401
|
Qiu J, Zhang J, Zhang M, Chen Z. [Study on bone-repairing biomaterial ytterbium oxide-hydroxyapatite]. Sheng Wu Yi Xue Gong Cheng Xue Za Zhi 1998; 15:26-7. [PMID: 12549347] [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
Hydroxyapatite was extensively used to repair osteoshortage recently. To improve its bondibility and X-ray obstructibility, we added ytterbium oxide of different proportions in the synthetic process of hydroxyapatite. Ytterbium oxide is characterized by high activity and X-ray obstructibility. A cheap biomaterial with good biocompatibility and high X-ray obstructibility has been got in this way.
Collapse
Affiliation(s)
- J Qiu
- Department of Dental Materials Science, College of Stomatology, West China University of Medical Sciences, Chengdu 610041
| | | | | | | |
Collapse
|
402
|
Jing H, Huang W, Qiu J. [Inhibitive effect of bcl-2 antisense oligodeoxynucleotide on Bcl-2 protein synthesis and cell proliferation in human laryngocarcinoma Hep-2 cells]. Zhonghua Er Bi Yan Hou Ke Za Zhi 1998; 33:17-20. [PMID: 11498881] [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: 02/21/2023]
Abstract
OBJECTIVES To evaluate the role of bcl-2 antisense oligodeoxynucleotide in the gene treatment of human laryngocarcinoma. METHODS An antisense oligodeoxynucleotide complementary to the initiation coden and the next four codens of bcl-2 mRNA was synthesized with an automatic DNA synthesizer. It was used to treat cultured Hep-2 cells to observe its effect on cell proliferation. In situ hybridization method and immunohistochemical technology were adopted to detect bcl-2 mRNA and protein and explore the effect of bcl-2 antisense oligodeoxynucleotide fragment on bcl-2 gene expression and protein synthesis and inhibition of cell proliferation. RESULTS Bcl-2 antisense oligodeoxynucleotide had an obvious effect on bcl-2 mRNA, but inhibited Bcl-2 protein synthesis significantly, the inhibitive rate had positive correlation with concentration of antisense oligodeoxynucleotide and time of action. Twenty mumol/L of antisense oligodeoxynucleotide could inhibit cell proliferation effectively. CONCLUSIONS It is suggested that bcl-2 antisense oligodeoxynucleotide might specifically inhibit bcl-2 protein synthesis and cell proliferation in Hep-2 cells at translation level.
Collapse
Affiliation(s)
- H Jing
- Department of Otorhinolaryngology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032
| | | | | |
Collapse
|
403
|
Abstract
The aim of this review is to summarize ways in which in vitro approaches have allowed us to investigate several aspects of gametogenesis in the male. In our laboratory, we have established both organ culture and cell co-culture methodologies and applied them to questions focused on cellular and molecular events important for development of primitive spermatogonia, or gonocytes, in testes of neonatal rats. We have described their postnatal reinitiation of mitosis and their migration to the basal lamina in anticipation of basal compartment formation and, through use of these in vitro systems, we have identified several mechanisms regulating these processes. These include matrix influence on mitosis and migration, adhesive mechanisms active between gonocytes and Sertoli cells, and involvement of the Kit receptor on germ cells and its ligand from Sertoli cells in supporting gonocyte migration, as described below.
Collapse
Affiliation(s)
- J M Orth
- Department of Anatomy & Cell Biology, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | | | | | | | | |
Collapse
|
404
|
Huang J, Qiu J, Huang J. [Pharmacologic studies on processed snakegall]. Zhong Yao Cai 1998; 21:29-31. [PMID: 12567967] [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 results showed that the processed snakegall could obviously relieve cough induced by the irritation of ammonia water in mice. It could also increase the secretion of respiratory tract and promote expectoration.
Collapse
Affiliation(s)
- J Huang
- Baiyunshan Pharmaceutical Factory, Guangzhou 510515
| | | | | |
Collapse
|
405
|
Gao W, Coulter RL, Lesht BM, Qiu J, Wesely ML. Estimating Clear-Sky Regional Surface Fluxes in the Southern Great Plains Atmospheric Radiation Measurement Site with Ground Measurements and Satellite Observations. ACTA ACUST UNITED AC 1998. [DOI: 10.1175/1520-0450(1998)037<0005:ecsrsf>2.0.co;2] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
406
|
Guan L, Chen Z, Qiu J. [A study on TF no-mix orthodontic adhesive]. Hua Xi Kou Qiang Yi Xue Za Zhi 1997; 15:331-2. [PMID: 11479982] [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: 02/20/2023]
Abstract
A no-mix orthodontic adhesive composed of primer and paste was developed. The adhesive eliminated the spatulation procedure to which most commercially available products were imperative, could quickly polymerize and cure by means of contact and slight compression of the primer with the paste. It featured high bond strength, convenient handling, enough working time, easy removal of extra adhesive around the bracket and no objectionable odour. The biological tests showed it was safe to use in orthodontic practice, and the results of clinical trials certified the reliable performance, effective bond and convenient use of the adhesive.
Collapse
Affiliation(s)
- L Guan
- Department of Dental Materials, College of Stomatology, West China University of Medical Sciences, China
| | | | | |
Collapse
|
407
|
Kawagoe M, Nakanishi M, Qiu J, Morita M. Growth and healing of a surface crack in poly(methyl methacrylate) under case II diffusion of methanol. POLYMER 1997. [DOI: 10.1016/s0032-3861(97)00153-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
408
|
Abstract
Angiotensin II (ANG II) and norepinephrine (NE) are important regulators of vascular function and structure. Recent studies showed that there are multiple interactions between these two potent vasoconstrictor agents. The present experiment was designed to investigate the effect of NE on the expression of the type 1 ANG II receptor (AT1) in the aorta and cultured vascular smooth muscle cells (VSMC) of rats. Rats were subcutaneously infused with either NE (0.5 microg x kg(-1) x min(-1), n = 6) or the alpha1-adrenoreceptor antagonist prazosin (3.5 microg x kg(-1) x min(-1), n = 6) for 2 wk. Body weight and tail cuff systolic blood pressure were not modified compared with the vehicle control (P > 0.05). Northern blot analysis showed that AT1 mRNA levels in aorta were decreased by 38% in NE-treated rats and increased 117% in prazosin-treated rats (P < 0.05) compared with control. To determine whether NE directly regulates expression of vascular AT1 mRNA and AT1 receptor density, Northern blot analysis and radioligand binding experiments were performed in cultured VSMC. Incubation of VSMC with NE (10(-7) M) led to 44% decrease in AT1 mRNA levels (P < 0.05) and 39% decrease in AT1 receptor density (P < 0.05). Prazosin, but not the alpha2-adrenoreceptor antagonist yohimbine, prevented NE-induced decrease in AT1 mRNA and AT1 receptor density in these cells. Taken together, our results indicate that vascular AT1 gene expression and receptor protein are regulated by ambient NE levels, and NE-induced downregulation of AT1 mRNA and receptor protein is mediated, at least in part, by activating alpha1-adrenoreceptors.
Collapse
MESH Headings
- Adrenergic alpha-Agonists/pharmacology
- Adrenergic alpha-Antagonists/pharmacology
- Animals
- Aorta, Thoracic/cytology
- Aorta, Thoracic/drug effects
- Aorta, Thoracic/metabolism
- Blotting, Northern
- Cells, Cultured
- Gene Expression/drug effects
- Male
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Norepinephrine/pharmacology
- Prazosin/pharmacology
- RNA, Messenger/metabolism
- Rats
- Rats, Wistar
- Receptors, Adrenergic, alpha-1/physiology
- Receptors, Angiotensin/genetics
- Receptors, Angiotensin/metabolism
Collapse
Affiliation(s)
- Y Du
- Department of Internal Medicine, Hypertension and Vascular Research, University of Texas Medical Branch, Galveston 77555-1065, USA
| | | | | | | |
Collapse
|
409
|
Qiu J, Zhu Q, Wang L. [Pathological types and pathomorphological characteristics of osteosarcoma]. Zhonghua Bing Li Xue Za Zhi 1997; 26:259-61. [PMID: 10374330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
|
410
|
Peng D, Liu Q, Zhao Z, Huang W, Qiu J. [An observation of the percutaneous absorption of total alkaloids and terpenoid lactones of Tripterygium wilfordii]. Zhong Yao Cai 1997; 20:524-7. [PMID: 12572524] [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 main ingredients of Tripterygium wilfordii are total alkaloids and terpenoid lactones. The authors studied the percutaneous absorption of these compounds on mice by means of ultravillet spectrophotometry. The results showed that these alksloids and lactones could pass through the skin of the mice. The rate of 12-hour percutaneous absorption was 13.40% for the former and 17.60% for the latter. After the application of Tripterygium wilfordii adhesive plaster to the human skin for 12 hours, the two ingredients were absorbed 17.34% and 22.13% respectively. This suggests that Tripterygium wilfordii can really be administered through the skin.
Collapse
Affiliation(s)
- D Peng
- Anhui College of TCM, Hefei, 230038
| | | | | | | | | |
Collapse
|
411
|
Li Y, Qiu J. [Alterations of retinoblastoma gene and its protein expression in aggressive bone tumors]. Zhonghua Bing Li Xue Za Zhi 1997; 26:262-5. [PMID: 10374331] [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: 02/12/2023]
Abstract
OBJECTIVE To study the association between RB gene and the oncogenesis of bone tumors. METHODS Southern blot and immunohistochemical techniques were used to detect the structural anomalies of RB gene in 34 cases of bone tumors and the expression of RB protein in 99 paraffin-embedded bone neoplasma. RESULTS The deletion and/or rearrangement of RB gene were detected only in 42.9% (9/21) of osteosarcoma; lack of RB protein expression was noticed in 12 cases including 7 cases of osteosarcoma (7/26, 26.9%) and 5 cases of chondrosarcoma (5/23, 21.7%). Beniga giant cell tumor of bone and chondroblastoma showed positive RB protein expression; osteosarcoma cells presenting poor differentiation and apparent atypia all showed no expression of RB protein. Most of the high-grade chondrosarcoma also had no RB protein expression. CONCLUSION The alterations of RB gene and loss of RB protein may play a role in the pathogenesis and progression of malignant bone neoplasms.
Collapse
Affiliation(s)
- Y Li
- Department of Pathology, Sun Yet-San University of Medical Science, Guangzhou
| | | |
Collapse
|
412
|
Abstract
We have previously shown that sodium restriction upregulates the genes encoding angiotensin II receptor (AT1) subtypes, AT1A and AT1B, in the adrenal gland and that this upregulation is mediated by activation of the AT1 receptor. There are multiple interactions between the renin-angiotensin and the adrenergic nervous systems; thus, we conducted the present experiment to investigate whether low sodium-induced upregulation of adrenal AT1A and AT1B is modulated by the alpha1-adrenoreceptor. Seven-week-old male Wistar rats were divided into four groups and given normal sodium diet (0.5%, NS), NS+prazosin (3.5 microg x kg(-1) x min(-1) by osmotic pump), low sodium diet (0.07%, LS), or LS+prazosin. Body weight and mean arterial pressure were not modified over the 2 weeks of treatment (P>.05). Pressor responses to bolus injection of the alpha1-agonist phenylephrine were inhibited in both prazosin groups, compared with NS and LS rats (P<.05). Adrenal AT1A mRNA, determined by Northern blot analysis, was increased in LS (P<.05) but not in NS+prazosin (P>.05), compared with NS. Prazosin enhanced the LS-induced increase of AT1A mRNA (P<.05). Adrenal AT1B mRNA was increased in both LS and NS+prasozin rats, compared with NS rats (P<.05). Prazosin also enhanced the LS-induced increase in AT1B mRNA (P<.05). Therefore, blockade of alpha1-adrenoreceptor results in an enhancement of LS-induced upregulation of adrenal mRNA for AT1A and AT1B. These data suggest that the sympathetic nervous system exerts an inhibitory action, via activation of the alpha1-adrenoreceptor, on AT1A and AT1B gene expression in the adrenal gland during sodium depletion.
Collapse
Affiliation(s)
- D H Wang
- Department of Internal Medicine, University of Texas Medical Branch, Galveston 77555-1065, USA.
| | | | | | | |
Collapse
|
413
|
Abstract
Rat gonocytes migrate to the basement membrane during the first postnatal week, a change in position crucial for their survival. These cells express the c-kit gene from the day of birth through Day 5 in vivo and develop the ability to migrate in Sertoli cell-gonocyte cocultures. In this study, we asked whether c-kit expression and synthesis of Kit protein are required for pseudopod production by gonocytes in vitro. To determine whether gonocyte migration in vitro is invariably accompanied by c-kit expression, we quantified percentages of gonocytes expressing c-kit with increasing time in vitro and correlated these data with pseudopod development by individual cells. We also determined the effect of exposure to Kit antibodies on gonocyte migration in vitro, and, conversely, asked whether addition of exogenous stem cell factor (SCF), the Kit ligand, stimulates pseudopod development. We found that 1) increasing numbers of gonocytes express c-kit with increasing time in vitro; 2) once these cells begin migrating in vitro, the appearance of a pseudopod on a gonocyte is absolutely correlated with kit expression by that cell; 3) incubating cocultures with Kit antibodies significantly reduces the number of cells with pseudopods, without any detectable decrease in numbers of gonocytes; and 4) addition of exogenous SCF to cocultures prepared on Day 5 results in a transient but significant increase in the percentage of gonocytes with pseudopods even though we found that Sertoli cells in the cultures produce endogenous SCF. Thus, our findings provide evidence to support a role for c-kit expression by neonatal gonocytes and, presumably, SCF expression by neonatal Sertoli cells in stimulating migration of these germ cells in vitro.
Collapse
Affiliation(s)
- J M Orth
- Department of Anatomy & Cell Biology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA.
| | | | | | | |
Collapse
|
414
|
Owan I, Burr DB, Turner CH, Qiu J, Tu Y, Onyia JE, Duncan RL. Mechanotransduction in bone: osteoblasts are more responsive to fluid forces than mechanical strain. Am J Physiol 1997; 273:C810-5. [PMID: 9316399 DOI: 10.1152/ajpcell.1997.273.3.c810] [Citation(s) in RCA: 346] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Mechanical force applied to bone produces two localized mechanical signals on the cell: deformation of the extracellular matrix (substrate strain) and extracellular fluid flow. To study the effects of these stimuli on osteoblasts, MC3T3-E1 cells were grown on type I collagen-coated plastic plates and subjected to four-point bending. This technique produces uniform levels of physiological strain and fluid forces on the cells. Each of these parameters can be varied independently. Osteopontin (OPN) mRNA expression was used to assess the anabolic response of MC3T3-E1 cells. When fluid forces were low, neither strain magnitude nor strain rate was correlated with OPN expression. However, higher-magnitude fluid forces significantly increased OPN message levels independently of the strain magnitude or rate. These data indicate that fluid forces, and not mechanical stretch, influence OPN expression in osteoblasts and suggest that fluid forces induced by extracellular fluid flow within the bone matrix may play an important role in bone formation in response to mechanical loading.
Collapse
Affiliation(s)
- I Owan
- Department of Anatomy, Indiana University Medical Center, Indianapolis 46202, USA
| | | | | | | | | | | | | |
Collapse
|
415
|
Qiu J, Zhou H, Aceto JF, Kieber-Emmons T. Cycle sequencing of filamentous phage DNA using a biotinylated primer and delta Taq DNA polymerase. Biotechniques 1997; 23:125-7. [PMID: 9232243 DOI: 10.2144/97231st03] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [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: 02/04/2023] Open
Abstract
We describe a rapid nonradioactive, double-stranded phage DNA sequencing method using ΔTaq DNA polymerase in cycle reaction for phage peptide-display library screening. This procedure is specific, rapid, sensitive and safe for the sequencing of large numbers of phage peptide-display colonies. In addition, thermal cycle sequencing with this chemiluminescent image detection protocol provides an inexpensive method for completing a large amount of sequencing reactions. Consequently, this method is especially useful for those extensively working on peptide mimics using phage display libraries.
Collapse
Affiliation(s)
- J Qiu
- School of Medicine, University of Pennsylvania, Philadelphia, USA
| | | | | | | |
Collapse
|
416
|
Chen H, Qiu J, Qiao L. [Immunohistochemical distribution of atrial natriuretic peptides in the external wall of cochlear duct of guinea pigs]. Lin Chuang Er Bi Yan Hou Ke Za Zhi 1997; 11:294-5. [PMID: 10322997] [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: 02/12/2023]
Abstract
The paper presents the distribution of the atrial natriuretic peptides (ANP) in the external wall of each turn of the cochlear duct of guinea pigs by an immunohistochemical technique (ABC method). ANP immunoreactivity (ANP-IR) was found in the strial vasculayis, sprial prominence, cells of external suicus and sprial ligament of the external wall of the vestibular canal and media canal. But no positive immunoreactive products were found in the spiral ligament of the external wall of scala tympanity. The results suggest that ANP of the external wall of the cochlear duct may play an important role in the formation of endolymphe. ANP-IR was difference in spiral ligament of in these scala. But their physiological function was different.
Collapse
Affiliation(s)
- H Chen
- Nanfang Hospital, First Military Medical University, Guangzhou
| | | | | |
Collapse
|
417
|
Liu W, Xu Y, Wong ST, Wang L, Qiu J, Yang N. Methane dehydrogenation and aromatization in the absence of oxygen on MoHZSM-5: A study on the interaction between Mo species and HZSM-5 by using 27Al and 29Si MAS NMR. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s1381-1169(96)00427-x] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
418
|
Huang W, Jiang H, Qiu J. [The effect of substance P upon middle ear effusion of secretory otitis media and the mode of action]. Lin Chuang Er Bi Yan Hou Ke Za Zhi 1997; 11:249-51. [PMID: 9812802] [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
This experiment aimed to explore the effects of substance P (SP) on secretory otitis media (SOM). Both immunohistochemistry ABC-GDN and image pattern analysis technique were adopted to investigate the relation between SP content of SOM middle ear mucosa and middle ear effusion, and observe the effect of SP receptor antagonist spantide and histamine H2 receptor blocker cimetidin on middle ear effusion. The findings showed: middle ear mucosa SP content tended to increase, and had positive correlation with middle ear effusion, intra-abdominally injecting 1 mg/ml Spantide and 1 mg/ml Cinetidin per day could have middle ear effusion decreased obviously, but the quantities of reduction were more significant. The results suggest that SP plays a role in SOM, might accelerate vasodilation and increase the permeability of cupillary in middle ear mucosa mediated by histamine.
Collapse
Affiliation(s)
- W Huang
- Department of Otolaryngology, Xijing Hospital, Fourth Military Medical University, Xi'an
| | | | | |
Collapse
|
419
|
Wang Y, Xia Q, Qiu J, Sun Y, Xiao S. Study on antifertility effect of a novel LHRH antagonist in male rats. Contraception 1997; 55:369-72. [PMID: 9262933 DOI: 10.1016/s0010-7824(97)00046-2] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The potential of a novel LHRH antagonist, TX54, to inhibit reproductive function in male rats was evaluated. After subcutaneous injection at a dosage of 200 micrograms/rat, once a week for 2 weeks, all the drug-treated male rats maintained mating behavior. But, only one out of seven female rats mated to treated males was pregnant with two fetuses. At the end of medication, sperm count and motility of caudal epididymal spermatozoa of the treated rats were reduced significantly (TX54 vs. control: 11.3 +/- 3.2 x 10(8)/mg epididymal plasma, 66.4 +/- 13.4% vs 18.4 +/- 2.4 x 10(8)/mg epididymal plasma, 83.0 +/- 2.7%). Suppression of serum testosterone by TX54 was not observed 48 h after drug injection and at the end of experiment. Morphological examination revealed that at the IX stage of seminiferous epithelium cycle, spermiation was impaired in TX54-treated rats. Less elongated spermatids were found in the lumen of seminiferous tubules of the treated rats. The size of Leydig cells decreased; psychosis and apoptosis features occurred.
Collapse
Affiliation(s)
- Y Wang
- National Research Institute for Family Planning, Beijing, China.
| | | | | | | | | |
Collapse
|
420
|
Qiu J, Xie R, Yuan G, Chen L, Li C. [Study on enterovirus aetiology of CNS infection in Shantou]. Zhonghua Shi Yan He Lin Chuang Bing Du Xue Za Zhi 1997; 11:174-6. [PMID: 15619830] [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: 05/01/2023]
Abstract
Enterovirus isolation and serological assay were done in 236 cases of CNS infection in Shantou. 62 strains of virus (from 55 cases) were isolated from 257 samples of 236 cases (24.1%). 48 cases were positive among 57 cases (84.2%) by serological assay. 78 cases were positive for virus isolation and/or serological assay (33.1%). Virus infection included 33 cases of poliovirus (including 6 polio-I, 18 polio-II, 4 polio-III, 5 mixed infections), 21 cases of Coxsackie virus (including 6 CoxA24,7 CoxB1,2 CoxB4 and 6 CoxB5), 11 cases of ECHO virus (including 5 ECHO-7,2 ECHO-24 and each one of ECHO-11, 12, 15, 27), 10 cases of Enterovirus (including 3 EV-70, 7 EV-71), and 3 cases of mixed viral infection.
Collapse
Affiliation(s)
- J Qiu
- The Second Affiliated Hospital of Medical College of Shantou University 515031
| | | | | | | | | |
Collapse
|
421
|
Catapano CV, Carbone GM, Pisani F, Qiu J, Fernandes DJ. Arrest of replication fork progression at sites of topoisomerase II-mediated DNA cleavage in human leukemia CEM cells incubated with VM-26. Biochemistry 1997; 36:5739-48. [PMID: 9153414 DOI: 10.1021/bi963101b] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [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: 02/04/2023]
Abstract
Recent studies have shown that the anticancer drugs VM-26 and mitoxantrone stabilize preferentially the binding of topoisomerase IIalpha to replicating compared to nonreplicating DNA. To further understand the mechanisms by which cleavable complex-forming topoisomerase II inhibitors interfere with DNA replication, we examined the effects of VM-26 on this process in human leukemia CEM cells. Both the inhibition of DNA synthesis and cell survival were directly related to the total amount of drug-stabilized cleavable complexes formed in VM-26-treated cells. DNA chain elongation was also inhibited in a concentration-dependent fashion in these cells, which suggested that VM-26-stabilized cleavable complexes interfered with the movement of DNA replication forks. To test this hypothesis directly, we monitored replication fork progression at a specific site of VM-26-induced DNA cleavage. A topoisomerase II-mediated cleavage site was detected in the first exon of the c-myc gene in VM-26-treated cells. This cleavage site was downstream of a putative replication origin located in the 5' flanking region of the gene. Replication forks, which moved through this region of the c-myc gene in the 5' to 3' direction, were specifically arrested at this site in VM-26-treated cells, but not in untreated or aphidicolin-treated cells. These studies provide the first direct evidence that a VM-26-stabilized topoisomerase II-DNA cleavable complex acts as a replication fork barrier at a specific genomic site in mammalian cells. Furthermore, the data support the hypothesis that the replication fork arrest induced by cleavable complex-forming topoisomerase II inhibitors leads to the generation of irreversible DNA damage and cytotoxicity in proliferating cells.
Collapse
Affiliation(s)
- C V Catapano
- Department of Experimental Oncology, Hollings Cancer Center, Medical University of South Carolina, Charleston 29425, USA
| | | | | | | | | |
Collapse
|
422
|
Hu JZ, Zhou J, Yang B, Li L, Qiu J, Ye C, Solum MS, Wind RA, Pugmire RJ, Grant DM. Dynamic nuclear polarization of nitrogen-15 in benzamide. Solid State Nucl Magn Reson 1997; 8:129-137. [PMID: 9203286 DOI: 10.1016/s0926-2040(96)01263-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A 15N dynamic nuclear polarization (DNP) experiment is reported in which a 15N DNP enhancement factor of approximately 2.6 x 10(2) is obtained on free radical doped samples of 99% 15N labeled benzamide. The free radicals BDPA (1:1 complex of alpha, gamma-bisdiphenylene-beta-phenylallyl with benzene) and DPPH (2,2-Di(4-tert-octylphenyl)-1-picrylhydrazyl) are used as dopants and the spin relaxation effects of adding these dopants are studied by means of changes in proton and nitrogen T1 values of the samples. The combination in solids of a very low natural abundance, 0.37%, a small gyromagnetic ratio, and a long spin-lattice relaxation time for 15N nuclei create severe sensitivity problems that, in large part, are ameliorated by the signal enhancement observed in the 15N DNP experiment on samples containing free electrons.
Collapse
Affiliation(s)
- J Z Hu
- Laboratory of Magnetic Resonance, and Atomic and Molecular Physics, Wuhan Institute of Physics, Chinese Academy of Sciences, People's Republic of China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
423
|
Harrison PR, Nibbs RJ, Bartholomew C, O'Prey J, Qiu J, Walker M, Clark AM, Leslie N, Ostertag W. Molecular mechanisms involved in long-term maintenance of erythroleukaemia cells by stromal cells. Leukemia 1997; 11 Suppl 3:474-7. [PMID: 9209429] [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: 02/04/2023]
Affiliation(s)
- P R Harrison
- Beatson Institute for Cancer Research, Beatson Laboratories, Glasgow, Scotland, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
424
|
Li E, Qiu J. [A technique of PVC detection in QRS wave]. Zhongguo Yi Liao Qi Xie Za Zhi 1997; 21:83-74. [PMID: 9647622] [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: 05/22/2023]
Abstract
A technique of PVC detection is described in this paper. The procedures of PVC analysis include noise detection, QRS detection, feature extraction and QRS wave classification. The interference is detected in hierarchy ways. A new non-linear transformation of ECG waveform is given to be taken as the QRS detection function. Taking this QRS detection function, the influence of noise and interference can be reduced greatly. By the technique of QRS template matching, QRS waveforms are sorted into different clusters in QRS wave form space. Then a linear classifier is used to identify the medical meaning of these clustes. Before the linear classifier is applied, the QRS waveforms are classified according to some special decision rules. 38 half-hour standard database is used to test the technique presented in this paper. The result shows t hat accuracy rate of PVC detection is better than 95%.
Collapse
|
425
|
Zhou Z, Chen J, Fang Z, Qiu J. [Enrichment and determination of trace chlorobenzene compounds in water]. Se Pu 1997; 15:176-7. [PMID: 15739417] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023] Open
Abstract
In this work, by using GDX-402 porous polymer beads as adsorbent and carbon disulfide as eluent, the conditions for enriching trace chlorobenzene compounds in water were investigated. Enriched eluate was directly injected into a column packed with 3.0% dihexyl sulfonic acid sodium/101 white support to be separated, and then detected by flame ionization detector under constant temperature. The method has been used successfully for the determination of trace of chlorobenzene compounds in water.
Collapse
Affiliation(s)
- Z Zhou
- Department of Applied Chemistry, Nanjing University of Chemical Technology, Nanjing, 210009
| | | | | | | |
Collapse
|
426
|
Kieber-Emmons T, Luo P, Qiu J, Agadjanyan M, Carey L, Hutchins W, Westerink MA, Steplewski Z. Peptide mimicry of adenocarcinoma-associated carbohydrate antigens. Hybridoma (Larchmt) 1997; 16:3-10. [PMID: 9085121 DOI: 10.1089/hyb.1997.16.3] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [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: 02/04/2023]
Abstract
Carbohydrate antigens have been identified as significant antigens in many human tumors either by analyzing antibodies in patients' sera or by using monoclonal antibodies of either mouse or human origin. Three carbohydrate epitopes present on cancer-associated mucins [sialyl-Lewis A (SLA), sialyl-Lewis X (SLX), and sialyl-Tn (STn)] may have functional significance in metastasis. Subsequently, these antigens are considered as targets for active specific immunotherapy. Carbohydrates, as T-cell-independent antigens, often elicit diminished immune responses. To overcome this drawback, carbohydrates are typically coupled to protein carriers to elicit immunoglobulin G (IgG) responses as opposed to low-affinity IgM responses, which often times accompanies carbohydrate-based immunizations. In addition, some complex carbohydrates are difficult to synthesize. This latter aspect is further magnified if one considers that clustering of epitopes on neoglycoproteins must be emulated in the synthesis process, leading to multiple presentation or tandem repeats of the synthetic carbohydrate immunogen. Here, we examine the hypothesis that peptides that mimic carbohydrates might be developed to induce immune responses that target and mediate the killing of tumor cells, particularly breast cancer cells in an adjuvant-type setting. We have found that carbohydrate-mimicking peptides retain carbohydrate-like conformations, inducing anti-carbohydrate immune responses against breast tumor cells and mediating their killing by a complement-dependent mechanism.
Collapse
Affiliation(s)
- T Kieber-Emmons
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia 19104, USA
| | | | | | | | | | | | | | | |
Collapse
|
427
|
Tarrerias AL, Qiu J, Eyraud PY, Vancina S, Roman Y, Roche J. [Colonic metastasis from kidney cancer. Presentation of 2 cases]. Gastroenterol Clin Biol 1997; 21:228-9. [PMID: 9161501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
428
|
Kawagoe M, Nomiya M, Qiu J, Morita M, Mizuno W. Fatigue behaviour of injection-moulded polymer blends of polypropylene and liquid crystalline polyester. POLYMER 1997. [DOI: 10.1016/s0032-3861(96)00476-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
429
|
Abstract
An electro-discharge compaction (EDC) fabrication window was established for producing commercially pure porous titanium dental implants of 4 mm diameter and 7 mm length with a solid titanium cap. The optimum input energy was in the range of 0.58-0.87 kJ g-1 for a powder column of 0.500 g. Input energy greater than 0.58 kJ g-1 resulted in an implant torque strength exceeding 30 N-cm (the retaining screw tightening torque), while input energy greater than 0.72 kJ g-1 exceeded 46.7 N-cm torque strength (at this level the retaining screw failed prior to the implant). The integrity of the internally threaded hole and hexagonal head of the cap were maintained throughout the EDC process. The EDC process did not after the strength and/or microstructure of the components, and the bead-cap interface was stronger than the bead-bead interface. EDC implants produced within the aforementioned window have sufficient compressive strengths and other physical properties to meet the requirement for titanium dental implants.
Collapse
Affiliation(s)
- J Qiu
- Department of Chemical and Materials Engineering, College of Engineering, University of Kentucky, Lexington 40506-0046, USA
| | | | | | | |
Collapse
|
430
|
Dong S, Zhu J, Kuang S, Qiu J, Wang Z, Chen S, Chen L. [Study of dominant negative effect of the PLZF-RARalpha against the wild-type RARalpha in acute promyelocytic leukemia]. Zhonghua Xue Ye Xue Za Zhi 1997; 18:8-12. [PMID: 15622742] [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: 05/01/2023]
Abstract
OBJECTIVE To explore the role of promyelocytic leukemia zinc finger (PLZF) gene on 11q23 and RARalpha gene on 17q21. METHODS Eight PLZF/RARalpha expression plasmids with deletions of different PLZF motifs were constructed by using PCR based-method. RESULTS AND CONCLUSION By transient co-transfection, it was confirmed that PLZF/RARalpha had a dominant negative effect against the wild-type RARalpha, the POZ domain of PLZF/RARalpha was responsible for the dominant negative effect and the PLZF/RARalpha may play certain role through a spatial interaction with POZ.
Collapse
Affiliation(s)
- S Dong
- Shanghai Institute of Hematology, Ruijin Hospital, Shanghai Second Medical University, Shanghai 200025
| | | | | | | | | | | | | |
Collapse
|
431
|
Abstract
Several clinically active anticancer drugs are known to interfere with DNA topoisomerase II activity. However, the importance of the individual alpha (170 kDa) and beta (180 kDa) isozymes as targets of topoisomerase II-active drugs is not clear. To address this question, human CCRF-CEM leukemia cells were incubated with bromodeoxyuridine, and either the nascent DNA or bulk DNA not undergoing replication was purified by immunoprecipitation with an anti-bromodeoxyuridine antibody. The topoisomerase II isozymes that coprecipitated with either the nascent DNA or bulk DNA were analyzed by Western blotting. The alpha isozyme formed complexes with nascent DNA in cells pretreated with either VM-26 or mitoxantrone, while the beta isozyme was only bound to bulk DNA. At moderately cytotoxic concentrations, VM-26 enhanced the binding of topoisomerase II alpha to nascent DNA at least 5.2-fold compared to bulk DNA. However, in VM-26 resistant CEM/VM-1 cells incubated with equitoxic concentrations of VM-26, topoisomerase II alpha complex formation with nascent DNA was decreased at least 5.5-fold compared to bulk DNA. Drug-induced binding of topoisomerase II beta with bulk DNA in CEM/VM-1 cells did not correlate with cytotoxicity. Collectively, these results indicate that the formation of VM-26 stabilized complexes of topoisomerase II alpha with nascent DNA are critical to the development of cytotoxicity, and that resistance of CEM/VM-1 cells to VM-26 is related to impaired formation of these complexes. The results also provide indirect evidence that topoisomerase II alpha is involved in DNA, replication.
Collapse
Affiliation(s)
- J Qiu
- Department of Experimental Oncology, Hollings Cancer Center, Medical University of South Carolina, Charleston 29425, USA
| | | | | |
Collapse
|
432
|
Berger EL, Guo X, Qiu J. Isolated prompt photon production in hadronic final states of e+e- annihilation. Phys Rev D Part Fields 1996; 54:5470-5495. [PMID: 10021235 DOI: 10.1103/physrevd.54.5470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
433
|
Abstract
Information gathered from mutant mouse models and from studies on normal puberal and adult animals points to the product of the c-kit gene, a tyrosine kinase surface receptor, and the kit-ligand (KL) as important for gametogenesis in males. In fetuses, KL serves as a survival factor for primordial germ cells, at least in vitro, and in adults activity of the c-kit gene has been indirectly related to survival and subsequent development of differentiating spermatogonia. However, because of the structural complexity of the seminiferous epithelium in adults, c-kit mRNA has not yet been definitively localized to one or more types of spermatogenic cells. In addition, no information is currently available regarding the possible involvement of the c-kit protein and its ligand in mediating germ cell development and/or Sertoli-germ cell interactions immediately after birth when events critical for later onset of spermatogenesis are ongoing. Thus, the aims of the current study were (1) to determine whether the c-kit gene is expressed in testes of neonatal and adult rats and, if so, by what specific cell types, and (2) to determine if those cells expressing the gene also produce the c-kit receptor protein. For this, we isolated total RNA from testes of pups aged days 1-5 and from adult rat testes, and probed for the presence of c-kit mRNA with Northern analysis. We identified the cells containing the c-kit message by carrying out in situ hybridization with digoxigenin-labeled probes, thus allowing the colorimetric signal to be assigned beyond doubt to individual cells in sections of testes. We also utilized Western analysis and immunolocalization to confirm the presence of the c-kit receptor protein in testes at these ages and to identify those cells types producing it. Our findings indicate that (1) neonatal gonocytes express the c-kit gene and produce the receptor protein on postnatal days 1 through 5, spanning the time when they resume dividing and migrating, and (2) spermatogonia and, to a lesser extent, spermatocytes and spermatids of adults express the gene but c-kit protein is present in detectable amounts only in spermatogonia and possibly a few early primary spermatocytes.
Collapse
Affiliation(s)
- J M Orth
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
| | | | | |
Collapse
|
434
|
Fanjul AN, Delia D, Pierotti MA, Rideout D, Yu JQ, Pfahl M, Qiu J. 4-Hydroxyphenyl retinamide is a highly selective activator of retinoid receptors. J Biol Chem 1996; 271:22441-6. [PMID: 8798408 DOI: 10.1074/jbc.271.37.22441] [Citation(s) in RCA: 138] [Impact Index Per Article: 4.9] [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: 02/02/2023] Open
Abstract
Retinoids have shown promise as anti-cancer and cancer preventative agents. All-trans-N-(4-hydroxyphenyl)retinamide (4HPR) belongs to a new group of retinoids that not only inhibit the proliferation of cancer cells but also can induce apoptosis in certain cancer cells. Because of its increased efficacy against cancer cells and its low toxicity it has been entered into a number of clinical trials. However, its mechanism of action is not known, and it had been assumed that it is not a true retinoid. Here we analyze its ability to function as an activator of nuclear retinoid receptors (RARs and RXRs). We observe that, in transactivation assays, 4HPR is a potent transactivator with RARgamma and a moderate activator with RARbeta but is not an activator with RARalpha and RXRalpha. Furthermore, RARgamma-selective transactivation by 4HPR is enhanced on some response elements and reduced on others when compared to natural retinoids. In contrast to transactivation, 4HPR in transrepression assays functions mostly with RARalpha, RARbeta, and RXRalpha. Optimal receptor activation is seen at 4HPR concentrations at which it is a potent growth inhibitor and inducer of apoptosis. We conclude that 4HPR is a highly selective activator of retinoid receptors. We propose that this selective activation of the nuclear receptors is likely to be the basis for its specific biological activities and its favorable pharmaceutical properties.
Collapse
Affiliation(s)
- A N Fanjul
- Sidney Kimmel Cancer Center, La Jolla, California 92037, USA
| | | | | | | | | | | | | |
Collapse
|
435
|
Qiu J, Song J. A rapid polarographic immunoassay based on the anodic current of metal labeling. Anal Biochem 1996; 240:13-6. [PMID: 8811873 DOI: 10.1006/abio.1996.0324] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A heterogeneous voltammetric immunoassay of human serum albumin (HSA) based on the anodic current of metal labeling was studied. HSA was covalently coupled to diethylenetriaminepentaacetic anhydride and labeled with In3+. A heterogeneous competitive immunochemical reaction was carried out in the wells of a microtiter plate. The In3+ label was released in 1 M HCl solution and determined by simplified anodic stripping neopolarography. HSA could be detected in the concentration range of 4.0-50 microg ml-1. The method was used to determine HSA in serum specimens, and the results were in good agreement with those obtained with dye binding spectrophotometry.
Collapse
Affiliation(s)
- J Qiu
- Institute of Electroanalytical Chemistry, Northwest University, Xian, 710069, People's Republic of China
| | | |
Collapse
|
436
|
Abstract
Circadian fluctuations in per mRNA and protein are central to the operation of a negative feedback loop that is necessary for setting the free-running period and for entraining the circadian oscillator to light-dark cycles. In this study, per mRNA cycling and locomotor activity rhythms were measured under different light and dark cycling regimes to determine how photoperiods affect the molecular feedback loop and circadian behavior, respectively. These experiments reveal that per mRNA peaks in abundance 4 h after lights-off in photoperiods of < or = 16 h, that, phase shifts in per mRNA cycling and behavioral rhythmicity occur rapidly after flies are transferred from one photoperiod to another, and that photoperiods longer than 20 h abolish locomotor activity rhythms and leave per mRNA at a median constitutive level. These results indicate that the per feedback loop uses lights-off as a phase reference point and suggest (along with previous findings for per01 and tim01) that per mRNA cycling is not regulated via simple negative feedback from the per protein.
Collapse
Affiliation(s)
- J Qiu
- Department of Biology and Institute of Bioscience and Technology, Center for Advanced Invertebrate Molecular Sciences, Texas A&M University, College Station 77843-3258, USA
| | | |
Collapse
|
437
|
Qiu J, Song J, Gao H. Direct determination of iron in ferritin using the polarographic catalytic current. Anal Bioanal Chem 1996; 356:101-3. [PMID: 15048378 DOI: 10.1007/s0021663560101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/1995] [Revised: 12/13/1995] [Accepted: 12/17/1995] [Indexed: 04/29/2023]
Abstract
A new method for the determination of iron in ferritin using the polarographic catalytic current has been developed. Iron is released in NaOH and triethanolamine (TEA) solution and subsequently determined based on the polarographic catalytic wave in the presence of bromate with the peak potential of -1.0 V (vs.SCE). The 2.5-derivative peak height of iron is linearly proportional to its concentration in the range of 8.0 x 10(-8)-1.0 x 10(-6) g/ml with a correlation coefficient of 0.9991. The method has been applied to the determination of iron in human fetal liver and horse-spleen ferritin and the recovery is 95-112%.
Collapse
Affiliation(s)
- J Qiu
- Institute of Electroanalytical Chemistry, Northwest University, 710069, Xian, People's Republic of China
| | | | | |
Collapse
|
438
|
Guo X, Qiu J. Nuclear dependence in direct photon production. Phys Rev D Part Fields 1996; 53:6144-6155. [PMID: 10019904 DOI: 10.1103/physrevd.53.6144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
439
|
Yang X, Chen X, Qiu J, Tian Q, Li Z, Zeng Y. Band bending within inhomogeneously doped semiconductors with multilevel impurities. II. Examples. Phys Rev B Condens Matter 1996; 53:13419-13426. [PMID: 9983087 DOI: 10.1103/physrevb.53.13419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
440
|
Zhou J, Yang B, Hu J, Hu H, Li L, Qiu J, Zeng F, Ye C. Investigation of a naphthalene pitch by high-resolution solid-state dynamic nuclear polarization. Solid State Nucl Magn Reson 1996; 6:127-133. [PMID: 8784951 DOI: 10.1016/0926-2040(95)01218-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The possibility of applying the dynamic nuclear polarization (DNP) technique to a study of char is explored with a naphthalene-derived pitch. It is shown that a 13C DNP enhancement factor of about 10(2) is obtained when the polarization is directly transferred from the unpaired electrons to the 13C nuclei. An undistorted spectrum with an enhancement factor of 8 is obtained by the DNP cross-polarization magic-angle spinning nuclear magnetic resonance (DNP-CP-MAS NMR) method. With such a high increase in S/N, it is possible to measure the 13C polarization time (Tp) and the spin-lattice relaxation time (T1) of the system in a reasonable experimental time. The resultant values are Tp = 19 s and T1 = 38 s, respectively. Based on the DNP enhancement as a function of the microwave frequency, it is found that the predominant DNP mechanism in the pitch is the solid-state effect.
Collapse
Affiliation(s)
- J Zhou
- Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics, Chinese Academy of Sciences, People's Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
441
|
|
442
|
Abstract
In Drosophila melanogaster, the emergence of adults from their pupal cases (eclosion) is gated by the circadian clock such that it occurs during a window of approximately 8-10 h starting 1-2 h before lights-on in 12-h light:12-h dark cycles (LD). This gate is shifted several hours earlier by the clock mutant per(s), indicating that the clock controls the phase of eclosion under these conditions. Both the day and the time of eclosion are determined by the interplay between developmental state and the circadian clock. At a certain phase of the circadian cycle, the circadian clock, either directly or through some circadian clock-controlled mechanism, measures development state, and those pharate adults that have reached a certain developmental state by this phase eclose during the first available gate, while those that have not wait until a subsequent gate. Using wing pigmentation as a late developmental state marker, an early boundary for when the circadian clock assesses developmental state occurs roughly at the time when lights go out during LD cycles. This event is shifted several hours earlier in per(s), showing that it is under circadian control. A fly's developmental state at the time of developmental assessment also influences when eclosion will occur (during the gate) in that flies whose wings have become pigmented early (12-24 h before assessment) will eclose earlier in the gate than those whose wings become pigmented late (0-12 h before assessment). These data suggest that the circadian clock (or some clock-controlled mechanism) measures developmental state (wing pigmentation) in wild-type flies between lights-off and expression of the first clock-regulated marker approximately 4-5 h before eclosion and that the developmental state of the fly determines both which gate is chosen for eclosion and when eclosion occurs during that gate.
Collapse
Affiliation(s)
- J Qiu
- Department of Biology, Texas A&M University, College Station 77843-3258, USA
| | | |
Collapse
|
443
|
Qiu J, Brackee GP, Plaut AG. Analysis of the specificity of bacterial immunoglobulin A (IgA) proteases by a comparative study of ape serum IgAs as substrates. Infect Immun 1996; 64:933-7. [PMID: 8641803 PMCID: PMC173859 DOI: 10.1128/iai.64.3.933-937.1996] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [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: 02/01/2023] Open
Abstract
Immunoglobulin A (IgA) proteases are bacterial enzymes with substrate specificity for human serum and secretory IgAs. To further define the basis of this specificity, we examined the ability of IgA proteases of Clostridium ramosum, Streptococcus pneumoniae (EC 3.4.24.13), Neisseria meningitidis (EC 3.4.21.72), and Haemophilus influenzae (EC 3.4.21.72) to cleave serum IgAs of gorillas, chimpanzees, and orangutans. All enzymes cleaved the IgAs of the three apes despite differences in ape IgA1 hinge sequence relative to the human prototype. To directly compare the ape and human hinge cleavage sites, the sites were identified in eight ape IgA digests. This analysis confirmed that ape proteins were all cleaved in the IgA hinge region, in all but one case after proline residues. The exception, C. ramosum protease, cleaved gorilla and chimpanzee IgAs at peptide bonds having no proline, but the scissile bonds were in the same hinge location as the Pro-221-Val-222 cleaved in human IgA1. These data indicate that proline is not an invariant substrate requirement for all IgA proteases and that the location of the scissile bond, in addition to its composition, is a critical determinant of cleavage specificity.
Collapse
Affiliation(s)
- J Qiu
- Gastroenterology Division, Department of Medicine, Tufts-New England Medical Center, Boston, Massachusetts 02111, USA
| | | | | |
Collapse
|
444
|
Berger EL, Guo X, Qiu J. Inclusive prompt photon production in hadronic final states of e+e- annihilation. Phys Rev D Part Fields 1996; 53:1124-1141. [PMID: 10020103 DOI: 10.1103/physrevd.53.1124] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
445
|
Roche J, Eyraud P, Ohanessian J, Qiu J, Revelin P, Ravaux S, Ninet J, Mahussier P, Volle L. Anévrisme de l'artère hépatique: à propos de sept cas. Rev Med Interne 1996. [DOI: 10.1016/s0248-8663(97)81114-9] [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: 12/01/2022]
|
446
|
Stenberg L, Qiu J, Lindahl G, Plaut AG. Lack of interference between IgA-binding proteins and IgA proteases of human pathogenic bacteria. J Med Microbiol 1996; 44:65-9. [PMID: 8544214 DOI: 10.1099/00222615-44-1-65] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Some human bacterial pathogens produce specific immunoglobulin A1 (IgA1) proteases that cleave the heavy chain of human IgA1, generating intact Fab and Fc fragments. Other pathogenic bacterial species express surface proteins which bind to the Fc part of human IgA in a non-immune manner. To analyse whether IgA-binding proteins affect the activity of IgA1 proteases, the ability of seven different IgA1 proteases to hydrolyse IgA1 in the presence of either of two different bacterial IgA-binding proteins was tested. Data obtained in two different types of experiment suggest that IgA1 bound to IgA-binding proteins still functions as a substrate for IgA1 proteases. As Fc fragments produced by cleaving IgA1 with IgA1 proteases still bind to IgA-binding proteins, we conclude that these two types of bacterial protein act independently of each other.
Collapse
Affiliation(s)
- L Stenberg
- Department of Medical Microbiology, Lund University, Sweden
| | | | | | | |
Collapse
|
447
|
Wang T, Wang J, Qiu J. [Observation on activity of carbonic anhydrase in the vestibule of guinea pigs]. Zhonghua Er Bi Yan Hou Ke Za Zhi 1996; 31:24-5. [PMID: 9275398] [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
The localization of carbonic anhydrase (CA) activity in the inner ear vestibule of guinea pigs were studied by histochemistry and cytochemistry. We found that numerous enzymatic reaction products were localized in the sterecocilia, cuticles of hair cells, no reaction product was seen in their cell bodies; revealed reaction products in the cell membrane, microvilli, lateral infolding and basolateral infolding of the supporting cell, dark cell, transitional cell and wall cell. It is suggeated that the CA is a membrane-associated CA and the membrane-associated CA plays an important role in the homeistasis of the vestibule and otolithic metabolism.
Collapse
Affiliation(s)
- T Wang
- 86th' Hospital of PLA, Anhui Dangtu
| | | | | |
Collapse
|
448
|
Abstract
Treatment of male rats with low dosages of cyclophosphamide causes a dramatic increase in early embryo death among their progeny without significantly affecting the general health of the male. It is hypothesized that cyclophosphamide exerts its effects by targeting specific components of spermatozoal nuclei. The purpose of the present studies was to investigate the effects of chronic cyclophosphamide treatment on spermatozoal DNA. Two approaches were pursued. The first was to determine total DNA damage by using the alkaline elution method. The second was to study spermatozoal DNA template function by using an in vitro DNA synthesis system. Adult male rats were treated with saline or cyclophosphamide (6.1 mg/kg/day) daily for 1 or 6 wk. Cauda epididymal spermatozoa were collected and subjected to alkaline elution using DNA-DNA dot hybridization to quantify the fractionated DNA. One week of treatment with cyclophosphamide caused DNA single strand breaks that could be detected only in the presence of proteinase K in the lysis solution; no DNA cross-links were observed in the animals that received 1-wk drug treatment. In contrast, 6 wk of treatment with cyclophosphamide induced a significant increase in both DNA single strand breaks and cross-links in spermatozoal nuclei; the cross-links were attributable primarily to DNA-DNA linkages. The availability of spermatozoal DNA for template function was not affected by 1 wk of treatment with cyclophosphamide but was markedly affected after 6 wk of treatment with this drug. It is proposed that during chromatin transition processes the male genome may be in an open dynamic state with many exposed sites that are vulnerable to alkylating agents. Since there is no DNA repair during spermiogenesis, damage to the genome by alkylation at this stage may be cumulative, resulting in the production of dysfunctional germ cells.
Collapse
Affiliation(s)
- J Qiu
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
| | | | | |
Collapse
|
449
|
|
450
|
Xiang J, Xie D, Qiu J. [Cryosurgical resection of pulmonary metastases (experience of twenty years)]. Zhonghua Wai Ke Za Zhi 1995; 33:639-40. [PMID: 8731905] [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: 02/01/2023]
Abstract
Cryosurgical resection of pulmonary metastases was performed in 112 patients from 1973 to 1993. The cumulative 1, 3, 5, 10 year survival rate was 80.37%, 41.81%, 28.01% and 17.28%. One patient died of respiratory failure after operation. Thirty-day mortality rate was 0.89%. The disease-free interval (DFI) between the control of primary tumor and appearance of metastases was significantly correlated with post-thoracotomy survival. The multiple factor analysis also demonstrated that DFI was the most important prognostic factor for patients after cryosurgical resection of pulmonary metastatic lesions. The overall 5 year survival rate of patients treated with cryosurgery in our report was higher than that of those treated by local resection of pulmonary metastases reported by other authors. Our results indicated that cryosurgical resection of pulmonary metastases was effective and safe, the survival time of most patients could be prolonged and some patients could be cured.
Collapse
Affiliation(s)
- J Xiang
- Cancer Hospital, Shanghai Medical University
| | | | | |
Collapse
|