Biomedical subjects

Y Ye

Publications and source records attributed to Y Ye.

At least 37 records · Page 2Linked to original sources

PubMed2001

8-Carboxamidocyclazocine analogues: redefining the structure-activity relationships of 2,6-methano-3-benzazocines.

Unexpectedly high affinity for opioid receptors has been observed for a novel series of cyclazocine analogues where the prototypic 8-OH was replaced by a carboxamido group. For mu and kappa opioid receptors, the primary carboxamido derivative of cyclazocine ((+/-)-15) displayed high affinity (Ki=0.41 and 0.53 nM, respectively) nearly comparable to cyclazocine. A high enantiopreference ((2R,6R,11R)-) for binding was also observed. Compound (+/-)-15 also displayed potent antinociception activity in mice when administered icv.

Amides↗

PubMed2001

Surface-enhanced Raman spectra study of metal complexes of N-D-glucosamine beta-naphthaldehyde and glycine and their interaction with DNA.

Copper(II), zinc(II), cobalt(II) and cobalt(III) complexes of N-D-glucosamine beta-naphthaldehyde (C17H19O6N, NG) and glycine were synthesized. The four novel metal complexes, Cu(II)C19H28O11N2(CuGNG), Zn(II)C19H24O9N2 (ZnGNG), Co(II)C19H28O11N2(Co(II)GNG) and Co(III)C21H29O12N2(Co(III)GNG) were characterized by means of infrared (IR), electronic absorption spectroscopy and NMR etc. The surface-enhanced Raman spectra of the four complexes and their interaction with DNA were studied. By comparison of the surface-enhanced Raman spectra (SERS), the information of the four complexes' SER active sites and adsorption orientation were obtained. Combined with fluorescence spectra of Ethidium bromide (EthBr) DNA system, we concluded that none of the four complexes intercalate into DNA and that the presence of the glycine ligand lowered the anticancer activity of NG series complexes.

Animals↗

PubMed2001

Protective role of cyclooxygenase inhibitors in the adverse action of passive cigarette smoking on the initiation of experimental colitis in rats.

Clinical and experimental findings had indicated that cigarette smoke exposure, and cyclooxygenase-2, are strongly associated with inflammatory bowel disease. The present study aimed to evaluate the role of cyclooxygenase-2 in the pathogenesis of experimental inflammatory bowel disease as well as in the adverse action of cigarette-smoke exposure. Rats were pretreated with different cyclooxygenase-2 inhibitors (indomethacin, nimesulide, or SC-236 (4-[5-(4-chlorophenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl]benzenesulfonamide)) along with cigarette-smoke exposure before 2,4,6-trinitrobenzenesulfonic acid-enema. Results indicated that pretreatment with cyclooxygenase-2 inhibitors not only protected against 2,4,6-trinitrobenzenesulfonic acid-induced inflammatory bowel disease, but also attenuated the potentiating effect of cigarette-smoke exposure on colonic damage. Furthermore, the colonic cyclooxygenase-2 protein and mRNA expression was markedly induced by 2,4,6-trinitrobenzenesulfonic acid-enema, and it was potentiated further by cigarette-smoke exposure, while the cyclooxygenase-1 expression was not changed. The present study suggests that the highly induced cyclooxygenase-2 expression not only plays a pathogenic role in 2,4,6-trinitrobenzenesulfonic acid-induced inflammatory bowel disease, but also contributes to the adverse action of cigarette-smoke exposure on this disorder.

Animals↗

PubMed2001

Livestock wastewater treatment by a mangrove pot-cultivation system and the effect of salinity on the nutrient removal efficiency.

The present investigation compared the capacity of greenhouse pot-cultivation systems under two salinity conditions (freshwater and saline water) with two mangrove species (Bruguiera gymnorrhiza and Kandelia candel) to remove nutrients from livestock wastewater. During the whole treatment period there were relatively stable leachate TOC concentrations for wastewater-treated pots. Leachate NH4(+)-N concentration of B. gymnorrhiza pots was generally lower than that of K. candel pots. Leachate PO4(3-)-P concentration of pots receiving wastewater under freshwater condition was higher than that under saline water condition. Soil inorganic N content was more than two times higher for the wastewater treatments than that for the controls under low salinity condition and slower rate of increase under saline water condition. Soil P nutrients of both total and extractable inorganic forms significantly increased for both systems due to the discharges of livestock wastewater under both salinity conditions. The rate of increase in P contents for plants receiving livestock wastewater was 1-4 times that of the controls, much more than that in N contents (0.04-1.30 times). N nutrient removal efficiencies were 84.3% (65.6% by soil and 18.7% by plant) and 95.5% (32.2% by soil and 63.4% by plant), respectively by Kandelia candel and B. gymnorrhiza pot-cultivation systems under freshwater condition. Under saline water condition, N nutrient removal efficiencies by K. candel and B. gymnorrhiza pot-cultivation systems were 92.7% (80.7% by soil and 12.0% by plant) and 98.0% (67.6% by soil and 30.3% by plant), respectively. P nutrient removal efficiencies by K. candel and B. gymnorrhiza systems under freshwater condition were 79.2% (76.6% by soil and 2.6% by plant) and 91.8% (88.2% by soil and 3.6% by plant), respectively. The corresponding values were 88.0% (84.2% by soil and 3.8% by plant) and 97.8% (95.9% by soil and 1.9% by plant) under saline water condition.

Agriculture↗

PubMed2001

Cloning and characterization of a novel gene (C17orf25) from the deletion region on chromosome 17p13.3 in hepatocelular carcinoma.

Using a combination of hybridization of PAC to a cDNA library and RACE technique, we isolated a novel cDNA, designated as C17orf25 (Chromosome 17 open reading frame 25, previously named it HC71A), from the deletion region on chromosome 17p13.3. The cDNA encodes a protein of 313 amino acids with a calculated molecular mass of 34.8 kDa. C17orf25 is divided into 10 exons and 9 introns, spanning 23 kb of genomic DNA. Northern blot analysis showed that the mRNA expression of C17orf25 was decreased in hepatocellular carcinoma samples as compared to adjacent noncancerous liver tissues from the same patients. The transfection of C17orf25 into the hepatocellular carcinoma cell SMMC7721 and overexpression could inhibit the cell growth. The above results indicate that C17orf25 is a novel human gene, and the cloning and preliminary characterization of C17orf25 is a prerequisite for further functional analysis of this novel gene in human hepatocellular carcinoma.

Amino Acid Sequence↗

PubMed2001

Connections between the dorsal raphe nucleus and a hindbrain region consisting of the cochlear nucleus and neighboring structures.

Previous studies have shown that neurons in the raphe nuclei respond to acoustic stimuli. The present study investigated connections between the dorsal raphe nucleus (DRN) and a hindbrain region consisting of the cochlear nucleus (CN) and neighboring structures. A mixture of one or more tracers (cholera toxin B, biotinylated dextran amine (BDA), and 3H-leucine) was injected into the cat DRN. Retrograde-labeling results are presented whereby a new structure, to be called the juxta-acoustico-floccular fascicle (JAFF), is identified. The JAFF is surrounded by the CN, flocculus, lateral cerebellar nucleus, lateral vestibular nucleus, and restiform body. The JAFF is closely associated with the infracerebellar nucleus (ICN). Labeled neurons projecting to the DRN were concentrated in the JAFF, embedded among axons. Less numerous labeled neurons were in the ICN and CN. Anterograde-labeling results are presented showing fibers labeled with BDA or with BDA and 3H-leucine in the CN, cochlear nerve and vestibular nerve, indicating that the DRN projects to these structures. The ascending and descending connections between the DRN and the above hindbrain region may mediate a reflex that may alter the sensitivity of the auditory system in response to biologically salient (e.g. threatening or attractive) stimuli.

Animals↗

PubMed2001

Metal binding affinity and structural properties of an isolated EF-loop in a scaffold protein.

To establish an approach to obtain the site-specific calcium binding affinity of EF-hand proteins, we have successfully designed a series of model proteins, each containing the EF-hand calcium-binding loop 3 of calmodulin, but with increasing numbers of Gly residues linking the loop to domain 1 of CD2. Structural analyses, using different spectroscopic methods, have shown that the host protein is able to retain its native structure after insertion of the 12-residue calcium-binding loop and retains a native thermal stability and thermal unfolding behavior. In addition, calcium binding to the engineered CD2 variants does not result in a significant change from native CD2 conformation. The CD2 variant with two Gly linkers has been shown to have the strongest metal binding affinity to Ca(II) and La(III). These experimental results are consistent with our molecular modeling studies, which suggest that this protein with the engineered EF-loop has a calmodulin-like calcium binding geometry and backbone conformation. The addition of two Gly linkers increases the flexibility of the inserted EF-loop 3 from calmodulin, which is essential for the proper binding of metal ions.

Amino Acid Motifs↗

PubMed2001

Myocardial creatine kinase kinetics and isoform expression in hearts with severe LV hypertrophy.

Left ventricular (LV) hypertrophy (LVH) results in a fetal shift in myocardial creatine kinase (CK) expression. Because CK plays an important role in intracellular energy production, transport, and utilization, this study was performed to characterize changes in CK expression and CK flux in severe pressure-overload LVH. Ascending aortic banding in 8-wk-old dogs resulted in LVH with a 92% increase in relative LV mass. In LVH hearts, CK-M isoform mRNA was decreased by 40% (P = 0.05) and protein was decreased by 50% (P < 0.01), whereas mitochondrial CK protein was decreased by 22% (P < 0.05). CK-B isoform mRNA was undetectable in normal hearts but was prominently expressed in LVH (P < 0.01); CK-B protein was increased by more than 10-fold in LVH (P < 0.01). Despite these changes, total CK activity was normal in LVH. Myocardial CK flux was examined using (31)P magnetic resonance spectroscopy magnetization transfer. The CK forward rate constant was similar in normal and LVH hearts at baseline and did not change in either group during dobutamine treatment. In hearts with LVH, the CK forward flux rate was reduced by approximately 60% (P < 0.05) and decreased further during dobutamine. Thus, although pressure-overload LVH caused alterations of expression of both CK mRNA and protein levels, LV performance and oxygen consumption in response to dobutamine were normal. However, myocardial free ADP was increased in LVH hearts. This finding suggests that the CK alterations result in a need for higher ADP levels to maintain ATP synthesis in the hypertrophied heart.

Animals↗

PubMed2001

Effects of augmented delivery of pyruvate on myocardial high-energy phosphate metabolism at high workstate.

This study was performed to determine whether the fall in myocardial high-energy phosphates (HEP) that occurs during high workstates can be ascribed to either inadequate glycolytic pyruvate generation and conversion to acyl-CoA or limitation of long-chain fatty acid transport into the mitochondria. This was tested by using infusions of either pyruvate or butyrate in anesthetized dogs. Pyruvate was used because it bypasses the glycolytic sequence of reactions, activates pyruvate dehydrogenase, and increases mitochondrial NADH concentration ([NADH(m)]) in isolated myocardium, whereas butyrate enters the mitochondria without need for transport by the rate-limiting, palmitoyl-carnitine transporter. Increasing blood pyruvate from 0.16 +/- 0.016 mM to >3 mM did not alter baseline HEP levels determined with (31)P nuclear magnetic resonance, but caused an increase in the rate-pressure product and a modest increase in myocardial oxygen consumption (MVO(2)). Infusion of dobutamine + dopamine (each 20 microg x kg(-1) x min(-1) iv) increased MVO(2) and caused decreases of myocardial phosphocreatine (PCr)/ATP. Pyruvate partially reversed the decrease of HEP levels produced by catecholamine stimulation, whereas butyrate had no effect. Neither pyruvate nor butyrate caused an increase of MVO(2) during catecholamine infusion. Deoxymyoglobin was not detected by (1)H magnetic resonance spectroscopyy in any group. The data demonstrate that carbon substrate availability to the mitochondria is not the only cause of the reduction of PCr/ATP that occurs at high workstates. Supplemental pyruvate (but not butyrate) attenuated the reduction of PCr/ATP during the high workstates; this may have resulted from direct effects on intermediary metabolism or from other effects such as the free radical scavenging activity of pyruvate.

Adenosine Triphosphate↗

PubMed2001

Overexpression of parathyroid hormone-related protein enhances apoptosis in the rat intestinal cell line, IEC-6.

We used the rat intestinal cell line, IEC-6, to study potential effects of overexpression of PTH-related protein (PTHrP) on apoptosis. A clonal line of PTHrP-overexpressing cells was established by stably transfecting parental cells with PTHrP complementary DNA in a sense orientation (sense). A similarly transfected line stably, transfected with empty vector, served as control (vector). Immunoreactive PTHrP, measured in culture medium, showed that sense cells secreted approximately 30 times as much PTHrP as did vector control cells. Apoptosis induced by serum withdrawal was evaluated by several methods. DNA laddering was demonstrable in sense-transfected cells as early as 12 h after serum withdrawal but not until later time points in vector-transfected control cells. Flow cytometric analysis of propidium iodide-stained cells showed a greater increase in the sub-G1 (apoptotic) population in sense cells, compared with vector. Fluorescent microscopy with Hoechst 33258 dye showed increased nuclear fragmentation and condensation in sense cells. Studies of apoptotic gene expression by ribonuclease protection assay, and protein by Western blot analysis, showed an enhanced ratio of Bax to Bcl-x(L) in sense cells. Mutation of the PTHrP nuclear localization amino acid sequence negated the ability of PTHrP to enhance apoptosis.

Animals↗

PubMed2001

Novel neuronal nitric oxide synthase (nNOS) selective inhibitor, aplysinopsin-type indole alkaloid, from marine sponge Hyrtios erecta.

Two novel aplysinopsin-type indole alkaloids, 1 and 2, and three known indole alkaloids were isolated from the marine sponge Hyrtios erecta. These compounds exhibited selective inhibitory activity against the neuronal isozyme of nitric oxide synthase (nNOS). Furthermore, new quinolone 7 was also isolated from the same marine sponge. The chemical structures of these new compounds were elucidated on the basis of spectroscopic analysis.

Animals↗

PubMed2001

Structural biology of the cell adhesion protein CD2: alternatively folded states and structure-function relation.

Cluster of differentiation 2 (CD2) is a cell surface glycoprotein expressed on most human T cells and natural killer (NK) cells and plays an important role in mediating cell adhesion in both T-lymphocytes and in signal transduction. The understanding of the biochemical basis of molecular recognition by the cell adhesion molecule CD2 has been advanced greatly through the determination of structures and the dynamic properties of the complexes and their individual components and through site-directed mutagenesis. A number of general principles can be derived from the structural and functional studies of the extracellular domains of CD2 and CD58 and their complex. Significant electrostatic interactions within the protein-protein interfaces contribute directly to the formation of macromolecular complexes of CD2 and CD58. Also, residues located on the protein-protein interface demonstrate a certain degree of conformational change upon the formation of a complex. Structural analysis of CD2 has revealed that this adhesion molecule exhibits strong conformational flexibility with a partial non-native helical conformation at high temperatures and in the presence of an organic solvent. In addition, it can be converted into a domain swapped dimer, or trimer and tetramer through hinge deletion. Thus, the conformational status of the adhesive proteins contributes to the regulation of cell adhesion and the folding of CD2.

Animals↗

PubMed2001

[Clinic intervention study on urogenital mycoplasma infection of pregnant women].

OBJECTIVE: To explore the hypothesis of pathogenic relationship between urogenital mycoplasma infection and adverse perinatal outcomes. METHODS: Four hundred and eighty-eight mycoplasma-positive pregnant women detected by culture method were randomly divided into erythromycine-intervention group and non-intervention group. Comparison was made on rate of reverse sero-conversion, of vertical transmission to mycoplasma and adverse perinatal outcomes incidence between groups. RESULTS: Ureaplasma urealyticum sero-conversion rate and rate of vertical-transmission in intervention group were significantly lower than in non-intervention group (P < 0.05). The incidences rates of preturm labor, post partum fever, puerperal infection and neonate pneumonia in intervention group were significantly lower than in non-intervention group (P < 0.05). CONCLUSION: Erythromycin is effective in control of ureaplasma urealyticum infection among pregnant women through cutting off vertical transmission passway and lowering adverse perinatal outcomes against ureaplasma urealyticum.

Anti-Bacterial Agents↗

PubMed2001

Myocardial protection with pinacidil induced hyperpolarized arrest during cardiopulmonary bypass.

OBJECTIVE: To investigate the myocardial protective effects of pinacidil-induced hyperpolarized arrest and compare with those afforded by conventional depolarized hyperkalemic arrest. METHODS: Eighteen dogs were equally divided into three groups: normothermic hyperpolarized group (Group A), hypothermic hyperpolarized group (Group B), and hyperkalemic group (Group C). Pinacidil (50 mumol/L) containing 37 degrees C St. Thomas solution (K+ 5 mmol/L, 10 ml/kg), pinacidil (50 mumol/L, Sigma, USA) containing 4 degrees C St. Thomas solution (K+ 5 mmol/L, 10 ml/kg) and 4 degrees C standard St. Thomas solution (K+ 16 mmol/L, 10 ml/kg) were infused respectively through the aortic root after aortic-clamping. Heart arrest and its recovery, ultrastructure of the myocardium, the level of serum myocardial enzymes, and lipid peroxide and adenine nucleotide of the myocardium were measured. Hemodynamics during ischemia and after reperfusion were observed. RESULTS: The percentages of normal mitochondria and glycogen did not change much during ischemia (except at 60 min) and after reperfusion in B Group, but declined markedly in Group C 30 min and 60 min after ischemia and 20 min after reperfusion (P < 0.01). In Group A, they were lower than those of Group B before ischemia, but higher than those of Group C. The recoveries of CO, SV, CI, LVSW, RVSW and MAP in Group B were significantly better than those in other two groups 15 min and 30 min after reperfusion (P < 0.05 and 0.01, respectively). However, they were still better in Group A than those in Group C (P < 0.05 and 0.01, respectively). The onset of heart arrest was faster in Groups C and B than that in Group A. Highly elevated serum myocardial enzymes were observed 60 min after ischemia and 20 min after reperfusion in Group C, while they were only mild in the hyperpolarized groups, especially in Group B, and their recoveries were rapid. Adenine nucleotides of the myocardium were better preserved in Group B than in other two groups 30 min, 60 min after ischemia, and 20 min after reperfusion (P < 0.05 and 0.01, respectively). They were also much better in Group A than in Group C (P < 0.05 and 0.01, respectively). Lipid peroxide of the myocardium were significantly lower in Group B than in other groups 20 min after reperfusion (P < 0.01), and they were lower in Group A than in Group C (P < 0.05). CONCLUSIONS: Myocardial protection for global ischemia during cardiopulmonary bypass (CPB) could be achieved with hyperpolarized heart arrest induced by pinacidil, an ATP-sensitive potassium channel opener, especially in the hypothermic state. The protection is weaker in normothermia but is still superior to that with traditional depolarized hyperkalemic arrest.

Adenine Nucleotides↗

PubMed2001

[Appraisal of renal failure reversing therapies in lupus nephritis].

OBJECTIVE: This study aimed to explore the therapies of reversing renal failure in lupus nephritis. METHODS: The research strategy was a retrospective cohort study. 173 patients were included in the study. All of them were consecutive in-patients of newly diagnosed renal failure (serum creatinine > 180 micromol/L) with lupus nephritis from 1991 to 1999 in the university hospital. The research factors included steroids, cyclophosphamide and cyclosporin. Steroids were divided to oral prednisone, intravenous dexamethasone and intravenous methylprednisolone pulse; cyclophosphamide dose intensity was divided into three grades: none, low dose (average dose 0.25 g/m(2) body surface area per week). 51 demographic, clinical and laboratory data were included in the study as possible confounding factors. The study end-point was recovery of renal function that was defined as a level of serum creatinine <or= 116 micromol/L in the azotemia patients or a 50% reduction of serum creatinine and discontinuation of dialysis in the uremic patients. The improvement had to be maintained for at least three months. Collection of the study factors and outcome variable was conducted by two separate, blinded groups of clinical specialists with two structured abstracting forms. RESULTS: The number of complete following up patients was 142 (82.1%). After over 6 months of following up, 93 cases (65.5%) recovered their renal function and 17 cases (12.0%) died. In COX proportional hazard regression model, cyclophosphamide therapy was significantly associated with the recovery of renal function. The adjusted hazard ratio (HR) to recovery of renal function was 4.41, 95% CI = 1.03 - 18.94 in low dose; and the HR was 13.29, 95% CI = 3.11 - 56.82 in high dose cyclophosphamide therapy. The gender, duration of renal dysfunction, small renal size, severe anemia and serum creatinine were also significantly associated with renal function recovery. Cyclophosphamide therapy was not significantly associated with death. The variables associated with death were low level of serum albumin and edema. CONCLUSION: Cyclophosphamide pulse was an efficient therapy in reversing renal failure of lupus nephritis, especially in the patients with short duration of renal failure, non-small in renal size, and non-severe anemia.

Administration, Oral↗

PubMed2001

[The effect of lactate-buffered peritoneal dialysis fluid in human peritoneal mesothelial cells function].

OBJECTIVE: To investigate the effect of lactate-buffered peritoneal dialysis fluid (L-PDF) on human peritoneal mesothelial cells (HPMC) function. METHODS: Mesothelial cells from human omentum were isolated and cultured in vitro. Proliferation of HPMC was detected by MTT assay. The quantity of interleukin-8 (IL-8) and fibronectin (FN) in culture supernatants was determined by ELISA. Reverse transcription and polymerase chain reaction amplification were used to detect the expression of IL-8 mRNA in HPMC. Total cellular protein in these supernatants was estimated by using Lowry method. RESULTS: L-PDF inhibited proliferation of HPMC in a time-dependent manner. The levels of IL-8 and FN in the supernatants were remarkably high, and expression of IL-8 mRNA was up-regulated in HPMC exposure to L-PDF. During a subsequent recovery period of 48 hours in culture medium containing lipopolysaccharide (LPS, 10 mg/L), enterotoxin of staphylococcus aureus (10 mg/L) or TNFalpha(10 x 10(6) U/L), the levels of FN in the supernatants increased (P < 0.05). The levels of IL-8 also increased in HPMC stimulated with TNFalpha(P < 0.01). CONCLUSION: L-PDF inhibited proliferation of HPMC and increased levels of IL-8 and FN in the HPMC.

Dialysis Solutions↗

PubMed2001

[Cricohyoidoepiglottopexy: a report of 21 cases].

OBJECTIVE: To assess the indications, function preserving and long term results of cricohyoidoepiglottopexy (CHEP) in the treatment of laryngeal carcinoma. METHOD: Twenty-one patients were underwent this procedure during the period from 1993 to 1999 in our department. There were 20 glottic cancers (7 T1N0M0, 10 T2N0M0, 3 T3N0M0) and 1 supraglottic type (T2N1M0) according to the 1997 UICC system. In these cases, 15 were the aged over 60 years. RESULT: First decannulation rate was 95.24%, and majority completed in 28 days post-operation. No patient was with cannula all his life. All cases could finally take food by mouth without aspiration. Speech was also satisfactory. The overall 3-year and 5-year survival rates were 87.50% and 75.00% respectively. No patient experienced local recurrence. CONCLUSION: This procedure is presented as a useful alternative to partial vertical laryngectomy and total laryngectomy in select cases of laryngeal carcinoma.

Adult↗

PubMed2001

[The design of a multifunctional mobile operating table].

This article introduces the principles and design of a multifunctional medical table which could be used to immobilize patient from/to bed to/from table, and it can also be used as an operating table. So the dangerous and serious patients can get continuous servo and monitoring during the transfer. The hydraulic pressure lifter, machinery transmission, flat movement and asymmetry structure are employed in the product.

Durable Medical Equipment↗