251
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Guan J, Siebel E, Fischer RD. μ-Oxo-bis[ mer-trichlorobis(tetrahydrofuran- O)zirconium(IV)]. Acta Crystallogr C 1999. [DOI: 10.1107/s0108270199007532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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252
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Kurdoglu B, Cheong N, Guan J, Corn BW, Curran WJ, Iliakis G. Apoptosis as a predictor of paclitaxel-induced radiosensitization in human tumor cell lines. Clin Cancer Res 1999; 5:2580-7. [PMID: 10499636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Paclitaxel is a deterpene with antitumor activity against a variety of human neoplasms. Paclitaxel cytotoxicity is thought to derive mainly from a stabilization of microtubules as a result of enhanced tubulin polymerization that leads to an accumulation of cells in the mitotic (M) phase of the cell cycle. Because cells in this phase of the cell cycle are known to be radiosensitive, it was thought that paclitaxel, in addition to its direct toxicity, may also sensitize tumor cell populations to radiation. Studies evaluating the radiosensitizing potential of paclitaxel in cultured cells have been equivocal, with only approximately 50% of the tested cell lines showing radiosensitization. To explain this variability, we advanced the hypothesis that the ability of paclitaxel to radiosensitize cells may be inversely correlated to the efficiency with which it induces apoptosis. To test this hypothesis, we studied paclitaxel-induced apoptosis and radiosensitization in seven human tumor cell lines. Approximately one-half of these cell lines showed radiosensitization that was associated with a low apoptotic index (<20% after a 48-h treatment with 10 or 20 nM paclitaxel). The results suggest that the level of apoptosis, after paclitaxel treatment, may predict for paclitaxel-induced radiosensitization, and that it could be introduced as a parameter for the optimization of combined treatment protocols.
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Affiliation(s)
- B Kurdoglu
- Department of Radiation Oncology, Kimmel Cancer Center, Jefferson Medical College, Philadelphia, Pennsylvania 19107, USA
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253
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Guan J, Yang H. [Medical value of humic acid]. Zhong Yao Cai 1999; 22:430-1. [PMID: 12908488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Affiliation(s)
- J Guan
- People's Hospital of Kaiping City, Guandong Province, Kaiping, 529300
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254
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Zhu XK, Guan J, Tachibana Y, Bastow KF, Cho SJ, Cheng HH, Cheng YC, Gurwith M, Lee KH. Antitumor agents. 194. Synthesis and biological evaluations of 4-beta-mono-, -di-, and -trisubstituted aniline-4'-O-demethyl-podophyllotoxin and related compounds with improved pharmacological profiles. J Med Chem 1999; 42:2441-6. [PMID: 10395485 DOI: 10.1021/jm990055f] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
As a continuation of our structure-activity relationship studies, several new 4-beta-substituted 4'-O-demethyl-4-desoxypodophyllotoxins bearing mono-, di-, or trisubstituted anilines have been synthesized and evaluated as inhibitors of DNA topoisomerase II and tumor cell growth in tissue culture. Selected compounds were further evaluated as cytotoxic agents using a clonogenic survival assay. The target compounds include 4'-O-demethyl-4beta-[(4' '-(benzimidazol-2' '-yl)anilino]-4-desoxypodophyllotoxin (21), 4'-O-demethyl-4beta-(-)-(4' '-camphanamido-anilino)-4-desoxypodophyllotoxin (25), 4-beta-disubstituted-anilino-4'-demethyl-4-desoxypodophyllotoxins (18-20, 26), 4-alpha-disubstituted-anilino-4'-demethyl-4-desoxypodophyllotoxin (27), 4-beta-trisubstituted-anilino-4'-demethyl-desoxypodophyllotoxin (22, 23), and 4'-O-demethyl-4beta-[4' '-(benzimidazol-2' '-yl)amino]-4-desoxypodophyllotoxin (24). Among the target series, 19, 21, and 24 displayed significant growth inhibitory action against a panel of tumor cell lines including human epidermoid carcinoma of the nasopharynx (KB) and its etoposide-resistant (KB7B) and vincristine-resistant (vin20c KB) subclones, lung carcinoma (A549), human ileocecal carcinoma (HCT-8), human kidney carcinoma (CAKI-1), breast adenocarcinoma (MCF-7), and human malignant melanoma (SK-MEL-2) cells. Compounds 19, 21, 24, and 25 were "cleavable-complex"-forming DNA topoisomerase II inhibitors with either improved or similar activity compared with the prototype drug etoposide (VP-16). Compound 21 was the most active analogue, being 10-fold more potent than etoposide in both cell killing and topoisomerase II inhibition in vitro assays. Using mouse models of antitumor activity, 21 was effective against (P388/0) leukemia but not against the growth of a (MCF7) mammary tumor.
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Affiliation(s)
- X K Zhu
- Division of Medicinal Chemistry and Natural Products, School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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255
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Abstract
The endothelial nitric oxide synthase (eNOS) gene is induced by a variety of extracellular signals under both in vitro and in vivo conditions. To gain insight into the mechanisms underlying environmental regulation of eNos expression, transgenic mice were generated with the 1,600-bp 5' flanking region of the human eNos promoter coupled to the coding region of the LacZ gene. In multiple independent lines of mice, transgene expression was detected within the endothelium of the brain, heart, skeletal muscle, and aorta. beta-galactosidase activity was consistently absent in the vascular beds of the liver, kidney, and spleen. In stable transfection assays of murine endothelial progenitor cells, the 1,600-bp promoter region was selectively induced by conditioned media from cardiac myocytes, skeletal myocytes, and brain astrocytes. Cardiac myocyte-mediated induction was partly abrogated by neutralizing anti-platelet-derived growth factor (PDGF) antibodies. In addition, promoter activity was upregulated by PDGF-AB. Analysis of promoter deletions revealed that a PDGF response element lies between -744 and -1,600 relative to the start site of transcription, whereas a PDGF-independent cardiac myocyte response element is present within the first 166 bp of the 5' flanking region. Taken together, these results suggest that the eNos gene is regulated in the cardiac endothelium by both a PDGF-dependent and PDGF-independent microvascular bed-specific signaling pathway.
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Affiliation(s)
- P V Guillot
- The Department of Medicine, Divisions of Molecular Medicine and Hematology-Oncology, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, USA
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256
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Guan J, Ye P, Wu J. [Analyses on structural and physicochemical properties of collagen hemostatic sponge]. Sheng Wu Yi Xue Gong Cheng Xue Za Zhi 1999; 16:10-2, 18. [PMID: 12553266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
The ultraviolet spectrum and aminoacid content of collagen hemostatic sponge prepared from bovine tendon were analyzed, and the struture and composition of collagen spoge were confirmed. Physicochemical properties measurements showed that collagen hemostatic sponge had excellently stable quality. It was concluded that the technology for preparing collagen hemostatic sponge was reasonable and reliable.
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Affiliation(s)
- J Guan
- Institute of Medical Equipment, Academy of Military Medical Sciences, Tianjin 300161
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257
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Mountjoy KG, Guan J, Elia CJ, Sirimanne ES, Williams CE. Melanocortin-4 receptor messenger RNA expression is up-regulated in the non-damaged striatum following unilateral hypoxic-ischaemic brain injury. Neuroscience 1999; 89:183-90. [PMID: 10051228 DOI: 10.1016/s0306-4522(98)00285-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Melanocortin peptides (alpha-melanocyte-stimulating hormone, adrenocorticotropin and fragments thereof) have been shown to have numerous effects on the central nervous system, including recovery from nerve injury and retention of learned behaviour, but the mechanism of action of these peptides is unknown. A family of five melanocortin receptors have recently been discovered, two of which (melanocortin-3 and melanocortin-4 receptors) have been mapped in the rat brain. We have tested the hypothesis that the expression of one or more of the messenger RNAs for three melanocortin receptors (melanocortin-3, melanocortin-4 and melanocortin-5 receptors) would be altered in rat brain following unilateral transient hypoxic-ischaemic brain injury. In this study, using in situ hybridization, we show that melanocortin-4 receptor messenger RNA was up-regulated in the striatum in the non-damaged hemisphere within 24 h after severe hypoxic-ischaemic injury compared with control brains (P<0.05). In a small group of animals, this induction was not blocked by treatment with the anticonvulsant, carbamazepine. Expression of melanocortin-3 receptor messenger RNA in the brain was not altered in this hypoxic-ischaemic injury model and melanocortin-5 receptor messenger RNA was not detected in either control or hypoxic-ischaemic injured rat brains. We hypothesize that the up-regulation of melanocortin-4 receptor messenger RNA expression in the contralateral striatum may be involved in transfer of function to the uninjured hemisphere following unilateral brain injury.
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MESH Headings
- Animals
- Brain Ischemia/metabolism
- Corpus Striatum/chemistry
- Corpus Striatum/cytology
- Functional Laterality
- Gene Expression/physiology
- Hippocampus/chemistry
- Hippocampus/cytology
- Hypoxia, Brain/metabolism
- Neurons/chemistry
- Neurons/physiology
- RNA, Messenger/metabolism
- Rats
- Rats, Wistar
- Receptor, Melanocortin, Type 4
- Receptors, Corticotropin/genetics
- Receptors, Corticotropin/metabolism
- Receptors, Melanocortin
- Receptors, Peptide/genetics
- Receptors, Peptide/metabolism
- Up-Regulation/physiology
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Affiliation(s)
- K G Mountjoy
- Department of Paediatrics, University of Auckland, New Zealand
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258
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Guan J, Waldvogel HJ, Faull RL, Gluckman PD, Williams CE. The effects of the N-terminal tripeptide of insulin-like growth factor-1, glycine-proline-glutamate in different regions following hypoxic-ischemic brain injury in adult rats. Neuroscience 1999; 89:649-59. [PMID: 10199602 DOI: 10.1016/s0306-4522(98)00338-8] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Insulin-like growth factor-1 has pleiotropic effects in the central nervous system and can act both as a survival and a differentiation factor. Insulin-like growth factor-1 can be proteolytically cleaved into des-N-(1-3)-insulin-like growth factor-1 and a N-terminal tripeptide fragment, glycine-proline-glutamate. Both insulin-like growth factor-1 and des-N-(1-3)-insulin-like growth factor-1 can improve neuronal survival after hypoxic-ischemic brain injury in vivo. The present study investigates the effects of glycine-proline-glutamate on different brain regions and neuronal populations after hypoxic-ischemic injury. Unilateral hypoxic-ischemic injury was induced in adult rats. Glycine-proline-glutamate (3 microg) was administered centrally 2 h after the injury and the extent of brain damage determined five days later. In a separate trial immunohistochemical techniques were used to determine the effects of glycine-proline-glutamate on specific populations of neurons in the striatum after the injury. Compared to the vehicle treatment, glycine-proline-glutamate (n=19) treatment reduced the extent of cortical damage and neuronal loss in the CA1-2 subregions of the hippocampus (P<0.05). In the striatum, there was a trend towards a reduction in neuronal loss after glycine-proline-glutamate treatment (P=0.053) compared to the vehicle (n=21)-treated animals. In a separate study, glycine-proline-glutamate (n=8) treatment prevented the loss of choline acetyltransferase (P<0.05), glutamate acid decarboxylase (P<0.05) and somatostatin (P<0.05) containing neurons in the ipsilateral striatum following hypoxic-ischemic brain injury and also increased the numbers of neuronal nitric oxide synthase (P<0.05) containing neurons in the contralateral side. These studies suggest that in addition to neuroprotective effects, glycine-proline-glutamate can influence neuronal activity after hypoxic-ischemic injury.
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Affiliation(s)
- J Guan
- Research Centre for Developmental Medicine and Biology, University of Auckland, New Zealand
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259
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Saura J, Curatolo L, Williams CE, Gatti S, Benatti L, Peeters C, Guan J, Dragunow M, Post C, Faull RL, Gluckman PD, Skinner SJ. Neuroprotective effects of Gly-Pro-Glu, the N-terminal tripeptide of IGF-1, in the hippocampus in vitro. Neuroreport 1999; 10:161-4. [PMID: 10094155 DOI: 10.1097/00001756-199901180-00031] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Insulin-like growth factor 1 (IGF-1) plays a critical role in CNS development. IGF-1 can block neuronal apoptosis in vitro and in vivo. IGF-1 is thought to be cleaved into des-N-(1-3)-IGF-1 and an amino terminal glycine-proline-glutamate (GPE tripeptide). Here we report a neuroprotective role for GPE tripeptide, with enhanced survival of the CA1-2 hippocampal neurons following an excitotoxic insult in vitro. Binding and displacement studies suggest uniquely distributed sites of action within the rat including the hippocampal CA1-2, pyriform cortex, amygdala, choroid plexus, blood vessels and to a lesser extent in the cortical regions. A similar pattern of binding was seen in the human. This finding could lead to new strategies to reduce neuronal death after injury and in disease.
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Affiliation(s)
- J Saura
- Department of Pharmacology, School of Medicine, University of Auckland, New Zealand
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260
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Guan J, Sun Y, Zhu D. [Retrospective study on the risk factors in patients with nosocomial bacterial L-form infection]. Zhonghua Liu Xing Bing Xue Za Zhi 1998; 19:339-42. [PMID: 10921118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
To survey the risk factors of nosocomial bacterial L-form infections, 22 risk factors were investigated and analysed with nonconditional logistic regression. Resutts showed through single factor regression that cancer, chronic disease, primary infection, longer than 3-week hospitalization before the onset of nosocomial infection, preventive use of antibiotics longer than 7 days, preventive use of cell wall depressive antibiotics, steroid use, anti-tumor drugs and urine guide technique were significant factors. Multiple factor regression demonstrated that two models including cell wall depressive antibiotics, primary infection, urine guide technique cell wall depressive antibiotics, primary infection, anti-tumor drugs and longer than 3-week hospitalization before the development of nosocomial infection were conjugated properly. It suggested that the surveillance of risk factors of nosocomial bacterial L-form infections was helpful to control nosocomial infections.
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Affiliation(s)
- J Guan
- Department of Rheumatology, General Hospital of PLA, Beijing
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261
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Guan J, Zhu XK, Tachibana Y, Bastow KF, Brossi A, Hamel E, Lee KH. Antitumor agents. Part 186: Synthesis and biological evaluation of demethylcolchiceinamide analogues as cytotoxic DNA topoisomerase II inhibitors. Bioorg Med Chem 1998; 6:2127-31. [PMID: 9881102 DOI: 10.1016/s0968-0896(98)00165-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Demethylation of colchiceinamide (2) and its analogues (3-10) afforded a novel class of mammalian DNA topoisomerase II inhibitors (2a-10a) without displaying tubulin inhibitory activity. All target compounds inhibited the catalytic activity of topoisomerase II at drug concentrations at 100 microM. An in vitro cytotoxicity assay indicated that compounds 3a and 8a were strong and tissue-selective cytotoxic agents against the MCF-7 breast cancer cell line (IC50 = 0.36 and 0.48 microgram/mL, respectively) and the CAKI-1 renal cancer cell line (IC50 = 0.72 and 0.96 microgram/mL, respectively).
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Affiliation(s)
- J Guan
- Natural Products Laboratory, School of Pharmacy, University of North Carolina at Chapel Hill 27599, USA
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262
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Guan J, Jin D, Jin L. [Apoptosis in multiple organs of rats in early stage of polytrauma combined with shock]. Zhonghua Yi Xue Za Zhi 1998; 78:741-5. [PMID: 11038825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
OBJECTIVE To discuss Apoptosis in multiple organs of rats in early stage of polytrauma combined with shock. METHODS DNA agarose gel electrophoresis, in situ end labeling (ISEL), light microscope and electron microscope were used and DNA fragmentation percentage (ap%) was detected. RESULTS The special ladder pattern for apoptosis was seen in thymus, spleen, liver, lung and intestine, but not in heart, kidney and brain. At 6 hours after resuscitation, the ap% of thymus, spleen, liver, lung and intestine increased together with the severity of trauma. In six-site trauma combined with hemorrhagic shock group, the ap% of these five organs increased significantly at 1 hour after resuscitation and most significantly at 3 hours. At this point, the ap% of spleen, liver, lung and intestine reached peak, and declined gradually afterward. But the ap% of thymus continued to increase after 3 hours and kept stable from 6 hours to 24 hours ISEL showed that there were positive responses of different degrees in these eight organs. It was feand Morphologically most apoptotic cells in the thymus were positioned in the cortex, and those in spleen in the growing center of white pulp, and those in liver in the border area of hepatic lobule and portal area, and apoptosis of multiple kinds of cells including alveolar epithelial cells, vascular endothelial cells and polymorphonuclear neutrophils was induced in lung, and intestinal apoptotic cells laid in the epithelium and lamina propria of mucosa. CONCLUSION Apoptosis was really induced in thymus, spleen, liver, lung and intestine in early stage of polytrauma combined with shock, which may play a role in early organ injury and late multiple organ failure.
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Affiliation(s)
- J Guan
- Department of Orthopaedics, NanFang Hospital, First Military Medical University, Guangzhou
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263
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Guan J. Base-free tris(indenyl)lanthanoid(III) complexes (Ln=La, Pr, Nd, Sm): solid-state structure and solution NMR/NIR–vis spectroscopy. J Organomet Chem 1998. [DOI: 10.1016/s0022-328x(98)00637-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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264
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Sui Z, Guan J, Hlasta DJ, Macielag MJ, Foleno BD, Goldschmidt RM, Loeloff MJ, Webb GC, Barrett JF. SAR studies of diaryltriazoles against bacterial two-component regulatory systems and their antibacterial activities. Bioorg Med Chem Lett 1998; 8:1929-34. [PMID: 9873461 DOI: 10.1016/s0960-894x(98)00325-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A series of diaryltriazole analogs was discovered to inhibit bacterial two-component regulatory systems in our primary assays, KinA/Spo0F and NRII/NRI. They also showed inhibitory activity in whole cell mechanism-based assays, and they possessed potent activities against several strains of Gram-positive pathogenic bacteria in the standard MIC broth assay.
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Affiliation(s)
- Z Sui
- R. W. Johnson Pharmaceutical Research Institute, Raritan, NJ 08869, USA
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265
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Hlasta DJ, Demers JP, Foleno BD, Fraga-Spano SA, Guan J, Hilliard JJ, Macielag MJ, Ohemeng KA, Sheppard CM, Sui Z, Webb GC, Weidner-Wells MA, Werblood H, Barrett JF. Novel inhibitors of bacterial two-component systems with gram positive antibacterial activity: pharmacophore identification based on the screening hit closantel. Bioorg Med Chem Lett 1998; 8:1923-8. [PMID: 9873460 DOI: 10.1016/s0960-894x(98)00326-6] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This SAR study has shown that the salicylanilide is the pharmacophore for inhibition of the bacterial two-component system. Hydrophobic substituents improve the potency of inhibitors in this series; however, hydrophobicity is not the sole determinant for inhibition; structural and electronic requirements also exist. Closantel (1) was found to inhibit a two-component system and to have antibacterial activity against drug resistant S. aureus and E. faecium.
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Affiliation(s)
- D J Hlasta
- R.W. Johnson Pharmaceutical Research Institute, Raritan, NJ 08869, USA
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266
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Abstract
To study the metabolic effects of insulin derived from islet grafts, oral glucose tolerance (OGT) and glucose turnover were examined in streptozotocin-induced diabetic Lewis rats rendered normoglycemic by syngeneic islet grafts in the renal subcapsular space (REN), in REN with renal vein-to-mesenteric vein anastomosis (REN-RMA), in the liver (intrahepatic [IH]), or in a parahepatic omental pouch (POP) and compared with normal rats. Normal OGT was found at 1 month posttransplant in all animals receiving approximately 3,000 islets, with hyperinsulinemic responses in the REN group compared with the other groups, and with higher C-peptide responses in the IH group than in the other groups (P < 0.05 by one-way analysis of variance). Glucose turnover studies in the insulin-stimulated steady state (INS-SS; infusion of insulin at 10 pmol x kg(-1) x min(-1)) at 2 months posttransplant showed that whole body glucose disappearance rates (Rd) were similar in all groups, but the REN group had higher steady-state insulin levels than the other groups. Glucose infusion rates (GIRs) were lower in the REN and IH groups than in the other groups. Apparent endogenous glucose production (EGP) was not completely inhibited in the REN and IH groups, while complete inhibition was observed in the other groups. When INS-SS insulin levels were matched to the level in REN rats by increasing the insulin infusion rate to 20 pmol x kg(-1) x min(-1) in REN-RMA, IH, and normal rats, GIR and Rd were elevated, exceeding those values in REN rats, but GIR in IH rats was still lower than in REN-RMA and normal rats. Thus, 1) in the REN group, impairment of inhibition of EGP and of stimulation of Rd by exogenous insulin contribute to insulin resistance; 2) in the IH group, incomplete inhibition of EGP is the major determinant of insulin resistance; and 3) with portal delivery of insulin in the REN-RMA and POP groups, normal insulin sensitivity is preserved. The present study confirms that hepatic portal delivery of islet secretions is necessary for physiological regulation of glucose metabolism. The study also suggests the IH grafts do not provide physiological regulation of glucose metabolism, raising the question of whether the liver is an appropriate site for insulin-secreting tissue replacement therapy in diabetes.
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Affiliation(s)
- J Guan
- Department of Physiology, London Health Sciences Centre, University of Western Ontario, Canada
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267
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Abstract
Transient neural injuries, such as asphyxia, can trigger considerable delayed neuronal death. Inappropriate induction of apoptosis is thought to play an important role in this process. Our studies have shown marked changes in the IGF system in the brain in response to these injuries with an induction of insulin growth factor (IGF)-1 and insulin growth factor binding protein (IGFBP)-2 and IGFBP-3 in glial cells in the region of injury. This suggests that the IGF-1 system may be an endogenous neuroprotective system. Earlier administration of IGF-1 - 2 h after injury reduced the phase of secondary neuronal loss suggesting that IGF-1 may well have therapeutic potential as a neuronal rescue agent. The action of IGF-1 appears to involve binding proteins, transport to the site of injury and the IGF-1 receptor and inhibition of apoptosis, but might also involve generation of GPE which itself appears to be neuroprotective. Together these results indicate considerable potential of these agents to treat stroke, perinatal asphyxia and other forms of acute brain injury.
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Affiliation(s)
- P D Gluckman
- Research Centre for Developmental Medicine and Biology, School of Medicine, University of Auckland, New Zealand.
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268
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Guan J, Zhu XK, Tachibana Y, Bastow KF, Brossi A, Hamel E, Lee KH. Antitumor agents. 185. Synthesis and biological evaluation of tridemethylthiocolchicine analogues as novel topoisomerase II inhibitors. J Med Chem 1998; 41:1956-61. [PMID: 9599244 DOI: 10.1021/jm980007f] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Several 1,2,3-tridemethyldeacetylthiocolchicine derivatives have been synthesized and evaluated for cytotoxic activity against various human tumor cell lines and for their inhibitory effects on DNA topoisomerases in vitro. Exhaustive demethylation of thiocolchicine analogues completely changes their biological profiles. Instead of displaying antitubulin activity, most target compounds inhibited topoisomerase II activity. Only compounds with a larger side chain, such as 15a, 23a, and 24a, did not interfere with topoisomerase II enzymatic functions. The cytotoxicity of target compounds was reduced by 3 orders of magnitude compared to that of colchicine in most cell lines. The hydrophilicity of phenolic compounds might prevent drug passage through the cell plasma membrane and, thus, be responsible for the relatively weak cytotoxicity. To test this hypothesis, 27-30 were prepared from 16a by protecting all hydroxy groups with esters with an aim to facilitate drug transportation. In vitro cytotoxicity assays indicated that 27 was more potent than its parent compound in all tested tumor cell lines and showed tissue selective cytotoxicity with a significant inhibitory effect against KB cells (IC50 = 2.7 microg/mL). Therefore, we propose that 27 acts as a prodrug, liberating 16a to exert its antitopoisomerase activity and, finally, to cause cell death.
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Affiliation(s)
- J Guan
- Natural Products Laboratory, Division of Medicinal Chemistry and Natural Products, School of Pharmacy, University of North Carolina at Chapel Hill, North Carolina 27599, USA
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269
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Guo Y, Guan J, Ge B. [P16 expression in lung cancer and its significance]. Zhonghua Yi Xue Za Zhi 1998; 78:354-5. [PMID: 10923439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
OBJECTIVE To study the relationship of suppressor gene p16 and lung cancer for prognosis evaluation. METHODS Immunohistochemical method was used to detect and analyse the expression of P16 protein of CDKN2 suppressor gene of 76 cases in formalin-fixed, paraffin-embedded tissue specimens of human lung cancer. RESULTS P16 positive rate was 45%: 52% for 23 of 44 cases of squamous carcinoma and 29% for 7 of 24 cases of adenocarcinoma. Differentiation degree and prognosis of lung cancer were associated significantly with P16 expression. P16 expression was somewhat related to clinical stage. CONCLUSION P16 gene plays a key role in the prognosis of patients with lung cancer.
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Affiliation(s)
- Y Guo
- Department of Thoracic Surgery, China-Japan Friendship Hospital, Beijing
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270
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Reddy K, Mallard C, Guan J, Marks K, Bennet L, Gunning M, Gunn A, Gluckman P, Williams C. Maturational change in the cortical response to hypoperfusion injury in the fetal sheep. Pediatr Res 1998; 43:674-82. [PMID: 9585015 DOI: 10.1203/00006450-199805000-00017] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A characteristic of perinatal encephalopathies are the distinct patterns of neuronal and glial cell loss. Cerebral hypoperfusion is thought to be a major cause of these lesions. Gestational age is likely to influence outcome. This study compares the cortical electrophysiologic and histopathologic responses to hypoperfusion injury between preterm and near term fetuses. Chronically instrumented 0.65 (93-99-d, n = 9) and 0.9 (119-133-d, n = 6) gestation fetal sheep underwent 30 min of cerebral hypoperfusion injury. The parasagittal cortical EEG and impedance (measure of cytotoxic edema) responses plus histologic outcome (3 d) were compared. The acute rise in impedance was similar in amplitude, but the onset was delayed (5.0 +/- 0.7 versus 9.1 +/- 1.1 min, p < 0.05) in the preterm fetuses relative to those near term. In contrast the extent of the secondary rise was reduced (p < 0.01) and peaked earlier in the preterm fetuses (19.8 +/- 1.0 versus 40.5 +/- 3.5 h, p < 0.01). Both groups had a similar fall in EEG spectral edge frequency. The preterm fetuses had a milder loss of EEG intensity at 72 h (-7.7 +/- 1.5 versus -12.8 +/- 0.9 dB, p < 0.05). At both ages there was a predominantly parasagittal cortical distribution of damage with a similar pattern of neuronal loss in the thalamus and striatum. There was extensive selective neuronal loss within the upper layers of the cortex in those near term. In contrast the preterm fetuses developed subcortical infarcts (p < 0.05). The cortical response to injury altered during the last trimester. The results suggest the severity of the delayed phase of cortical neuronal injury and selective neuronal loss increased near term. In contrast, the preterm fetuses had a more rapidly evolving injury leading to necrosis of the subcortical white matter.
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Affiliation(s)
- K Reddy
- Research Centre for Developmental Medicine and Biology, Department of Paediatrics, University of Auckland, New Zealand
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271
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Wu J, Ye P, Sun W, Guan J, Duan L. [Collagen sponge and its hemostatic properties]. Sheng Wu Yi Xue Gong Cheng Xue Za Zhi 1998; 15:63-5. [PMID: 12549357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
Soluble collagen was extracted from bovine tendon in acid solution. Collagen sponge hemostatics were prepared by means of lyophibization. The amino acid and UV spectrum analyses were made to confirm the composition of the soluble collagen. The results of experiments on rabbits indicated the collagen sponge prepared in the authors' lab had excellent hemostatic and adhesive properties in vivo surgical tests.
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Affiliation(s)
- J Wu
- Institute of Medical Equipment, Academy of Military Medical Sciences, Tianjin 300161
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272
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Bai Y, Guan J, Pi J. [Protective effects of exogenous superoxide dismutase on rabbit retinal injury by acute intraocular hypertension]. Zhonghua Yan Ke Za Zhi 1997; 33:429-32. [PMID: 10680544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
OBJECTIVE To study active oxygen and free radical injury in rabbit retina during elevated intraocular pressure and the protective effect of exogenous superoxide dismutase (SOD) on the retinal damage by the hypertension. METHODS Lipid peroxidative product, malondialdehyde (MDA), activity of SOD and glutathione peroxidase (GSH-Px), reduced GSH in the retinal tissue were measured during 24 h after the release of an ocular hypertension, 6.67 kPa (1 kPa = 7.5 mmHg) maintaining for 1.5 h, and the effects of retrobulbarly injected Cu-Zn-SOD on the level of MDA and the activity of SOD in the retinal tissue after the release of ocular hypertension for 12 h were observed. RESULTS MDA increased gradually during 0-12 h after the release of ocular hypertension and maintained at a relatively high level in 12-24 h. The activity of SOD and GSH-Px was lower than normal level immediately after the release, and then increased to a certain different extent. But the activity of SOD began to decrease gradually 4 h after the release. GSH had no significant changes during 24 h after the release. Retrobulbar injection of Cu-Zn-SOD reduced the production of MDA in the retinal tissue and enhanced SOD activity. CONCLUSIONS Active oxygen and free radicals participate the rabbit retinal injury by elevated intraocular pressure. A high dose of Cu-Zn-SOD retrobulbar injection plays a beneficial role in enhancing the antioxidative ability of the retina.
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Affiliation(s)
- Y Bai
- Department of Ophthalmology, China Medical University, Shenyang
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273
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Folz RJ, Guan J, Seldin MF, Oury TD, Enghild JJ, Crapo JD. Mouse extracellular superoxide dismutase: primary structure, tissue-specific gene expression, chromosomal localization, and lung in situ hybridization. Am J Respir Cell Mol Biol 1997; 17:393-403. [PMID: 9376114 DOI: 10.1165/ajrcmb.17.4.2826] [Citation(s) in RCA: 125] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Extracellular superoxide dismutase (EC-SOD) is the major extracellular antioxidant enzyme. We have determined the primary structure of mouse EC-SOD by characterization of complementary DNA (cDNA) clones and by amino-acid sequence analysis of purified protein. cDNA sequence analysis indicates that mouse EC-SOD is synthesized as a 251-amino-acid precursor protein with a predicted molecular weight of 27,400 D. Amino-terminal micro sequence analysis of purified mature mouse lung EC-SOD demonstrated the sequence to begin with SSFDLADRLDPV-. These results indicate that EC-SOD as initially synthesized contains a 24-amino-acid precursor peptide, and that the mature protein is 227 amino acids in length. Computer algorithms that predict the most likely site of cotranslational signal peptidase cleavage suggest that processing will occur between amino acids 18 and 19 or 20 and 21, which implies that EC-SOD may be initially synthesized as a pre-pro-protein. Like human EC-SOD, mature mouse EC-SOD is glycosylated. The full-length mouse EC-SOD cDNA is 1,834 base pairs long and is 82% (79% for protein) identical to rat EC-SOD, but only 60% (60% for protein) identical to human EC-SOD. The mouse EC-SOD gene locus (Sod3) was mapped by interspecific backcross haplotype analysis as being 0.9 +/- 0.9 centimorgans distal to the Qdpr locus on mouse Chromosome 5, a position suggesting that the human homologue of EC-SOD will map close to the human QDPR locus (4p15.3). Of nine tissues examined by Northern blot analysis, those of the kidney and lung are by far the major tissues that express EC-SOD messenger RNA. Using in situ hybridization in the mouse lung, we demonstrate EC-SOD gene expression to be highly localized to alveolar Type II epithelial cells. These data suggest that alveolar Type II cells play a central role in mediating EC-SOD antioxidant function in the lung.
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Affiliation(s)
- R J Folz
- Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA.
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274
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Yang L, Guan J, Gao S. [An experimental study on effect of atrial natriuretic peptide on intraocular pressure of white rabbits]. Zhonghua Yan Ke Za Zhi 1997; 33:149-51. [PMID: 10437024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
OBJECTIVE To study the therapeutic effect of atrial natriuretic peptide (ANP) on glaucoma. METHODS Various doses of ANP were injected subconjunctivally in albino rabbits, and their effects on intraocular pressures (IOPs) were observed. RESULTS The IOPs were significantly decreased by the subconjunctival injection of 20, 30, 40 micrograms of ANP, and with a dose of 40 micrograms, the maximum effect of IOP lowering of 0.88-0.15 kPa maintaining for the longest time 7.5 hours was obtained. Generally, one hour after the injection, the maximum effect could be seen. A dose-effect relationship that is the degree of the reduction of IOP increasing with the dose increase of ANP could be observed. CONCLUSION This study indicates that ANP might play an effective therapeutic role in glaucoma.
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Affiliation(s)
- L Yang
- Ophthalmology Department, 210 PLA Hospital, Dalian
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275
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Abstract
We determined the metabolic effects of insulin derived from renal subcapsular islet grafts, either with systemic delivery of insulin through renal venous drainage (REN) or with portal delivery of insulin after renal vein-to-superior mesenteric vein anastomosis (RMA), in streptozotocin-induced diabetic Lewis rats, in comparison with normal rats. After gavage glucose, the plasma glucose responses were similar to normal in REN and RMA rats; however, hyperinsulinemia occurred in REN rats (area under the concentration curves [AUCs] of insulin, 27 +/- 3 nmol x 1(-l) min) in comparison with RMA (14 +/- 2) and normal rats (19 +/- 2), P < 0.003, with no difference in C-peptide responses. The ratio of AUC C-peptide to AUC insulin was lower in REN (2.0 +/- 0.2) than in RMA (3.4 +/- 0.3) and normal animals (3.2 +/- 0.3), P < 0.0005. In euglycemic-hyperinsulinemic clamp studies using the same insulin infusion rate (10 pmol x kg(-1) x min(-1), insulin resistance was found in REN animals (mean glucose infusion rate [GIR], REN: 7.5 +/- 1.2; RMA: 12.0 +/- 1.2; normal: 12.7 +/- 1.0 mg x kg(-1) x min(-1); P < 0.008), with higher steady-state insulin levels in REN (554 +/- 63 pmol/l) than in RMA (291 +/- 26) and normal rats (269 +/- 60), P < 0.0001. With matching steady-state insulin levels in RMA and REN rats during infusion of insulin at 20 pmol x kg(-1) x min(-1) in RMA rats (steady-state insulin 623 +/- 64 pmol/l), GIR was 15.7 +/- 0.7 mg x kg(-1) x min(-1). Thus, systemic delivery of insulin from islet grafts is associated with hyperinsulinemia, insulin resistance, and decreased metabolic clearance of insulin. These abnormalities are prevented by portal delivery of insulin from islet grafts in the same site. The findings are consistent with the hypothesis that portal delivery of insulin is important in maintenance of normal whole-body insulin sensitivity.
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Affiliation(s)
- J Guan
- Department of Physiology, University of Western Ontario, London, Canada
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276
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Guan J, Yang J. [Effects of iron deficiency on expression of transferrin receptor in human lymphocytes]. Zhonghua Yu Fang Yi Xue Za Zhi 1997; 31:34-6. [PMID: 9812635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Cell culture in vitro, ABC-ELISA,RNA dot blot and atom absorption spectrum analysis were used to study biological effects of low concentration of iron citrate (Fe-cit) on the expression of transferrin receptor (TfR) in healthy human peripheral lymphocytes. Results showed that TfR increased by 36%, 50%, and 67% in groups with 1.25 x 10(-5), 5 x 10(-6) Fe-cit and without it, respectively as compared with a control group with 2.5 x 10(-5) mol/L Fe-cit. Levels of TfR-mRNA also increased with decrease of iron in substrate. Iron concentration within cells correlated inversely to the change in the number of TfR. It indicated that iron deficiency could regulate the number of TfR in lymphocytes and its gene expression.
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Affiliation(s)
- J Guan
- Department of Nutrition, Third Military Medical University, Chongqing
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277
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Pankewycz OG, Miao L, Isaacs R, Guan J, Pruett T, Haussmann G, Sturgill BC. Increased renal tubular expression of transforming growth factor beta in human allografts correlates with cyclosporine toxicity. Kidney Int 1996; 50:1634-40. [PMID: 8914030 DOI: 10.1038/ki.1996.479] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Cyclosporine A (CsA) is a potent immunosuppressive drug that inhibits the transcription of several proinflammatory cytokines including interleukin-2. In contrast, CsA stimulates transcription of the pleuripotent cytokine, transforming growth factor-beta (TGF beta). Since the effect of CsA in transplant recipients is unpredictable, we examined whether tissue levels of TGF beta protein in renal allografts correlate with in vivo CsA responsiveness. Intra-allograft TGF beta protein content was assessed in renal biopsies by immunohistochemical means using the mouse anti-TGF beta monoclonal antibody (Mab), 1D11. We studied 68 specimens: 21 with acute CsA toxicity (ACT), 11 with acute tubular necrosis (ATN) and 36 with acute cellular rejection (ACR). Intensity of TGF beta immunostaining was evaluated in a blinded fashion using a scale from 0 to 3+. In biopsies with histological evidence of CsA toxicity, 77% demonstrated intense (2 to 3+) TGF beta immunostaining. TGF beta protein was detected in both proximal and distal tubules but was either absent or present in low levels within glomeruli and interstitium. In contrast, only one of the 11 biopsies with ATN had minimal staining (1+) for TGF beta. The remaining 10 biopsies with ATN were negative for TGF beta immunostaining. In biopsies with ACR, the levels of renal TGF beta were more variable with 36% showing intense (2 to 3+) staining and 64% having minimal or no (0 to 1+) tubular TGF beta. Within the first 18 months post-transplantation, patients with intense TGF beta staining and ACR underwent an average of 4.1 +/- 1.8 allograft biopsies and suffered 33% graft losses. During the same period of time, the patients with ACR and absent or low (0 to 1+) TGF beta levels underwent only 2.1 +/- 1.2 biopsies, maintained better late renal function and suffered 4% graft losses. In conclusion, we demonstrate that TGF beta protein levels in renal allografts correlate with CsA effect and differentiate ACT from ATN. In CsA treated patients who develop ACR, TGF beta levels predict the subsequent clinical course and graft function. Therefore, evaluating tissue levels of TGF beta may offer unique diagnostic and prognostic benefits in the care of patients receiving CsA based immunosuppression.
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Affiliation(s)
- O G Pankewycz
- Department of Medicine, Health Sciences Center, University of Virginia, Charlottesville, USA
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278
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Li Z, Wan L, Guan J. [Measures combating pre-hospital sudden death]. Zhonghua Yi Xue Za Zhi 1996; 76:809-12. [PMID: 9275528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To study pre-hospital sudden death so as to reduce the death rate. METHOD 814 pre-hospital deaths were randomly selected from January 1990 to May 1994 for a retrospective study. RESULTS 616 deaths (75.7%) showed a history of cardiac disease and hypertension. The age for high sudden death rate ranged from 50 to 69 years (53.9%). Most of the cases (87.8%) were found in their homes. 21 cases (2.58%) successfully recovered. CONCLUSIONS The key points to improve the success rate of pre-hospital sudden death are: completing Beijing Emergency Medical Center's emergency care network so as to decrease the emergency care radium and shorten the emergency care time; disseminating emergency care knowledge on CPR and CPR technique.
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Affiliation(s)
- Z Li
- Beijing Emergency Medical Center
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279
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Wang H, Zhang Y, Guan J. [Apparent accommodation in pseudophakic eyes after implantation of posterior chamber intraocular lenses]. Zhonghua Yan Ke Za Zhi 1996; 32:291-4. [PMID: 9590848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To study the question about apparent accommodation in pseudophakic eyes after implantation of posterior chamber intraocular lens (IOL). METHODS The distant and near vision, refraction, pupillary size and shape, the depth of anterior chamber before and after mydriasis of 68 patients (73 eyes) with rigid posterior chamber IOL implantation were examined when the correcting lenses were worn, their powers of apparent accommodation were measured by HS-9D Accommod-Polyrecorder. RESULTS The mean value of apparent accommodation was 1.53 +/- 0.59D. There was a negative correlation between apparent accommodation of pupillary diameter (r = -0.62). The apparent accommodation in the group with normal pupillary movement is greater than that in the group with abnormal one. A mean change of anterior chamber depth, 0.4 mm, before and after mydriasis was found. It appears that rigid posterior chamber implants do move backward on ciliary muscle relaxation. There was a positive correlation between apparent accommodation and the degree of IOL movement (r = 0.47). No significant correlation was found between apparent accommodation and the anterior chamber depth before mydriasis and age (r = 0.26, r = 0.22), etc. CONCLUSION The apparent accommodation is the result of the change of focus depth in the eye which is caused by the cooperation of several factors such as corneal astigmatism, pupillary size and movement, etc. So optimal postoperative myopic astigmatism and good pupillary movement are beneficial to apparent accommodation in an eye with posterior chamber IOL implantation.
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Affiliation(s)
- H Wang
- Department of Ophthalmology, First Affiliated Hospital, China Medical University, Shenyang
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280
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Guan J, Fan M, Cao S. [Reversion of malignant phenotypes of human lung squamous carcinoma cells by ornithine decarboxylase antisense RNA]. Zhonghua Zhong Liu Za Zhi 1996; 18:81-3. [PMID: 9206034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Abnormally elevated activity of ornithine decarboxylase (ODC), with subsequent polyamine accumulation are intimately associated with the genesis, development and metastasis of cancer. Therefore, ODC antisense RNA was used to transfect human lung squmous carcinoma cell line LTEP-78. Compared with the parental cells, growth of the antisense transfected LTEP-78 cells arrested in G0/G1 phase and colony formation in soft agar and tumorigenicity in nude mice were significantly reduced. Nucleic acid hybridization demonstrated the expression of ODC antisense RNA and the content of ODC mRNA was markedly reduced. The results suggest that the reversion of malignant phenotypes of human lung squamous carcinoma cells is associated with the control of polyamine biosynthesis.
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Affiliation(s)
- J Guan
- China-Japan Friendship Institute of Clinical Medical Sciences, Beijing
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281
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Guan J, Williams CE, Skinner SJ, Mallard EC, Gluckman PD. The effects of insulin-like growth factor (IGF)-1, IGF-2, and des-IGF-1 on neuronal loss after hypoxic-ischemic brain injury in adult rats: evidence for a role for IGF binding proteins. Endocrinology 1996; 137:893-8. [PMID: 8603600 DOI: 10.1210/endo.137.3.8603600] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Insulin-like growth factor (IGF)-1, IGF binding protein (IGFBP)-2, and IGFBP-3 are expressed in the rat brain in regions of neuronal loss by 3 days after hypoxic- ischemic (HI) brain injury and IGF-2 somewhat later. Central administration of rh-IGF-1 after HI injury reduces neuronal loss in vivo. To clarify the mode of action of IGF-1 and the potential role of IGFBPs, the effects of IGF-1, IGF-2, des(1-3)-N-IGF-1 (des-IGF-1), an analogue of IGF-1 with low affinity for IGFBPs, and IGF-1 combined with IGF-2 were compared 2 h after administration into the lateral cerebral ventricle after an HI injury. Unilateral HI was induced in adult rats by right carotid artery ligation followed by 10- min exposure to 6%O2. The extent of neuronal loss was determined in the cortex, striatum, hippocampus, dentate gyrus, and thalamus 5 days later. Central administration of 20 micrograms IGF-1 (n = 17) reduced neuronal loss in all regions (P < 0.01). Neither 20 micrograms IGF-2 (n = 17), 2 micrograms des-IGF-1 (n = 10), nor 20 micrograms des-IGF-1 (n = 17) reduced neuronal loss. There was a trend towards a reduction in neuronal loss after 150 micrograms des-IGF-1 (n = 20). IGF-2 alone increased neuronal loss in the hippocampus and dentate gyrus compared with the same regions in vehicle-treated animals (P < 0.05). Coadministration of 30 micrograms IGF-2 blocked the neuroprotective effects of 20 micrograms IGF-1 (n = 18, P < 0.05) and reduced the accumulation of [3H]IGF-1 in the injured hemisphere (n = 4) (P < 0.05). These observations suggest a role for IGFBPs in targeting the neuroprotective actions of IGF-1. IGF-2 may antagonize the protective effect of IGF-1 by displacing it from IGFBPs.
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Affiliation(s)
- J Guan
- Research Centre for Developmental Medicine and Biology, University of Auckland, New Zealand
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282
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Guan J, Skinner SJ, Beilharz EJ, Hua KM, Hodgkinson S, Gluckman PD, Williams CE. The movement of IGF-I into the brain parenchyma after hypoxic-ischaemic injury. Neuroreport 1996; 7:632-6. [PMID: 8730846 DOI: 10.1097/00001756-199601310-00061] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The movement of peptides from CSF into the parenchyma is thought to be slow and diffusion limited. However IGF-I can reduce neuronal loss at distal sites when given centrally 2 h after hypoxic-ischaemic (HI) injury. The present study determined the distribution of [3H]IGF-I given into the lateral ventricle after unilateral HI injury in adult rats. Radioactivity in the injured cortex peaked immediately after administration then rapidly declined. Autoradiography demonstrated radioactivity in the perivascular spaces and in the corpus callosum and external capsule of the injured hemisphere. HPLC and radioimmunoassay confirmed a rise in intracerebral IGF-I levels (from 159 +/- 9 to 401 +/- 88 ng g-1). These data suggest that injury can enhance the movement of IGF-I into the cerebrum via the white matter tracts and perivascular spaces.
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Affiliation(s)
- J Guan
- Research Centre for Developmental Medicine & Biology, University of Auckland, New Zealand
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283
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Abstract
To compare the metabolic effects of portal and systemic delivery of insulin, we used portal-caval transposition (PCT) in rats to provide total systemic diversion of splanchnic venous blood. PCT rats exhibited normal weight gain, liver histology, liver-function tests, glycosylated hemoglobin, arterial blood pressure, and hepatic blood flow. Mean liver weight relative to body weight was 12% lower in PCT rats than in sham-operated control (CTR) rats 30 days following transposition. Indwelling venous catheters were established to facilitate metabolic studies in conscious, minimally restrained animals. Postabsorptive plasma glucose and C-peptide (CPEP) levels were similar in PCT and CTR rats; however, postabsorptive immunoreactive insulin (IRI) levels were elevated in PCT rats (67 +/- 3.1 v 49 +/- 3.5 pmol.L-1, P < .002, n = 11 v 11), as were postabsorptive plasma glucagon levels (570 +/- 67 v 240 +/- 11 ng.L-1, P < .001, n = 11 v 16) at similar body weights. The postabsorptive CPEP/IRI concentration ratio was lower in PCT than in CTR rats (4.0 +/- 0.3 v 6.0 +/- 0.6, P < .02), suggesting reduced hepatic extraction of insulin. Insulin sensitivity (IS), determined by minimal model analysis of frequently sampled intravenous glucose tolerance tests yielding the sensitivity index (SI), was reduced in PCT compared with CTR (61 +/- 5.6 v 86 +/- 9.0 (mumol.L-1)-1.min-1, P < .04, n = 9 v 10). During euglycemic-hyperinsulinemic clamps, glucose infusion rates (GIRs) from 60 to 120 minutes were lower in PCT than in CTR rats (6.0 +/- 0.3 v 8.0 +/- 0.4 g.kg-1.min-1, P < .002, n = 9 v 7) with matching plasma IRI levels, confirming the reduced IS in PCT rats. Areas under the concentration curves ([AUCs] 0 to 150 minutes) for glucose tolerance tests (gavage) indicated that plasma glucose excursion was similar in PCT and CTR rats whereas AUC IRI was significantly higher in PCT than in CTR rats (23 +/- 1.3 v 18 +/- 0.6 nmol.L-1.min, P < .009, n = 11 v 11). However, AUC CPEP for oral glucose tolerance tests was lower in PCT than in CTR rats (55 +/- 3.4 v 68 +/- 4.8 nmol.L-1.min, P < .05), indicating decreased insulin secretion. Thus, the mean ratio AUC CPEP/AUC IRI was significantly lower in PCT rats (2.5 +/- 0.2 v 3.8 +/- 0.3, P < .002), again suggesting reduced hepatic extraction of insulin. Thus, euglycemia after PCT was accompanied by elevated postabsorptive and glucose-stimulated levels of IRI in systemic blood, postabsorptive hyperglucagonemia, and decreased insulin secretion in response to glucose challenge (gavage), with diminished hepatic extraction of insulin and decreased IS. The PCT model illustrates the insulin-resistant adaptive state that results from systemic delivery of insulin, and indicates the importance of hepatic portal delivery of insulin and possibly of other gastroenteropancreatic hormones in the maintenance of IS and physiological metabolic control.
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Affiliation(s)
- M P Williamson
- Department of Medicine, University Hospital, London, Ontario, Canada
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284
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Guan J, Behme MT, Zucker PF, Dupre J, Stiller CR. Portal insulin delivery prevents hyperinsulinemia in rats with renal-mesenteric vein anastomosis after renal islet transplants. Transplant Proc 1995; 27:3237. [PMID: 8539931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- J Guan
- University Hospital, London, Ontario, Canada
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285
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Guan J, Zucker PF, Atkison P, Behme MT, Dupre J, Stiller CR. Liver-omental pouch and intrahepatic islet transplants produce portal insulin delivery and prevent hyperinsulinemia in rats. Transplant Proc 1995; 27:3236. [PMID: 8539930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- J Guan
- University Hospital, London, Ontario, Canada
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286
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Williams C, Guan J, Miller O, Beilharz E, McNeill H, Sirimanne E, Gluckman P. The role of the growth factors IGF-1 and TGF beta 1 after hypoxic-ischemic brain injury. Ann N Y Acad Sci 1995; 765:306-7. [PMID: 7486621 DOI: 10.1111/j.1749-6632.1995.tb16592.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- C Williams
- Research Centre for Developmental Medicine and Biology, University of Auckland, New Zealand
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287
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Guan J, Casida ME, Köster AM, Salahub DR. All-electron local and gradient-corrected density-functional calculations of Nan dipole polarizabilities for n=1-6. Phys Rev B Condens Matter 1995; 52:2184-2200. [PMID: 9981295 DOI: 10.1103/physrevb.52.2184] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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288
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Crittenden B, Guan J, Ng W, Thomas W. Pressure, concentration and temperature profiles in a 5A zeolite adsorbent bed during pressurisation and depressurisation with air. Chem Eng Sci 1995. [DOI: 10.1016/0009-2509(94)00519-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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289
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Gong Y, Deng C, Li S, Li L, Guan J. [Radiolabelling and assay of Chinese agkistrodon acutus venom with carrier-free Na 125I]. Hua Xi Yi Ke Da Xue Xue Bao 1995; 26:116-9. [PMID: 7657328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Chinese agkistroden acutus venom (CAAV) was radiolabelled with carrier-free Na 125I by the method of Iodogen. The specific activity and radiochemical purity for radiolabelled products were 4236.5 x 10(10) Bq/mmol and 98%, respectively. Each CAAV molecule carried 0.52 125I atom. Physical and chemical characterization of radiolabelled CAAV was similar to unradiolabelled CAAV. Binding analysis showed that 125I-CAAV was bound to platelet in a saturable manner. Binding sites per platelet were 13,255 +/- 6292/platelet. The dissociation constant (Kd) was 3.2 +/- 0.69 x 10(-10) mol/L. These results are similar to binding sites of other snake venom on platelet. The investigation showed that radiolabelled CAAV made by our laboratory was useful for radioligand binding assay.
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Affiliation(s)
- Y Gong
- Department of Internal Medicine, Guangzhou Medical College
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290
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Sirimanne ES, Guan J, Williams CE, Gluckman PD. Two models for determining the mechanisms of damage and repair after hypoxic-ischaemic injury in the developing rat brain. J Neurosci Methods 1994; 55:7-14. [PMID: 7534364 DOI: 10.1016/0165-0270(94)90034-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Hypoxic-ischaemic (HI) brain injury can lead to selective neuronal loss or pannecrosis. Different mechanisms of damage and recovery may be associated with either pattern of cell loss. Two preparations were developed to investigate the role of growth factors and other mechanisms associated with either of these patterns of damage in the developing brain. Twenty-one-day-old Wistar rats underwent permanent unilateral right carotid artery ligation. Following surgery, ligated rats were warmed for 2 h at 34 degrees C with 85 +/- 5% relative humidity and then exposed to either 15 or 60 min of 8% O2. The rats were killed and brains perfusion fixed 5 days post-hypoxia for histological analysis. Rats exposed to 15 min of hypoxia-ischaemia suffered no mortality and 90% developed selective neuronal loss in the frontoparietal cortex and hippocampal CA1 region of the ipsilateral hemisphere. Rats exposed to 60 min of hypoxia consistently developed cortical pannecrosis and cellular loss in the striatum, thalamus, hippocampus and dentate gyrus of the ipsilateral hemisphere. The advantage of these models were ease of preparation, consistent neuronal loss scores and low mortality. The ability to induce either selective neuronal loss or pannecrosis provides an opportunity to investigate the mechanisms of damage or recovery associated with each pattern of cell loss.
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Affiliation(s)
- E S Sirimanne
- Research Centre for Developmental Medicine and Biology, University of Auckland, New Zealand
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291
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292
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Guan J, Shen Q, Jin S, Lin Y. Tris(tert-butylcyclopentadienyl)neodymium-μ-chloro-tris(tetrahydrofuran)lithium, [Nd(η5-tBuCp)3(μ-Cl)Li(thf)3]. Acta Crystallogr C 1994. [DOI: 10.1107/s010827019301193x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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293
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McNeill H, Williams C, Guan J, Dragunow M, Lawlor P, Sirimanne E, Nikolics K, Gluckman P. Neuronal rescue with transforming growth factor-beta 1 after hypoxic-ischaemic brain injury. Neuroreport 1994; 5:901-4. [PMID: 8061292 DOI: 10.1097/00001756-199404000-00012] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Transforming growth factor-beta 1 (TGF-beta 1) mRNA is induced from 5 h to 3 days following hypoxic-ischaemic brain injury. Cell death also develops during this time suggesting that extracellular accumulation of this peptide may be involved in the processes that regulate cell loss. We examined the effect of rhTGF-beta 1 (0,2.5, 10,50 ng) injected into the cerebral lateral ventricle of rats 2 h after severe hypoxic-ischaemic brain injury. Histological outcome and B4-isolectin histochemistry were assessed 5 and 2 days, respectively following hypoxia. Treatment with 10 ng TGF-beta 1 reduced the microglia reaction (p < 0.05), the magnitude of neuronal loss (p < 0.01) and the area of cortical infarction (p < 0.05). Exogenous TGF-beta 1 given soon after hypoxic-ischaemic brain injury may have therapeutic potential and act by inhibiting the microglial reaction.
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Affiliation(s)
- H McNeill
- Research Center for Developmental Medicine and Biology, University of Auckland School of Medicine, New Zealand
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294
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Abstract
OBJECTIVES To guide development of a hepatitis B control program in China, we investigated village doctors' sterilization practices, injection use, vaccination levels, and knowledge and counseling skills. METHODS The head doctor from each village health station in a rural county (n = 260) completed a self-administered questionnaire. RESULTS Of the respondents, 94.2% reported adequate sterilization of needles; however, inadequate sterilization of syringes and acupuncture needles was common. Injections were found to be frequent and profitable. Of head doctors, 16.2% reported that most infants in their villages are vaccinated against hepatitis B. There was very high knowledge of modes of hepatitis B transmission, but it was not used to formulate advice for a hypothetical carrier. Knowledge of the consequences, prevalence, and use of condoms to prevent sexual transmission was lower. CONCLUSIONS The sterilization of acupuncture needles, reuse of syringes, and frequent injections are practices that may transmit the hepatitis B virus. Research into issues of vaccine acceptance is needed to expand immunization. A review of treatment practices and better training in counseling for village doctors is suggested.
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Affiliation(s)
- S Clayton
- School of Public Health, University of California, Los Angeles 90024-1772
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295
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Gluckman PD, Guan J, Beilharz EJ, Klempt ND, Klempt M, Miller O, Sirimanne E, Dragunow M, Williams CE. The role of the insulin-like growth factor system in neuronal rescue. Ann N Y Acad Sci 1993; 692:138-48. [PMID: 8215018 DOI: 10.1111/j.1749-6632.1993.tb26212.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- P D Gluckman
- Research Center for Developmental Medicine and Biology, School of Medicine, University of Auckland, New Zealand
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296
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Abstract
Intraventricular injection of insulin-like growth factor 1 (IGF-1) 2 h after hypoxic-ischemic injury reduces neuronal loss. To clarify the mode of action, we compared histological outcome between treatment groups in the following three studies: 0, 0.5, 5, and 50 micrograms IGF-1 given 2 h after injury; 0 and 20 micrograms IGF-1 given 1 h before; and 20 micrograms IGF-1 and insulin or vehicle alone given 2 h after. Unilateral hypoxic-ischemic injury was induced in adult rats by ligation of the right carotid and exposure to 6% O2 for 10 min. Histological outcome was evaluated in the cortex, striatum, and hippocampus 5 days later. Five to 50 micrograms IGF-1 reduced the incidence of infarction and neuronal loss in a dose-dependent manner in all regions (p < 0.05), and 50 micrograms reduced the infarction rate from 87 to 26% (p < 0.01). Pretreatment did not alter outcome. IGF-1 improved outcome compared with equimolar doses of insulin (p < 0.05) and did not affect systemic glucose concentrations or cortical temperature. The results indicate that the neuronal protective effects of IGF-1 are specific and are not mediated via insulin receptors, hypothermia, or hypoglycemic mechanisms. Centrally administered IGF-1 appears to provide worthwhile trophic support to cells within most cerebral structures after transient hypoxic-ischemic injury.
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Affiliation(s)
- J Guan
- Department of Paediatrics, University of Auckland, New Zealand
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297
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298
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Deng C, Li S, Li G, Qiao X, He C, Guan J. [Alpha 2 megaloglobulin inhibits the activation of rabbit platelet by Chinese Agkistrodon acutus venom]. Hua Xi Yi Ke Da Xue Xue Bao 1992; 23:416-9. [PMID: 1284793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
An in vitro study of alpha 2-mengaloglobulin (alpha 2MG) in the inhibition of the activation of washed rabbit platelet by Chinese Agkistrodon acutus venom (CAAV) was reported. Results showed that CAAV induced aggregation rate of washed rabbit platelet was positively related to the CAAV concentration, and the maximal aggregation rate was 43.8 +/- 9.9% at the concentration of 100 micrograms/ml. Meanwhile the release of serotonin (5-HT) and platelet factor 4(PF4) from the platelet reached maximum at the CAAV concentrations of 0.81 +/- 0.07 microgram/ml and 39.08 +/- 2.78%, respectively. Platelet aggregation and the release of 5-HT and PF4 induced by CAAV could be inhibited by the addition of 0.25% alpha 2 MG into the platelets both 1 minute before and 1 minute after the addition of CAAV. When alpha 2 MG was added to the platelets 1 minute prior to the addition of CAAV, the platelet aggregation and the ultrastructural changes which could be induced by CAAV were not observed, and the morphology of the rabbit platelets was the same as that of the normal counterparts.
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299
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Gluckman P, Klempt N, Guan J, Mallard C, Sirimanne E, Dragunow M, Klempt M, Singh K, Williams C, Nikolics K. A role for IGF-1 in the rescue of CNS neurons following hypoxic-ischemic injury. Biochem Biophys Res Commun 1992; 182:593-9. [PMID: 1370886 DOI: 10.1016/0006-291x(92)91774-k] [Citation(s) in RCA: 256] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Three days after unilateral hypoxic-ischemic injury in infant rats insulin-like growth factor 1 (IGF-1) production by astrocytes was enhanced in the injured region. This was associated with increased expression of mRNA for IGF binding protein-3 but not for binding protein-1. In adult rats a single lateral cerebroventricular injection of IGF-1 two hours following a similar injury markedly reduced neuronal loss. It is suggested that endogenous IGF-1 is neurotrophic and that centrally administered IGF-1 may have therapeutic potential for brain injury.
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Affiliation(s)
- P Gluckman
- Department of Paediatrics, University of Auckland, New Zealand
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300
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Deng C, He J, Yue S, Deng C, Guan J. [The influence of Chinese Agkistrodon acutus enzyme (CAAE) on the functions of washed human platelets]. Hua Xi Yi Ke Da Xue Xue Bao 1991; 22:432-4. [PMID: 1814829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The effects of the activation and influence of CAAE on washed human platelets were investigated. Our findings were: (1) CAAE could induce aggregation and alpha-granule release reaction in the washed human platelet suspension; thus it could activate the platelets; (2) the aggregation effect of CAAE was inhibited by albumin and affected by Ca2+, Mg2+ concentration; (3) heparin and/or AT III did not inhibit the aggregation activation of CAAE, but alpha 2MG markedly inhibited it; (4) the aggregation activity of CAAE was associated with the serine protease activity. The mechanism of CAAE-induced aggregation mainly follows the prostaglandins-endoperoxides thromboxane A2 pathway.
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