Adult↗

PubMed1999

[Surgical management of subglottic carcinoma].

OBJECTIVE: To explore the clinical features and the methods of surgery and functional restoration of subglottic carcinoma. METHODS: Thirteen cases with primary subglottic carcinoma were treated surgically in this department from 1981 to 1997. Among them, six had T1-2N0 lesions, one had T3N0 lesion and six had T3-4N1-2 lesions. Four cases underwent total laryngectomy and nine had subglottic partial laryngectomy. The extensive subglottic partial laryngectomy was performed on patients with tracheal invasion. The defects of larynx were reconstructed by using unilateral or bilateral pedicled musculocutaneous flap, myofascial flap accordingly. T-shape silastic tube was placed in to the reconstructed cavity of larynx during the operation and the patients were decannulated in 2 to 6 months. Unilateral radical neck dissection was performed on 4 patients and bilateral on 2. RESULTS: All cases had restored the function of phonation except for 4 who underwent total laryngectomy. Five out of 9 (55.6%) were decannulated. The swallowing function was restored in all patients. The 3-year and 5-year survival rates were 100% and 66.7% in the cases with total laryngectomy, 88.9% and 75.0% with subglottic partial laryngectomy, respectively. CONCLUSION: It is possible to detect early subglottic carcinoma by using fiberoptic laryngoscopy routinely with the combination of stroboscopy, CT, MRI in male patients over 40 with hoarseness. It is practical that the whole or partial function of larynx could be restored in most cases with subglottic carcinoma after partial laryngectomy or subtotal laryngectomy. Unilateral or bilateral neck dissection should be performed on patients with T3 or T4 lesion. Postoperative radiotherapy is necessary.

Adult↗