801
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Zhang G, Huang T, Stevens C, Harris E, Lin K, Forster K. Composite Plans and Biological Effective Dose Distributions over Multi-modality/Multi-plan Radiotherapy for Plan Evaluation and Toxicity Risk Analysis. Int J Radiat Oncol Biol Phys 2008. [DOI: 10.1016/j.ijrobp.2008.06.168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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802
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Zhang G, Shan W, Wang Z, Wu X. Attenuation of seizure in P77PMC rats with an HSV-vector expressing IL-1ra in brain. SCIENCE IN CHINA. SERIES C, LIFE SCIENCES 2008; 41:93-8. [PMID: 18726276 DOI: 10.1007/bf02882711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/1997] [Indexed: 11/28/2022]
Abstract
Cloned human IL-1ra (IL-1 receptor antagonist, IL-1ra) cDNA is inserted into pHSVLac, resulting in recombinant named pHSV-IL-1ra. pHSVLac and pHSV-IL-lra were packaged into HSV-1 particles using HSV-1 ts K as helper virus. The results showed that: (i) vero cell infected by pHSV-IL-1ra particles showed IL-1ra expression; expression of beta-galactosidase is observed in meninges and some neurons closed to ventricular and maintained for 8 weeks in rats after intracerebroventricular injection of pHSV-IL-1ra particles; (ii) transgenic expression of IL-lra by pHSVIL-lra injection significantly inhibited seizure attacks of P77PMC rat. These studies indicate that HSV-1 vector expressing IL-1ra in brain attenuated seizure attacks of P77PMC rat.
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803
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Lei W, Fang R, Zhang G, Chen X, Zhang X. Recombination with coat protein transgene in a complementation system based onCucumber mosaic virus (CMV). SCIENCE IN CHINA. SERIES C, LIFE SCIENCES 2008; 44:263-73. [PMID: 18726406 DOI: 10.1007/bf02879333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2000] [Indexed: 10/22/2022]
Abstract
In order to study the feasibility ofCucumber mosaic virus (CMV) as an expression vector, the full-length cDNA of RNA 3 from strain SD was cloned and the sequence around the start codon of the coat protein (CP) gene was modified to create anNsi I site for insertion of foreign genes. The CP gene was replaced by the green fluorescent protein (GFP) gene. The cDNAs of Fny RNAs 1 and 2 and the chimeric SD RNA 3 were cloned between the modified 35S promoter and terminator. Tobacco protoplasts were transfected with a mixture of the viral cDNAs containing 35S promoter and terminator as a replacement vector and expressed GFP. A complementation system was established when the replacement vector was inoculated onto the transgenic tobacco plants expressing SD-CMV CP. GFP was detected in the inoculated leaves in 5 of 18 tested plants and in the first upper systemic leaf of one of the 5 plants ten days after inoculation. However, no GFP could be detected in all the plants one month after inoculation. Recombination between the CMV vector and the CP transgene was proved by retro-transcriptional polymerase chain reaction (RT-PCR) and verified by DNA sequencing. Our results argue against the feasibility of the CMV-based replacement vector trans-complemented by the CP transgene, and at the same time, enlighten ways to improve the CMV-based expression vector and the biosafety of CMV CP-mediated virus resistant transgenic plants.
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804
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Terry AV, Warner SE, Vandenhuerk L, Pillai A, Mahadik SP, Zhang G, Bartlett MG. Negative effects of chronic oral chlorpromazine and olanzapine treatment on the performance of tasks designed to assess spatial learning and working memory in rats. Neuroscience 2008; 156:1005-16. [PMID: 18801413 DOI: 10.1016/j.neuroscience.2008.08.030] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2008] [Revised: 07/24/2008] [Accepted: 08/16/2008] [Indexed: 10/21/2022]
Abstract
Learning potential and memory capacity are factors that strongly predict the level of rehabilitation and the long-term functional outcome in patients with schizophrenia. Unfortunately, however, the effects of antipsychotic drugs (i.e. the primary treatments for schizophrenia) on these components of cognition are unclear, particularly when they are administered chronically (i.e. a standard clinical practice). In this rodent study we evaluated the effects of different time periods (ranging from 2 weeks to 6 months) of oral treatment with the first generation antipsychotic chlorpromazine (10.0 mg/kg/day), or the second generation antipsychotic olanzapine (10.0 mg/kg/day) on the repeated acquisition of a water maze task (i.e. a method of assessing spatial learning potential in a repeated testing format). We assessed locomotor function (in an open field) and employed a radial arm maze (RAM) task to assess antipsychotic effects (5.0 and 10.0 mg/kg/day doses) on spatial working memory during the treatment period between 15 days and 2 months. Finally, we conducted experiments using liquid chromatography/tandem mass spectrometry (LC-MS/MS) to evaluate the therapeutic relevance of our method of drug delivery (oral administration in drinking water). In the water maze experiments, both antipsychotics were associated with impairments in acquisition in the earlier test sessions that could eventually be overcome with repeated testing while olanzapine also impaired retention in probe trials. Both antipsychotics were also associated with impairments in delayed non-match-to-position trials in the RAM and some impairments of motor function (especially in the case of olanzapine) as indicated by slightly reduced swim speeds in the water maze and decreased activity in some components of the open field assessment. Finally, LC-MS/MS studies indicated that the method of antipsychotic administration generated clinically relevant plasma levels in the rat. These animal data indicate that chronic oral treatment with chlorpromazine or olanzapine can impair the performance of tasks designed to assess specific components of cognition that are affected in schizophrenia.
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805
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Feng S, Zhang G, Yuan H, Yang M, Chen Y, Zhang S. Perovskite-type LnFeO 3(Ln= Y, Pr, Nd, Sm, Gd, Tb, Dy, Ho ) prepared by mild hydrothermal method. Acta Crystallogr A 2008. [DOI: 10.1107/s0108767308080914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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806
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Terkawi MA, Zhang G, Jia H, Aboge G, Goo YK, Nishikawa Y, Yokoyama N, Igarashi I, Kawazu SI, Fujisaki K, Xuan X. C3 contributes to the cross-protective immunity induced by Babesia gibsoni phosphoriboprotein P0 against a lethal B. rodhaini infection. Parasite Immunol 2008; 30:365-70. [PMID: 18533933 DOI: 10.1111/j.1365-3024.2008.01026.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have studied the impact of complement component 3 (C3) deficiency on the progression of lethal Babesia rodhaini infection in immune mice. A B. gibsoni ribosomal phosphoprotein P0 (BgP0) previously reported to be a cross-protective antigen against Babesia infection was used to immunize C57BL/6 wild-type (WT) and C3-deficient (C3-/-) mice. Test mice were immunized intraperitoneally (i.p.) with recombinant BgP0 (rBgP0), while controls either were immunized with PBS or did not receive any immunization. Following the immunization regime, test WT mice induced a specifically strong humoral response consisting of mixed immunoglobulins IgG1 and IgG2 associated with high production of IFN-gamma in the supernatant of splenocytes. While test C3-/- mice had significantly decreased total IgG, IgG1 and IgG2b responses, the secretions of IL-12 and IFN-gamma tended to be lower than those in WT mice. Furthermore, partial protection was only observed in rBgP0-immunized WT mice but not in C3-/- mice or controls. Indeed, rBgP0-immunized WT mice showed significant reductions in the initiation of parasitaemia correlated with delayed mortalities and considerable survival rates. Taken together, our results indicate that cross-protection was impaired in C3-/- mice in view of the decrease in the antibody responses and cytokine production and the high susceptibility to infection.
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807
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Watson D, Hu M, Zhang G, Wang YM, Sartor M, Fletcher J, Alexander SI. PRIOR SENSITISATION LIMITS LONG TERM ALLOGRAFT SURVIVAL ACROSS A MAJOR MHC MISMATCH AFTER PRUNING ALLOREACTIVE T CELLS. Transplantation 2008. [DOI: 10.1097/01.tp.0000331333.66416.0b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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808
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Zhang G, Solomon P, Rival R, Fenton RS, Cole P. Nasal Airway Volume and Resistance to Airflow. ACTA ACUST UNITED AC 2008; 22:371-5. [DOI: 10.2500/ajr.2008.22.3187] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Background In modern rhinological practice and research, rhinomanometry and acoustic rhinometry are widely used. The goal of this study was to determine whether there is correlation between rhinomanometrically derived nasal airflow resistances and acoustic rhinometrically derived nasal airway volumes. Methods To achieve the goal, a prospective cross-sectional study of a total of 316 patients complaining of nasal obstruction was performed. Resulting data were compared by means of Spearman rank correlations of the total number of patients and of subgroups. Results The total number of patients, and most subgroups, in both their untreated and decongested states showed significant negative correlation unilaterally between nasal airflow resistances and nasal volumes. Conclusion Rhinomanometric nasal airflow resistances and concurrent acoustic rhinometric nasal airway volumes are closely correlated. The combination of the two objective methods provides insight into nasal airflow physiology and nasal airway anatomy.
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809
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Zhu C, Xu H, Zhang G, Lu C, Ji M, Wu W. Myeloid Differentiation Factor 88–Silenced Bone Marrow–Derived Dendritic Cells Exhibit Enhanced Tolerogenicity in Intestinal Transplantation in Rats. Transplant Proc 2008; 40:1625-8. [DOI: 10.1016/j.transproceed.2008.01.070] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2007] [Accepted: 01/16/2008] [Indexed: 11/29/2022]
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810
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Zhang G, Huang T, Stevens C, Lin K, Forster K. WE-C-AUD C-02: Use of Deformable Image Registration in Generating Composite Plans Over Multi Treatment Modalities and Multi-Stage Planning. Med Phys 2008. [DOI: 10.1118/1.2962699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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811
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Zhang G, Niu Y, Jiang Z, Yi B, Kessel D, Ampey L, Yu C. SU-GG-T-70: Three-Field IMRT for Large Breasts. Med Phys 2008. [DOI: 10.1118/1.2961821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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812
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Ye J, Zhang G, Liu X, Yang Q, Li P, Huang J, Li Y. [Apoptosis of active T lymphocytes induced by human laryngocarcinoma cell line]. LIN CHUANG ER BI YAN HOU TOU JING WAI KE ZA ZHI = JOURNAL OF CLINICAL OTORHINOLARYNGOLOGY, HEAD, AND NECK SURGERY 2008; 22:560-563. [PMID: 18800686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
OBJECTIVE To observe the expression of Fas receptor and ligand in human laryngocarcinoma cell line, Hep-2 and to investigate the possible mechanism of immune escape through Fas/FasL pathway in Hep-2 cell. METHOD The mRNA and protein expressions of Fas and FasL in Hep-2 cell were analyzed by RT-PCR and flow cytometry (FCM). Growth curve of Jurkat cell was drawer based on the results of MMT, and apoptosis of Jurkat cell were determined by FCM and Hoechst 33342 staining after coculturing with Hep-2 cell. RESULT The expressions of Fas and FasL in Hep-2 cell line were evaluated by flow cytometry and the mean fluorescence intensity were (32.91 +/- 5.6) and (25.57 +/- 7.1) respectively. After coincubation with Hep-2 cell (1 X 10(9)/L), the apoptosis rates of Jurkat cells were (38.95 +/- 0.11) % and (13.28 +/- 0.14) %, with planting concentration at 1 x 10(8)/L and 5 x 10 (8)/L respectively. In contrast, the apoptosis rate of Jurkat cultured separately was (7.53 +/- 0.17)%. The proliferation of Jurkat cell was obviously inhibited after coculture. However, the apoptosis rate was significantly decreased after adding neutralizing antibody of FasL. CONCLUSION Laryngocarcinoma cell could induce apoptosis of T lymphocytes through Fas-FasL system, thus it provided a potential mechanism to escape from immune surveillance of host.
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813
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An S, Wu Y, Zhu J, Chen Z, Zhang G, Wang Z, Xie Z, Chen S, Huang Y, Guo A, Lin J. Elevated expression level of laminin 5 γ2 chain may be a negative predictive factor for the response to gefitinib in lung cancer. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.14664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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814
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Zhu J, Wu Y, Zhong W, Zhang G, Li R, Zhang X, Guo A, Zhang Y, An S, Mok TS. Better survival with epidermal growth factor receptor exon 19 deletion than with exon 21 mutation in gefitinib-treated non-small cell lung cancer patients is due to differential inhibition of downstream signals. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.14501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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815
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Sousa AA, Aronova MA, Kim YC, Dorward LM, Zhang G, Leapman RD. Reprint of "On the feasibility of visualizing ultrasmall gold labels in biological specimens by STEM tomography" [J. Struct. Biol. 159 (2007) 507-522]. J Struct Biol 2008; 161:336-51. [PMID: 18342743 DOI: 10.1016/s1047-8477(08)00063-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2007] [Revised: 06/15/2007] [Accepted: 06/19/2007] [Indexed: 11/25/2022]
Abstract
Labeling with heavy atom clusters attached to antibody fragments is an attractive technique for determining the 3D distribution of specific proteins in cells using electron tomography. However, the small size of the labels makes them very difficult to detect by conventional bright-field electron tomography. Here, we evaluate quantitative scanning transmission electron microscopy (STEM) at a beam voltage of 300kV for detecting 11-gold atom clusters (Undecagold) and 1.4nm-diameter nanoparticles (Nanogold) for a variety of specimens and imaging conditions. STEM images as well as tomographic tilt series are simulated by means of the NIST Elastic-Scattering Cross-Section Database for gold clusters embedded in carbon. The simulations indicate that the visibility in 2D of Undecagold clusters in a homogeneous matrix is maximized for low inner collection semi-angles of the STEM annular dark-field detector (15-20mrad). Furthermore, our calculations show that the visibility of Undecagold in 3D reconstructions is significantly higher than in 2D images for an inhomogeneous matrix corresponding to fluctuations in local density. The measurements demonstrate that it is possible to detect Nanogold particles in plastic sections of tissue freeze-substituted in the presence of osmium. STEM tomography has the potential to localize specific proteins in permeabilized cells using antibody fragments tagged with small heavy atom clusters. Our quantitative analysis provides a framework for determining the detection limits and optimal experimental conditions for localizing these small clusters.
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816
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Shen H, Huang H, Wang J, Ye S, Li W, Wang K, Zhang G, Wang P. Neonatal vaccination with Bacillus Calmette-Guérin elicits long-term protection in mouse-allergic responses. Allergy 2008; 63:555-63. [PMID: 18307575 DOI: 10.1111/j.1398-9995.2008.01637.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Mycobacterium bovis Bacillus Calmette-Guérin (BCG) vaccination has been shown to inhibit allergic airway inflammation in animal models, associated with the regulation of allergen-specific T-cell immunity. However, little is known about whether neonatal BCG treatment could inhibit allergic inflammation by regulating allergen-specific T-cell response in aged mice. This study was aimed to investigate the impact of neonatal BCG treatment on allergic asthma and possible mechanism(s) underlying the action of BCG in different ages of mice. METHODS C57BL/6 neonates were vaccinated with BCG on days 1, 7 and 14, sensitized with ovalbumin (OVA) at 5 and 7 weeks of age, and then challenged with allergen at 9 or 45 weeks of age for early- or late-challenged asthma. Their airway inflammation and allergen-specific T-cell responses were characterized. RESULTS Following early-challenge, BCG vaccination inhibited airway hyper-responsiveness (AHR), infiltration of eosinophils and mucous overproduction (P < 0.05), and shifted OVA-specific predominant Th2- to Th1-type cytokine responses in both the bronchoalveolar lavage fluid and the splenocyte supernatants (P < 0.05). In late-challenged mice, neonatal BCG treatment attenuated AHR and eosinophilia (P < 0.05), but failed to modulate allergen-specific cytokine responses. CONCLUSIONS Our data suggest that neonatal BCG vaccination has a long-term effect on inhibiting AHR and eosinophilia, which is associated with the modulation of Th1/Th2 cytokine production in early-, but not in late-challenged mice. Thus, different mechanisms may mediate the long-term protective effect of BCG neonatal vaccination differently in younger adult and aged mice.
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817
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Ye J, Fang P, Zhang G, Huang X, Wang T, Huang Z, Xie M, Li Y. [Prevalence and prognostic factors for postoperative complications of uvulopalatopharyngoplasty in patients with obstructive sleep apnea hypopnea syndrome]. LIN CHUANG ER BI YAN HOU TOU JING WAI KE ZA ZHI = JOURNAL OF CLINICAL OTORHINOLARYNGOLOGY, HEAD, AND NECK SURGERY 2008; 22:393-396. [PMID: 18652310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
OBJECTIVE To explore the complication incidence and risk factors within immediate 24 hours after uvulopalatopharyngoplasty in patients with obstructive sleep apnea hypopnea syndrome (OSAHS) and provide theoretical foundation for preventing postoperative complication incidence. METHOD 162 patients undergoing UPPP procedure between Mar, 2002, and Oct 2006, were analysed retrospectively. All patients were divided into two groups according to the development of postoperative complications or not. The retrospective chart review focused on the demographic data and pertinent history, preoperative sleep evaluation, surgical and anesthetic management, and need for postoperative interventions. Potential risk factors were first evaluated with univariate analysis followed by multivariate logistic regression with the occurrence of complications within immediate 24 hours after operation as the dependent variable. RESULT A total of 162 consecutive cases for UPPP were enrolled into current study. 31 cases (19.1%) had postoperative complications necessitating a medical intervention, including respiratory complications (n =21, 13.0%), cardiovascular complications (n =6, 3.7%) and hemorrhage (n =9, 5.6%). The differences in body mass index (BMI), apnea-hypopnea index (AHI), lowest oxygen saturation (LSAT) and difficult intubation were significant between two groups. Risk factors for postoperative complications were BMI (OR =1.136, 95% CI: 1.007-2.558, P =0.049), preoperative AHI (OR =4.828, 95% CI: 1.827-13.924, P =0.012) and difficult intubation (OR = 1.971, 95% CI: 1.251- 4.839, P =0.034). CONCLUSION Baseline BMI and AHI, difficult intubation in anaesthetic procedure were the most important predictors of postsurgical morbidity. Keeping in mind the aforementioned cautionary notes, aggressively preoperative preparation should be applied for such populations to avoid the occurrence of postoperative complications.
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818
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Zhang G, Niu F, Busse HJ, Ma X, Liu W, Dong M, Feng H, An L, Cheng G. Hymenobacter psychrotolerans sp. nov., isolated from the Qinghai--Tibet Plateau permafrost region. Int J Syst Evol Microbiol 2008; 58:1215-20. [DOI: 10.1099/ijs.0.65588-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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819
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Yang Q, Li Y, Zou Y, Kang Z, Liu X, Zhang G, Wang X, Wang T. [Computer-assisted three-dimensional reconstruction and spatial stereotaxis study of optic canal with multiplayer spiral computed tomographic]. LIN CHUANG ER BI YAN HOU TOU JING WAI KE ZA ZHI = JOURNAL OF CLINICAL OTORHINOLARYNGOLOGY, HEAD, AND NECK SURGERY 2008; 22:306-311. [PMID: 18589801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
OBJECTIVE To provide efficient support for transnasal endoscopic optic canal decompression with more applied and sufficient imaging study on the optic canal. METHOD Three-dimensional reconstruction, stereotaxis and related anatomic data of lateral wall of sphenoid-ethmoidal sinuses were got by Multiplanar spiral computed tomographic (MSCT) and AW4.1 software on 14 cases of traumatic optic neuropathy. The data were compared with the results of operations. RESULT 1) The scan plane of nasal-processus clinoideus anterior accorded with optic canal completely; 2) The length of the optic canal were (11.83+/-2.31) mm; 3) Locating mark of optic canal and enhanced internal carotid artery in CT scans which accorded with operations completely were synchronously displayed in sagittal 3D images of lateral wall of sphenoid-ethmoidal sinuses in the whole range. CONCLUSION The scan plane of nasal-processus clinoideus anterior is the best plane for the CT study of optic canal; Preoperative spatial stereotaxis of optic canal can be simply made by MSCT with good quality to actually reflect personal condition of optic canal and its relationship with lateral wall of sphenoid-ethmoidal sinuses and internal carotid artery exactly and directly. It is better than traditional CT films. And it provides supports for scheduling operation and help getting safe and effective transnasal endoscopic optic canal decompression by sufficient and practical imagings.
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820
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Sousa AA, Hohmann-Marriott M, Aronova MA, Zhang G, Leapman RD. Determination of quantitative distributions of heavy-metal stain in biological specimens by annular dark-field STEM. J Struct Biol 2008; 162:14-28. [PMID: 18359249 PMCID: PMC2705981 DOI: 10.1016/j.jsb.2008.01.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2007] [Revised: 01/16/2008] [Accepted: 01/17/2008] [Indexed: 11/24/2022]
Abstract
It is shown that dark-field images collected in the scanning transmission electron microscope (STEM) at two different camera lengths yield quantitative distributions of both the heavy and light atoms in a stained biological specimen. Quantitative analysis of the paired STEM images requires knowledge of the elastic scattering cross sections, which are calculated from the NIST elastic scattering cross section database. The results reveal quantitative information about the distribution of fixative and stain within the biological matrix, and provide a basis for assessing detection limits for heavy-metal clusters used to label intracellular proteins. In sectioned cells that have been stained only with osmium tetroxide, we find an average of 1.2+/-0.1 Os atom per nm(3), corresponding to an atomic ratio of Os:C atoms of approximately 0.02, which indicates that small heavy atom clusters of Undecagold and Nanogold can be detected in lightly stained specimens.
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821
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Zhang G, Wang X, Zhi A, Bao Y, Yang Y, Qu M, Luo J, Li Q, Guo J, Wang Z, Yang J, Xing G, Chai S, Shi T, Liu Q. Development of a lateral flow immunoassay strip for screening of sulfamonomethoxine residues. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2008; 25:413-23. [DOI: 10.1080/02652030701561452] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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822
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Aronova MA, Kim YC, Harmon R, Sousa AA, Zhang G, Leapman RD. Reprint of "Three-dimensional elemental mapping of phosphorus by quantitative electron spectroscopic tomography (QuEST)" [J. Struct. Biol. 160 (2007) 35-48]. J Struct Biol 2008; 161:322-35. [PMID: 18342742 DOI: 10.1016/s1047-8477(08)00062-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2007] [Revised: 06/15/2007] [Accepted: 06/18/2007] [Indexed: 10/22/2022]
Abstract
We describe the development of quantitative electron spectroscopic tomography (QuEST), which provides 3-D distributions of elements on a nanometer scale. Specifically, it is shown that QuEST can be applied to map the distribution of phosphorus in unstained sections of embedded cells. A series of 2-D elemental maps is derived from images recorded in the energy filtering transmission electron microscope for a range of specimen tilt angles. A quantitative 3-D elemental distribution is then reconstructed from the elemental tilt series. To obtain accurate quantitative elemental distributions it is necessary to correct for plural inelastic scattering at the phosphorus L(2,3) edge, which is achieved by acquiring unfiltered and zero-loss images at each tilt angle. The data are acquired automatically using a cross correlation technique to correct for specimen drift and focus change between successive tilt angles. An algorithm based on the simultaneous iterative reconstruction technique (SIRT) is implemented to obtain quantitative information about the number of phosphorus atoms associated with each voxel in the reconstructed volume. We assess the accuracy of QuEST by determining the phosphorus content of ribosomes in a eukaryotic cell, and then apply it to estimate the density of nucleic acid in chromatin of the cell's nucleus. From our experimental data, we estimate that the sensitivity for detecting phosphorus is 20 atoms in a 2.7 nm-sized voxel.
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823
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Cai Z, Zhang G, Zhou Z, Bembas K, Drebin JA, Greene MI, Zhang H. Differential binding patterns of monoclonal antibody 2C4 to the ErbB3-p185her2/neu and the EGFR-p185her2/neu complexes. Oncogene 2008; 27:3870-4. [PMID: 18264138 DOI: 10.1038/onc.2008.13] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
2C4 (Pertuzumab, Omnitarg) is a monoclonal antibody targeting p185(her2/neu), which is overexpressed in 30% of invasive breast cancer. 2C4 is currently in phase II clinical trials for several types of cancers. This antibody has been reported to disrupt the association between p185(her2/neu) and ErbB3. In our studies of epidermal growth factor receptor (EGFR)-p185(her2/neu) heterodimerization, we noted that 2C4 formed associations with the EGFR-p185(her2/neu) receptor complex. Our data argue against 2C4 as a universal heterodimerization blocker for p185(her2/neu), but indicate that cocktails of monoclonal antibodies binding distinct interaction surfaces of p185(her2/neu) will emerge as the most potent targeted therapy.
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824
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Zhang G, Zhang YF, Fang L. Theoretical study of simultaneous water and VOCs adsorption and desorption in a silica gel rotor. INDOOR AIR 2008; 18:37-43. [PMID: 18093128 DOI: 10.1111/j.1600-0668.2007.00502.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
UNLABELLED One-dimensional partial differential equations were used to model the simultaneous water and VOC (Volatile Organic Compound) adsorption and desorption in a silica gel rotor which was recommended for indoor air cleaning. The interaction among VOCs and moisture in the adsorption and desorption process was neglected in the model as the concentrations of VOC pollutants in typical indoor environment were much lower than that of moisture and the adsorbed VOCs occupied only a minor portion of adsorption capacity of the rotor. Consequently VOC transfer was coupled with heat and moisture transfer only by the temperatures of the rotor and the air stream. The VOC transfer equations were solved by discretizing them into explicit up-wind finite differential equations. The model was validated with experimental data. The calculated results suggested that the regeneration time designed for dehumidification may be prolonged to allow complete removal of the VOC pollutants from the rotor. The regeneration temperature designed for dehumidification provides considerable efficiency for indoor air cleaning. The application of the model in estimating the cleaning capacity of the rotor for VOC pollutants was demonstrated. PRACTICAL IMPLICATIONS Silica gel rotors, usually used to dehumidify air, were found to be effective to remove VOCs by experiments recently. But the removal characteristics of VOCs are different from that of moisture. Therefore, the rotor structure and operating parameters for dehumidification needs to be optimized for the use of removing moisture and VOCs. This paper gives a way for the optimization.
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825
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Zhang G, Le Souef PN. From the authors. Eur Respir J 2008. [DOI: 10.1183/09031936.00127907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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