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Yan C, Rill WL, Malli R, Hewetson J, Naseem H, Tammariello R, Kende M. Intranasal stimulation of long-lasting immunity against aerosol ricin challenge with ricin toxoid vaccine encapsulated in polymeric microspheres. Vaccine 1996; 14:1031-8. [PMID: 8879098 DOI: 10.1016/0264-410x(96)00063-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Intranasal (i.n.) immunization with ricin toxoid (RT) vaccine encapsulated in poly (lactide-co-glycolide) microspheres (RT-PLG-Ms) and poly (L-lactide) microspheres (RT-PLA-Ms) stimulated systemic and mucosal immune responses and protected mice from aerosolized ricin intoxication. High titers of anti-ricin IgG2a were stimulated in the serum of mice with one or two doses of RT-Ms 6 weeks postimmunization. However, in the lungs, no IgG2a or total IgG was elicited either with RT-Ms or with aqueous RT. At 6 weeks postimmunization, a single dose of the RT-Ms stimulated secretory IgA (sIgA) in the lungs of four of six mice, but a second immunizing dose did not enhance the stimulation. A single dose of aqueous RT vaccine failed to stimulate sIgA in the lungs, while, a second dose induced sIgA in 50% of the mice. One or two i.n. doses of RT-Ms protected most of the mice against lethal aerosol-delivered ricin toxin 6 weeks postimmunization. In contrast, protection was absent or marginal after one or two doses of aqueous RT vaccine. In both studies, the protection against lethal aerosol challenge was significantly better with one dose of RT-Ms than with two doses of aqueous vaccine, which may be attributed to the induction of sIgA in the lungs and the serum. Duration of the IgG2a and IgA in the serum, particularly that of IgG2a was much longer after the administration of RT-Ms than after the aqueous vaccine. The geometric mean IgG2a titers stimulated with two doses of RT-Ms remained high during 40 weeks postimmunization and were up to 25 times higher than the titers induced with aqueous RT vaccine. After 6 weeks, the IgG2a induced by two doses of aqueous vaccine was no longer detectable. Persistence of antibody response was predictive of efficacy. At 1 year postimmunization with two doses of RT-Ms, 100% of mice were protected against lethal ricin challenge. However, at the same time no protection was afforded by two doses of aqueous RT. The results of the present study consistently demonstrated the advantages of microencapsulated RT vaccine to stimulate effective and long-lasting protection by i.n. administration.
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Jaspan JB, Sullivan K, Garry RF, Lopez M, Wolfe M, Clejan S, Yan C, Tenenbaum S, Sander DM, Ahmed B, Bryer-Ash M. The interaction of a type A retroviral particle and class II human leukocyte antigen susceptibility genes in the pathogenesis of Graves' disease. J Clin Endocrinol Metab 1996; 81:2271-9. [PMID: 8964863 DOI: 10.1210/jcem.81.6.8964863] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We have previously reported that over 85% of patients with Graves' disease have detectable serum antibodies against a human intracisternal type A retroviral particle (HIAP), which are not present in age- and gender-matched controls, suggesting a role for HIAP in triggering the autoimmune process leading to Graves' disease. To investigate the interaction of this viral particle with genetic factors, 35 members of 3 kindreds, selected because of a high family prevalence of Graves' disease (a total of 11 members affected), were examined for clinical signs of thyroid dysfunction, goiter, and opthalmopathy. Thyroid function tests and autoimmune serological profiles were also obtained. In addition, subjects were tested for the presence of antibodies against HIAP by means of immunoblot analysis of their sera, and their human leukocyte antigen (HLA) class II alleles were determined by DNA methodology. Molecular genetic analyses enabled the detection of postulated HLA susceptibility haplotypes in each family. These families had 8, 4, and 5 members, respectively, with such apparent susceptibility genes and 11, 5, and 9 members, respectively, with immunological evidence of retroviral exposure. In the presence of both factors (codetected in a total of 15 members of the 3 kindreds), the incidence of Graves' disease was 100%, 67%, and 80%, respectively. One additional member of family B and 3 in family C with both viral and genetic susceptibility factors were found to have serological abnormalities and/or goiter and ocular signs consistent with evolving or preclinical Graves' disease. In families A and C, tight linkage between HLA haplotypes and Graves' disease was demonstrated in a manner consistent with recessive inheritance. The association between the occurrence of both anti-HIAP-I antibody positivity and HLA susceptibility and the presence of Graves' disease was highly significant (P < 0.001). The pathogenesis of Graves' disease in these families appears to be attributable to the interaction between the immune response to an intracisternal type A retroviral particle and immunogenetic susceptibility, leading to the autoimmune processes that underlie Graves' disease, with subsequent development of the characteristic features of the illness. Data from these families suggest that both of these factors are necessary for final disease expression. These results imply that serological evidence of retroviral exposure together with genetic HLA susceptibility are the two major predisposing factors underlying the pathogenesis of Graves' disease. Further studies will establish whether prospective identification of persons at risk for Graves' disease is possible by this means.
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Shen X, Yan C, Zhou J. [Relationship between lead content in umbilical blood and neurobehavioral development in infants]. ZHONGHUA YU FANG YI XUE ZA ZHI [CHINESE JOURNAL OF PREVENTIVE MEDICINE] 1996; 30:68-70. [PMID: 8758849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
One hundred and thirty-two babies were selected and their umbilical blood lead level were determined as a marker to reflect their exposure, to study the diagnostic criteria for lead poisoning in young children. And, mental development index (MDI) and psychomotor development index (PDI) of three-month babies in Bayley scales of infant development were used as effective indicators to study levels of lead on their development. Results indicated that both MDI and PDI in infants with blood lead levels of greater than or equal to 0.48 mumol/L were obviously lower than those with less than 0.48 mumol/L. All children were divided into two groups (high-blood-lead and low-blood-lead) according to the cut-off values for blood lead of 0.72, 0.48, and 0.24 mumol/L, respectively, and the difference in MDI and PDI between the two groups decreased gradually with the cut-off value shifted down, and there was no difference in them between the two groups when the cut-off point lowering down to 0.24 mumol/L. Therefore, the authors recommended that a level of 0.48 mumol/L of blood lead be used as diagnostic criteria for lead poisoning in young children.
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Dulay MT, Yan C, Rakestraw DJ, Zare RN. Automated capillary electrochromatography: reliability and reproducibility studies. J Chromatogr A 1996; 725:361-6. [PMID: 8900577 DOI: 10.1016/0021-9673(95)01000-9] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The routine application of capillary electrochromatography (CEC) is demonstrated by incorporating 75 microns I.D. capillaries packed with 3 microns octadecylsilica (ODS) particles into a commercial CZE instrument. A mixture of several neutral compounds is separated into its components with an average efficiency up to 181 000 plates/m in less than 8 min. Hundreds of consecutive runs are performed over a period of weeks from which it is concluded that the reproducibility of the capacity factors is better than 2% and that CEC separations can be achieved in a reliable and routine manner.
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280
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Jensen JA, Yan C, Kummel AC. Direct chemisorption site selectivity for molecular halogens on the Si(111)-(7 x 7) surface. PHYSICAL REVIEW LETTERS 1996; 76:1388-1391. [PMID: 10061708 DOI: 10.1103/physrevlett.76.1388] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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281
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Yan C, Sever Z, Whitsett JA. Upstream enhancer activity in the human surfactant protein B gene is mediated by thyroid transcription factor 1. J Biol Chem 1995; 270:24852-7. [PMID: 7559607 DOI: 10.1074/jbc.270.42.24852] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Surfactant protein B (SP-B) is selectively expressed in bronchiolar and alveolar epithelial cells of the lung. We identified an upstream enhancer located in the 5'-flanking region of the human SP-B gene (-439 to -331 base pair, hSP-B(-439/-331)) by deletion analysis of SP-B-luciferase constructs assessed in transfection assays in vitro. The element cis-activated the expression of an SV40 promoter-luciferase reporter gene in a human pulmonary adenocarcinoma cell line (H441-4). Three distinct binding sites for the nuclear transcription protein, thyroid transcription factor 1 (TTF-1), were identified, and the purified TTF-1 homeodomain was bound to bhe region of hSP-B(-439/-331). Co-transfection of H441-4 cells with the expression vector pCMV-TTF-1 trans-activated the native human SP-B promoter and the SV40 promoter fused with the SP-B enhancer. Mutations of the TTF-1 binding sites in the upstream enhancer blocked TTF-1 binding and transactivation activity. In summary, TTF-1 interacts with distinct proximal (-80 to -110) and distal (-439 to -331) cis-acting elements than regulate lung epithelial cell-specific transcription of the human SP-B gene.
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282
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Yan C, Zhao AZ, Bentley JK, Loughney K, Ferguson K, Beavo JA. Molecular cloning and characterization of a calmodulin-dependent phosphodiesterase enriched in olfactory sensory neurons. Proc Natl Acad Sci U S A 1995; 92:9677-81. [PMID: 7568196 PMCID: PMC40865 DOI: 10.1073/pnas.92.21.9677] [Citation(s) in RCA: 131] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The sensing of an odorant by an animal must be a rapid but transient process, requiring an instant response and also a speedy termination of the signal. Previous biochemical and electrophysiological studies suggest that one or more phosphodiesterases (PDEs) may play an essential role in the rapid termination of the odorant-induced cAMP signal. Here we report the molecular cloning, expression, and characterization of a cDNA from rat olfactory epithelium that encodes a member of the calmodulin-dependent PDE family designated as PDE1C. This enzyme shows high affinity for cAMP and cGMP, having a Km for cAMP much lower than that of any other neuronal Ca2+/calmodulin-dependent PDE. The mRNA encoding this enzyme is highly enriched in olfactory epithelium and is not detected in six other tissues tested. However, RNase protection analyses indicate that other alternative splice variants related to this enzyme are expressed in several other tissues. Within the olfactory epithelium, this enzyme appears to be expressed exclusively in the sensory neurons. The high affinity for cAMP of this Ca2+/calmodulin-dependent PDE and the fact that its mRNA is highly concentrated in olfactory sensory neurons suggest an important role for it in a Ca(2+)-regulated olfactory signal termination.
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Villacres EC, Wu Z, Hua W, Nielsen MD, Watters JJ, Yan C, Beavo J, Storm DR. Developmentally expressed Ca(2+)-sensitive adenylyl cyclase activity is disrupted in the brains of type I adenylyl cyclase mutant mice. J Biol Chem 1995; 270:14352-7. [PMID: 7782295 DOI: 10.1074/jbc.270.24.14352] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The type I Ca(2+)-sensitive adenylyl cyclase has been implicated in several forms of synaptic plasticity in vertebrates. Mutant mice in which this enzyme was inactivated by targeted mutagenesis show deficient spatial memory and altered long term potentiation (Wu, Z. L., Thomas, S. A., Villacres, E. C., Xia, Z., Simmons, M. L., Chavkin, C., Palmiter, R. D., and Storm, D. R. (1995) Proc. Natl Acad Sci. U. S. A. 92, 220-224). Long term potentiation in the CA1 region of the rat hippocampus develops during the first 2 weeks after birth and reaches maximal expression at postnatal day 15 with a gradual decline at later stages of development. Here we report that Ca(2+)-stimulated adenylyl cyclase activity in rat hippocampus, cerebellum, and cortex increases significantly between postnatal days 1-16. This increase appears to be due to enhanced expression of type I adenylyl cyclase rather than type VIII adenylyl cyclase, the other adenylyl cyclase that is directly stimulated by Ca2+ and calmodulin. Type I adenylyl cyclase mRNA in the hippocampus increased 7-fold during this developmental period. The developmental expression of Ca(2+)-stimulated adenylyl cyclase activity in mouse brain was attenuated in mutant mice lacking type I adenylyl cyclase. Changes in expression of the type I adenylyl cyclase during the period of long term potentiation development are consistent with the hypothesis that this enzyme is important for neuroplasticity and spatial memory in vertebrates.
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284
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Yan C, Diels JC. Two-dimensional imaging and three-dimensional reconstruction of low reflectivity surfaces by using the range-gating upconversion second-harmonic method. APPLIED OPTICS 1995; 34:2993-2997. [PMID: 21052453 DOI: 10.1364/ao.34.002993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Three-dimensional images of objects with very low reflectivity are obtained through a nonlinear upconversion gating with amplified femtosecond laser pulses. The current sensitivity of 10(-10) of the incident pulse intensity can be improved by use of better nonlinear crystals and higher-intensity gating pulses. The intensity rejection ratio between two coherent pulses with a delay of a few millimeters between them is better than 2 orders of magnitude. The depth resolution is ~15 µm. The transverse resolution of 300 µm is mainly limited by the two-dimensional detector that was used.
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285
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Yan C, Rill WL, Malli R, Hewetson J, Tammariello R, Kende M. Dependence of ricin toxoid vaccine efficacy on the structure of poly(lactide-co-glycolide) microparticle carriers. Vaccine 1995; 13:645-51. [PMID: 7668034 DOI: 10.1016/0264-410x(94)00026-j] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Biodegradable microparticles made of poly(lactide-co-glycolide) (PLG) were used for protracted and pulsed-release of the incorporated ricin toxoid (RT) vaccine to reduce the multiple immunization doses and the time required to induce complete protection against lethal aerosol-borne ricin challenge. The release rate of RT encapsulated in PLG microparticles was controlled by polymer selection and varying the preparation procedures, which allowed us to control microparticle size and the distribution of the vaccine in the polymeric matrix. PLG-microparticles in which RT vaccine was distributed heterogeneously in small pockets stimulated a rapid antibody response which was independent of the polymeric composition of the carriers. PLG-microparticles in which RT vaccine was distributed homogeneously throughout the polymeric matrix induced a slower antibody response, which depended on the polymeric composition of the carriers. Administration of RT in homogeneous microparticles made from 50/50 PLG or 100% polylactide stimulated two distinct anti-ricin IgG peaks, while RT in heterogeneous microparticles stimulated identical IgG peaks. An early (3 weeks) and long-lasting (1 year or longer) anti-ricin antibody response was evoked by a single administration of encapsulated RT vaccine when prepared by the above-mentioned conditions. In contrast, three administrations of the aqueous RT were required to stimulate similar antibody response. Reduction of immunization time from 6 to 4 weeks was achieved with RT encapsulated in small homogeneous microparticles but not with homogeneous large microparticles. These results demonstrated the usefulness of biodegradable microparticles to improve the efficacy of immunization with RT vaccine and probably many other vaccines as well.
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286
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Jensen JA, Yan C, Kummel AC. Energy Dependence of Abstractive Versus Dissociative Chemisorption of Fluorine Molecules on the Silicon (111)-(7X7) Surface. Science 1995; 267:493-6. [PMID: 17788782 DOI: 10.1126/science.267.5197.493] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Scanning tunneling microscopy and monoenergetic molecular beams have been used to obtain real-space atomic images of the competition between abstractive and dissociative chemisorption. The size distribution of Si-F adsorbates on the Si(111)-(7x7) surface was examined as a function of the incident translational energy of the F(2) molecules. For F(2) molecules with 0.03 electron volt of incident energy, the dominant adsorbate sites were isolated Si-F species. As an F(2) molecule with low translational energy collides with the surface, abstraction occurs and only one of the F atoms chemisorbs; the other is ejected into the gas phase. For F(2) molecules with 0.27 electron volt of incident energy, many adjacent Si-F adsorbates (dimer sites) were observed because F(2) molecules with high translational energy collide with the surface and chemisorb dissociatively so that both F atoms react to form adjacent Si-F adsorbates. For halogens with very high incident energy (0.5-electron volt Br(2)), dissociative chemisorption is the dominant adsorption mechanism and dimer sites account for nearly all adsorbates.
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Liu JW, Andrews PC, Mershon JL, Yan C, Allen DL, Ben-Jonathan N. Peptide V: a VGF-derived neuropeptide purified from bovine posterior pituitary. Endocrinology 1994; 135:2742-8. [PMID: 7988466 DOI: 10.1210/endo.135.6.7988466] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The objective of this study was to purify PRL-releasing factor (PRF) from the bovine posterior pituitary (PP) and determine its structure. Five hundred bovine PPs were acid extracted and fractionated using gel filtration chromatography followed by semipreparative and analytical HPLC. PRF activity was determined by an in vitro bioassay. After six chromatographic steps, a single peak with PRF activity was resolved. As determined by mass spectrometry and microsequencing, this peak contained a major peptide composed of 30 amino acids with a mol wt of 3708K. A synthetic peptide was then produced by solid-phase synthesis. When tested both in vivo and in vitro, the synthetic peptide lacked PRF activity. Further HPLC fractionation under different conditions resolved the synthetic peptide from a highly purified PRF activity. This indicated that the isolated peptide was coincidentally eluted with PRF during the purification. The major isolated peptide has 94% identity with a sequence at the C-terminus of a rat protein named VGF. VGF is a nerve growth factor-inducible protein that has been identified in PC12 cells and is localized in selected sites throughout the central nervous system. The isolated peptide has an Arg-Arg cleavage site at its junction within the VGF protein. Based on this information, we named this substance Peptide V (VGF-derived peptide). We postulate that Peptide V is: 1) a natural cleavage product of the VGF protein; 2) produced and processed either in the hypothalamus or within the pituitary proper, and 3) a releasable peptide that fulfills one or more endocrine functions.
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288
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Sagawa M, Saito Y, Takahashi S, Sato M, Kamma K, Usuda K, Endo C, Yan C, Sakurada A, Aikawa K. [Significance of surgical treatment for bone metastasis from lung cancer]. KYOBU GEKA. THE JAPANESE JOURNAL OF THORACIC SURGERY 1994; 47:1001-6. [PMID: 7990276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
To assess significance of surgical therapy for patients who had metastatic bone tumor from primary lung cancer, sites of recurrence in patients who underwent surgical resection for lung cancer lesions were analyzed. Clinical courses of patients who underwent surgical therapy for metastatic bone tumor were analyzed, too. 1) From 1985 to 1989, 88 patients died from lung cancer in our hospital who has underwent pulmonary resection for lung cancer lesions. Of these, 22 patients had metastatic bone tumor. Sixty patients died who had underwent complete resection for lung cancer lesions. In eight patients of these 60 cases, bone were first site of recurrence. Of these eight patients, length from pulmonary resection to detection of bone metastasis were 4-23 months. In the other hand, length from detection of bone metastasis of death were 3-24 months. There was no correlation between two length. All of these eight patients had another metastatic lesions at the time of death. 2) From 1985 to July 1993, twelve patients underwent surgical therapy for their bone metastasis of primary lung cancer. Of these, four had metastatic cancer in thoracic vertebral body, two had in clavicle, two had in rib, three had in femoral bone, another had in tibial bone. Objective of operation were improvement of paralysis or pain, prevention of fracture, and so on. Most cases succeeded to get improvement in a short time, but some cases got worse soon. Surgical treatment was effective to improve paralysis or pain, and to increase quality of life. But it can not be effective except appropriate management in a short time because another symptom raise soon.
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289
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Tamai K, Majima A, Yan C. [Hypothermic effects on uveal blood flow and postoperative inflammation in vitrectomy]. NIPPON GANKA GAKKAI ZASSHI 1994; 98:832-6. [PMID: 7976843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Hypothermic effects on uveal blood flow and postoperative inflammation were evaluated in experimental vitrectomy on albino rabbits. Solutions used for intraocular perfusion were maintained at 9 degrees C and 22 degrees C. Following the vitrectomy, the rabbits' intraocular spaces were irrigated for 60 minutes. The temperature at various sites and the uveal blood flow were measured before and during the procedure. Aqueous protein concentrations were checked on postoperative days 1, 7, and 14. Another solution maintained at 37 degrees C was used as a control. There was a larger decrease in temperature at the retina than there was at the choroid and the ciliary body. Blood flow at the ciliary body decreased to 76.0% and 77.0% at the choroid after 60 minutes of irrigation at 9 degrees C. The decrease at 22 degrees C were 91.0% and 88.3%, respectively. Aqueous protein concentrations at both 9 degrees C and 22 degrees C were significantly lower than at 37 degrees C on the first postoperative day in the eyes irrigated for 60 minutes. In the eyes irrigated for 30 minutes, however, no significant differences were seen. Hypothermia during a prolonged vitrectomy operation seems to decrease inflammation in early postoperative stages.
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290
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Shoukri M, Abdul-Razzak A, Yan C. Hysteresis effects in countercurrent gas-liquid flow limitations in a vertical tube. CAN J CHEM ENG 1994. [DOI: 10.1002/cjce.5450720404] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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291
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Yan C, Jensen JA, Kummel AC. Large island formation versus single-site adsorption for Cl2 chemisorption onto Si(111)-7 x 7 surfaces. PHYSICAL REVIEW LETTERS 1994; 72:4017-4020. [PMID: 10056358 DOI: 10.1103/physrevlett.72.4017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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292
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Dong ZW, Yan C, Yi W, Cui YQ. Detection of congenital cytomegalovirus infection by using chorionic villi of the early pregnancy and polymerase chain reaction. Int J Gynaecol Obstet 1994; 44:229-31. [PMID: 7909761 DOI: 10.1016/0020-7292(94)90171-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVE To detect congenital cytomegalovirus (CMV) infection of chorionic villi in early pregnancy. METHODS Extraction of DNA of chorionic villi and amplification of the gene of major immediate-early (MIE) antigen of CMV using a polymerase chain reaction (PCR). RESULTS Sixty-eight specimens of chorionic villi and 16 specimens were positive for CMV infection by PCR. The incidence of congenital CMV infection in the first trimester of pregnancy was 23.5%. CONCLUSIONS The risk of transmission of CMV from mother to fetus in early pregnancy is very high and potential CMV carriers may transmit CMV to their fetus in early pregnancy.
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293
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Yan C, Bentley JK, Sonnenburg WK, Beavo JA. Differential expression of the 61 kDa and 63 kDa calmodulin-dependent phosphodiesterases in the mouse brain. J Neurosci 1994; 14:973-84. [PMID: 8120637 PMCID: PMC6577557] [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] Open
Abstract
Based on their relative abundance and regulation by Ca2+ and by phosphorylation in vitro, it is thought that the Ca2+/calmodulin-dependent phosphodiesterases (CaM-PDEs) are important modulators of cyclic nucleotide function in the brain. Two of the most abundant CaM-PDEs in the brain are the 61 kDa and 63 kDa isozymes. In this study, the regional and cellular expression of mRNA encoding these two different isoforms in mouse brain has been determined by in situ hybridization. The 63 kDa CaM-PDE mRNA has a wide-spread but uneven distribution. Very strong hybridization signals are present in the caudate-putamen, nucleus accumbens, olfactory tubercle, and dentate gyrus of the hippocampus. Somewhat lesser amounts of 63 kDa CaM-PDE mRNA are present in the olfactory bulb and piriform cortex. Weaker but still easily discernible hybridization signals are seen in several layers of the cerebral cortex, CA1 and CA3 regions of the hippocampus, amygdaloid nuclear complex, thalamus, hypothalamus, midbrain, brainstem, cerebellum, and spinal cord. A weak hybridization signal was detected in the globus pallidus of the basal ganglia. In general, the distribution of the 63 kDa CaM-PDE is very similar to that of dopamine receptors, suggesting that it may modulate dopamine function. In contrast, the 61 kDa CaM-PDE mRNA has a more limited and much different distribution, with the highest level of expression in the cerebral cortex and in the pyramidal cells of the hippocampus. A moderate hybridization signal was detected in the medial habenula and amygdaloid nuclear complex. In addition, small subsets of neurons in several other regions showed specific hybridization. Both PDE mRNAs appear to be localized exclusively in neuronal cell bodies. Their distinct distribution suggests important but different physiological roles for these two isozymes in the regional regulation of cyclic nucleotides in the CNS. Since these two isozymes are differentially phosphorylated by cAMP-dependent and Ca2+/CaM-dependent protein kinases, the differential expression also provides a potential mechanism by which these PDEs can differentially regulate cAMP and cGMP in different brain areas. The high expression levels in specific subsets of neurons also suggest that agents increasing Ca2+ in these neurons will increase the rate of cyclic nucleotide degradation.
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Yan C, Mélèse T. Multiple regions of NSR1 are sufficient for accumulation of a fusion protein within the nucleolus. J Cell Biol 1993; 123:1081-91. [PMID: 8245119 PMCID: PMC2119886 DOI: 10.1083/jcb.123.5.1081] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
NSR1, a 67-kD nucleolar protein, was originally identified in our laboratory as a nuclear localization signal binding protein, and has subsequently been found to be involved in ribosome biogenesis. NSR1 has three regions: an acidic/serine-rich NH2 terminus, two RNA recognition motifs, and a glycine/arginine-rich COOH terminus. In this study we show that NSR1 itself has a bipartite nuclear localization sequence. Deletion of either basic amino acid stretch results in the mislocation of NSR1 to the cytoplasm. We further demonstrate that either of two regions, the NH2 terminus or both RNA recognition motifs, are sufficient to localize a bacterial protein, beta-galactosidase, to the nucleolus. Intensive deletion analysis has further defined a specific acidic/serine-rich region within the NH2 terminus as necessary for nucleolar accumulation rather than nucleolar targeting. In addition, deletion of either RNA recognition motif or point mutations in one of the RNP consensus octamers results in the mislocalization of a fusion protein within the nucleus. Although the glycine/arginine-rich region in the COOH terminus is not sufficient to bring beta-galactosidase to the nucleolus, our studies show that this domain is necessary for nucleolar accumulation when an RNP consensus octamer in one of the RNA recognition motifs is mutated. Our findings are consistent with the notion that nucleolar localization is a result of the binding interactions of various domains of NSR1 within the nucleolus rather than the presence of a specific nucleolar targeting signal.
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Yan C, Tamm I. Identification of a new interferon-alpha/beta-inducible DNA-binding protein that interacts with the regulatory element A of 2',5'-oligoadenylate synthetase ME-12 gene. JOURNAL OF INTERFERON RESEARCH 1992; 12:425-30. [PMID: 1289410 DOI: 10.1089/jir.1992.12.425] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A new interferon (IFN)-stimulated response factor (ISRF) has been identified in nuclear extracts of IFN-alpha/beta-treated murine BALB/c-3T3 fibroblasts by the mobility-shift electrophoresis assay. The factor, ISRF-2, displays murine 2',5'-oligoadenylate (2-5A) synthetase ME-12 gene 5' regulatory element A specificity and differs from the previously described IFN response element B-specific factor ISRF-1 in several aspects. ISRF-2 is restricted to the nucleus, whereas ISRF-1 exists in the cytoplasm and translocates into the nucleus upon treatment of cells with IFN-alpha/beta. The ionic strength requirement of ISRF-2 for maximal DNA-binding activity is lower than that of ISRF-1. The DNA-binding activity of ISRF-2, but not that of ISRF-1, is markedly suppressed by Mg2+. In common with ISRF-1, the phosphorylated form of ISRF-2 appears to be required for DNA-binding activity. A model is proposed for the mechanism whereby murine IFN-alpha/beta regulates 2-5A synthetase ME-12 gene expression.
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Abstract
An all-optical three-dimensional imaging system based on direct upconversion of depth-resolved images is described. Femtosecond gating of the signal provides a depth resolution in the microm range and a discrimination of the image against scattered light.
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297
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Yan C, Tamm I. Molecular cloning and characterization of additional factors that bind to the interferon-alpha/beta response element B of the murine (2'-5')oligoadenylate synthetase ME-12 gene. Proc Natl Acad Sci U S A 1992; 89:8859-63. [PMID: 1409578 PMCID: PMC50023 DOI: 10.1073/pnas.89.19.8859] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The function of interferon (IFN) response elements (IREs) may be classified into two classes according to the location of the IRE in the polymerase II transcription promoter: located upstream of the core promoter, or located within the core promoter. Thus, the IRE-binding factors (IREBFs) can serve as sequence-specific transcription factors that activate IFN-inducible gene transcription and they can participate in preinitiation complex formation. In the murine and human (2'-5')oligoadenylate synthetase genes the IRE is located within the core promoter region. For this reason, it is important to isolate cDNAs encoding protein factors that can bind to this IRE and determine their functional roles in the regulation of expression of the IFN-inducible (2'-5')oligoadenylate synthetase gene. We have isolated three groups of cDNAs that encode IREBFs. Here we report on clone 38 cDNA, which contains an open reading frame encoding a protein of 277 amino acids that is designated IREBF-2. The C terminus of IREBF-2 is extremely proline-rich and contains a high percentage of short-armed amino acids. IREBF-2 shares marked similarity with some gene products of the herpes group of viruses. These gene products are potent transcription activators. IREBF-2 is constitutively expressed in BALB/c 3T3 cells.
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298
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Kondo T, Kurokawa H, Fujiwara M, Toyama H, Sakakura K, Ishii J, Nomura M, Yan C, Xu SQ, Hishida H. Evaluation of the effect of PTCR/PTCA by 99mTc-MIBI myocardial imaging in acute and old myocardial infarction. Chin Med J (Engl) 1992; 105:822-7. [PMID: 1291199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
This study is to clarify the ability of technetium-99m-Hexakis-2-methoxyisobutyl isonitrile(MIBI) myocardial scintigraphy for assessment of the effect of PTCR/PTCA as compared with conventional thallium-201 myocardial scintigraphy (201Tl). 99mTc-MIBI (740-888MBq) was injected before emergency PTCR/PTCA, and the initial imaging was performed immediately after PTCR/PTCA in 4 patients with acute myocardial infarction (AMI). On the other hand, in 2 patients with old myocardial infarction (OMI), 201Tl and MIBI myocardial imagings were performed before and one week after rescue PTCA. The defect area on the follow-up MIBI imaging was smaller than that on the initial MIBI imaging in 2 patients with successful emergency PTCR/PTCA. But in the other 2 AMI patients with unsuccessful reperfusion, the defect area did not significantly decrease after PTCR/PTCA. Reperfusion was successful in one of the two patients with OMI. In both the two patients with OMI, the MIBI defect area did not significantly decrease after rescue PTCA. MIBI myocardial scintigraphy is a useful noninvasive method for evaluating the effect of emergency PTCR/PTCA for myocardial salvage in patients with AMI, because MIBI is a kit type agent, and it does not redistribute.
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299
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Chen X, Wu Y, Zhong D, Li L, Tan T, Xie X, Yan C, Li X. [Hepatic carcinoma treated by hepatic arterial embolization using 131I and chemotherapeutic agent gelatin microspheres: report of 9 cases]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1992; 23:420-3. [PMID: 1338993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Nine patients with inoperable hepatoma were treated by using hepatic arterial embolization 131I and chemotherapeutic agent gelatin microsphere (131I-CA-GM). The emission CT after operation detected that the microspheres were concentrated on tumor area. The ratio between the radioactivity in tumor and that in liver was 4.1:1. A case died of ictopic embolization; the others survived 3, 4, 5, 19, 24, 7, 8, and 12 months respectively. Three of them were still alive. 131I-CA-GM has triple anticarcinogenic actions, including the arterial occlusion, targeting chemotherapy and internal radiation. The microspheres can selectively accumulate in the tumor artery and can be easily traced by gamma-camera or emission CT. 131I-CA-GM is a hopeful embolic agent for the treatment of liver cancer, but some problems about ectopic arterial embolization should be further studied.
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300
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Lai M, Diels JC, Yan C. Transversely pumped 11-pass amplifier for femtosecond optical pulses. APPLIED OPTICS 1991; 30:4365-4367. [PMID: 20717209 DOI: 10.1364/ao.30.004365] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
An off-axis near-concentric interferometer is used for multiple passages through a small (2-mm-diameter) cylindrical volume of amplifying dye. The gain volume is pumped transversely by a copper-vapor laser, in a geometry designed for uniform pump. Pulse-to-pulse reproducibility better than 1% is obtained by operating with full saturation and using a solvent with a vanishing temperature-induced change in index of refraction (dn/dT = 0).
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