351
|
Du XY, Pan H, Jin Y, Zhu H, Wu XF, Zhou YC. Purification, cDNA cloning and molecular characteristic of a fibrinolytic enzyme from the venom of Agkistrodon acutus. JOURNAL OF NATURAL TOXINS 1998; 7:159-72. [PMID: 9678189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A nonglycoprotein-like fibrinolytic enzyme ((FIB-I) was purified from the crude venom of Agkistrodon acutus by CM-Sepharose CL-6B and DEAE-Sepharose CL-6B ion exchange chromatography and then by FPLC through Superose 12 gel filtration. Its molecular weight is about 23 kDa and isoelectric point is near 6.0. It not only has fibrinolytic and caseinolytic activity, but also can hydrolyze BAEE. The local hemorrhagic activity was found in mice after the subcutaneous injection of this enzyme. EDTA can inhibit its fibrinolytic activity completely, but PMSF and arrowhead proteinase inhibitor have no such obvious inhibitory effect, thus implying that FIB-I is a metalloproteinase. The N-terminal ten amino acid residues 'STEFQRYMEI' of FIB-I was elucidated. A full-length cDNA gene of this enzyme was cloned by using RT-PCR from the total RNA extracted from the snake venom gland and FIB-I was expressed in E. coli. Having analyzed the sequence, we found that it had a typical zinc-chelating characteristic as 'HEXXHXXGXXHD.'
Collapse
|
352
|
Pan H, Feng L, Lu H, Xu C, Zhang P, Zhang Z. Aging of human mature erythrocytes is like a process of apoptosis in enucleated cell. CHINESE MEDICAL SCIENCES JOURNAL = CHUNG-KUO I HSUEH K'O HSUEH TSA CHIH 1998; 13:20-3. [PMID: 11717918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Apoptosis of nucleated cells is well known, but how about the unnucleated cells is still not elucidated. In the present paper, the morphological and biochemical features of the aged erythrocytes were observed and compared with the characteristic events of apoptosis. Membrane of aged erythrocytes tends to shrink, protrude, from vesicle and lose lipid asymmetry. Aged erythrocytes were removed by phagocytosis. Both of the events are very similar to the apoptotic nucleated cells. The authors suggested that aging of erythrocytes is also a process of apoptosis.
Collapse
|
353
|
Delwart EL, Pan H, Neumann A, Markowitz M. Rapid, transient changes at the env locus of plasma human immunodeficiency virus type 1 populations during the emergence of protease inhibitor resistance. J Virol 1998; 72:2416-21. [PMID: 9499102 PMCID: PMC109541 DOI: 10.1128/jvi.72.3.2416-2421.1998] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Plasma human immunodeficiency virus type 1 (HIV-1) populations were genetically analyzed at their most variable locus, the envelope gene, during the rapid emergence of resistance to protease inhibitor monotherapy. Plasma virus populations remained genetically constant prior to drug treatment and during the 1 to 2 weeks following initiation of therapy, while viremia fell 10- to 100-fold. Concomitant with rapid plasma viremia rebounds associated with the emergence of drug-resistant virus, marked alterations were then detected at the env locus. Plasma population changes lasted only a few weeks before the reappearance of the pretreatment envelope variants. The emergence of resistance to single protease inhibitors was therefore associated with major but transient changes at a nonselected locus. Selection for resistance to single protease inhibitors thus appears to be more complex than the continued replication of a large, random, and therefore genetically representative sampling of the pretreatment plasma population. The possibility that drug-privileged anatomical sites containing distinct envelope variants and/or a small effective HIV-1 population size account for these results is discussed.
Collapse
|
354
|
Lu Y, Xu C, Yang Y, Pan H. [The effect of antioxidant sodium ferulate on human lymphocytes apoptosis induced by H2O2]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 1998; 20:44-8. [PMID: 11367733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
OBJECTIVE Sodium ferulate is a potent antioxidant purified from ferula assafoetida L. The effect of sodium ferulate on apoptosis of human lymphocytes induced by H2O2 in vitro was studied. METHODS Apoptosis was detected by light and electron microscopic, DNA electrophoresis and Flow cytometric cell cycle analysis. mitochondrial function was detected by MTT method. BCL-2 and Bax expression was detected by confocal laser scanning microscope. RESULTS The morphological and biochemical changes characteristic of apoptosis were partially restored after treatment with sodium ferulate, Immunofluorescence assay showed a decrease in BCL-2 and an increase in Bax oncogene proteins in lymphocytes treated with H2O2 and an improvement of cell apoptosis was found after sodium ferulate treatment. CONCLUSION Oxidative stress can induce apoptosis in lymphocytes, and this induction can be partly prevented by sodium ferulate.
Collapse
|
355
|
Abstract
Multi-level models for estimating conditional and unconditional longitudinal growth norms are presented. The procedure involves transforming the original growth measurements to Normality and modelling these with a two-level random coefficient model. Growth norms for any desired time interval and function can be derived. Height and weight data are used for illustration.
Collapse
|
356
|
Ouyang B, Pan H, Lu L, Li J, Stambrook P, Li B, Dai W. Human Prk is a conserved protein serine/threonine kinase involved in regulating M phase functions. J Biol Chem 1997; 272:28646-51. [PMID: 9353331 DOI: 10.1074/jbc.272.45.28646] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Human prk encodes a novel protein serine/threonine kinase capable of strongly phosphorylating casein but not histone H1 in vitro. prk expression is tightly regulated at various levels during different stages of the cell cycle in lung fibroblasts. The Prk kinase activity is relatively low during mitosis, G1, and G1/S, and peaks during late S and G2 stages of the cell cycle. Recombinant human Prk expressed through the baculoviral vector system is capable of phosphorylating Cdc25C, a positive regulator for the G2/M transition. Human prk shares significant sequence homology with Saccharomyces cerevisiae CDC5 and Drosophila melanogaster polo, both of which are essential for mitosis and meiosis. Full-length prk transcripts greatly potentiate progesterone-induced meiotic maturation of Xenopus laevis oocytes. On the other hand, antisense prk transcripts significantly delay and reduce the rate of oocyte maturation. When expressed in a CDC5 mutant strain of S. cerevisiae, human Prk, but not a deletional mutant protein, fully rescues the temperature-sensitive phenotype of the budding yeast. Taken together, prk may represent a new protein kinase, playing an important role in regulating the onset and/or progression of mitosis in mammalian cells.
Collapse
|
357
|
Pan H, Feng B, Marzluf GA. Two distinct protein-protein interactions between the NIT2 and NMR regulatory proteins are required to establish nitrogen metabolite repression in Neurospora crassa. Mol Microbiol 1997; 26:721-9. [PMID: 9427402 DOI: 10.1046/j.1365-2958.1997.6041979.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Nitrogen metabolism is a highly regulated process in Neurospora crassa. The structural genes that encode nitrogen catabolic enzymes are subject to nitrogen metabolite repression, mediated by the positive-acting NIT2 protein and by the negative-acting NMR protein. NIT2, a globally acting factor, is a member of the GATA family of regulatory proteins and has a single Cys2/Cys2 zinc finger DNA-binding domain. The negative-acting NMR protein interacts via specific protein-protein binding with two distinct regions of the NIT2 protein, a short alpha-helical motif within the NIT2 DNA-binding domain and a second motif at its carboxy terminus. Deletions of segments of NIT2 throughout most of its length result in truncated proteins, which are still functional for activating gene expression; most of these mutant NIT2 proteins still allow proper nitrogen repression of nitrate reductase synthesis. In contrast, deletions or certain amino acid substitutions within the zinc finger and the carboxy-terminal tail result in a loss of nitrogen metabolite repression. Those mutated forms of NIT2 that are insensitive to nitrogen repression have also lost one of the NIT2-NMR protein-protein interactions. These results provide compelling evidence that the specific NIT2-NMR interactions have a regulatory function and play a central role in establishing nitrogen metabolite repression.
Collapse
|
358
|
Pan H, Yin C, Van Dyke T. Apoptosis and cancer mechanisms. CANCER SURVEYS 1997; 29:305-27. [PMID: 9338106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
For nearly two decades, studies in the cancer research field focussed on identifying genes that act as positive and negative regulators of cell growth. Only relatively recently was it recognized that the regulation of cell death (apoptosis) is also an important modulator of tumorigenesis. At least two genes linked to human cancers, BCL2 and TP53, have been shown to regulate apoptosis. The correlation between apoptosis modulating genes and human tumours raises an important question as to how dysregulation of apoptosis contributes to neoplastic transformation and malignant cell growth. Cell culture studies have clearly demonstrated that TP53 can induce and BCL2 can suppress apoptosis in response to various stimuli. Studies of mammalian viruses, which possess mechanisms for both inducing and evading apoptosis, have also extended our understanding of this process. On the basis of such findings, several animal models have been developed which begin to address the role of apoptosis regulation in tumorigenesis. This chapter discusses those animal models, focussing on bcl-2 (and its relatives) and p53.
Collapse
|
359
|
Delwart EL, Pan H, Sheppard HW, Wolpert D, Neumann AU, Korber B, Mullins JI. Slower evolution of human immunodeficiency virus type 1 quasispecies during progression to AIDS. J Virol 1997; 71:7498-508. [PMID: 9311829 PMCID: PMC192096 DOI: 10.1128/jvi.71.10.7498-7508.1997] [Citation(s) in RCA: 149] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The evolution of human immunodeficiency virus type 1 (HIV-1) quasispecies at the envelope gene was studied from the time of infection in 11 men who experienced different rates of CD4+ cell count decline and 6 men with unknown dates of infection by using DNA heteroduplex mobility assays. Quasispecies were genetically homogeneous near the time of seroconversion. Subsequently, slower proviral genetic diversification and higher plasma viremia correlated with rapid CD4+ cell count decline. Except for the fastest progressors to AIDS, highly diverse quasispecies developed in all subjects within 3 to 4 years. High quasispecies diversity was then maintained for years until again becoming more homogeneous in a subset of late-stage AIDS patients. Individuals who maintained high CD4+ cell counts showed continuous genetic turnover of their complex proviral quasispecies, while more closely related sets of variants were found in longitudinal samples of severely immunocompromised patients. The limited number of variants that grew out in short-term PBMC cocultures were rare in the uncultured proviral quasispecies of healthy, long-term infected individuals but more common in vivo in patients with low CD4+ cell counts. The slower evolution of HIV-1 observed during rapid progression to AIDS and in advanced patients may reflect ineffective host-mediated selection pressures on replicating quasispecies.
Collapse
|
360
|
Takigawa M, Okawa T, Pan H, Aoki C, Takahashi K, Zue J, Suzuki F, Kinoshita A. Insulin-like growth factors I and II are autocrine factors in stimulating proteoglycan synthesis, a marker of differentiated chondrocytes, acting through their respective receptors on a clonal human chondrosarcoma-derived chondrocyte cell line, HCS-2/8. Endocrinology 1997; 138:4390-400. [PMID: 9322955 DOI: 10.1210/endo.138.10.5265] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Both insulin-like growth factor (IGF)-I and IGF-II increased the synthesis of cartilage-type, large proteoglycan in a human chondrosarcoma-derived chondrocyte cell line, HCS-2/8. In contrast to the stimulatory effects of IGFs on costal chondrocytes of the young rabbit, the stimulatory effect of IGF-II on proteoglycan synthesis in HCS-2/8 cells was more potent than that of IGF-I. IGF-II, but not IGF-I, increased calcium influx into HCS-2/8 cells, and there was a close relation between the stimulation of proteoglycan synthesis and the calcium influx. [125I]IGF-I bound to HCS-2/8 cells, and this binding was competitively inhibited by low concentrations of unlabeled IGF-I, higher concentrations of IGF-II, and much higher concentrations of insulin. [125I]IGF-II also bound to the cells, and its binding was competitively inhibited by IGF-II and slightly inhibited by higher concentrations of IGF-I and much higher concentrations of insulin. When radioligand-receptor complexes were separated by SDS-PAGE and subjected to autoradiography, two major bands at 260 and 130 kDa were observed, which correspond to the IGF type II receptor (IGF-IIR) and the alpha subunit of the IGF type I receptor (IGF-IR), indicating the presence of both receptors. When confluent cultures of HCS-2/8 cells were maintained in serum-free medium, proteoglycan synthesis did not decrease unless the medium was repeatedly replaced. Conditioned medium of HCS-2/8 cells stimulated the HCS-2/8 cells to synthesize proteoglycans. RIA revealed that the cells produced both IGF-II and IGF-I. Transcripts of messenger RNAs of both IGF-I and IGF-II and both IGF-IR and IGF-IIR also were detectable by Northern analysis. Both anti-IGF-IR antibody and anti-IGF-II antibody inhibited proteoglycan synthesis. Mannose-6-phosphate, which is known to bind to IGF-IIR, stimulated proteoglycan synthesis, potentiated IGF-II-stimulated proteoglycan synthesis, and enhanced the binding affinity for IGF-II but not for IGF-I. Even in the presence of anti-IGF-IR antibody, IGF-II and mannose-6-phosphate stimulated proteoglycan synthesis in the cells. [Leu27]IGF-II, an IGF-II analogue with high affinity only for IGF-IIR, strongly stimulated proteoglycan synthesis in HCS-2/8 cells but [Arg54, Arg55]IGF-II, which binds to only IGF-IR, also stimulated proteoglycan synthesis in the cells. These findings indicate that IGF-I and IGF-II act as autocrine differentiation factors for this chondrocytic permanent cell line, HCS-2/8, mainly via respective receptors.
Collapse
MESH Headings
- Analysis of Variance
- Animals
- Antibodies/pharmacology
- Blotting, Northern
- Bone Neoplasms/chemistry
- Bone Neoplasms/metabolism
- Bone Neoplasms/pathology
- Calcium/metabolism
- Cartilage/chemistry
- Cartilage/cytology
- Cartilage/metabolism
- Cell Differentiation
- Cells, Cultured
- Chondrosarcoma/chemistry
- Chondrosarcoma/metabolism
- Chondrosarcoma/pathology
- Culture Media, Conditioned/pharmacology
- Electrophoresis, Polyacrylamide Gel
- Gene Expression Regulation
- Gene Expression Regulation, Neoplastic
- Humans
- Insulin-Like Growth Factor I/metabolism
- Insulin-Like Growth Factor I/pharmacology
- Insulin-Like Growth Factor I/physiology
- Insulin-Like Growth Factor II/metabolism
- Insulin-Like Growth Factor II/pharmacology
- Insulin-Like Growth Factor II/physiology
- Iodine Radioisotopes
- Male
- Mannosephosphates/pharmacology
- Protein Binding
- Proteoglycans/biosynthesis
- RNA, Messenger/analysis
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rabbits
- Receptor, IGF Type 1/analysis
- Receptor, IGF Type 1/genetics
- Receptor, IGF Type 1/physiology
- Receptor, IGF Type 2/analysis
- Receptor, IGF Type 2/genetics
- Receptor, IGF Type 2/physiology
- Tumor Cells, Cultured
Collapse
|
361
|
Pan H, Wang Z, Zhu Y. [An experimental study on the effect of nitric oxide synthase in bronchial asthma]. ZHONGHUA NEI KE ZA ZHI 1997; 36:680-4. [PMID: 10436984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
To study the role of nitric oxide synthase (NOS) in rat experimental bronchial asthma. 3H-arginine/3H-L-citrulline conversion technique was used to assay NOS activity of rat lung tissue and histochemical staining method for detect NADPH-d diaphorase. The results revealed that there were significant increase in the level of iNOS activity in asthma group from 152.39% to 249.40%, but the cNOS activity reduced from 64.84% to 61.81% (P < 0.05-0.01). Histochemical staining of NADPH-d showed deep staining of trachial and bronchial epithelium in asthma group. These results suggested that NOS plays a role in regulating airway inflammation and bronchial responsiveness. cNOS possesses a down regulatory effect, while iNOS upregulatory. The occurrence of airway inflammation is earlier than that of smooth muscle contraction and endothelial injury.
Collapse
|
362
|
Pan H, Barany G, Woodward C. Reduced BPTI is collapsed. A pulsed field gradient NMR study of unfolded and partially folded bovine pancreatic trypsin inhibitor. Protein Sci 1997; 6:1985-92. [PMID: 9300498 PMCID: PMC2143794 DOI: 10.1002/pro.5560060919] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Pulsed field gradient NMR was used to measure the hydrodynamic behavior of unfolded variants of bovine pancreatic trypsin inhibitor (BPTI). The unfolded BPTI species studied were [R]Abu, at pH 4.5 and pH 2.5, and unfolded [14-38]Abu, at pH 2.5. These were prepared by chemical synthesis. [R]Abu is a model for reduced BPTI; all cysteine residues are replaced by alpha-amino-n-butyric acid (Abu). [14-38]Abu retains cysteines 14 and 38, which form a disulfide bond, while the other cysteine residues are replaced by Abu. In the PFG experiments, the diffusion coefficient is measured as a function of protein concentration, and the value of D degree -the diffusion coefficient extrapolated to infinite dilution-is determined. From D degree, a value of the hydrodynamic radius. Rh, is computed from the Stokes-Einstein relationship. At pH 4.5, [R]Abu has an Rh value significantly less than the value calculated for a random coil, while at pH 2.5 the experimental Rh value is the same as for a random coil. In view of the changes in NMR detected structure of [R]Abu at pH 4.5 versus pH 2.5 (Pan H, Barbar E, Barany G, Woodward C. 1995. Extensive non-random structure in reduced and unfolded bovine pancreatic trypsin inhibitor. Biochemistry 34:13974-13981), the collapse of reduced BPTI at pH 4.5 may be associated with the formation of non-native hydrophobic clusters of pairs of side chains one to three amino acids apart in sequence. The diffusion constant of [14-38]Abu was also measured at pH 4.5, where the protein is partially folded. An increase in hydrodynamic radius of partially folded [14-38]Abu, relative to native BPTI, is similar to the increase in radius of gyration measured for other proteins under "molten globule" conditions.
Collapse
|
363
|
Zhang Y, Pan H, Chen S, Meng Y, Kang S. [Minor alkaloids from the capsule of Papaver nudicaule L]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1997; 22:550-1, 576. [PMID: 11038947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Two minor alkaloids were isolated from the capsule of Papaver nudicaule. On the basis of physicochemical methods and spectroscopic analysis, they were identified as chelidonine, 5-hydroxy-2-hydroxymethylpyridine. Chelidonine was isolated from this plant and 5-hydroxy-2-hydroxymethylpyridine was isolated from genus for the first time.
Collapse
|
364
|
Bird LE, Hâkansson K, Pan H, Wigley DB. Characterization and crystallization of the helicase domain of bacteriophage T7 gene 4 protein. Nucleic Acids Res 1997; 25:2620-6. [PMID: 9185573 PMCID: PMC146783 DOI: 10.1093/nar/25.13.2620] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Limited proteolysis of bacteriophage T7 primase/helicase with endoproteinase Glu-C produces several proteolytic fragments. One of these fragments, which is derived from the C-terminal region of the protein, was prepared and shown to retain helicase activity. This result supports a model in which the gene 4 proteins consist of functionally separable domains. Crystals of this C-terminal fragment of the protein have been obtained that are suitable for X-ray diffraction studies.
Collapse
|
365
|
Okimura A, Okada Y, Makihira S, Pan H, Yu L, Tanne K, Imai K, Yamada H, Kawamoto T, Noshiro M, Yan W, Kato Y. Enhancement of cartilage matrix protein synthesis in arthritic cartilage. ARTHRITIS AND RHEUMATISM 1997; 40:1029-36. [PMID: 9182912 DOI: 10.1002/art.1780400606] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE To investigate whether the synthesis of cartilage matrix protein (CMP) is enhanced in arthritic cartilage. METHODS The content of CMP in human and pig cartilage was determined by immunoblotting, and CMP-producing chondrocytes in osteoarthritic (OA) and rheumatoid arthritic (RA) joints were immunostained. RESULTS CMP was undetectable in the condylar cartilage and disc of pigs, whereas it was abundant in the rib and tracheal cartilage of the same animals. By immunohistochemical analysis, CMP was localized in only a few chondrocytes (5%) in normal human joints, whereas numerous chondrocytes (>60%) were immunostained in RA joints. The number of CMP-producing cells was also increased in OA cartilage (>40%). Immunoblotting analyses confirmed that the CMP content in the cartilage from OA and RA patients was much higher than that in normal cartilage. CONCLUSION These findings demonstrate that articular chondrocytes can synthesize CMP, although it is suppressed under physiologic conditions. The results also suggest that articular chondrocytes express CMP in response to arthritic stimuli.
Collapse
|
366
|
Yan W, Pan H, Ishida H, Nakashima K, Suzuki F, Nishimura M, Jikko A, Oda R, Kato Y. Effects of concanavalin A on chondrocyte hypertrophy and matrix calcification. J Biol Chem 1997; 272:7833-40. [PMID: 9065448 DOI: 10.1074/jbc.272.12.7833] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Resting chondrocytes do not usually undergo differentiation to the hypertrophic stage and calcification. However, incubating these cells with concanavalin A resulted in 10-100-fold increases in alkaline phosphatase activity, binding of 1,25(OH)2-vitamin D3, type X collagen synthesis, 45Ca incorporation into insoluble material, and calcium content. On the other hand, other lectins tested (including wheat germ agglutinin, lentil lectin, pea lectin, phytohemagglutinin-L, and phytohemagglutinin-E) marginally affected alkaline phosphatase activity, although they activate lymphocytes. Methylmannoside reversed the effect of concanavalin A on alkaline phosphatase within 48 h. Concanavalin A did not increase alkaline phosphatase activity in articular chondrocyte cultures. In resting chondrocyte cultures, succinyl concanavalin A was as potent as concanavalin A in increasing alkaline phosphatase activity, the incorporation of [35S]sulfate, D-[3H]glucosamine, and [3H]serine into proteoglycans, and the incorporation of [3H]serine into protein, although concanavalin A, but not succinyl concanavalin A, induced a rapid change in the shape of the cells from flat to spherical. These findings suggest that concanavalin A induces a switch from the resting, to the growth-plate stage, and that this action of concanavalin A is not secondary to changes in the cytoskeleton. Chondrocytes exposed to concanavalin A may be useful as a novel model of endochondral bone formation.
Collapse
|
367
|
Ilyina E, Roongta V, Pan H, Woodward C, Mayo KH. A pulsed-field gradient NMR study of bovine pancreatic trypsin inhibitor self-association. Biochemistry 1997; 36:3383-8. [PMID: 9116018 DOI: 10.1021/bi9622229] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Previous studies have produced conflicting interpretations regarding the aggregation state of BPTI in solution. Here, pulsed-field gradient NMR self-association measurements have been performed with BPTI under a variety of temperature, pH, salt, urea conditions, and protein concentrations. Relative to the standard proteins, lysozyme, ribonuclease, and ubiquitin, diffusion constants indicate that BPTI dimerizes at concentrations above about 3 mg/mL and below 280 K. At higher temperatures, a marked self-association is observed above 10 mg/mL. The apparent lack of significant effects from variations in pH and NaCl concentration suggests minimal contribution to the aggregation process from charge-charge interactions. In contrast, in nondenaturing concentrations of urea (2 M), BPTI behaves as a monomer, suggesting that hydrophobic and polar residues modulate BPTI association. The BPTI surface shows that while one side is highly charged, the opposite side, composed mostly of hydrophobic and some hydrophilic residues, is feasible as an interface for BPTI self-association.
Collapse
|
368
|
Hashimoto K, Noshiro M, Ohno S, Kawamoto T, Satakeda H, Akagawa Y, Nakashima K, Okimura A, Ishida H, Okamoto T, Pan H, Shen M, Yan W, Kato Y. Characterization of a cartilage-derived 66-kDa protein (RGD-CAP/beta ig-h3) that binds to collagen. BIOCHIMICA ET BIOPHYSICA ACTA 1997; 1355:303-14. [PMID: 9061001 DOI: 10.1016/s0167-4889(96)00147-4] [Citation(s) in RCA: 125] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A 66-kDa collagen fiber-associated protein (RGD-CAP) was isolated from a fiber-rich fraction of pig cartilage by ultrafiltration and collagen-affinity chromatography. Amino acid sequencing and cDNA cloning indicated that the RGD-CAP is identical or closely related to beta ig-h3 protein which is induced in human adenocarcinoma cells by transforming growth factor-beta (TGF-beta) (Skonier, J., Neubauer, M., Madisen, L., Bennett, K., Plowman, G.D., and Purchio, A.F. (1992) DNA Cell. Biol. 11, 511-522). The RGD-CAP, as well as beta ig-h3, has the RGD sequence in the C-terminal region. The native RGD-CAP bound to type I, II, and IV collagens even in the presence of 1 M NaCl. A recombinant preparation of RGD-CAP expressed in Escherichia coli cells also bound to collagen but not to gelatin. The RGD-CAP mRNA was expressed in chondrocytes throughout all stages, although the expression level was highest during the prehypertrophic stage. In addition, TGF-beta increased the RGD-CAP mRNA level in chondrocyte cultures. Since RGD-CAP transcripts were found in most tissues, this novel collagen-binding protein may play an important role in cell-collagen interactions in various tissues including developing cartilage.
Collapse
|
369
|
Pan H, Wang HY, Friedman E, Gershon MD. Mediation by protein kinases C and A of Go-linked slow responses of enteric neurons to 5-HT. J Neurosci 1997; 17:1011-24. [PMID: 8994056 PMCID: PMC6573160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/1996] [Revised: 10/21/1996] [Accepted: 11/22/1996] [Indexed: 02/03/2023] Open
Abstract
5-HT activates the peristaltic reflex and is the neurotransmitter of a subset of myenteric interneurons. Hyperpolarizing afterpotential (AH)/type 2 neurons respond to 5-HT with a long-lived depolarization that is caused by the inhibition of a Ca(2+)-activated K+ conductance (gKCa). This effect is mediated by a G-protein-coupled receptor, 5-HT1P. 5-HT1P agonists specifically activate G alpha o, the immunoreactivity of which was found to be highly abundant and membrane-associated in almost all enteric neurons. Responses of hyperpolarizing AH/type 2 neurons to 5-HT were inhibited by intracellular injection of GDP beta S or anti-G alpha o Fab fragments but were potentiated and prolonged by intracellular GTP gamma S. Responses to 5-HT were antagonized by pertussis toxin, downregulation of protein kinase C (PKC) and inhibitors of phosphatidylcholine phospholipase C (PC-PLC), PKC (including pseudosubstrate peptides, chelerythrine, and the alpha/beta isoform-specific inhibitor Go 6976), protein kinase A (PKA), and adenylate cyclase. Responses to 5-HT were mimicked by activators of PKC, and 5-HT induced a concentration-dependent increase in the membrane-associated PKC activity in isolated myenteric ganglia. Immunocytochemical studies suggested that the most abundant isoforms of PKC in enteric neurons are alpha and delta. These data suggest that signal transduction of the 5-HT1P-mediated slow response to 5-HT involves activation of PC-PLC by G alpha o to liberate diacylglycerol, which stimulates PKC (most likely alpha). PKC probably activates adenylate cyclase, which through cAMP, activates PKA. Activation of both PKA and PKC lead to closure of gKCa.
Collapse
|
370
|
Ma X, Ma D, Pan H, Ma D. [Determination of emodin in kangnaoshuai capsules and in radix Polygoni multifori by thin layer chromatography scanning]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1997; 22:31-2, 61. [PMID: 10683908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
The content of emodin in Kangnaoshuai Capsules was determined by TLC scanning. The method is simple and the result is accurate. The average recovery is 99.17% and RSD is 1.14%. The content of emodin in Radix Polygoni Multiflori was also determined by the same method. The method is useful in quality control of products.
Collapse
|
371
|
Li B, Ouyang B, Pan H, Reissmann PT, Slamon DJ, Arceci R, Lu L, Dai W. Prk, a cytokine-inducible human protein serine/threonine kinase whose expression appears to be down-regulated in lung carcinomas. J Biol Chem 1996; 271:19402-8. [PMID: 8702627 DOI: 10.1074/jbc.271.32.19402] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
We have cloned and characterized a putative protein serine/threonine kinase termed prk through a combination of polymerase chain reaction and conventional cDNA library screening approaches. There are apparently two distinct domains within prk protein deduced from its nucleotide sequences. The amino-terminal portion has the feature of the catalytic domain of a serine/threonine kinase and shows strong homology to mouse fnk and other polo family kinases including mouse snk, human and murine plk, Drosophila polo, and yeast Cdc5. The carboxyl-terminal portion, presumably the regulatory domain, shares extensive homology to mouse fnk. Northern blotting analyses reveal that prk expression is restricted to a very limited number of tissues with placenta, ovaries, and lung containing detectable amounts of prk mRNA. prk mRNA expression is also detected at a low level in the megakaryocytic cell line Dami, MO7e, and three brain glioma cell lines. In addition, refeeding of serum-deprived MO7e, Dami, and K562 cells of hematopoietic origin and GMOO637D of lung fibroblasts rapidly activates prk mRNA expression with its peak induction around 2 h after serum addition. prk gene activation by the serum requires no new protein synthesis. The recombinant cytokines such as interleukin-3 and thrombopoietin also activate prk mRNA expression in MO7e cells. Furthermore, a survey of RNAs isolated from the tumor and the uninvolved tissues from 18 lung cancer patients reveals that prk mRNA expression is significantly down-regulated in tumor tissues. Southern blotting analysis indicates that the prk gene is present in a single copy in the genome of tumors and normal cells. Taken together, these results suggest that prk expression may be restricted to proliferating cells and involved in the regulation of cell cycle progression. The molecular cloning of prk cDNA will facilitate the study of its biological role as well as its potential role in tumorigenesis.
Collapse
|
372
|
Li B, Pan H, Winkelmann JC, Dai W. Thrombopoietin and its alternatively spliced form are expressed in human amygdala and hippocampus. Blood 1996; 87:5382-4. [PMID: 8652856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
|
373
|
Wang HY, Fiorica-Howells E, Pan H, Gershon MD, Friedman E. Myenteric ganglionic 5-hydroxytryptamine(1P) signal transmission is mediated via Go protein. J Pharmacol Exp Ther 1996; 277:518-24. [PMID: 8613962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The role of G proteins in mediating the signal transduction of the guinea pig myenteric ganglionic 5-hydroxytryptamine (5-HT)1P receptors was examined. Stimulation of ganglionic membranes with 5-HT in the presence of [35S]GTPgammaS or [alpha 32P]GTP increased guanine nucleotide binding to G(alpha)o but not to G(alpha)s, G(alpha)i or G(alpha)q in a concentration-dependent fashion. Pertussis toxin pretreatment markedly reduce this 5-HT induced response. Similarly, the 5-HT1P receptor-mediated slowly developing and long-lasting depolarizing response is potentiated by GTPgammaS and is inhibited by GDPbetaS or pertussis toxin. The activation of G(alpha)o by 5-HT also was mimicked by the 5-HT1P agonist, 5-hydroxyindalpine and was blocked by the selective 5-HT1P antagonist, N-acetyl-5-hydroxytryptophyl-5-hydroxytryptophan amide. These data provide compelling evidence to suggest that transmembrane signaling for the 5-HT1P receptors in isolated myenteric ganglia is transduced by the trimeric Go protein.
Collapse
|
374
|
Nakamura S, Kamihagi K, Satakeda H, Katayama M, Pan H, Okamoto H, Noshiro M, Takahashi K, Yoshihara Y, Shimmei M, Okada Y, Kato Y. Enhancement of SPARC (osteonectin) synthesis in arthritic cartilage. Increased levels in synovial fluids from patients with rheumatoid arthritis and regulation by growth factors and cytokines in chondrocyte cultures. ARTHRITIS AND RHEUMATISM 1996; 39:539-51. [PMID: 8630101 DOI: 10.1002/art.1780390402] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To investigate the roles of SPARC (secreted protein, acidic and rich in cysteine) (osteonectin) in arthritis, using cartilage and synovium specimens and synovial fluids (SF) from patients with rheumatoid arthritis (RA) or osteoarthritis (OA), and to examine the effects of cytokines, growth factors, and hormones on SPARC synthesis by chondrocytes in culture. METHODS SPARC in cartilage and synovium was immunostained with monoclonal antibodies. SPARC synthesis by cultured chondrocytes was measured by Northern blot analysis, immunoblotting, and sandwich enzyme-linked immunosorbent assay. RESULTS SPARC was identified in numerous chondrocytes in the superficial and middle zones and in regenerating chondrocytes of RA and OA joints, whereas such staining was absent in these zones of normal cartilage, except for weak signals from a few chondrocytes in the deep zone. In addition, SPARC synthesis was enhanced in synovial cells of RA and OA joints. The average SPARC level in SF was 10-fold higher in the RA than in the OA population. In rabbit articular chondrocyte cultures, administration of transforming growth factor beta 1 (TGF beta 1) and bone morphogenetic protein 2 increased SPARC levels at 24-48 hours, whereas interleukin-lbeta (IL-1 beta), IL-1 alpha, tumor necrosis factor alpha, lipopolysaccharide, phorbol myristate acetate, basic fibroblast growth factor, and dexamethasone decreased SPARC levels at 24-72 hours. TGF beta increased SPARC messenger RNA (mRNA) levels at 24 hours, whereas IL-1 beta caused a marked decrease in SPARC mRNA levels at 24 hours. Furthermore, IL-1 decreased the glycosylation of SPARC. CONCLUSION These findings suggest that various growth factors and cytokines, including TGF beta 1 and IL-1 beta, regulate the production of SPARC by chondrocytes at pre- and posttranslational levels, and that SPARC synthesis is markedly enhanced in arthritic joints.
Collapse
|
375
|
Bai X, Huang Z, Mo Z, Pan H, Ding H. [Effects of total saponins of semen ziziphi Spinosae on brain damages and brain biochemical parameters under cerebral ischemia of rats]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1996; 21:110-2, inside back cover. [PMID: 8758767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Total saponins of Semen Ziziphi Spinosae (ZS) can reduce the contents of water and MDA in ischemic rat's brain tissues, elevate the activity of SOD, CK and LDH, cut down the content of lactate and alleviate the damages of nerve cells in brain. The study shows that ZS possesses protective effects on cerebral ischemic injuries.
Collapse
|
376
|
Hötten GC, Matsumoto T, Kimura M, Bechtold RF, Kron R, Ohara T, Tanaka H, Satoh Y, Okazaki M, Shirai T, Pan H, Kawai S, Pohl JS, Kudo A. Recombinant human growth/differentiation factor 5 stimulates mesenchyme aggregation and chondrogenesis responsible for the skeletal development of limbs. Growth Factors 1996; 13:65-74. [PMID: 8962721 DOI: 10.3109/08977199609034567] [Citation(s) in RCA: 135] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We have expressed and biologically characterized recombinant human growth/differentiation factor 5 (huGDF5). This protein is composed of a mature homodimer consisting of 15 kD subunits. Using recombinant expressed protein, we have demonstrated that huGDF5 in vitro stimulated mesenchyme aggregation and chondrogenesis in rat limb bud cells. In vivo, partially purified huGDF5 induced cartilage and bone formation in muscular tissues of rodents. However, in contrast to the effects of other BMPs, as for example BMP-2, the osteoblastic MC3T3-E1 cells did not respond to huGDF5 as measured by alkaline phosphatase activity. These results suggest that the action of GDF5 may be relatively specific for chondrogenesis during the entire process of the endochondral bone formation. GDF5 may control the morphogenesis of cartilaginous tissue, including joints, in the skeletal development of limbs.
Collapse
|
377
|
Abstract
The effect of a strong magnetic field on the egg hatching of Heliothis virescens (Tobacco bugworm) in a 7 Tesla field was studied, and apparent biological effects of the magnetic field were observed. On average of three batches of eggs in this study, the hatching of the eggs in the 7 T field was delayed about 21.7 +/- 0.9 h and the hatching rate was reduced to about 58 +/- 8% compared to those of eggs in 1.4 Gauss field. No apparent effect of the 1600 Gauss fringe field of the 7 T magnet on the egg hatching of Heliothis virescens was observed.
Collapse
|
378
|
Pan H, Wu J, Zheng S. [Inhibition of colorectal carcinoma induced by 1, 2-dimethylhydrazine in mice with tea polyphenols]. ZHONGHUA YU FANG YI XUE ZA ZHI [CHINESE JOURNAL OF PREVENTIVE MEDICINE] 1995; 29:356-9. [PMID: 8697942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Colorectal cancer was induced by subcutaneous injection of 1,2-dimethylhydrazine (DMH) in mice, and the animals were administered orally with 0.4% of tea polyphenols (TP) simultaneously for 20 weeks to study its preventive effects. Results showed incidence of colorectal cancer in mice administered with TP was significantly lower than in positive controls (P < 0.05), and average number of tumor foci and proportion of adenocarcinoma were significantly fewer in TP group than in positive controls (P < 0.01). Level of cytochrome P450 (CP450) in liver microsome of the mice administered with TP was lower than that both in negative and positive controls (P < 0.01), and activities of superoxide dismutase (SOD) in liver tissue were higher than those in positive controls (P < 0.01), but lower than in negative controls (P < 0.01). Proliferative index of epithelial cells in mice was not obviously influenced by TP. It suggested that TP could have preventive effects on experimental colorectal cancer with a possible mechanism of lowering CP450 and increasing the activity of SOD in the liver.
Collapse
|
379
|
Pan H, Barbar E, Barany G, Woodward C. Extensive nonrandom structure in reduced and unfolded bovine pancreatic trypsin inhibitor. Biochemistry 1995; 34:13974-81. [PMID: 7577994 DOI: 10.1021/bi00043a002] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Two-dimensional 1H NMR spectra of an analog of reduced BPTI at pH 4.5, 1 degrees C, have been assigned. Spectra indicate considerable conformational averaging, as expected for a flexible, unfolded protein. The presence of extensive nonrandom structure is detected by the presence of NHi-NHi + 1 and aromatic-aliphatic NOEs. Sequential amide-amide NOEs indicate that turn-like conformations are significantly populated at 18 pairs of residues along the chain. Many of these are located in a turn, loop, or helix in native BPTI, but six are observed for contiguous pairs in the segment composed of residues 29-35, which in native BPTI constitute a strand of extended sheet. A novel finding for unfolded proteins is our observation of NOEs implying non-native hydrophobic interactions. Multiple aromatic-aliphatic NOEs are observed for pairs of residues that are within 1-3 residues of each other. Most are non-native and involve residues in both strands of the central antiparallel strand-turn-strand of native BPTI comprised of residues 18-35. All NOEs reported for oligopeptides spanning the BPTI sequence [Kemmink, J., & Creighton, T. (1993) J. Mol. Biol. 234, 861-878] are observed in reduced BPTI, but many others are present as well. Similar spectra are obtained for naturally occurring BPTI reduced by dithiothreitol, BPTI with cysteines replaced by alpha-amino-n-butyric acid, and BPTI mutant F45A reduced by dithiothreitol.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|
380
|
Wang L, Rayanade RJ, Garcia D, Patel K, Pan H, Sehgal PB. Modulation of interleukin-6-induced plasma protein secretion in hepatoma cells by p53 species. J Biol Chem 1995; 270:23159-65. [PMID: 7559462 DOI: 10.1074/jbc.270.39.23159] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The ability of p53 species (wild-type and mutant) to modulate the "differentiated" response of human hepatoma cell lines Hep3B and HepG2 to interleukin-6 (IL-6) was investigated. Transient transfection experiments were carried out in Hep3B and HepG2 cell cultures in which IL-6 was used to activate a beta-fibrinogen (beta Fib) enhancer/reporter construct containing two copies of the 36-base pair IL-6-response element (IL-6RE) (p beta FibCAT). Cotransfection with constitutive expression vectors for wild-type (wt) human or murine p53 inhibited the activation of the p beta FibCAT reporter by IL-6 in both Hep3B and HepG2 cells. Several mutant p53 species either did not inhibit the activation of p beta FibCAT or up-regulated the response. Hepatoma cell lines stably expressing the Val-135 temperature-sensitive mutant of murine p53 (wt-like at 32.5 degrees C and mutant-like at 37 degrees C) were derived from Hep3B cells and tested for the temperature-sensitive phenotype of their ability to synthesize and secrete fibrinogen and alpha 1-antichymotrypsin in response to IL-6. In an experimental protocol in which the parental Hep3B cells did not show a significant difference in plasma protein secretion at the two temperatures, hepatoma line 3 (p53Val-135+) had a greater response to IL-6 at 37 degrees C than parental Hep3B cells, while line 3 cells had a reduced response to IL-6 at 32.5 degrees C. Similarly, hepatoma lines 1 and 2 (both p53Val-135+) had reduced IL-6 responsiveness at 32.5 degrees C, whereas line 22 (transfected with pSVneo alone) and the parental Hep3B cells did not. These data indicate that mutations in p53 contained in tumor cells can modulate the "differentiated" response of these cells to cytokines.
Collapse
|
381
|
Pan H, Griep AE. Temporally distinct patterns of p53-dependent and p53-independent apoptosis during mouse lens development. Genes Dev 1995; 9:2157-69. [PMID: 7657167 DOI: 10.1101/gad.9.17.2157] [Citation(s) in RCA: 185] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Programmed cell death, or apoptosis, is a critical event in the development of multicellular organisms, and its perturbation is implicated in many diseases including cancer. The tumor suppressor protein p53 is known to mediate apoptosis induced by the DNA tumor virus oncoproteins, adenovirus E1A (AdE1A) and SV40 T antigen (SV40 Tag). We have recently demonstrated that the E6 and E7 oncoproteins of human papillomavirus type 16 (HPV-16) modulate apoptosis when expressed in the lens of transgenic mice. In this study we have identified the pathways that mediate E7 induction and E6 inhibition of apoptosis during different stages in the development of the lens. E7 transgenic mice made p53-null were only partially rescued in their apoptotic phenotype, indicating that both p53-dependent and -independent pathways mediate E7-induced apoptosis in the lens. The E6 transgene and p53-null genotype acted additively to reduce levels of apoptosis induced by E7 in neonatal lenses, indicating that E6 modulates apoptosis at least in part through p53-independent mechanisms. The partial reduction in E7-induced apoptosis by the p53-null genotype correlated with an increased incidence of lens tumors in adult E7 transgenic mice. Analyses of embryonic lenses at E13.5, E15.5, and E17.5 revealed a temporally distinct activation of p53-dependent and -independent apoptosis in the E7 lens. During the early stages of lens development, apoptosis was highly p53-dependent, whereas at later stages, apoptosis occurred through both p53-independent and -dependent pathways. This later time correlates temporally with the time of normal fiber cell denucleation, which can be inhibited by E6 through a p53-independent mechanism. These data suggest a similarity between the mechanism regulating E7-induced, p53-independent apoptosis and the apoptotic-like developmental process of fiber cell denucleation, and the mechanisms through which E6 suppresses both processes.
Collapse
|
382
|
Abstract
Five new compounds, viz. 3,4-dimethoxyphenyl 2-O-(3-O-methyl-alpha-L-rhamnopyranosyl)-beta-D-glucopyranoside, 4'-hydroxyphenacyl beta-D-glucopyranoside, (2R,3R)-2,3-dihydro-7-hydroxy-2-(4'- hydroxy-3'-methoxyphenyl)- 3-hydroxymethyl-5-benzofuranpropanol 4'-O-(3-O-methyl-alpha-L-rhamnopyranoside), 1-(4'-hydroxy-3'-methoxyphenyl)-2-[4"-(3-hydroxypropyl)-2"-methoxyphe noxy]-1,3-propanediol 4'-O-beta-D-xylopyranoside and 3'-O-methylcatechin 7-O-beta-D-glucopyranoside, together with several known compounds were isolated from the root bark of Picea abies. The structures were elucidated on the basis of chemical and spectroscopic evidence.
Collapse
|
383
|
Ashby CR, Pan H, Minabe Y, Toor A, Fishkin L, Wang RY. Comparison of the action of the stereoisomers of the psychostimulant 4-methylaminorex (4-MAX) on midbrain dopamine cells in the rat: an extracellular single unit study. Synapse 1995; 20:351-61. [PMID: 7482294 DOI: 10.1002/syn.890200408] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
In this study, we examined and characterized the action of the stereoisomers of 2-amino-4-methyl-delta 2-5-phenyl-oxazoline (4-methylaminorex, 4-MAX) on spontaneously active dopamine (DA) neurons in the substantia nigra pars compacta (SNC or A9) and ventral tegmental area (VTA or A10) in anesthetized male rats. This was accomplished using the technique of extracellular single unit recording. The intravenous (i.v.) administration of the stereoisomers of 4-MAX (0.1-6.4 mg/kg) produced a dose-dependent suppression of the basal firing rate of A10 DA cells with the following rank order of potency: trans 4S,5S > cis 4R,5S approximately cis 4S,5R >> trans 4S,5S 4-MAX. The rank order of potency of the isomers of 4-MAX to suppress the firing of A9 DA cells was trans 4S,5S = cis 4R,5S = cis 4S,5R >> trans 4R,5R. The trans 4S,5S isomer was 5-fold more potent in suppressing DA cell firing in the A10 compared to the A9 area. The suppressant action of the isomers on A9 and A10 DA cells was reversed by the i.v. administration of haloperidol and the D2/D3 receptor antagonists (-)-sulpiride and (-)-eticlopride but not by the D1 receptor antagonists SCH 23390 and SCH 39166. In addition, the suppressant action of the trans 4S,5S isomer on A10 DA cells was not antagonized or reversed by the i.v. administration of the receptor antagonists granisetron (5-HT3), ritanserin (5-HT2A,C), idazoxan (alpha 2), phentolamine (peripheral alpha 1), (+/-)-pindolol (5-HT1A,B beta) or prazosin (alpha 1). The pretreatment of animals with either alpha-methyl-p-tyrosine (AMPT) or reserpine, but not p-chlorophenylalanine (PCPA), (+/-)-fluoxetine or tomoxetine, significantly attenuated the suppression of A10 DA cell firing produced by trans 4S,5S 4-MAX. Overall, our results suggest that the suppressant action of 4-MAX on midbrain DA cell firing may be mediated by the release of DA, which subsequently interacts with D2/D3 receptors.
Collapse
|
384
|
Sehgal PB, Wang L, Rayanade R, Pan H, Margulies L. Interleukin-6-type cytokines. Ann N Y Acad Sci 1995; 762:1-14. [PMID: 7668520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
|
385
|
Pan H, Galligan JJ. Effects of 5-HT1A and 5-HT4 receptor agonists on slow synaptic potentials in enteric neurons. Eur J Pharmacol 1995; 278:67-74. [PMID: 7664814 DOI: 10.1016/0014-2999(95)00101-p] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Intracellular electrophysiological methods were used to examine the effects of 5-hydroxytryptamine (5-HT), 5-carboxamidotryptamine (5-CT), 5-methoxytryptamine (5-MeOT), 4-amino-5-chloro-2-methoxy-N-(4-[1-azabicyclo[3,3,1]nonyl]) benzamide hydrochloride (renzapride), cis-4-amino-5-chloro-N[1-[3- (4-fluorophenoxy)propyl]-3-methoxy-4-piperidinyl[-2-methoxybenzamide monohydrate (cisapride) and endo-N-(8-methyl-8-azabicyclo[3.2.1]oct-3-yl)-2,3-dihydro-3- (1-methyl)ethyl-2-oxo-1 H-benzimidazole-1-carboxamidehydrochloride (BIMU 8) on noncholineric slow excitatory postsynaptic potentials (slow EPSPs) in myenteric afterhyperpolarization (AH) neurons of guinea pig ileum. 5-HT (0.01-1 microM) and 5-CT (0.001-0.1 microM) produced a concentration-dependent inhibition of slow EPSPs. The 5-HT1A receptor antagonist 1-(2-methoxyphenyl)-4-[4-(2-phthalimidobutyl]piperazine (NAN-190) produced rightward shifts in 5-HT and 5-CT concentration-response curves; facilitation of slow EPSPs was never observed. 5-MeOT caused a depolarization and inhibited spike afterhyperpolarizations in a concentration-dependent manner but this effect was not blocked by the 5-HT3/5-HT4 receptor antagonist, tropisetron (1 microM). Renzapride (0.01-0.3 microM), cisapride (0.01-1.0 microM) and BIMU 8 (0.01-1.0 microM) did not change the membrane potential of any neuron tested. Renzapride and BIMU 8 did not change the amplitude of slow EPSPs. In 13 of 19 neurons cisapride did not change the amplitude of slow EPSPs; in 6 neurons cisapride (1 microM) reversibly inhibited the slow EPSP. Responses to substance P which mimicked the slow EPSP were not affected by cisapride.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|
386
|
Liao R, Li S, Liu Y, Guo Y, Pan H, Tao X. The relation of the location of haptics of posterior chamber intraocular lenses and peripheral anterior synechia. YAN KE XUE BAO = EYE SCIENCE 1995; 11:37-40. [PMID: 8575604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
PURPOSE To investigate the occurrence, outcome and influencial factors of the peripheral anterior synechia (PAS) following implantation of posterior chamber intraocular lenses for finding a way to reduce the PAS. SUBJECTS 40 eyes of 38 senile cataract patients with normal chamber angle and intraocular pressure (IOP) preoperatively were examined. METHODS Extracapsular cataract extraction was performed under microscope with insertion of a posterior chamber lens implant vaulted anteriorly by 10 degrees. Gonioscopy and slit-lamp examination and photography of the operated eyes were performed 3 to 6 months postoperatively. RESULTS PAS were found in 20 (50%) of the 40 eyes. Among the 20 eyes with PAS the locations of 23 haptics in 17 eyes corresponded with those of the PAS. PAS were seen more frequently with vertically sulcus-fixated haptics than with the horizontally capsular-fixated haptics, showing a significant difference (P < 0.05). 88% of the eyes with PAS had pupillary deformation, but their visual acuities and IOP were not affected. CONCLUSIONS PAS is more likely to occur with vertically sulcus-fixated IOL. Rotating the capsular-fixated haptics to the horizontal position may reduce the incidence of PAS. Gonioscopy should be a routine follow-up examination.
Collapse
|
387
|
Ratcliffe SG, Masera N, Skinner AM, Jones J, Morrell D, Pan H, Price DA, Preece MA, Clayton PE. Urinary insulin-like-growth factor I in normal children: relationship to age, pubertal status and urinary growth hormone. GROWTH REGULATION 1995; 5:53-9. [PMID: 7749348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Authentic insulin-like growth factor 1 (IGF-I) can be detected in human urine at one thousandth of the serum level, with which it correlates closely. The aim of this study was to establish the normal range of urinary IGF-I (uIGF-I) in relation to age, sex, and pubertal status, and to define the relationship between uIGF-I and urinary growth hormone (uGH). IGF-I was measured by RIA after acid extraction of IGF-I binding protein, and separation by gel chromatography in 302 healthy children (149 boys and 153 girls) in whom uGH had already been measured. The mean amount of uIGF-I excreted each night ranged from 17.5 ng (males) and 14.9 ng (females) at pubertal stage I (PS 1), to a peak of 66.8 ng (males) at PS 4, and 55.8 ng (females) at PS 3, coinciding with peak uGH excretion. Highly significant correlations were found between uGH and uIGF-I both before and during puberty (P < 0.01). These findings extend the range of non-invasive investigation available in growth disorders and physiological studies.
Collapse
|
388
|
Wu XR, Wang ZH, Shan WS, Yuan BQ, Liang WL, Pan H. Preliminary molecular neurobiology study on the pathogenesis of primary epilepsy. PROGRESS IN BRAIN RESEARCH 1995; 105:283-8. [PMID: 7568888 DOI: 10.1016/s0079-6123(08)63305-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
|
389
|
Li JH, Pan H, Wu ZP, Chen YL, Chu XM, Lin SS. Determination of free digoxin in sera of 8 patients with chronic cardiac insufficiency. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1995; 16:47-50. [PMID: 7771196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
AIM To establish a method for the determination of free digoxin in serum for clinical use and to study the relationship between the free and total digoxin concentrations in chronic cardiac insufficiency patients receiving digoxin with different renal function. METHODS The ultrafiltration with fluorescence polarization immunoassay was used to determine the concentration of free digoxin. RESULTS The concentrations of digoxin standards in serum were 0.96, 1.92, and 3.84 nmol.L-1. The relative standard deviation was < 7% for intra-day and < 6% for inter-day determinations. The average recovery was 99.95 +/- 2.18%. The ratio of free/total digoxin in chronic cardiac insufficiency patients with renal dysfunction was lower than that in patients with normal kidneys (63.5 +/- 4.7% vs 75.1 +/- 3.9%, P < 0.01). CONCLUSION The present method is simple and reliable. In these patients there is an over-measurement for total digoxin concentration, suggesting the presence of elevated endogenous digoxin-like immunoreactive substances.
Collapse
|
390
|
Dai W, Pan H, Kwok O, Dubey JP. Human indoleamine 2,3-dioxygenase inhibits Toxoplasma gondii growth in fibroblast cells. JOURNAL OF INTERFERON RESEARCH 1994; 14:313-7. [PMID: 7897249 DOI: 10.1089/jir.1994.14.313] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Interferon-gamma (IFN-gamma) is known to inhibit the growth of Toxoplasma gondii both in vivo and in vitro. The IFN-gamma induced anti-toxoplasma activity in human cells is strongly correlated with the degradation of the essential amino acid L-tryptophan in vitro. Destruction of L-tryptophan is due to an increased activity of indoleamine 2,3-dioxygenase (IDO), which is transcriptionally activated by IFN-gamma. To determine if indoleamine 2,3-dioxygenase alone is sufficient to block the T. gondii growth, we transfected human fibroblast cells with an IDO cDNA expression plasmid using a metallothionein-inducible promoter. We showed that IDO mRNA and its enzymatic activity are inducible in fibroblast cells transfected with right-orientation IDO cDNA upon addition of CdCl2 to culture medium. The elevated IDO enzyme activity is strongly correlated with an inhibition of T. gondii growth. No IDO mRNA nor enzyme activity is induced by CdCl2 in reverse orientation transfected cells, and no adverse effects were observed on T. gondii growth in cells transfected with the reverse IDO-construct or in control parent cells with or without supplementation of CdCl2. Our observations along with the recent report by Habara-Ohkubo et al. (Infect. Immun. 61, 1810-1813, 1993) suggest that IFN-gamma-induced antitoxoplasma activity is due at least in part to the activation of IDO gene.
Collapse
|
391
|
Kim YJ, Pan H, Verma AK. Non-AP-1 tumor promoter 12-O-tetradecanoylphorbol-13-acetate-responsive sequences in the human ornithine decarboxylase gene. Mol Carcinog 1994; 10:169-79. [PMID: 8043198 DOI: 10.1002/mc.2940100308] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
To define the mechanisms of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced transcription of the ornithine decarboxylase (ODC) gene, we isolated a genomic clone (hODC41B) of ODC from a human leukocyte genomic DNA library. The restriction endonuclease map, in comparison with the previously published sequences of the human ODC gene, indicated that hODC41B contained a 15.7-kb sequence that extended from the sixth exon to about 10 kb upstream of the ODC gene. A 2.5-kb genomic fragment containing the 5' flanking region and the first exon was subcloned and sequenced. Sequence analysis revealed multiple putative promoter/enhancer elements (a TATA box, a CAAT box, 17 GC boxes, and a cAMP-responsive element) but no consensus AP-1 sequences (TGAGTCA) in the 2.5-kb 5' flanking region. However, three AP-1 sequences were located in introns 3, 5, and 11. We constructed a series of chimeric genes containing part of the first exon and increasingly longer 5' flanking sequences of the ODC gene fused to either bacterial chloramphenicol acetyltransferase (CAT) or luciferase reporter genes. TPA inducibility was determined by transient transfection and measurement of CAT or luciferase expression in HeLa cells. The induction of CAT activity by TPA decreased with decreasing lengths of the 5' flanking sequences up to nt -82. The TPA induction from the construct -72 ODC CAT was threefold to sevenfold, and the TPA inducibility of the same fragment was about ninefold to 30-fold with the luciferase reporter gene. Further deletion analysis revealed TPA-responsive sequences in ODC nt -42 to +54. Gel mobility shift assays using alpha-32P-end labeled ODC nt -42 to +60 revealed that nt -42 to +60 specifically bound HeLa cell nuclear proteins. HeLa cell nuclear protein binding to ODC nt -42 to +60 could not be completely competed by AP-1-, AP-2-, AP-3-, or SP1-responsive sequences.
Collapse
|
392
|
Abstract
At all ages XXX girls had significantly smaller head circumferences than control girls. Their IQ deficit was 24 points and IQ at age seven correlated significantly with head circumference at birth. In XXY boys, head circumference was significantly reduced at birth and up to nine years of age. The XXY boys' IQ deficit was 22 points, but IQ did not correlate with head circumference, as reductions in the two parameters did not always occur in tandem. The ratio of height-to-head circumference differed most in this group and could be useful in clinical recognition of this condition. XYY boys' head size did not differ from controls, despite their greater height, lower IQ scores indicating an adverse effect of an additional Y chromosome on brain development. The major factor affecting IQ outcome in the cohort was abnormal karyotype, with smaller effects from social class and head growth.
Collapse
|
393
|
Pan H, Griep AE. Altered cell cycle regulation in the lens of HPV-16 E6 or E7 transgenic mice: implications for tumor suppressor gene function in development. Genes Dev 1994; 8:1285-99. [PMID: 7926731 DOI: 10.1101/gad.8.11.1285] [Citation(s) in RCA: 333] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Tumor suppressor proteins are believed to play a role in regulating cell cycle control during mammalian development. The E6 and E7 oncoproteins from human papillomavirus type 16 are known to affect cell growth control, at least in part, through their inactivation of cellular tumor suppressor gene products, p53 and Rb, respectively. Therefore, these viral proteins can serve as trans-dominant repressors of tumor suppressor gene function. To study the potential role of p53 and Rb in murine lens morphogenesis, we generated transgenic mice in which the expression of E6 or E7 was directed to the developing lens. Transgenic mice expressing E7 exhibited microphthalmia and cataracts, whereas transgenic mice expressing E6 exhibited cataracts without noticeable microphthalmia. Microscopic analysis of the lenses from neonatal and adult E7 transgenic mice revealed inhibition of lens fiber cell differentiation, induction of cell proliferation in spatially inappropriate regions of the lens, and apoptosis. Transgenic mice expressing a mutant E7 that is defective in Rb/p107 binding exhibited normal eyes, suggesting that the activity of Rb and/or Rb-like proteins is required for the perturbation of lens development and induction of apoptosis in E7 mice. Microscopic analysis of lenses from E6 neonatal and adult transgenic mice indicated the presence of nuclei in elongated fiber cells, suggesting that E6 inhibits lens fiber cell denucleation. Furthermore, expression of E6 inhibited the apoptotic-like DNA degradation observed in the lenses of nontransgenic 15.5-day embryos. In lenses from neonatal E6 x E7 double transgenic mice, the level of apoptosis was reduced compared with that seen in lenses from neonatal E7 mice. In adults E6 x E7 double transgenic mice, lens tumors developed, whereas in E6 or E7 only transgenic mice, tumors did not. Taken together, these results point to specific roles in lens morphogenesis for Rb and p53 and to the necessity of these tumor suppressor gene products in regulating exit from the normal cell division cycle in differentiating lens fiber cells.
Collapse
|
394
|
Dai W, Pan H, Hassanain H, Gupta SL, Murphy MJ. Molecular cloning of a novel receptor tyrosine kinase, tif, highly expressed in human ovary and testis. Oncogene 1994; 9:975-9. [PMID: 8108143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Using a combination of polymerase chain reaction and conventional cDNA library screening approaches, we have cloned and characterized a putative receptor tyrosine kinase termed tif. The extracellular domain of tif has an immunoglobulin-like loop and a fibronectin type III structure. The intracellular domain contains a tyrosine kinase domain. Compared with ryk, a ubiquitously expressed receptor tyrosine kinase, tif expression is tissue-specific with human ovary and testis containing the highest amount of tif mRNA. Many other tested human tissues such as heart, liver, pancreas and thymus do not contain detectable levels of tif mRNA. The molecular cloning and characterization of tif cDNA will facilitate the identification of a potential ligand(s) for the putative receptor and the study of its biological role.
Collapse
|
395
|
Pan H, Galligan JJ. 5-HT1A and 5-HT4 receptors mediate inhibition and facilitation of fast synaptic transmission in enteric neurons. THE AMERICAN JOURNAL OF PHYSIOLOGY 1994; 266:G230-8. [PMID: 8141296 DOI: 10.1152/ajpgi.1994.266.2.g230] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The actions of 5-hydroxtryptamine (5-HT)1A and 5-HT4 receptor agonists on fast excitatory postsynaptic potentials (EPSPs) in myenteric neurons of guinea pig ileum were studied in vitro. Intracellular electrophysiological methods were used to record EPSPs. 5-HT (0.1 microM), 5-carboxamidotryptamine (0.001-0.1 microM), 8-hydroxydipropylaminotetralin (0.003-0.3 microM), and 5-methoxytryptamine (5-MeOT; 0.3 microM) inhibited EPSPs. Agonist inhibition of EPSPs was blocked by the 5-HT1A receptor antagonists, spiperone and NAN-190. In the presence of NAN-190 (0.3 microM), 5-HT (0.001-0.1 microM) increased EPSP amplitude. 5-MeOT (0.001-0.1 microM), renzapride (0.01-0.3 microM), cisapride (0.01-1 microM), and BIMU 8 (0.003-0.1 microM) increased EPSP amplitude but did not change the membrane potential of any neuron. EPSP potentiation induced by each agonist was blocked by the 5-HT3/5-HT4 receptor antagonist, tropisetron (1 microM), but not by the 5-HT3 receptor antagonist, ondansetron (1 microM). Potentiation of fast EPSPs by 5-HT (0.1 microM) desensitized, whereas renzapride (0.1 microM) responses did not. Desensitization induced by BIMU 8 was variable. These data indicate that enteric 5-HT1A and 5-HT4 receptors function to inhibit and facilitate transmitter release, respectively. 5-HT4-mediated facilitation of ganglionic neurotransmission could contribute to the prokinetic effects of cisapride and renzapride.
Collapse
|
396
|
Ratcliffe SG, Read G, Pan H, Fear C, Lindenbaum R, Crossley J. Prenatal testosterone levels in XXY and XYY males. HORMONE RESEARCH 1994; 42:106-9. [PMID: 7995613 DOI: 10.1159/000184157] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
It has been postulated that behavioural differences between normal males and those with an additional X or Y chromosome may be related to pre- or postnatal hormonal variations. The prenatal hormone status was investigated using amniotic fluid obtained at antenatal diagnosis between 16 and 20 weeks gestation from fetuses with sex chromosome abnormalities and from controls of the same gestational age. After log transformation, the (geometric) mean testosterone levels were XY 439.4 pmol/l, range 165-1,027 (n = 29), XYY 490.7 pmol/l, range 224-1,092 (n = 20); and XXY 419 pmol/l, range 87-1,021 (n = 20). There were no significant differences between the three male groups and all three were significantly higher than the XX fetuses at 147.0 pmol/l, range 41-474 (p < 0.001). These findings give no support to the hypothesis that prenatal testosterone levels contribute to later behavioural characteristics.
Collapse
|
397
|
Abstract
Longitudinal measurements of height, sitting height and leg length are compared between 11 XXX girls identified by cytogenetic screening, and 16 chromosomally normal controls from the same population using a nonparametric method. While height velocity did not differ between the two groups either during the pubertal or the mid-childhood spurts, leg length velocity was significantly increased during the mid-childhood spurt, between 4 and 9 years of age. A further contribution to the increased leg length came from the slower decline in leg length velocity at the end of the pubertal spurt. The possible mechanisms involved in these changes are discussed.
Collapse
|
398
|
Lambert PF, Pan H, Pitot HC, Liem A, Jackson M, Griep AE. Epidermal cancer associated with expression of human papillomavirus type 16 E6 and E7 oncogenes in the skin of transgenic mice. Proc Natl Acad Sci U S A 1993; 90:5583-7. [PMID: 8390671 PMCID: PMC46765 DOI: 10.1073/pnas.90.12.5583] [Citation(s) in RCA: 105] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Certain "high-risk" anogenital human papillomaviruses (HPVs) have been associated with the majority of human cervical carcinomas. In these cancers, two papillomaviral genes, E6 and E7, are commonly expressed. In this study we provide evidence that expression of the E6 and E7 genes from the high-risk HPV-16 in the skin of transgenic mice potentiated the development of preneoplastic lesions, and a high percentage of these epidermal lesions subsequently developed into locally invasive cancers. High levels of E6/E7 expression were found in these tumors relative to the preneoplastic lesions, and expression was localized to the proliferating, poorly differentiated epidermal cells. Also, the p53 and Rb genes were found to be intact, not mutationally inactivated, in representative skin tumors. These findings demonstrate that the E6 and E7 genes from a papillomavirus etiologically associated with human cervical cancer can contribute to the development of epidermal cancers in an animal model.
Collapse
|
399
|
Abstract
The availability of a cohort of eight unselected XYY boys identified by newborn cytogenetic screening has enabled their growth to be studied longitudinally in comparison with controls from the same population. While no difference had been found in dimensions at birth, increased height velocity in childhood resulted in the XYY boys being 7.6 cm taller at the onset of their pubertal growth spurt. Increased intensity of growth at puberty with a peak height velocity of 10.6 cm/year contributed to their adult height of 188.1 cm. XYY boys showed twice the male-female difference in height implying that genes on the Y chromosome exert a quantitative effect on the sexual dimorphism of growth.
Collapse
|
400
|
Preece MA, Pan H, Ratcliffe SG. Auxological aspects of male and female puberty. ACTA PAEDIATRICA (OSLO, NORWAY : 1992). SUPPLEMENT 1992; 383:11-3; discussion 14. [PMID: 1458004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|