[Labor induction in women at term with mifepristone and it's safety].
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Abortifacient Agents, Steroidal↗
Biomedical subjects
N Zhang
Publications and source records attributed to N Zhang.
[Determination of serum proteins by high performance capillary zone electrophoresis].
The separation method of serum proteins was established with an untreared 50 microns i.d. x 47 cm (40 cm to detector) capillary and detection of absorbance at 200 nm. Analysis was performed by pressure injectction 17.23 kPa.s and by applying 23 kV in the constant voltage mode. Serum samples were diluted 40-folds with assay buffer (12.5 mmol/L sodium borate, 1 mmol/L calcium lactate, 0.7 mmol/L magnesium sulfate, 1 mmol/L EDTA were mixed). A normal control serum protein was separated into 6 fractions. In pregnant serum, the alpha 0 was an additionally unknown fraction. Comparison of capillary electrophoresis with conventional cellulose acetate electrophoresis for analysis of serum proteins from normal control, pregnant women multiple myeloma and tonic rachitis patients indicates that capillary clectrophoresis is a new technique for the analysis of serum proteins because of its high efficiency, on-line data processing and automation. Capillary electrophoresis is the reliable technique for clinical diagnosis of serum protein abnormalities.
Albumins↗
[A clinical and pathological study on cervical lymph node metastasis in the clinical N0 patient with laryngeal carcinoma].
OBJECTIVE: To study the characteristics of the cervical lymph node metastasis in negative nodes (N0) with clinically with laryngeal carcinoma patients and its implication in clinical treatment. METHODS: Forty patients with laryngeal carcinomas of No category were divided randomly into two groups: 13 radical neck dissections (RND) and 27 functional neck dissections (FND) were performed. Lymph nodes were studied histologically. RESULTS: On an average, 34.2 lymph nodes were obtained in one side of neck in RND group, and 27.4 in FND group (t = 0.86, P > 0.05). The metastases rates were 30.8% (4/13) in RND group and 33.3% (9/27) in FND group, and the total metastasis rate was 32.5% (13/40). Twelve of 13 patients (92.3%) who had positive nodes involved only the levels II and III, and 32 of 33 positive nodes (96.9%) were located in the levels II and III. The 3-year survival rates of the two groups were 69.2% (9/13) and 77.8% (21/17), respectively with no statistical difference (chi 2 = 0.3418, P > 0.5). Total 3-year survival rate was 75% (30/40). CONCLUSION: The supraomohyoid (level Io II and III) or lateral neck (level II, III and IV) dissections seem suitable for the treatment laryngeal carcinoma patients with clinically negative neck nodes.
Adult↗
On-line coupling of polymerase chain reaction and capillary electrophoresis for automatic DNA typing and HIV-1 diagnosis.
We demonstrate an integrated on-line system with a fused-silica capillary as the microreactor for PCR and capillary gel electrophoresis with laser-induced fluorescence detection for DNA typing and disease diagnosis. Two applications have been investigated: the four short tandem repeat (STR) loci vWA, THO1, TPOX and CSF1PO (CTTv) for DNA typing, and DNA probe for human immunodeficiency virus (HIV-1) diagnosis. The CTTv are important loci in forensic and genetic linkage analysis. The PCR technique is a powerful tool in HIV research because it can detect the presence of the virus before any antibody response in the infected person. Thus it is important for early diagnosis. Multiplexed PCR in a fused-silica capillary, on-line injection, DNA denaturation and calibration based on a standard ladder have been successfully combined. Also, on-line liquid flow management, DNA separation and detection have been completely integrated.
Autoanalysis↗
An anti-sense construct of full-length ATM cDNA imposes a radiosensitive phenotype on normal cells.
The cloning of a full-length cDNA for the gene (ATM) mutated in the human genetic disorder ataxia-telangiectasia (A-T) has been described recently. This cDNA, as well as a fragment representing a functional region from ATM, are capable of rescuing various aspects of the radiosensitive phenotype in A-T cells. We have subcloned full-length ATM cDNA in the opposite orientation in an EBV-based vector under the control of an inducible promoter to determine whether this anti-sense construct might sensitize control lymphoblastoid cells to ionizing radiation. The effectiveness of expression of this construct in control cells was monitored by loss of ATM protein which was evident over a period 6-12 h after induction. Under these conditions radiosensitivity was enhanced approximately threefold in control cells, approaching the degree of radiosensitivity observed in A-T cells. Expression of the anti-sense construct also increased the number of radiation-induced chromosomal breaks and led to the appearance of radioresistant DNA synthesis in these cells. Abrogation of the G1/S checkpoint was evident from the loss of the p53 response and that of its downstream effector, p21/WAF1, post-irradiation. The extent of accumulation of transfected cells in G2/M phase at 24 h post-irradiation was similar to that observed in A-T cells and the induction of stress-activated protein kinase by ionizing radiation was prevented by antisense ATM cDNA expression. These data demonstrate that full-length ATM anti-sense cDNA, by reducing the amount of ATM protein, is effective in imposing a series of known defects characteristic of the A-T phenotype. This inducible system provides an experimental model to further investigate mechanisms underlying radiosensitivity and cell cycle control.
Ataxia Telangiectasia↗
Defects in somite formation in lunatic fringe-deficient mice.
Segmentation in vertebrates first arises when the unsegmented paraxial mesoderm subdivides to form paired epithelial spheres called somites. The Notch signalling pathway is important in regulating the formation and anterior-posterior patterning of the vertebrate somite. One component of the Notch signalling pathway in Drosophila is the fringe gene, which encodes a secreted signalling molecule required for activation of Notch during specification of the wing margin. Here we show that mice homozygous for a targeted mutation of the lunatic fringe (Lfng) gene, one of the mouse homologues of fringe, have defects in somite formation and anterior-posterior patterning of the somites. Somites in the mutant embryos are irregular in size and shape, and their anterior-posterior patterning is disturbed. Marker analysis revealed that in the presomitic mesoderm of the mutant embryos, sharply demarcated domains of expression of several components of the Notch signalling pathway are replaced by even gradients of gene expression. These results indicate that Lfng encodes an essential component of the Notch signalling pathway during somitogenesis in mice.
Animals↗
Cloning and expression of the ataxia-telangiectasia gene in baculovirus.
The gene mutated in the human genetic disorder ataxia-telangiectasia, ATM, is implicated in the response to radiation-induced DNA damage and to a more widespread signalling defect. The ATM protein is predominantly a nuclear protein where it interacts with p53 and c-Abl as part of a radiation signal transduction pathway(s). We describe here the cloning of full-length ATM cDNA in a baculovirus vector to produce recombinant protein. Expression of ATM, as a soluble protein, was observed by 36 h post-infection using immunoblotting with anti-ATM antibody. The presence of a hexahistidine tag on ATM was used as the basis for purification of the protein by affinity chromatography. The protein yield was only 20 ng/100 ml of infected cells, presumably because of the size of the protein and adverse effects on cell growth when overexpressed. ATM was found to have autophosphorylation activity in immunoprecipitates with antibodies directed against the hexahistidine tag sequence. These results demonstrate that ATM can be expressed inefficiently in baculovirus infected insect cells and the data suggest that it phosphorylates itself.
Animals↗
Retrograde cerebral perfusion enhances cerebral protection during prolonged hypothermic circulatory arrest: a study in a chronic porcine model.
BACKGROUND: This study was undertaken to confirm earlier findings that retrograde cerebral perfusion (RCP) can improve cerebral outcome after prolonged hypothermic circulatory arrest (HCA), and to determine whether RCP with inferior vena caval occlusion, which is more effective in removing particulate emboli, is superior to conventional RCP in enhancing cerebral protection. METHODS: Sixty-two pigs (27 to 30 kg) were randomly assigned to undergo one of the following for 90 minutes at 20 degrees C: antegrade cerebral perfusion (ACP); conventional RCP (RCP); RCP with occlusion of the inferior vena cava (RCP-O), or HCA with the head packed in ice. RCP flow was regulated to a sagittal sinus pressure of 20 mm Hg. Hemodynamic, electrophysiologic, and metabolic monitoring were carried out until 4 hours after rewarming, daily behavioral and neurologic assessments until elective sacrifice on day 7, and histologic analysis of the brain after death. RESULTS: Complete behavioral recovery was seen in all surviving animals by day 5 after ACP or RCP, but in only 83% after RCP-O and 50% after HCA (p = 0.001). A histopathologic score of 2 or more, indicating more than mild injury, was not found in any animal after ACP, in 27% after RCP, in 47% after HCA, and in 68% after RCP-O (p = 0.002). The median oxygen consumption was 6.66 mL/min after ACP, 1.37 mL/min with RCP, and 1.02 mL/min with RCP-O (p < 0.0001). The median amount of fluid sequestered was 2,450 mL after RCP-O, 760 mL after RCP, and -200 mL after ACP (p < 0.0001). CONCLUSIONS: Conventional RCP without inferior vena caval occlusion results in a significantly better outcome than RCP-O after prolonged HCA, despite more efficient cerebral perfusion during RCP-O, and also provides cerebral protection superior to prolonged HCA alone, but care must be taken during its implementation to minimize cerebral edema and other possible causes of retroperfusion-related cerebral injury.
Animals↗
Can retrograde perfusion mitigate cerebral injury after particulate embolization? A study in a chronic porcine model.
OBJECTIVE: We assessed the impact on histologic and behavioral outcome of an interval of retrograde cerebral perfusion after arterial embolization, comparing retrograde cerebral perfusion with and without inferior vena caval occlusion with continued antegrade perfusion. METHODS: Sixty Yorkshire pigs (27 to 30 kg) were randomly assigned to the following groups: antegrade cerebral perfusion control; antegrade cerebral perfusion after embolization; retrograde cerebral perfusion control; retrograde cerebral perfusion after embolization; retrograde cerebral perfusion with inferior vena cava occlusion, retrograde cerebral perfusion with inferior vena cava occlusion control, and retrograde cerebral perfusion with inferior vena cava occlusion after embolization. After cooling to 20 degrees C, a bolus of 200 mg of polystyrene microspheres 250 to 750 (microm diameter (or saline solution) was injected into the isolated aortic arch. After 5 minutes of antegrade cerebral perfusion, 25 minutes of antegrade cerebral perfusion, retrograde cerebral perfusion, or retrograde cerebral perfusion with inferior vena cava occlusion was instituted. After the operation, all animals underwent daily assessment of neurologic status until the time of death on day 7. RESULTS: Aortic arch return, cerebral vascular resistance, and oxygen extraction data during retrograde cerebral perfusion showed differences, suggesting that more effective flow occurs during retrograde cerebral perfusion with inferior vena cava occlusion, which also resulted in more pronounced fluid sequestration. Microsphere recovery from the brain revealed significantly fewer emboli after retrograde cerebral perfusion with inferior vena cava occlusion. Behavioral scores showed full recovery in all but one control animal (after retrograde cerebral perfusion with inferior vena cava occlusion) by day 7 but were considerably lower after embolization, with no significant differences between groups. The extent of histopathologic injury was not significantly different among embolized groups. Although no histopathologic lesions were present in either the antegrade cerebral perfusion control group or the retrograde cerebral perfusion control group, mild significant ischemic damage occurred after retrograde cerebral perfusion with inferior vena cava occlusion even in control animals. CONCLUSIONS: Although effective washout of particulate emboli from the brain can be achieved with retrograde cerebral perfusion with inferior vena cava occlusion, no advantage of retrograde cerebral perfusion with inferior vena cava occlusion after embolization is seen from behavioral scores, electroencephalographic recovery, or histopathologic examination; retrograde cerebral perfusion with inferior vena cava occlusion results in greater fluid sequestration and mild histopathologic injury even in control animals. Retrograde cerebral perfusion with inferior vena cava occlusion shows clear promise in the management of embolization, but further refinements must be sought to address its still worrisome potential for harm.
Animals↗
Evidence that oxidized proteins are substrates for N-terminal arginylation.
While the posttranslational N-terminal arginylation of proteins has been demonstrated in a variety of eukaryotic cells including neurons and their axons, the targets of the reaction are poorly understood. Several lines of evidence suggest that arginylation may be a cytoprotective mechanism used by cells to target oxidatively damaged (and thus potentially toxic) proteins for degradation. In the present experiments, we have begun to test this hypothesis by incubating oxidized test proteins in a rat brain extract capable of arginylating endogenous proteins. Bovine serum albumin, pancreatic ribonuclease-A and the A-chain of insulin were chosen as test proteins and either oxidized by metal catalyzed oxidation or purchased in their oxidized forms and incubated with the extract and [3H]Arg. SDS PAGE of the incubation product showed [3H]Arg migrating with the oxidized forms of BSA and RNase but not with the un-oxidized form of BSA. Following incubation with the oxidized A-chain of insulin, analysis of the [3H]product by SDS PAGE and HPLC showed co-migration of [3H]Arg with A-chain standards and amino acid sequencing showed [3H]Arg at the N-terminus of the A-chain of insulin. The data suggest that oxidative damage to a protein may be a signal for its N-terminal arginylation.
Animals↗
Trace analysis of benzalkonium chloride on skin by flow injection ionspray mass spectrometry-mass spectrometry.
A method for the analysis of trace-level benzalkonium chloride has been established using flow injection ionspray mass spectrometry-mass spectrometry with multiple reaction monitoring. Quantification was carried out using an external standard based on peak area summation of each benzalkonium ion (C8, C10, C12, C14, C16 and C18) in the mass spectra. The multiple reaction monitoring technique provides additional specificity for identification and quantification. The quantification linear dynamic range was found to be 5.0-100.0 ng ml-1, the correlation coefficient > 0.999, and the detection limit 1.2 ng ml-1. The method was applied to quantify benzalkonium chloride on skin, which was sampled with a D-SQUAME tape from skin surface and extracted from the tape with methanol.
Anti-Infective Agents, Local↗
Pituitary adenomas: the effect of gamma knife radiosurgery on tumor growth and endocrinopathies.
Seventy-three patients have been treated with Gamma Knife radiosurgery (GKR) for pituitary adenomas. 12 had undergone surgery prior to GKR. Three had had previous radiation therapy. The prescription dose administered to the tumor margin ranged from 9 to 35 Gy. 65 patients were followed up for an average of 29 months. A slight expansion of tumor volume occurred in 3 cases. Otherwise, the tumor volume remained unchanged or decreased in the remainder. Endocrine changes were present in all except 3 cases. GKR was followed by a speedy decrease in raised serum hormone levels in the case of both growth hormone (GH)and adrenocortico-tropic hormone (ACTH). In 3 patients there was some visual deterioration associated with a slight increase in tumor volume. In 2 cases, the tumors were removed surgically. Some preliminary conclusions may be drawn. The dose required to correct an endocrinopathy may be higher than that required for control of tumor growth. The recommended prescription dose for endocrine-active adenomas may be more than 30 Gy. While clinical improvement may be noted in patients with raised serum prolactin levels (PRL), normalization of the endocrinopathy may be less readily achieved than in the case of raised GH and ACTH levels. Gamma Knife radiosurgery as a primary treatment of pituitary adenomas can be safe and effective.
Adenoma↗
Gamma knife radiosurgery for hemangioblastomas.
Thirteen patients (11 males, 2 females) with cerebral hemangioblastomas (HABs) were treated with Gamma Knife radiosurgery (GKR). Four patients had multiple lesions in the brain. The remainder had a single lesion. The total number of lesions was 20. Eight cases had recurrent or residual HABs after surgery. In one case diagnosis was confirmed following surgical resection 22 months after GKR. One case was diagnosed by computed tomography (CT), magnetic resonance imaging (MRI) and digital subtraction angiography (DSA). Three patients had von Hippel Lindau (VHL) disease. The mean tumor diameter was 20 mm (range 7.5 to .55 mm). The mean margin dose was 18 Gy (range 12 to 24 Gy). In 5 cases, there was an improvement of symptoms and reduction in tumor volume. In 4 cases the tumor volume and clinical status remained unchanged. In 3 patients, there was clinical deterioration. The cause of this was an increase in tumor cyst volume in 2 cases. Subsequent surgery resulted in clinical improvement. In a third patient with multiple lesions, deterioration was the result of adverse radiation effects in the medulla oblongata. Three patients were subjected to post GKR-surgery with subsequent histopathology. In one, this was due to cyst expansion. In one, it was at the patient's insistence in the presence of a stable clinical and radiological picture. In a third patient with a temporal lobe tumor, it was because of late-developing epileptic seizures. The histopathological findings in these patients showed varying degrees of small vessel thickening and occlusion together with loss of tumor cells. The observations varied in degree according to the time between GKR and the secondary operation. These findings indicate the effectiveness of the treatment. The reduction in vascularity suggests that GKR could make subsequent surgery less hazardous. The observations of this study suggest that while GKR is not adequately reliable for the control of HAB cysts, it can be an effective treatment for solid tumors, especially those in eloquent regions.
Adolescent↗
A résumé of epidemiological surveys of several main rheumatic diseases in China.
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Arthritis, Rheumatoid↗
[Efficacy of cyclosporin A in the treatment of aplastic anemia and its mechanism].
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Anemia, Aplastic↗
[Single-tube nested polymerase chain reaction technique in detecting Mycobacterium tuberculosis DNA].
OBJECTIVE: To study the sensitivity and specificity of single-tube nested polymerase chain reaction (SN-PCR) technique in detecting Mycobacterium tuberculosis DNA in paraffin-embedded tissues. METHOD: BCG DNA and the paraffin-embedded tissues of 30 cases with typical tuberculous lymphadenitis were examined to detect the IS6110 specific insertion sequences DNA of Mycobacterium tuberculosis complex by general PCR(G-PCR), double-tube nested PCR (DN-PCR) and SN-PCR techniques. RESULT: Fifteen fg or more BCG DNA could show positive results by DN-PCR and SN-PCR techniques, while 480 fg by G-PCR method. The positive rates of G-PCR, DN-PCR, and SN-PCR in detecting Mycobacterium tuberculosis DNA in 30 cases with tuberculous lymphadenitis were 43%, 100%, and 100% respectively, all of which were significantly different (P < 0.01) from that of the acid-fast staining method (10%). Significant differences in the positive rates also existed between G-PCR and DN-PCR, G-PCR and SN-PCR (both P < 0.01), while the positive rates of DN-PCR and SN-PCR were found same. CONCLUSION: The sensitivities of nested PCR techniques in detecting Mycobacterium tuberculosis are significantly higher than that of G-PCR, whereas the sensitivities as well as the specificities of SN-PCR and DN-PCR are the same. Thus SN-PCR seems more practicable.
DNA, Bacterial↗
[Application of maxillary bone eversion reduction on benign tumor in nasal cavity and paranasal sinus invading the skull base].
OBJECTIVE: To investigate the operative methods for benign tumors in nasal cavity and paranasal sinus invading the skull base. METHODS: Six cases of benign tumors in nasal cavity and paranasal sinus invading the skull base were reported. Of them, 3 were ossifying fibromas, 1 osteoma, 1 osteochondroma and 1 giant osteoid osteoma. The tumors were removed by combined approaches through unilateral maxillary bone eversion reduction. RESULTS: No complication was found. Follow-up was made 2-3 years after operation. Five cases were uneventful, 1 had a relapse of tumor but still alive. CONCLUSIONS: The method is appropriate for treating benign tumors in nasal cavity and paranasal sinus invading the skull base.
Adult↗
[Study on the chemical components of Rabdosia excisa].
Four kinds of components were extracted and separated from the stems and leaves of Rabdosia excisa. They had been identified as Kamebakaurin, Ursolic acid, Daucosterol and Liquiritin respectively by physical and chemical methods, as well as spectrum data. It was first time that Liquiritin was obtained from the Robdosia family, and its 13C-NMR data of Liquiritin had not been reported before.
Chromatography, Thin Layer↗