Biomedical subjects
Publications and source records attributed to Z Yang.
The following case describes the roentgenographic and clinical findings of a condition of interest to the orthopedic surgeon. Initial history, physical findings, and roentgenographic examinations are found on this page. The final clinical and roentgenographic differential diagnosis can be found on the pages that follow.
Neuron-specific enolase (NSE) levels of cerebrospinal fluid (CSF) were measured in 39 patients with ischemic stroke and 15 controls. There was a significant increase of CSF NSE in acute ischemic stroke patients as compared with the controls. The altered CSF NSE levels correlated well with the infarct size in CT scan. The CSF NSE levels were higher in 6-multiinfarct dementia (MID) patients who were diagnosed after 6-month follow-up than those in 22 non-MID patients of this series. Our research supports the view that CSF NSE can be a useful biochemical marker for brain ischemia. The importance of CSF NSE in the study of dementia related to ischemic stroke is worth further studies.
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BACKGROUND: Advanced glycation end products (AGE), the reactive derivatives of nonenzymatic glucose-protein condensation reactions, are implicated in the multiorgan complications of diabetes and aging. An AGE-specific cellular receptor complex (AGE-R) mediating AGE removal as well as multiple biological responses has been identified. By screening an expression library using antibody against a previously identified component of the AGE-R complex p90, a known partial cDNA clone was isolated with homology to galectin-3, a protein of diverse identity, and member of the galectin family. MATERIALS AND METHODS: To explore this unexpected finding, the nature of the interactions between galectin-3 and AGE was studied using intact macrophage-like RAW 264.7 cells, membrane-associated and recombinant galectin-1 through -4, and model AGE-ligands (AGE-BSA, FFI-BSA). RESULTS: Among the members of this family (galectin-1 through 4), recombinant rat galectin-3 was found to exhibit high-affinity 125I-AGE-BSA binding with saturable kinetics (kD 3.5 x 10(7) M-1) that was fully blocked by excess unlabeled naturally formed AGE-BSA or synthetic FFI-BSA, but only weakly inhibited by several known galectin-3 ligands, such as lactose. In addition to the p90, immunoprecipitation with anti-galectin-3, followed by 125I-AGE-BSA ligand blot analysis of RAW 264.7 cell extracts, revealed galectin-3 (28 and 32 kD), as well as galectin-3-associated proteins (40 and 50 kD) with AGE-binding activity. Interaction of galectin-3 with AGE-BSA or FFI-BSA resulted in formation of SDS-, and beta-mercaptoethanol-insoluble, but hydroxylamine-sensitive high-molecular weight complexes between AGE-ligand, galectin-3, and other membrane components. CONCLUSIONS: The findings point toward a mechanism by which galectin-3 may serve in the assembly of AGE-R components and in the efficient cell surface attachment and endocytosis by macrophages of a heterogenous pool of AGE moieties with diverse affinities, thus contributing to the elimination of these pathogenic substances.
The expressions and significance of proliferating cell nuclear antigen (PCNA) were studied by immunohistochemical method in 40 cases of gallbladder carcinoma and 42 cases of cholangiocarcinoma. The counting score of positive cells was significantly lower in cases of well-differentiation, histologic grade I and without metastasis than that in cases of poor-differentiation, histologic grade III and with metastasis. Close correlations were found between the survival time and the counting score of PCNA. These results suggested the cholangiocarcinoma and gallbladder carcinoma with highly positive cell rate might have poor prognosis, and PCNA might be an important marker reflecting the biological behavior and having prognostic value.
We designed and synthesized twelve new 3,4-dimethoxybenzoyl-piperazine derivatives. These chemical structures (TM-1-TM-12) were confirmed by means of IR, MS, H-NMR and elemental analysis. Compounds (OPC-8212 TM-1, TM-2, VPA) were tested for positive inotropic activity. The results showed that compounds OPC-8212 and VPA possessed positive inotropic activity (P < 0.05). Further pharmacological studies will be made.
This paper reports the karyological studies on the fruit of Gardenia jasminoides and G. jasminoides var. grandiflora. The chromosome numbers are 2n = 22 and the places of centromere are metacentric and submedian. The fruit of G. jarminoides is more primary than Gardenia jarminoidce var. grandiflora in karyotype.
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This experiment studied the changes in cartilage collagen content during 1-20 weeks after allografting of cartilage. The results showed that the collagen content was reduced beginning from the 3rd week, and reached the lowest point in the 4th week (P < 0.05). Then it rose continuously and attained the normal level in the 8th week (P > 0.05). The study suggests that the changes in cartilage collagen content may help us to assess the cartilage structure and the elasticity after a cartilage allotransplantation.
The levels of testosterone secreted by rat's Leydig cells in varied concentrations of V2O5 (0.125, 0.,25, 0.5, 2 and 3 mmol/L) were assayed. The result showed there was no obvious relation between the level of testosterone and the concentration of V2O5. This in vitro study in accord with the result of whole animal research indicates that Leydig cell is not the target of V2O5.
In order to improve perfusion of coronary artery in case of coronary artery stenosis, effect of intra-aortic balloon pumping (IABP) on coronary blood flow (CBF) was investigated. To this end hemodynamic parameters of heart functions with and without stenosis were analysed under IABP. Hemodynamic effect of IABP was obviously influenced by the coronary artery stenosis.
Neuron-specific enolase (NSE) levels of cerebrospinal fluid (CSF) were measured in 39 patients with ischemic stroke and 15 controls. There was a significant increase of CSF NSE in patients with acute ischemic stroke as compared with the controls. The altered CSF NSE levels were well correlated with the infarct size in CT scan. The CSF NSE levels were higher in 6-patients who were diagnosed as multi-infarct dementia (MID) after 6-month follow-up than in 22 non-MID patients of this series. Our research supports the view that CSF NSE can be a useful biochemical marker for brain ischemia. The importance of CSF NSE for dementia related to ischemic stroke is worth further studying.
A variety of criteria were tested for identifying errors in protein crystal coordinates. Statistical analysis was based on comparisons of a highly refined crystal structure and several preliminary models derived from molecular replacement. A protocol employing temperature factors, real-space fit residuals, geometric strains, dihedral angles and shifts from the previous refinement cycle is developed. These results are generally applicable to the detection of errors in partially refined protein crystal structures.
Despite the widespread occurrence of acidic sulfur oxides in the ambient environment and their potential risks to human health, effects associated with pulmonary immune defenses have been poorly studied. The current in vivo study was designed to provide some insight into this relatively unexplored area by investigating the impact of inhaled sulfuric acid on immune defense mechanisms critical for maintaining pulmonary resistance against infectious diseases. Results of this study demonstrate that repeated inhalation of sulfuric acid reduces the uptake and intracellular killing of pathogenic bacteria by exposed pulmonary macrophages, and depresses the activity/production of important biological modifiers critical for maintaining pulmonary immunocompetence. These findings have important implications for human health, and may contribute to a better understanding of the possible mechanism(s) underlying the epidemiological evidence which suggests an association between total sulfates in the ambient air and increased incidence of acute bronchitis and lower respiratory illness in school-age children.
Beta-endorphin(beta EP)1-31, a potent opioid peptide of proopiomelanocortin (POMC) derivatives, is produced and released from neurons at arcuate nuclei of the rat hypothalamus. Although dexamethasone (DM) suppresses the production and secretion of POMC related peptides from rat pituitary corticotrophs, the effect of glucocorticoids on the function of hypothalamic beta EP neurons remains unclear. Employing long term monolayer cultures of neonatal rat hypothalamic cells, we report here that 4 day treatment with 10 microM of forskolin increased ir-beta EP levels in cell content and culture media by approximately 1.7 (P < 0.05) and 4.1 times (P < 0.01) above vehicle treated control cultures (mean +/- S.E.M., 47.3 +/- 2.6 pg/well and 40.4 +/- 3.0 pg/well; n = 3) respectively. Although 4 day treatment with DM alone had little effect on the release and the cell content of ir-beta EP, it significantly enhanced forskolin-induced elevation of ir-beta EP levels in cell content and in culture media. The effect of DM was dose-related and time-dependent, with an EC50 of about 1 nM; at this concentration DM enhanced ir-beta EP secretion about 2.1 times (P < 0.01) above that induced by 10 microM of forskolin alone. Furthermore, the potentiating effect of DM was specifically suppressed by 100 nM of RU38486 (P < 0.01), a glucocorticoid receptor antagonist, but not by an equivalent dose of RU28318, a mineralocorticoid receptor antagonist. In addition, Northern blot analysis showed that forskolin (10 microM) increased the abundance of POMC mRNA 1.4 fold above that of vehicle treated control cultures. Whereas by itself, DM (10 nM) had little effect on the level of POMC mRNA, it enhanced forskolin-stimulated increase of the abundance of POMC mRNA approximately 2.6 times. Moreover, DM also augmented 1.6 times (P < 0.05) forskolin-induced but not 3-isobutyl-1-methylxanthine (IBMX)-induced increase of cAMP production (5.5 +/- 0.4 pmol/well; mean +/- S.E.M., n = 3) in the cultures. Taken together, our findings suggest that in contrast to the inhibitory effect on pituitary corticotrophs, glucocorticoids enhance the production and secretion of beta EP from rat hypothalamic neurons by facilitating the stimulatory effect mediated, in part, through the adenylyl cyclase-cAMP system.
The antigenic determinants of the blood group P family (P1, P, Pk, and LKE antigens) are chemically based on Gal alpha 4Gal. For human erythrocytes it has been claimed that the majority of P1 determinants are expressed in glycoproteins, mainly band 4.5 (Haselberger, C. G., and Schenkel-Brunner, H. (1982) FEBS Lett. 149, 126-128). In the present work, the existence of Gal alpha 4Gal in glycoproteins of erythrocyte membranes (ghosts) of P1 positive and negative human individuals was carefully analyzed on replicas of sodium dodecyl sulfate-polyacrylamide electrophoresis gels using specific reagents (Escherichia coli HB101/pDC1 expressing the Pap gene and monoclonal antibodies with specificities for P1 and Pk antigens). No binding to glycoproteins was detected with any of these ligands when the ghosts had been pretreated with butanol to remove glycolipids. Therefore, all antigenic determinants of the P blood group family on human red cells are exclusively expressed in glycolipids and are absent from glycoproteins.
Post-translational modifications of the water-soluble human lens crystallins from young adult donors were identified and located using electrospray ionization mass spectrometric analysis of the intact proteins and fast atom bombardment mass spectrometry of enzymatic digests. Peptides corresponding to all of the sequences of alpha A-, alpha B-, and beta B2-crystallins were found, permitting the entire sequences to be searched for modifications. The major portions of these three crystallins were not modified. Modifications of alpha A-crystallin that were detected included 2 phosphorylated Ser residues (1 of which appears to be unique to human lenses), deamidation at some Gln and Asn residues, a disulfide bond between Cys-131 and Cys-142, and loss of the COOH-terminal Ser residue. Three phosphorylated Ser residues, but no deamidation, were found in alpha B-crystallin. The molecular weights of neither the intact protein nor the peptides in the enzymatic digests indicated any post-translational modification of the principal beta-crystallin, beta B2. The molecular weights of the other beta- and gamma-crystallins for which sequences have been published suggested the presence of post-translational modifications or errors in the published sequences. Although enough peptides were found to establish the presence of specific proteins, peptides corresponding to all portions of these proteins were not found, and elucidation of these structures is not yet complete. This mass spectrometric characterization of the total water-soluble proteins from normal young adult lenses provides a reference data base for future investigations of the modifications present in aged and cataractous lenses.
Erythroid cells regulate heme biosynthesis in a manner that is distinct from all other cell types. While heme negatively regulates the synthesis of the housekeeping delta-aminolevulinate synthase (ALAS-N) in all non-erythroid cells, the expression of an erythroid-specific isozyme (ALAS-E) is developmentally regulated in red blood cells. As a first step towards understanding the molecular basis for the transcriptional regulation of ALAS-E during erythropoiesis, we cloned and characterized the chicken ALAS-E locus. This gene spans 18 kbp and is composed of eleven exons. The intron/exon structure of erythroid ALAS was found to be conserved among several vertebrate species. Direct RNA sequencing identified a 5' untranslated region that is derived from two continuous exons and is predicted to form a very stable stem-loop structure that bears resemblance to the ferritin iron-responsive element. Tissue-specific expression of the ALAS-E gene was analyzed by transient transfection assays in hematopoietic cells of both erythroid and non-erythroid origins. These experiments identified distal (-784 to -505 bp) and proximal (-155 to +21 bp) promoter elements which are required for high level, erythroid-specific transcription.