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Li EW, Gao K, Jia ZJ. ent-Kaurenoids from the roots of Cacalia pilgeriana. JOURNAL OF ASIAN NATURAL PRODUCTS RESEARCH 2007; 9:191-5. [PMID: 17566909 DOI: 10.1080/10286020500530656] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Two new ent-kaurenoids,19-acetoxyl-ent-3beta,17-dihydroxykaur-15-ene (1), 19-acetoxyl-ent-3beta-hydroxykaur-15-en-17-al (2), together with seven known ent-kaurenoids: ent-kaur-16-en-19-al (3), ent-kaur-16-en-19-oic acid (4), ent-kauran-16beta,17-diol (5), ent-15beta, 16beta-epoxy-17-hydroxykauran-19-oic acid (6),19-acetyl-ent-3beta-hydroxyl-kaur-16-ene (7), ent-3beta,19-dihydroxykaur-16-ene (8), ent-17-hydroxykaur-15-ene (9), were isolated from Cacalia pilgeriana. Their structures were elucidated by spectroscopic methods including 2D NMR spectral analysis.
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Wang L, Lu XF, Lu YR, Liu J, Gao K, Zeng YZ, Li SF, Li YP, Cheng JQ, Tan WD, Wan L. Immunogenicity and immune modulation of osteogenic differentiated mesenchymal stem cells from Banna minipig inbred line. Transplant Proc 2006; 38:2267-9. [PMID: 16980061 DOI: 10.1016/j.transproceed.2006.06.048] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Mesenchymal stem cells (MSCs) represent a good choice for cell transplantation due to their multilineage differentiation ability and low immunogenicity. Our previous in vitro studies indicated that undifferentiated swine MSCs show low immunogenicity suppressing the proliferative responses of human peripheral blood lymphocyte to several antigens. In this study, we investigated the immunogenicity and immune modulation ability of osteogenic differentiated MSCs. SLA class I (P1, P14) was detectable by reverse-transcriptase polymerase chain reaction on both differentiated and undifferentiated MSCs. SLA class II (SLA-DRA, SLA-DQA) was only detectable on differentiated MSCs mixed lymphocyte reaction assays demonstrated that both differentiated and undifferentiated MSCs failed to stimulate proliferative responses by human peripheral blood lymphocytes (hPBLs). Furthermore, as undifferentiated MSCs, osteogenic differentiated MSCs also suppressed hPBL proliferation to phytohemaglutinin.
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Smith GI, Yeo D, Clark J, Choy ET, Gao K, Oates J, O'Brien CJ. Measures of health-related quality of life and functional status in survivors of oral cavity cancer who have had defects reconstructed with radial forearm free flaps. Br J Oral Maxillofac Surg 2006; 44:187-92. [PMID: 16095776 DOI: 10.1016/j.bjoms.2005.06.022] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2004] [Accepted: 06/24/2005] [Indexed: 11/17/2022]
Abstract
The aim of this study was to evaluate (by postal questionnaire) quality of life and function in patients who have had resections of oral cancer and reconstruction by radial forearm flaps. Between October 1987 and December 2002, 258 patients had reconstructions by radial forearm flaps after resection of tumours in the oral cavity. Of these, 139 surviving patients were identified from the database and were sent questionnaires comprising five sections: Functional Assessment of Cancer Therapy-General (FACT-G) and -Head and Neck (FACT-HN); University of Washington Quality of Life Scale (UWQoL); Performance Status Scale for Head and Neck Cancer (PSS-HN); and the final section addressed dental rehabilitation and morbidity at the donor site. Sixty-three questionnaires (45%) were returned. In 17 (27%), parts of the questionnaire were incomplete. The median UWQoL score was 623/900, FACT-G was 92/108, FACT-HN was 31/48, and PSS-HN showed that eating in public, understandability of speech and normality of diet were 75/100, 75/100 and 50/100, respectively. The effect of stage and site on quality of life and function did not reach statistical significance. The effect of radiotherapy on speech (p=0.036) and diet (p=0.007) was significant. Patients who worried about their cancer returning had a lower UWQoL score (p=0.016). Ninety percent regarded their arm as disfigured, but 81% felt comfortable wearing short-sleeved shirts. Sensation and function of the hand were reported as normal in 87 and 92%, respectively. We conclude that patients who have had oral cancer have a persistent reduction in quality of life and function long after completion of treatment. The effects can be assessed by postal questionnaire, but the low rate of return (45%) and difficulties with completion reduce the quality of the data. Quality of life and function are essential components of improvements in outcome.
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Muzina DJ, Elhaj O, Gajwani P, Gao K, Calabrese JR. Lamotrigine and antiepileptic drugs as mood stabilizers in bipolar disorder. Acta Psychiatr Scand Suppl 2005:21-8. [PMID: 15833097 DOI: 10.1111/j.1600-0447.2005.00523.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVE To review the clinical trials literature on the use of antiepileptic drugs (AED) as mood stabilizers and to suggest an evidence-based approach when utilizing these agents in bipolar disorder. METHOD The literature is reviewed and subdivided into the following sections: carbamazepine and oxcarbazepine, valproate, lamotrigine, gabapentin and other AED, and discussion. RESULTS Data exist to support the use of carbamazepine and valproate - and to a lesser extent, oxcarbazepine - in the management of acute manic episodes associated with bipolar I disorder. Lamotrigine, gabapentin, and other AED have not demonstrated consistent anti-manic effects. Clinical trials data favor lamotrigine over all other AED in the treatment of acute bipolar I depression and in rapid cycling bipolar disorder (particularly type II), although the absence of an active comparator in these lamotrigine trials must be noted. Lamotrigine, carbamazepine, and valproate all have evidence supporting their roles as potential long-term mood stabilizers to prevent bipolar relapse, with lamotrigine having a stronger effect in the prevention of depression. CONCLUSION The AED are a heterogeneous group of medications with differential spectrum of efficacy in the treatment of bipolar disorder.
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Smith GI, O'Brien CJ, Choy ET, Andruchow JL, Gao K. Clinical outcome and technical aspects of 263 radial forearm free flaps used in reconstruction of the oral cavity. Br J Oral Maxillofac Surg 2005; 43:199-204. [PMID: 15888352 DOI: 10.1016/j.bjoms.2004.11.024] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2004] [Indexed: 11/29/2022]
Abstract
BACKGROUND The aim of this study was to report the applications, complications, and limitations of the radial forearm flap when used for reconstruction after excision of cancers in the mouth. PATIENTS AND METHODS We reviewed records in our database from October 1987 to December 2002; a total of 505 patients had surgical defects of the head and neck reconstructed with a radial forearm flap: 258 patients had oral cancers, of whom 173 were men and 85 women, median age was 70 years. Five patients had two reconstructions (total 263), of which 247 were fasciocutaneous and 16 osseofasciocutaneous flaps. Mucosal squamous carcinoma accounted for 97% of the primary cancers. RESULTS There were nine failures of the flap (3.4%) and four episodes of partial necrosis. Four patients (2%) died within 30 days of operation. Orocutaneous fistulas appeared in nine patients (3.4%), 10 patients had wound infections, and nine had haematomas. The nine failed flaps were replaced by a second free flap in one patient, a pectoralis major flap in three, a buccinator myomucosal flap in one, a skin graft in one, and the remaining three defects healed by secondary intention. There was one failure and one partial failure among the 16 osseofasciocutaneous flaps.
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Smith GI, O'Brien CJ, Clark J, Shannon KF, Clifford AR, McNeil EB, Gao K. Management of the neck in patients with T1 and T2 cancer in the mouth. Br J Oral Maxillofac Surg 2005; 42:494-500. [PMID: 15544877 DOI: 10.1016/j.bjoms.2004.06.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/29/2004] [Indexed: 09/30/2022]
Abstract
UNLABELLED Our aim in this retrospective study was to evaluate the extent of control of metastatic disease in the neck and the survival of patients with T1 and T2 oral cancer. METHODS All 171 patients with T1 and T2 squamous cell carcinoma (SCC) in the mouth were identified from our computerised database. All had had primary tumours resected and 21 patients with palpable neck nodes had therapeutic neck dissections. Among 150 patients with no palpable nodes, 75 had elective neck dissections, and 75 were observed. The decision to do an elective neck dissection was based on clinical criteria and was not randomised. RESULTS Cervical nodes contained metastases in 17 of 21 patients who had therapeutic, and 27 of 75 who had elective, neck dissections. Neck metastases developed subsequently in 15 of 75 patients in the observed group, and 9 of these were salvaged by therapeutic neck dissection. The 5-year disease free survival was 19/21 after therapeutic dissection, 72/75 after elective dissection, and 69/75 in the observed group. Patients with cervical nodal metastases had significantly reduced 5-year survival compared with those without (63% and 91%, P = 0.003).
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Danko I, Cronin-Hennessy D, Park C, Park W, Thayer J, Thorndike E, Coan T, Gao Y, Liu F, Stroynowski R, Artuso M, Boulahouache C, Blusk S, Dambasuren E, Dorjkhaidav O, Mountain R, Muramatsu H, Nandakumar R, Skwarnicki T, Stone S, Wang J, Mahmood A, Csorna S, Bonvicini G, Cinabro D, Dubrovin M, Bornheim A, Lipeles E, Pappas S, Shapiro A, Sun W, Weinstein A, Briere R, Chen G, Ferguson T, Tatishvili G, Vogel H, Watkins M, Adam N, Alexander J, Berkelman K, Boisvert V, Cassel D, Duboscq J, Ecklund K, Ehrlich R, Galik R, Gibbons L, Gittelman B, Gray S, Hartill D, Heltsley B, Hsu L, Jones C, Kandaswamy J, Kreinick D, Kuznetsov V, Magerkurth A, Mahlke-Krüger H, Meyer T, Mistry N, Patterson J, Pedlar T, Peterson D, Pivarski J, Richichi S, Riley D, Sadoff A, Schwarthoff H, Shepherd M, Thayer J, Urner D, Wilksen T, Warburton A, Weinberger M, Athar S, Avery P, Breva-Newell L, Potlia V, Stoeck H, Yelton J, Eisenstein B, Gollin G, Karliner I, Lowrey N, Plager C, Sedlack C, Selen M, Thaler J, Williams J, Edwards K, Besson D, Gao K, Gong D, Kubota Y, Li S, Poling R, Scott A, Smith A, Stepaniak C, Urheim J, Metreveli Z, Seth K, Tomaradze A, Zweber P, Ernst J, Arms K, Eckhart E, Gan K, Gwon C, Severini H, Skubic P, Dytman S, Mueller J, Nam S, Savinov V, Huang G, Miller D, Pavlunin V, Sanghi B, Shibata E, Shipsey I. Measurement of the decay rate of Ξc0→pK-K-π+ relative to Ξc0→Ξ-π+. Int J Clin Exp Med 2004. [DOI: 10.1103/physrevd.69.052004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Chen HF, Dong XC, Zen BS, Gao K, Yuan SG, Panaye A, Doucet JP, Fan BT. Virtual screening and rational drug design method using structure generation system based on 3D-QSAR and docking. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2003; 14:251-264. [PMID: 14506869 DOI: 10.1080/1062936032000101493] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
An efficient virtual and rational drug design method is presented. It combines virtual bioactive compound generation with 3D-QSAR model and docking. Using this method, it is possible to generate a lot of highly diverse molecules and find virtual active lead compounds. The method was validated by the study of a set of anti-tumor drugs. With the constraints of pharmacophore obtained by DISCO implemented in SYBYL 6.8, 97 virtual bioactive compounds were generated, and their anti-tumor activities were predicted by CoMFA. Eight structures with high activity were selected and screened by the 3D-QSAR model. The most active generated structure was further investigated by modifying its structure in order to increase the activity. A comparative docking study with telomeric receptor was carried out, and the results showed that the generated structures could form more stable complexes with receptor than the reference compound selected from experimental data. This investigation showed that the proposed method was a feasible way for rational drug design with high screening efficiency.
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Delalande O, Gao K, Fan BT, Zakrzewska K, El Fassia N, Jia ZJ, Zheng RL, Panaye A, Doucet JP. Docking study of cistanoside C to telomeric DNA fragment. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2002; 13:675-688. [PMID: 12570045 DOI: 10.1080/1062936021000043427] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Experiments show that the natural products phenyl propanoid glycosides (PPGs) extracted from the plant Pedicularis spicata are capable of repairing DNA damaged by oxygen radicals. Based on kinetic measurements and experiments on tumor cells, a theoretical study of the interaction between PPG molecule Cistanoside C and telomeric DNA fragment has been carried out. The docking calculations performed using JUMNA software showed that the Cistanoside C could be docked into the minor groove of telomeric DNA and form complexes with the geometry suitable for an electron transfer between guanine radical and the ligand. Such complexes can be formed without major distortions of DNA structure and are further stabilized by the interaction with the saccharide side-groups.
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Gao K, Mason P. Physiological and anatomic evidence for functional subclasses of serotonergic raphe magnus cells. J Comp Neurol 2001; 439:426-39. [PMID: 11596064 DOI: 10.1002/cne.1360] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Serotonergic cells in the medullary nucleus raphe magnus (RM) and adjacent nucleus reticularis magnocellularis (NRMC) project to the spinal cord where they are likely to modulate nociceptive transmission. Previous studies have suggested that these cells are physiologically and anatomically heterogeneous. In the present investigation, we examined whether subclasses of serotonergic RM and NRMC cells can be delineated based on their response to a visceral stimulus, and whether any such subclasses are morphologically distinct. Most RM and NRMC serotonergic cells tested (81 of 116) responded to retraction of the descending aorta into a polyethylene tube (the snare stimulus) with 57% of all cells tested excited and 13% inhibited. Responses of serotonergic cells to the snare outlasted the stimulus, were not reflective of evoked cardiovascular changes, and were observed in sino-aortic deafferented rats, evidence that the snare stimulus does not influence serotonergic cell discharge through activation of baroreceptors. Because serotonergic cells responsive to the snare were also responsive to mechanical brushing within the retroperitoneum, the snare is likely to change serotonergic cell discharge by means of the activation of mechanosensitive visceral afferents. Intracellular labeling of physiologically characterized serotonergic RM and NRMC cells showed that cells that were responsive to the snare stimulus had simpler axonal collateralization patterns than cells that were unresponsive to the snare stimulus. This association between morphological and physiological properties provides additional evidence that subpopulations of serotonergic cells exist and serve varied physiological functions.
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Chen X, Chen G, Xiao B, Shi W, Xu H, Gao K. Comparison of T-lymphocyte subsets and phenotypes between HIV-positive subjects and HIV-negative subjects. CHINESE MEDICAL SCIENCES JOURNAL = CHUNG-KUO I HSUEH K'O HSUEH TSA CHIH 2001; 16:185. [PMID: 12899337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
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Gao K, Mason P. The discharge of a subset of serotonergic raphe magnus cells is influenced by baroreceptor input. Brain Res 2001; 900:306-13. [PMID: 11334811 DOI: 10.1016/s0006-8993(01)02294-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In order to determine whether serotonergic cells in the medullary raphe magnus (RM) receive baroreceptor input, cells were tested for their responses to descending aortic occlusion, aortic nerve stimulation, or systemic phenylephrine administration in the lightly anesthetized rat. Serotonergic cells were identified physiologically by a quantitative analysis of their slow and steady discharge. Greater than 40% of the serotonergic RM cells tested responded to brief occlusion of the descending aorta at the level of the coeliac arteries, a stimulus that elevated blood pressure by about 30 mmHg. Similarly, about 40% of the serotonergic RM cells responded to stimulation of the aortic nerve, a nerve that contains primarily baroreceptor afferents from the aortic arch. Greater than 70% of RM serotonergic cells responded to phenylephrine administration which elevated blood pressure by an average of 50 mmHg. Serotonergic cell responses to all methods of baroreceptor activation were small in magnitude and were largely restricted in time to the stimulus duration. The results indicate that a subset of serotonergic cells in RM are influenced by baroreceptor activity.
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Su RB, Li J, Gao K, Pei G, Qin BY. Influence of idazoxan on analgesia, tolerance, and physical dependence of morphine in mice and rats in vivo. Acta Pharmacol Sin 2000; 21:1011-5. [PMID: 11501055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
AIM To study the influence of idazoxan (Ida), an antagonist of imidazoline receptors (I-R), on analgesia, tolerance, and physical dependence of morphine. METHODS The effects of Ida on pain threshold and morphine analgesia were observed in mouse acetic acid writhing test and 55 degrees C hot plate test. The effect of Ida on morphine tolerance and physical dependence were observed in mouse tolerant model and in mice and rat models. RESULTS Ida (3-9 mg/kg) significantly decreased the pain threshold by 120% in acetic acid writhing test and by 39% in 55 degrees C hot plate test of mice, respectively. It inhibited the analgesic effect of morphine in a dose-dependent manner. Ida promoted the development of tolerance to morphine in mice and induced the abstinence syndrome in morphine-dependent mice and rats similar to naloxone. CONCLUSION I-R and its endogenous ligand agmatine might participate in the pain threshold and influence morphine analgesia as well as negatively regulate tolerance to and physical dependence on morphine.
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Gao K, Mason P. Serotonergic Raphe magnus cells that respond to noxious tail heat are not ON or OFF cells. J Neurophysiol 2000; 84:1719-25. [PMID: 11024064 DOI: 10.1152/jn.2000.84.4.1719] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Pharmacological studies have suggested that serotonergic cells in RM contribute to both the inhibition and facilitation of spinal nociceptive transmission. Physiological studies in the medullary nucleus raphe magnus (RM) and adjacent nucleus reticularis magnocellularis have identified putative nociceptive-inhibitory OFF cells and nociceptive-facilitatory neurons ON cells by their responses to noxious thermal stimulation. The present study was designed to determine 1) whether any serotonergic RM cells respond to noxious thermal stimulation and 2) whether noxious heat-responsive serotonergic cells should be classified as ON or OFF cells. Serotonergic cells (n = 150) were identified by physiological criteria in anesthetized rats; 30 of 32 cells tested contained serotonin immunoreactivity. Noxious tail heat elicited a neuronal response in less than a quarter of the serotonergic cells. Most serotonergic cells that responded to tail heat were excited (n = 25), while a small minority of the cells tested were inhibited (n = 8). The tail heat-evoked responses of serotonergic cells were small in magnitude, averaging five to eight spikes in 10 s. Excitatory responses rarely persisted for more than 10 s, while inhibitory responses rarely persisted for more than 20 s. The tail heat-evoked responses of serotonergic cells were compared to those of non-serotonergic cells (n = 186). Non-serotonergic cells that responded to noxious tail heat had significantly greater response magnitudes, averaging 75-95 spikes in 10 s, than heat-responsive serotonergic cells. In addition, most heat-responsive non-serotonergic cells responded for at least 30 s after stimulus onset. These results demonstrate that the tail heat-evoked responses of serotonergic RM cells are qualitatively and quantitatively distinct from those of non-serotonergic ON and OFF cells. It is therefore unlikely that serotonergic RM cells, even the subpopulation that responds to noxious tail heat, share a physiological function with ON and OFF cells.
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Gao K, Zhou L, Chen J, Li F, Zhang L. [Experimental study on decoctum Agrimonia pilosa Ledeb-induced apoptosis in HL-60 cells in vitro]. ZHONG YAO CAI = ZHONGYAOCAI = JOURNAL OF CHINESE MEDICINAL MATERIALS 2000; 23:561-2. [PMID: 12575284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
In this study, MTT assay, cell morphology and flow cytometry were used to explore Agrimonia pilosa Ledeb on HL-60 cells in vitro. The data suggested that Agrimonia pilosa Ledeb had the effects of growth inhibition in HL-60 cells. After treated with decoctum Agrimonia pilosa Ledeb, cells underwent apoptosis with typical morphological feature. DNA histograms by flow cytometric analysis displayed distinct apoptotic peak.
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Wang Y, Gao K, Xu X, Yuan W, Keqin G, Xing X. Early evolution of discoglossid frogs: new evidence from the Mesozoic of China. THE SCIENCE OF NATURE - NATURWISSENSCHAFTEN 2000; 87:417-20. [PMID: 11091967 DOI: 10.1007/s001140050753] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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92
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Gao K, Orgel LE. A convenient synthesis of a novel nucleoside analogue: 4-(alpha-diformyl-methyl)-1-(beta-D-ribofuranosyl)-2-pyrimidinone. NUCLEOSIDES, NUCLEOTIDES & NUCLEIC ACIDS 2000; 19:935-40. [PMID: 10893712 DOI: 10.1080/15257770008033033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The nucleoside analogue 4-(alpha-diformyl-methyl)-1-(beta-D-ribofuranosyl)-2-pyrimidinone (5) was prepared from the corresponding 4-methyl pyrimidinone nucleoside by means of the Vilsmeier reaction. The unprotected nucleoside can be phosphorylated directly with phosphorus oxychloride in triethyl phosphate.
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93
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Su BN, Yang L, Gao K, Jia ZJ. Aquaticol, a bis-sesquiterpene and iridoid glucosides from Veronica anagallis-aquatica. PLANTA MEDICA 2000; 66:281-283. [PMID: 10821060 DOI: 10.1055/s-2000-8564] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Aquaticol, an unusual bis-sesquiterpene was isolated from the medicinal plant Veronica anagallis-aquatica, in addition to 11 known compounds, aucubin, geniposidic acid, mussaenoside, catalposide, verproside, amphicoside, catalpol, boschnaloside, shanzhiside methyl ester, sitosterol and beta-stigmast-4-en-6 beta-ol-3-one. The structure of aquaticol was determined by spectroscopic means and by X-ray crystallographic analysis.
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Abstract
The chemical investigation of Ligularia fischeri afforded three new eremophilenolides which were identified as 6 beta-methoxy-8 beta-hydroxy-eremophil-7(11)-en-12,8 alpha-olide, ligufischerin, and 6-oxo-8 beta-hydroxy-eremophil-7(11)-en-12,8 alpha-olide by 1D- and 2D-NMR spectra. In addition, six known eremophilenolides were also obtained.
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Gao K, Orgel LE. Polyphosphorylation and non-enzymatic template-directed ligation of oligonucleotides. ORIGINS LIFE EVOL B 2000; 30:45-51. [PMID: 10836264 DOI: 10.1023/a:1006683507864] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Oligonucleotide 5'-polyphosphates are formed under potentially prebiotic conditions from oligonucleotide 5'-phosphates and sodium trimetaphosphate. Oligonucleotides activated as polyphosphates undergo template-directed ligation. We believe that these reactions could have produced longer oligonucleotide products from shorter substrates under prebiotic conditions.
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Gao K, Orgel LE. Nucleic acid duplexes incorporating a dissociable covalent base pair. Proc Natl Acad Sci U S A 1999; 96:14837-42. [PMID: 10611299 PMCID: PMC24734 DOI: 10.1073/pnas.96.26.14837] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We have used molecular modeling techniques to design a dissociable covalently bonded base pair that can replace a Watson-Crick base pair in a nucleic acid with minimal distortion of the structure of the double helix. We introduced this base pair into a potential precursor of a nucleic acid double helix by chemical synthesis and have demonstrated efficient nonenzymatic template-directed ligation of the free hydroxyl groups of the base pair with appropriate short oligonucleotides. The nonenzymatic ligation reactions, which are characteristic of base paired nucleic acid structures, are abolished when the covalent base pair is reduced and becomes noncoplanar. This suggests that the covalent base pair linking the two strands in the duplex is compatible with a minimally distorted nucleic acid double-helical structure.
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Ou S, Gao K, Li Y. An in vitro study of wheat bran binding capacity for Hg, Cd, and Pb. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 1999; 47:4714-4717. [PMID: 10552878 DOI: 10.1021/jf9811267] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Water-soluble dietary fiber (WSDF), water-insoluble dietary fiber (WIDF) from wheat bran, and the carboxymethylated product of WIDF (CIDF), all having low contents of protein, ash, and phytic acid, were evaluated for their scavenging capacity for three heavy metals, Hg, Cd, and Pb. The results showed that WIDF had higher BC(max) (maximum amount of bound heavy metal ions) and BC(min) values (minimum concentration of heavy metal ions below which the ions cannot be bound by dietary fibers) than WSDF at two pH conditions (pH 2.0 and 7.0). Carboxymethylation of WIDF improved its binding capacity for heavy metals (increase in BC(max) and decrease in BC(min)). The pH value significantly affected the binding capacity for heavy metals; BC(max) sharply increased and BC(min) sharply decreased for each heavy metal ion for all of the dietary fibers when the pH was raised from 2.0 to 7.0. The binding capacity of dietary fibers for heavy metals was slightly affected by amino acids, calcium, iron, and zinc but significantly affected by copper. Colon fermentation released part of the heavy metal ions from dietary fibers. From the results it can be concluded that dietary fibers from wheat bran can effectively bind all three tested metal ions to prevent the body from being affected by their toxicity.
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Su B, Zhu Q, Gao K, Yuan C, Jia Z. Lignan and phenylpropanoid glycosides from Lancea tibetica and their antitumor activity. PLANTA MEDICA 1999; 65:558-561. [PMID: 10483379 DOI: 10.1055/s-1999-14026] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A new lignan glucoside, the first 7,9'-monoepoxyte-trahydrofuran type lignan with the cis-relationship of H-7 and H-8, named tibeticoside (1), as well as ten known compounds have been isolated from the medicinal plant (roots, stems and leaves) Lancea tibetica. The structure of tibeticoside (1) has been elucidated on the basis of chemical and spectral evidence, especially by 2D-NMR (1H-1H COSY, HMQC, HMBC, NOESY). In addition, sylvatesmin (6) exhibited effective antitumor activity on B16 cells.
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Yang B, Lu Y, Gao K, Deng Z. Study on the hydrolyzate of sugarcane bagasse to ethanol by fermentation. CHINESE JOURNAL OF BIOTECHNOLOGY 1998; 13:253-61. [PMID: 9631261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Study of glucose and xylose utilization by Pichia stipitis in a limited oxygen supply condition revealed that the rate of glucose utilization decreased rapidly while that of xylose decreased slowly until the time that glucose and xylose were shown to level out, at which point the rate of xylose utilization increased rapidly. Based on the results, ethanol fermentation technology in continuous connective tower fermenters was advanced, e.g., fermentation by P. stipitis in an airlift loop tower focusing on xylose utilization and then residue glucose utilization by Saccharomyces cerevisiae in an overflow tower. When the fed hydrolyzate of bagasse was concentrated in five folds and the dilution rate was 0.1 h-1, the total utilization ratio of reducing sugar was 97.2%; the concentration of ethanol was 46.4 g/L.h.
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Gao K, Chen DO, Genzen JR, Mason P. Activation of serotonergic neurons in the raphe magnus is not necessary for morphine analgesia. J Neurosci 1998; 18:1860-8. [PMID: 9465010 PMCID: PMC6792633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
A wealth of pharmacological and behavioral data suggests that spinally projecting serotonergic cells mediate opioid analgesia. A population of medullary neurons, located within raphe magnus (RM) and the neighboring reticular nuclei, contains serotonin and is the source of serotonin in the spinal dorsal horn. To test whether serotonergic neurons mediate opioid analgesia, morphine was administered during recordings from medullary cells that were physiologically characterized as serotonergic (5HTp) by their slow and steady discharge pattern in the lightly anesthetized rat. Selected 5HTp cells (n = 14) were intracellularly labeled, and all contained serotonin immunoreactivity. The discharge of most 5HTp cells was not affected by an analgesic dose of systemic morphine. In a minority of cases, 5HTp cells either increased or decreased their discharge after morphine administration. However, morphine altered the discharge of some 5HTp cells in the absence of producing analgesia and conversely did not alter the discharge of most 5HTp cells in cases in which analgesia occurred. RM cells with irregular discharge patterns and excitatory or inhibitory responses to noxious tail heat were classified as ON and OFF cells, respectively. All ON and OFF cells that were intracellularly labeled (n = 9) lacked serotonin immunoreactivity. All ON cells were inhibited, and most OFF cells were excited by systemic morphine. Because 5HTp cells do not consistently change their discharge during morphine analgesia, they are unlikely to mediate the analgesic effects of morphine. Instead, nonserotonergic cells are likely to mediate morphine analgesia in the anesthetized rat. In light of the sensitivity of morphine analgesia to manipulations of serotonin, serotonin release, although neither necessary nor sufficient for opioid analgesia, is proposed to facilitate the analgesic effects of nonserotonergic RM terminals in the spinal cord.
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