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Biomedical subjects

Y Ling

Publications and source records attributed to Y Ling.

At least 55 records · Page 3Linked to original sources
PubMed1998

[The pathological action of surrounding connective tissues of alar cartilage in the cleft lip nose].

OBJECTIVE: This study was to explore the pathological action of the adjacent connective tissues of alar cartilage in unilateral cleft lip nose. METHODS: Anatomic-histological and pathoanatomical study was carried on 40 normal cadavers and 30 patients with secondary deformities of unilateral cleft lip during their operations. RESULTS: Six kinds of connective tissues with different histological features were found between the alar cartilage and adjacent skin, cartilage or bone. There was no histological difference in each connective tissue between the normal and the cleft lip nose. In the cleft lip nose, due to histological differences among the six connective tissues, there existed various changes of pathological dislocations between the alar cartilage and adjacent skin, cartilage or bone. CONCLUSION: The authors suggest that the surrounding connective tissues of the alar cartilage play an important role and be the intrinsic basis to produce the characteristic deformities of the cleft lip nose. The result is helpful in understanding the anatomical and histological features of the connective tissues around the alar cartilage and the deformities of the unilateral cleft lip nose so as to select a reasonable operation method.

Abnormalities, Multiple↗
PubMed1998

[Anatomic study of the musculus depressor septi nasi in unilateral cleft lip nasal deformity].

OBJECTIVE: This study was to investigate the nasal musculature and its relationship with the deformities of the unilateral cleft lip nose. METHOD: The anatomic and histological examination and comparison of the musculus depressor septi nasi (MDSN) were performed in 33 normal cadavers and 30 patients with unilateral cleft lip undergoing the operation for secondary nasal deformities. RESULT: It was found that the MDSN in the cleft side of a unilateral cleft lip nose is lacking. CONCLUSION: Because of the anatomic deficiency on the cleft side, the function of the normal side is pathologically increased. The functional imbalance between the normal and abnormal side may bring about dislocation and malformation of the base of nasal columella as well as the septal structures.

Abnormalities, Multiple↗
PubMed1998

[Chemical constituents of Taraxacum sinicum Kitag].

Five compounds were separated from Taraxacum sinicum by means of solvent extraction and rechromatography on silical gel. Their structures were established as caffeic acid, ferulic acid, chlorogenic acid, luteolin and diosmetin by spectral analysis and chemical evidence. All the compounds were isolated from this plant for the first time. Chlorogenic acid and diosmetin have not been discovered from Taraxacum genus previously.

Asteraceae↗
PubMed1998

[Steroids and lipids from Spirodela polyrrhiza].

Two steroids and two lipids were isolated from the ethanolic extract of Spirodela polyrrhiza. Their structures were identified by spectral analysis and chemical evidence, which were identified as stigmasterol, monopalmitic glycerate, daucosterol and palmitic acid. Monopalmitic glycerate was discovered from this plant for the first time.

Chromatography, Thin Layer↗
PubMed1998

[A quantitative measurement of retinal nerve fiber layer thickness by optical coherence tomography in normal Chinese people].

PURPOSE: To measure retinal nerve fiber layer(RNFL) thickness in normal Chinese people for the use of early diagnosis in glaucomatous patients. METHODS: Optical Coherence Tomography(OCT) was used in 111 eyes of 77 Subjects to create cylindrical cross sections of the RNFL around the optic nerve head with scan diameter of 3.46 mm. The differences in RNFL thickness were analyzed with age, sex, either eye. RESULTS: We found a decrease in RNFL thickness with aging especially in the superior quadrant(P < 0.05), but there weren't significant difference between right and left eyes, neither the sex(P > 0.05). The Mean RNFL thickness of different ages(mean +/- s) was as following: the superior quadrant 128.00 +/- 10.31-149.00 +/- 13.17, the inferior quadrant 132.95 +/- 9.54-142.33 +/- 10.60, the overall mean RNFL thickness 109.00 +/- 4.72-114.28 +/- 7.98 microns. CONCLUSION: The preliminary study showed that neither sex nor either eye were associated with significant differences in RNFL thickness. It is necessary to define the normative value by age group on a larger scale.

Adolescent↗
PubMed1997

Synthesis and structure-activity relationships of 17beta-substituted 14beta-hydroxysteroid 3-(alpha-L-rhamnopyranoside)s: steroids that bind to the digitalis receptor.

The preparation of 17beta-substituted 14beta-hydroxysteroid C-3 alpha-L-rhamnopyranosides is described. These derivatives have a 14beta,20-ether, 14beta,20-lactone, or 17beta-CH2CH2OH, -CH2CH2NH2, -CH=CHNO2(E), -CH=CHCOOH(E), -CH(OH)CH2NO2(R), -CH(OMe)CH2NO2(R), -CH2-CH2COOH, or -CH(OH)CH2NH2(R) group. Derivatives were assayed in a radioligand binding assay for [3H]ouabain in membranes from canine heart muscle. The digitalis "receptor" comprises isoenzymes of the ion-pumping enzyme, Na+,K+-ATPase. The 17beta-CH=CHNO2(E), 17beta-CH=CHCOOH(E), and 17beta-CH(OMe)CH2NO2(R) derivatives were the most potent and equivalent to ouabain with low-nanomolar IC50 values. The very potent binding affinity of the disubstituted compound 17beta-CH(OMe)CH2NO2(R) further demonstrates that 17beta-unsaturated substitution is not required for potent binding affinity. This observation may be of value in the separation of cardiotonic and cardiotoxic effects. Tosylation of the 17beta-CH2OH, prepared from the 17beta-CHO by lithium aluminum hydride reduction, yielded the 14beta,17beta-ether. Synthesis of the 17beta-CH2COOH gave the epimeric 14alpha,17alpha- and 14beta,17beta-lactones. Structures have been established by NMR analysis.

Animals↗
PubMed1997

Molecular characterization of the B-box protein-protein interaction motif of the ETS-domain transcription factor Elk-1.

The ternary complex factor (TCF) subfamily of ETS-domain transcription factors form ternary complexes with the serum response factor (SRF) and the c-fos SRE. Extracellular signals are relayed via MAP kinase signal transduction pathways through the TCF component of the ternary complex. Protein-protein interactions between TCFs and SRF play an essential role in formation of this ternary complex. A 30 amino acid sequence encompassing the TCF B-box is sufficient to mediate interactions with SRF. In this study we have identified amino acids which are critical for this interaction and derived a molecular model of the SRF binding interface. Alanine scanning of the Elk-1 B-box reveals five predominantly hydrophobic residues which are essential for binding to SRF and for ternary complex formation in vitro and in vivo. These amino acids are predicted to lie on one face of an alpha-helix. Peptides encompassing the B-box retain biological activity and have helix-forming propensity. alpha-Helix and ternary complex formation is disrupted by the introduction of helix-breaking proline residues. Our results are consistent with a model in which the Elk-1 B-box forms an inducible alpha-helix which presents a hydrophobic face for interaction with SRF. We discuss the wider applicability of our results to similar short protein-protein interaction motifs found in other transcription factors.

3T3 Cells↗
PubMed1997

2/3 osteotomy for lengthening the mandible in dogs by gradual distraction.

Successful lengthening of the mandible by gradual distraction has been reported previously. There are various methods for osteotomy before distraction osteogenesis. In this paper, a new type of osteotomy, performed on growing dogs as a model, is reported. Ten mongrel dogs, aged 6 months, were studied. A unilateral 2/3 osteotomy was performed, and an external lengthening device was fixed to the mandible perpendicular to the osteotomy. Seven days after the operation, the mandible was lengthened by 1 mm per day. The dogs were sacrificed for histological study at the end of the distraction on days 14, 28, 56 and 120 following completion of the distraction.

Animals↗
PubMed1997

The ETS-domain transcription factor family.

During recent years, several significant discoveries have been made concerning the function of ETS-domain transcription factors. This family of transcription factors was originally defined on the basis of the conserved primary sequence of their DNA-binding domains. The ETS DNA-binding domain is also conserved at the structural level and is a divergent member of the winged helix-turn-helix superfamily of DNA binding proteins. This sequence conservation is reflected by their overlapping DNA-binding specificities based on the central GGAA/T motif. In addition to DNA-protein interactions, protein-protein interactions with partner proteins often play major roles in targeting ETS-domain proteins to specific promoters. Several such partner proteins have been identified. ETS-domain proteins function as either transcriptional activators or repressors and their activities are often regulated by signal transduction pathways, including the MAP kinase pathways. Specific links between such pathways and ETS-domain proteins have been established in several different experimental systems. ETS-domain transcription factors regulate a diverse array of biological functions including mammalian haematopoiesis and Drosophila eye development. In vertebrates, many ETS-domain proteins regulate embryonic and adult haematopoiesis. Deregulation of ETS-domain protein activity often leads to tumorigenesis. Future work will uncover further details of how these transcription factors work at the molecular level to regulate specific biological processes.

Adult↗
PubMed1997

Pilot-scale extraction of PHB from recombinant E. coli by homogenization and centrifugation.

A new method of poly-beta-hydroxybutyrate (PHB) extraction from recombinant E. coli is proposed, using homogenization and centrifugation coupled with sodium hypochlorite treatment. The size of PHB granules and cell debris in homogenates was characterised as a function of the number of homogenization passes. Simulation was used to develop the PHB and cell debris fractionation system, enabling numerical examination of the effects of repeated homogenization and centrifuge-feedrate variation. The simulation provided a good prediction of experimental performance. Sodium hypochlorite treatment was necessary to optimise PHB fractionation. A PHB recovery of 80% at a purity of 96.5% was obtained with the final optimised process. Protein and DNA contained in the resultant product were negligible. The developed process holds promise for significantly reducing the recovery cost associated with PHB manufacture.

Biotechnology↗
PubMed1997

[The different influences of splenectomy plus ligation of pericardial vein and shunt on portal hypertensive gastropathy].

A prospective and controlled study has been made to probe into the different influences of splenectomy plus ligation of pericardial vein (SPLPY) and shunt on portal hypertensive gastropathy (PHG). 26 patients with cirrhosis of liver and portal hypertension admitted from January 1994 to April 1996 were randomized into two groups. One group was treated with SPLPV (15 cases), and the other shunt (11 cases). Gastroscopy was made in all patients pre- and postoperatively to observe the changes of gastric mucosa. It has been shown that SPLPV exacerbate PHG (P < 0.05) and the shunt has an opposite effect (P < 0.05). We consider that it is necessary to modify SPLPV and reevaluate the clinical effects of the both.

Adult↗
PubMed1997

[Method of mRNA differential display and its application in life science].

The changes of mRNA expression level control cell function. Many factors such as individual development, cell proliferation and differentiation, and even apoptosis, physiological stimuli, and drug treatment will change the level of gene expression. Comparisons of gene expression in different cell types provide the underlying information for analyzing the molecular and cellular mechanisms of the physiological processes. A method of mRNA differential display is developed recently, providing a powerful and useful tool, which can efficiently and rapidly isolate the genes that display a difference in transcription. These genes may play important role in cell function.

Animals↗
PubMed1996

Identification of the high affinity receptor binding region in human immunoglobulin E.

We have investigated the capacity of N- and C-terminally truncated and chimeric human (h) IgE-derived peptides to inhibit the binding of 125I-labeled hIgE, and to engage cell lines expressing high and low affinity receptors (Fc-epsilon-RI/II). The peptide sequence Pro343-Ser353 of the hC-epsilon-3 domain is common to all h-epsilon-chain peptides that recognize hFc-epsilon-RI. This region in IgE is homologous to the A loop in C-gamma-2 that engages the rat neonatal IgG receptor. Optimum Fc-epsilon-RI occupancy by hIgE occurs at pH 6.4, with a second peak at 7.4. N- or C-terminal truncation has little effect on the association rate of the ligands with this receptor. Dissociation markedly increases following C-terminal deletion, and hFc-epsilon-RI occupancy at pH 6.4 is diminished. His residue(s) in the C-terminal region of the epsilon-chain may thus contribute to the high affinity of interaction. Grafting the homologus rat epsilon-chain sequence into hIgE maintains hFc-epsilon-RI interaction without conferring binding to rat Fc-epsilon-RI. hFc-epsilon-RII interaction is lost, suggesting that these residues also contribute to hFc-epsilon RII binding. h-epsilon-chain peptides comprising only this sequence do not block hIgE/hFc-epsilon-RI interaction or engage the receptor. Therefore, sequences N- or C-terminal to this core peptide provide structures necessary for receptor recognition.

Animals↗
PubMed1996

Treatment of tuberculous pleurisy with effusion by artificial pneumothorax.

57 patients were divided into two groups at random. The patients of two groups were all given standard treatments with anti-tuberculous drugs. Treatment group received artificial pneumothorax to help the cure. Results showed that the frequency and quantity of drawing liquid in the treatment group were obviously less than those in the control group and the duration of the complete liquid absorption was shortened markedly in the treatment group and that total effective rate in treatment group (92.5%) was obviously higher than that of the control group (83.33%). We found that the artificial pneumothorax could raise the intra-pleural pressure by 0.20-0.39 kPa, reduce leakage in parietal pleurae and increase the absorption in visceral layer evidently. As it can isolate the two layers of pleurae from one another by the air in thorax, the incidence of pleurae adhesion can be decreased.

Adolescent↗
PubMed1996

The effect of dexrazoxane (ICRF-187) on doxorubicin- and daunorubicin-mediated growth inhibition of Chinese hamster ovary cells.

Dexrazoxane (ICRF-187) is clinically used to reduce doxorubicin-induced cardiotoxicity. Because dexrazoxane, doxorubicin and daunorubicin all act on DNA topoisomerase II, a study was undertaken to see what effect dexrazoxane had on the growth inhibitory effects of doxorubicin and daunorubicin towards Chinese hamster ovary cells. Dexrazoxane exhibited significant antagonism of doxorubicin- and daunorubicin-mediated growth inhibition when the cells were preincubated with dexrazoxane before the anthracycline was added. Continuous exposure of cells to either anthracycline and low concentrations of dexrazoxane resulted in additive growth inhibitory effects at low anthracycline concentrations, and no effect at higher anthracycline concentrations.

Animals↗
PubMed1996

Dynamic changes of mechanically activated channels and K+ channels at injury site of peripheral nerve in rat.

Ectopic ion channels developed locally at the injury site after nerve damage by light ligation around common sciatic nerve of the rats. Different channel types have different processes of formation, accumulation and degeneration. During the first three days after injury, mechanically activated channels that are modulated by CA++ channel activities first appeared. As the nerve fibers begin to be excited by TEA, a blocker of K+ channels, suggesting that the accumulation of K+ channels, the responsibility of mechanically activated channels was declining. Onset of K+ channels was from the 3rd postoperative day and lasted up to the fiftieth day. This time course of K+ channel development was closely related to allodynia and hyperalgesia of neuropathic animal behaviour. The results suggest that chronic contraction injury induces a dynamic change in the ectopic mechanically activated channels and K+ channels at the injury site of nerve and there is an interchange in the development time courses of the mechanically activated channels and K+ channels.

Action Potentials↗