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Biomedical subjects

Q Ye

Publications and source records attributed to Q Ye.

At least 91 records · Page 5Linked to original sources
PubMed1999

Existence of multiple novel Gs alpha splice variants in acute leukemia patients.

The alpha subunit of the stimulatory G protein, Gs alpha, is involved in stimulation of the adenylate cyclase pathway of signal transduction. In this study, we investigated the status of the Gs alpha gene in 29 acute leukemia patients and identified three novel splice variants (designated Gs alpha L-1, Gs alpha L-2, and Gs alpha L-3), possibly derived from aberrant splicing. All of the splice variants have in-frame deletions, removing the functional domain responsible for GTPase activity of Gs alpha, and would encode truncated proteins of 160(Gs alpha L-1), 90(Gs alpha L-2) and 70(Gs alpha L-3) amino acids, respectively. The data suggest that these novel products may be implicated in an as-yet-unidentified signal transduction pathway in hematopoietic cells.

Acute Disease↗
PubMed1999

Crystallization and X-ray crystallographic analysis of m-calpain, a Ca2+-dependent protease.

The absolute requirement of Ca(2+) for proteolytic activity is a feature unique to the calpains, a family of heterodimeric cysteine proteases. Conditions are described which give rise to diffraction-quality crystals of m-calpain in two crystal forms, P1 and P2(1). Data have been collected from native crystals of m-calpain in both P1 and P2(1) forms, to 2.6 and 2.15 A, respectively. Selenomethionine-containing crystals have been grown in both forms, and anomalous data from the P2(1) selenomethionine enzyme provided the location of 17 of the 19 Se atoms in the protein.

Animals↗
PubMed1999

Long-term observation of subcutaneous tissue reaction to synthetic auditory ossicle (Bioceram) in rats.

To evaluate biocompatibility to tissue in long-term implantation, Bioceram discs made of aluminum oxide (Al2O3) were implanted subcutaneously within the interscapular region of 64 rats for six to 20 months. Histological sections stained with haematoxylin and eosin (H&E) and the surface of the implant material were observed using light microscopy. Different cell types and the thickness of fibrous capsules surrounding the implants were examined quantitatively by light microscopy. Small numbers of macrophages (2.8 +/- 0.7%) and lymphocytes (2.7 +/- 0.9%) were observed at six months after implantation, gradually decreasing to zero at 16, 18 and 20 months. Neither neutrophils nor foreign body giant cells were seen in any specimens. The thickness of fibrous capsules surrounding the implants was closely related to the shape of the implant, but there was no significant change between six and 20 months after implantation. No change in Bioceram surfaces were observed under stereoscopic microscopy from six to 20 months after implantation. The study results indicate that Bioceram is a satisfactory biocompatible material for reconstructive surgery from the viewpoint of long-term tissue response. Present results of experiments with Bioceram are also compared to previous results with Apaceram and different tissue responses of the two materials are discussed.

Aluminum Oxide↗
PubMed1999

Long-term microstructural analyses of hydroxyapatite implanted in rats using laser-Raman spectrometry and scanning electron microscopy.

To investigate the long-term surface microstructure of a synthetic auditory ossicle (Apaceram) composed of dense hydroxyapatite (HA), thin HA disks were implanted subcutaneously into the interscapular regions of 12 rats. After 6, 14 and 20 months, implanted HA surfaces were observed using stereoscopic microscopy, scanning electron microscopy (SEM) and laser-Raman spectrometry. Visual observation by SEM at 6 months and by stereoscopic microscopy at 14 months indicated a progressive degradation of the HA disk surfaces implanted in the subcutaneous tissue. Visual observation by SEM at 14 and 20 months and by stereoscopic microscopy at 20 months indicated a progressive redeposition on the surfaces of the implants. Raman spectra compared half-peak breadths of v1 signal (PO4(3-), 960 cm(-1)) on the gray and white surface areas of implanted HA disks observed by stereoscopic microscopy. Analysis demonstrates that demineralization at 14 months and remineralization at 20 months occur on the gray areas; demineralization at 6 months and remineralization at 14 months occur on the white areas.

Animals↗
PubMed1999

Glyoxal-guanine DNA adducts: detection, stability and formation in vivo from nitrosamines.

The glyoxal-deoxyguanosine adduct (gG) is formed from alpha-nitrosamino aldehydes and dG in vitro and in vivo from nitrosamines carrying the 2-hydroxyethyl side-chain as well as from N-nitrosomorpholine. The structures of all of the diastereomeric forms of both the cis and trans isomers of the adduct have been investigated by ab initio calculations and with nuclear magnetic resonance spectroscopy at 500 MHz. The preferred orientation of the OH groups is trans, but at equilibrium a small amount of the cis isomer was observed. The pH-independent equilibrium constant for the hydrolysis of the gG adduct is K = 1.36 x 10(-4) mol/L, and its rate of formation at pH 7.3 is k = 5.3 min-1 mol-1. In acid (pH 2), the hydrolysis of the nucleosidic linkage is nearly twice as rapid as the hydrolysis of gG to glyoxal and dG. We used a gG analogue to explore a number of reductive methods for derivatization of the adduct, but all of the processes either gave low yields or product mixtures which rendered them impractical for derivatizing the adduct in DNA. A 32P-postlabelling method for detection of the pH-sensitive gG adduct has been developed, which permitted detection of the adduct in the liver DNA of male Wistar rats after administration of selected nitrosamines. The levels of adducts found were: N-nitrosodiethanolamine > 2-hydroxyethylmethynitrosamine > N-nitrosomorpholine > 2-hydroxyethyethylnitrosamine. In separate experiments, N-nitrosodiethanolamine gave greater adduct levels than its metabolite 2-hydroxy-N-nitrosomorpholine. Mechanistic pathways for the generation of gG adducts in vitro and in vivo are discussed.

Animals↗
PubMed1999

[A novel alternative splicing mode of the erythropoietin receptor gene in rats].

OBJECTIVE: To detect new alternative splicing mode of erythropoietin receptor (EpoR) gene in normal rats. METHODS: Total RNAs were isolated from bone marrow mononuclear cells of normal Wistar rats. Reverse transcriptase polymerase chain reaction (RT-PCR) of the total RNAs was done and the amplified products were sequenced. RESULTS: After RT-PCR with a pair of primers (sense: 637/657 bp, and antisence: 903/882 bp), two bands were detected, the expected band (267 bp) and a longer one (346 bp) which had a 79 bp insert between 736th and 737th bases from the first ATG of the rat EpoR nucleotide. Sequence analysis showed that the 79 bp insert was the retaining intron 5 with a C-to-T point mutation at 16th base and an insertion of G base between 49th and 50th base. The insertion of G base caused a shift in reading frame and resulted EpoR with a truncated intracellular domain. CONCLUSION: A new alternative splicing of EpoR mRNA encoding truncated intracellular domain was identified in normal Wistar rats. Its implication in rat erythropoiesis remains to be determined.

Alternative Splicing↗
PubMed1999

[Study of the relation between MMP2, MMP9 and nasopharyngeal carcinoma].

OBJECTIVE: To evaluate the role of matrix metalloproteinase (MMP) in the invasion and metastasis of nasopharyngeal carcinoma (NPC). METHOD: Twenty-six cases of NPC were studied by immunohistochmical method using monocolonal antibody to MMP2 and MMP9. RESULT: It was showed that there were significantly correlation between MMP2 or MMP9 and the invasion and metastasis of NPC. The positive rate of MMP2 and MMP9 were higher in NPC with cervical lymph node involvement than that of no cervical lymph node involvement. And they were lower in well differentiated NPC than poorly differentiated NPC. CONCLUSION: The results indicate that MMP2 and MMP9 may play a critical role in assisting carcinoma cell to degrade basement membrane to invade surrounding tissues and to form metastatic colonies in lymph nodes.

Adult↗
PubMed1999

[Treatment of late thoracolumbar fracture by transpedicular decompression using "PUMC trephine" 26 cases report].

OBJECTIVE: To introduce a new operation to treat late thoracolumbar fracture cases with neurological deficit or with kyphosis. METHODS: 26 cases were treated with "PUMC trephine" (designed by professor Ye Qibin). RESULTS: The kyphosis was (29.7 +/- 14.5) degrees Cobb's angle in pre-operation and (10 +/- 11.8) degrees in post-operation (P < 0.01). The angle of correction was (19.7 +/- +9.9) degrees. The height of the anterior edge of traumatic-vertebra was (16.3 +/- 5.7) mm in pre-operation and (22.2 +/- 6.3) mm in post-operation. The corrected height was (6.5 +/- 3.2) mm. The neurological deficit also got a better recovery in 17 of 19 cases, 12 of 15 cases obtained complete cure of incontinence. 11 of 15 case had sexual function recovery after following up 1-9 years (average 5.2 years) cases. CONCLUSIONS: Using "PUMC trephine" procedure was a new, simple, safety and less-traumatic technique for treatment of late thoracolumbar fracture through posterior approach.

Adult↗
PubMed1999

[The surgical treatment of congenital kyphosis].

OBJECTIVE: To summarize the treatment experience of congenital kyphosis, compare the results of several surgical procedures and conclude the lessons of failure cases with surgical treatment. METHODS: Retrospective analysis of 33 patients with surgical treatment of congenital kyphosis. These patients had a follow-up of 6 months to 14 years with an average follow-up of 5 years and 6 months. RESULTS: Among the 33 cases, the average age at surgery was 16.5 years old and the average kyphosis was 90.2 degrees. Four had anterior fusion, and 7 had posterior fusion only, and 22 had combined anterior and posterior fusion. The percentage of correction of the 3 procedures above mentioned was 32.7%, 34.4% and 41.2% respectively. All of the patients with incomplete paraplegia, but 2 had been recovered completely. CONCLUSIONS: The combined anterior and posterior fusion had a better correction than the anterior group or posterior group alone.

Adolescent↗
PubMed1999

[Detection of human papillomavirus in laryngeal carcinoma with digoxigenin labelled probe prepared by polymerase chain reaction].

OBJECTIVE: To study the relationship between laryngeal carcinoma and human papillomavirus (HPV), and describe distribution, expression of genome types of HPV in laryngeal carcinoma. METHODS: We used a non-radioactive digoxigenin labeled probe prepared by polymerase chain reaction (PCR) to test the fresh tissue samples from 146 cases with different laryngeal lesions. The labelled probe of HPV consensus primers was obtained, which enabled detection of nine types of HPV DNAs that were HPV 6, 11, 16, 18, 31, 33, 35, 42 and 58. The genome types of HPV DNA positive cases were determined by using multiple primers PCR. RESULTS: The results turned out to be as follows: The HPV infection positive rate was 45.6%(31/68) for laryngeal carcinoma, 20.0% (3/15) for neck metastatic lymphnode, 11.8%(2/17) for precarcinomatous lesions and 6.3%(1/16) for vocal cord polypus. 15 cases of normal tissues adjacent to carcinoma and another 15 normal tissues opposite to the carcinoma were all HPV DNA negative. HPV16, 18 types are the main types of laryngeal carcinoma and HPV6, 11 types often appear in benign lesions of larynx. CONCLUSION: These results implicated that the occurrence and development of laryngeal carcinoma may be closely related to HPV infection.

DNA Probes, HPV↗
PubMed1999

Failure and complication following surgical treatment of scoliosis--an analysis of 101 cases.

Complications occur frequently after surgical treatment of scoliosis. In order to prevent from them effectively, 101 cases with failure and postoperative complications were analysed. They included rod fracture in 22 cases (15 Harrington rods, 4 Zielke rods, and 3 Luque rods); recurrence of curve severity in 12 cases; broken or loossened luque wires in 15 cases; loss of thoracic kyphosis (flat back) in 6 cases; progressive kyphosis with or without paraplegia following incorrect posterior decompression in 5 cases; and increased unbalance of shoulders after instrumentation in 2 cases due to neglect of the tilting of the first thoracic vertebra. Infection occurred in 8 cases (incision infection 7 cases, deep wound infection in 1 case); and pneumothorax in 1 case. They were induced by biomechanical factors in 23 cases (22.8%), incorrect selections of indications in 29 cases (28.7%), operational mistakes in 37 cases (36.6%), internal fixation factors in 15 cases (14.9%). The authors hold that there are quite a lot of factors leading to occurrence of complications and the effective way for prevention from them is to understand the factors and main technical points related to internal fixation.

Equipment Failure↗
PubMed1999

[Investigation of the reaction of iso-propylamine on propylene oxide by Fourier transform infrared spectroscopy].

Fourier transform infrared spectroscopy method has been developed for in-situ monitoring the reaction of iso-propylamine on propylene oxide without the need to sample the reaction medium. The profile of the reaction and the influences of conditions can be directly reflected in the feature absorbance changes of the reactant and product at 826 cm(-1) and 1069 cm(-1), respectively. It is shown that the in situ infrared spectroscopy is a powerful technique to investigate the mechanism and kinetics of the reaction and to optimize the control conditions.

English Abstract↗
PubMed1999

[Monitoring glucoamylase fermentation with infrared spectroscopy].

The glucoamylase fermentation was investigated with Fourier transform infrared spectroscopy. During the cultivation, the variation of carbon and nitrogen source can be reflected from the infrared spectra. In most cases, the complex media are used to cultivate cells or bacteria. It is difficult to construct calibration samples with synthetic mixtures which can represent the composition of real broth. The infrared spectral data of the real broth and off-line chemical analysis results were used to establish the calibration model. The model is successfully used to predict the concentrations of total sugar, reduced sugar, and nitrogen in real broth. The correlation coefficients between the infrared analysis results and chemical analysis are 0.999, 0.990 and 0.974 for total sugar, reduced sugar and nitrogen, respectively. The bacteria, culture and operating condition are relatively stable during the practical productive processes. The method can be used to monitor the industrial processes.

Aspergillus niger↗
PubMed1998

Column switching in high-performance liquid chromatography with tandem mass spectrometric detection for high-throughput preclinical pharmacokinetic studies.

A high-throughput liquid chromatography-tandem mass spectrometry method is described for the determination of multiple compounds in dog and rat plasma. After acetonitrile precipitation of plasma proteins, the analytes are pre-concentrated and back-flushed on a reversed-phase column for separation using a switching valve. The analytes are ionized using TurboIon Spray in a positive mode, and detected by multiple reaction monitoring. Automatic tuning software is used for fast method development. The data processing is greatly speeded up by using a powerful quantitation software package. Chromatography of multiple compounds takes only 4 min. The linear calibration curve ranges from 0.5 to 1000 ng/ml. This method was successfully used in the analysis of multi-compounds for preclinical pharmacokinetic studies.

Animals↗
PubMed1998

Lymphoid/nonlymphoid compartmentalization of donor leukocyte chimerism in rat recipients of heart allografts, with or without adjunct bone marrow.

BACKGROUND: The role of leukocyte migration and chimerism in organ allograft acceptance has been obscured by the lack of information about the late localization of the donor cells. METHODS: Male Lewis rat-->female Brown Norway abdominal heart transplantation was performed under tacrolimus immunosuppression (days 0-13, 20, and 27) with or without donor bone marrow and (in bone marrow subgroups) a 1-week postoperative course of a possibly chimerism-enhancing drug. Using rat sex-determining region-Y-specific oligonucleotide primers, we determined the donor DNA concentration by polymerase chain reaction in serial venous blood samples for 100 days and in tissue specimens when animals were killed. RESULTS: Chimerism was detected out to 56 days in 89% of the blood samples but in none of the samples at 100 days. However, donor DNA was detected when animals were killed in 95% of the native hearts, 80% of the skin biopsy specimens, and 23% of the spleens. The presence and quantity of early and late chimerism were strongly correlated the administration of adjunct bone marrow and with a reduction in the vasculopathy and inflammation index in the cardiac allografts. Marginally significant further increases in chimerism and/or reductions in chronic heart rejection beyond those achieved with adjunct bone marrow alone were associated with additional treatment with the growth factors Flt-3 ligand, granulocyte colony-stimulating factor, and a recombinant molecular variant of interleukin-6 (interleukin-6 mutein) but not with hepatocyte growth factor or lisofylline. CONCLUSIONS: The previously suspected shift of early chimerism in the blood and lymphoid organs to dominance in host nonlymphoid tissues is consistent with the dual mechanisms of clonal exhaustion and immune indifference, governed by antigen migration and localization, that have been postulated elsewhere to account for organ allograft acceptance.

Adjuvants, Immunologic↗
PubMed1998

Purification, crystallization and preliminary X-ray analysis of the Escherichia coli phytase.

A recombinant form of Escherichia coli phytase, which hydrolyzes phytic acid into phosphate and myo-inositol, has been expressed, purified and crystallized. Crystals have been obtained by the method of bulk crystallization in 10 mM sodium acetate buffer (pH 4.5) without using a conventional precipitant. The enzyme crystallized in space group P21, with unit-cell dimensions a = 74.9, b = 72.2, c = 82.4 A, and beta = 92.0 degrees. Crystals diffract to at least 2.2 A at a rotating-anode X-ray source and a 2.3 A resolution data set has been collected, giving completeness of 98.0% and an Rsym of 0.072. Assuming there are two phytase molecules in the asymmetric unit, the solvent content is calculated to be 42.1%. A self-rotation function shows a clear twofold non-crystallographic symmetry relating two molecules of E. coli phytase in the asymmetric unit.

6-Phytase↗
PubMed1998

Structure of type III antifreeze protein at 277 K.

Fish antifreeze proteins (AFP's) depress the freezing point of blood and other body fluids below that of the surrounding seawater by binding to and inhibiting the growth of seed ice crystals. The high-resolution crystal structure of type III AFP, determined at room temperature, reveals a remarkably flat surface containing most of the ice-binding residues [Jia et al. (1996). Nature (London), 384, 285-288]. Since AFP's function at temperatures close to 273 K, it is important to know whether the structure determined at room temperature undergoes any change at much lower temperature. Therefore, type III AFP has been crystallized at 277 K and its structure determined. Although crystallization conditions at 277 K were similar to those at approximately 295 K, crystal growth took much longer at the lower temperature. Crystals grown at the two temperatures were isomorphous. Initial crystals appeared within 40-50 d and grew to their final size in about 8-12 months, instead of a couple of days at approximately 295 K. The type III antifreeze protein structure from crystals grown at 277 K was essentially the same as that determined at approximately 295 K, with the exception of some minor changes in side-chain conformation. The result is an indication that temperature has a minimal effect on the structure of type III AFP, thus lending increased physiological validity to the room-temperature structure which was used for the initial ice-binding modelling.

Animals↗