751
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Yu W, Santhanagopalan V, Sewell AK, Jensen LT, Winge DR. Dominance of metallothionein in metal ion buffering in yeast capable of synthesis of (gamma EC)nG isopeptides. J Biol Chem 1994; 269:21010-5. [PMID: 8063718] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The relationship of yeast metallothionein (MT) and (gamma EC)nG isopeptides (phytochelatins) in metal ion buffering was assessed. The effect of constitutive expression of yeast metallothionein (MT) genes on accumulation of metal-(gamma EC)nG isopeptide (phytochelatin) complexes was analyzed in Candida glabrata and Schizosaccharomyces pombe cultures incubated in the presence of cadmium salts. Constitutive expression of the Saccharomyces cerevisiae MT (CUP1) gene inhibited the accumulation of metal-phytochelatin complexes in both C. glabrata and S. pombe. Intracellular Cd(II) sequestration occurred by formation of CdMT complexes. Phytochelatin (gamma EC)nG complexes appear to function in metal buffering in cells when MT genes are not present or expressed. A third condition in which metal-(gamma EC)nG complexes are observed is when constitutively expressed MT does not accumulate. We observed that C. glabrata lacking the AMT1 gene necessary for copper induction of the MT genes expressed MTII constitutively, but this expression does not lead to CdMTII accumulation. Only Cd-(gamma EC)nG complexes accumulate. Likewise, metal exposed cultures of S. cerevisiae (cup1) transformed with C. glabrata MTII under the constitutive ADH1 promoter resulted in constitutive expression of MTII and accumulation of CuMTII complexes but no CdMTII complexes. The inability of constitutively expressed C. glabrata MTII to buffer Cd(II) ions may arise in part from an inherent kinetic lability of CdMTII complexes. Incubation of ZnMTII with a metallochromic chelator, 4-(2-pyridylazo)resorcinol resulted in greater Zn(II) loss than Zn(II) complexes with CUP1 MT and C. glabrata MTI. C. glabrata MTII appears to be the first MT described which forms an unstable Cd(II) complex.
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Affiliation(s)
- W Yu
- Department of Medicine, University of Utah Health Science Center, Salt Lake City 84132
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752
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Abstract
The quinoxaline NBQX (2,3-dihydroxy-6-nitro-7-sulfamoylbenzo (F) quinoxaline) is a potent non-NMDA receptor antagonist, which appears to be relatively free of antagonistic action at the glycine binding site of the NMDA receptor. However, we report here that at 50 microM, NBQX significantly attenuated the inhibitory currents induced by the exogenous application of 100 microM glycine as observed using whole-cell recordings from ganglion cells in a slice preparation of the tiger salamander retina. In contrast, NBQX had no effect on GABA-mediated inhibition. This observation suggests that care should be taken when attributing the action of NBQX solely to its antagonism of non-NMDA glutamate receptors, particularly when higher concentrations are used.
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Affiliation(s)
- W Yu
- Department of Physiology, University of Minnesota, Minneapolis 55455
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753
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Yu W, Santhanagopalan V, Sewell A, Jensen L, Winge D. Dominance of metallothionein in metal ion buffering in yeast capable of synthesis of (gamma EC)nG isopeptides. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)31922-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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754
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Sullivan JL, Yu W, Saied SO. ARXPS and LEISS characterizations for chemically etched and ion-bombarded GaAs(100) surfaces. SURF INTERFACE ANAL 1994. [DOI: 10.1002/sia.7402201109] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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755
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Lustig RH, Hua P, Yu W, Ahmad FJ, Baas PW. An in vitro model for the effects of estrogen on neurons employing estrogen receptor-transfected PC12 cells. J Neurosci 1994; 14:3945-57. [PMID: 8207498 PMCID: PMC6576956] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Estrogen alters neurite outgrowth, neuritic spine development, and synaptogenesis in estrogen-responsive areas of the rat brain. However, examination of the specific effects of estrogen on neurons in vivo has been difficult. An in vitro model for the effects of estrogen on neurons was developed, using the PC12 rat pheochromocytoma cell line. Wild-type cells (PC12-WT) were stably transfected either with an expression vector coding for the full-length cDNA for the human estrogen receptor (hER), or with a control vector. Resultant clones were isolated, screened for incorporation of vector and expression of ER mRNA and protein, and analyzed for morphologic responses to estrogen. PC12-WT, NEO9 (ER-negative), and SER8 (ER-positive) cells exposed to 100 ng/ml NGF exhibited dose-responsive neurite outgrowth within 2 d by light microscopy (LM). Coadministration of 10(-10) to 10(-9) M estradiol (E2) had minimal effects on neurite outgrowth, neuritic spine development, or interneuritic connections in NEO9 or PC12-WT cells, but in SER8 cells E2 led to additive and dose-dependent increases in neurite outgrowth, spine development, and interneuritic connectivity. Coincubation of SER8 cells with E2 and the antiestrogen ICI 164,384 negated estrogenic effects on spine development and interneuritic connectivity. At the electron microscopic (EM) level, intercellular abutments of NEO9 or PC12-WT cells contained few and rudimentary gap junctions, with no increase by E2. However, SER8 cells exhibited augmented basal frequencies of gap junctions that increased with E2 incubation. Microinjection of Lucifer yellow into PC12-WT and NEO9 cells demonstrated low frequencies of dye coupling and no change with E2, but SER8 cells demonstrated increased dye-coupling frequency with E2 coincubation. The results suggest that SER8 cells recapitulate estrogen effects on neurons in vivo. Estrogen appears to induce an inherent neural morphologic program in estrogen receptor (ER)-containing cells. These three cell lines provide a unique in vitro system for studying mechanisms of estrogen-neuron interactions.
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Affiliation(s)
- R H Lustig
- Department of Pediatrics, University of Wisconsin, Madison 53792
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756
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Jiang YL, Yu W, Fan S, Lang WJ, Chen ZQ. [Clinical application of cluster analysis in repairing prosthesis ears]. Shanghai Kou Qiang Yi Xue 1994; 3:71-3. [PMID: 15160143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Along with developments and progresses of microsurgery,plastic surgery became very often used method to reconstruct orofacial defects,but for missing ears the prosthesis methods are still a better way comparing surgery The main merits are :no wound,short treatment time,100% success rate,easily figure established.For simplified steps and saving time in the procedure of making prosthesis ears.300 different types ears from recording cases models are analysed and special different type wax-up ears and special models are made to provide different patients as needing for selection.
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Affiliation(s)
- Y L Jiang
- Department of Prosthodontics,School of Stomatology,Shanghai Second Medical University. Shanghai 200011,China
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757
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Abstract
BACKGROUND/AIMS Enteroendocrine cell subpopulations are uniquely distributed along the crypt-villus and cephalocaudal axes of the small intestine. These regional differences in enteroendocrine cell expression, which are maintained in spite of rapid turnover of the epithelium, serve as descriptive markers of physiological differences along the length of the bowel. This study aimed to determine the influence of luminal contents on the maintenance of regional differentiation patterns of enteroendocrine and enterocytic phenotypes. METHODS Sections of jejunum and ileum were surgically transposed in rats, leaving the innervation and blood supply to the transposed segments intact. The animals were killed 1, 4, and 8 weeks after surgery. Enteroendocrine cell subpopulations and enterocytic cell markers were studied immunohistochemically. RESULTS No change in regional expression patterns was seen in response to the altered luminal environment by any of the enterocytic markers and four of the five enteroendocrine cell subpopulation markers. Eight weeks after surgery, the number of gastrin-expressing enteroendocrine cells increased in ileal segments transplanted proximally. CONCLUSIONS Although luminal signals can affect intestinal stem cells to alter their proliferation rates, the luminal environment has only limited effects on the regional-specific expression of enteroendocrine or enterocytic products.
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Affiliation(s)
- K D Aiken
- Department of Pathology, Washington University School of Medicine, St. Louis, Missouri
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758
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Yu W, Baas PW. Changes in microtubule number and length during axon differentiation. J Neurosci 1994; 14:2818-29. [PMID: 8182441 PMCID: PMC6577472] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Hippocampal neurons in culture initially extend several minor processes that are approximately 20 microns in length. The first minor process to grow approximately 10 microns longer than the others will continue to grow rapidly and become the axon (Goslin and Banker, 1989). We sought to define changes in the microtubule (MT) array that occur during axon differentiation. In theory, axon differentiation could involve an increase in MT number, MT length, or some combination of both. To address this issue, we first serially reconstructed the entire MT array of a minor process from a cell whose axon had not yet differentiated. This minor process contained 182 MTs that ranged in length from 0.14 to 20.09 microns. The average MT length was 3.87 +/- 3.83 microns, and the total MT length was 704 microns. We then reconstructed the MT arrays of a minor process and the 56 microns axon from a cell that had undergone axon differentiation. The minor process contained 157 MTs that ranged in length from 0.24 to 17.95 microns. The average MT length was 3.91 +/- 4.84 microns, and the total MT length was 600 microns. The axon contained 1430 MTs that ranged in length from 0.05 to 40.14 microns. The average MT length was 4.02 +/- 5.28 microns, and the total MT length was 5750 microns. These data indicate that a shift occurs toward shorter as well as longer MTs, but that virtually no change in average MT length occurs during axon differentiation. Thus, elongation of existing MTs cannot account for the major expansion of the MT array that occurs as a minor process becomes an axon. In contrast, the number of MTs increases by approximately 10-fold as a minor process differentiates and grows into an axon of the length we analyzed. Based on these data, we conclude that the MT array of a minor process is substantially expanded as it differentiates into an axon, and that the principal mechanism by which this expansion occurs is the copious addition of new MTs.
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Affiliation(s)
- W Yu
- Department of Anatomy, University of Wisconsin Medical School, Madison 53706
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759
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May J, White G, Waugh R, Yu W, Harris J. Treatment of complex abdominal aortic aneurysms by a combination of endoluminal and extraluminal aortofemoral grafts. J Vasc Surg 1994; 19:924-33. [PMID: 8170049 DOI: 10.1016/s0741-5214(94)70020-6] [Citation(s) in RCA: 144] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
PURPOSE The purpose of this study was to test the hypothesis that abdominal aortic aneurysms (AAA) whose morphology makes them unsuited for repair with an endoluminal tube graft can be treated by a combination of a transluminally placed aortofemoral graft and a femorofemoral crossover graft. In addition the technique involves either ligation or balloon occlusion of the contralateral common iliac and internal iliac arteries in such a manner that excludes the AAA from the circulation. METHODS We report the use of this technique in three male patients with 6.4 to 7.0 cm diameter AAA. Two had renal impairment and cardiac function too poor to permit open repair, and the third had an unfavorable abdomen caused by previous surgery and the presence of a permanent colostomy. Each patient had an individually tailored Dacron tube graft constructed on the basis of preoperative arteriograms and computed tomography scans. The grafts were delivered transluminally into the aorta through a sheath in the iliac arteries and anchored proximally with a stainless steel stent under radiographic control. The grafts were then anastomosed distally to the femoral artery. RESULTS Recovery was complicated by a midgraft stenosis corrected by percutaneous balloon dilation in one patient, an episode of pulmonary edema in the second and an unexplained pyrexia in the third. Follow-up with duplex scanning confirmed normal flow through the grafts and the presence of thrombus between the prosthetic graft and the aneurysmal sac. CONCLUSIONS We conclude that transluminal placement of an aortofemoral graft combined with a femorofemoral crossover graft is feasible in patients who are unsuited to repair with an endoluminal tube graft. The outcome with this technique is not known and requires further careful evaluation.
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Affiliation(s)
- J May
- Department of Vascular Surgery, Royal Prince Alfred Hospital, Sydney, NSW, Australia
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760
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Yu W, Martin SA. Enhancement of ion transmission at low collision energies via modifications to the interface region of a spectrometer. J Am Soc Mass Spectrom 1994; 5:460-469. [PMID: 24222601 DOI: 10.1016/1044-0305(94)85062-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/1993] [Revised: 01/12/1994] [Accepted: 01/12/1994] [Indexed: 06/02/2023]
Abstract
The transmission efficiency of precursor and product ions decreases significantly at lower collision energies in a four-sector tandem mass spectrometer. In an effort to improve the overall ion transmission in this energy regime three modifications were made in the interface region between the two stages of mass analysis. An einzel lens was inserted prior to the deceleration lens of the collision cell block to reduce the precursor ion beam diameter. The collision cel1 block was reduced in thickness while maintaining the collision path length, thus increasing the number of ions which entered and exited the gas chamber, while removing any stray electrical fields. Finally, a second active focusing element was incorporated after the collision cell block to enhance the collection efficiency of the product ions. A tandem mass spectrum of angiotensin I obtained with this interface, at a collision cell block potential of 9200 volts, exhibited classical high energy collision-induced dissociation (CID) fragmentation patterns, a precursor ion transmission of 92% and an overall CID efficiency of approximately 7.5%. These improvements have resulted in a dramatically higher overall ion transmission at high collision cell potentials as well as sufficient sensitivity in acquiring good quality CID spectra in the lower collision energy regime (i.e., 60 eV). (460-469).
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Affiliation(s)
- W Yu
- Genetics Institute, One Butt Road, 01810, Andover, MA
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761
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Yu W, Wang Y, Xie Y. [Kaschin-Beck's disease in children's wrists: radiographic findings]. Zhongguo Yi Xue Ke Xue Yuan Xue Bao 1994; 16:126-9. [PMID: 7987939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Based on the analysis of hand radiographs in 208 children with Kaschin-Beck's disease, the author's chief conclusions are as follow: The more severe Kaschin-Beck's is, the more opportunity the carpals have to be involved. Generally speaking, the capitatum and hamatum are frequently involved if the disease involves the carpals.
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Affiliation(s)
- W Yu
- PUMC Hospital, CAMS, Beijing
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762
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Wan X, Yu W, Yang H, al-Abdullah I, Coddington D, Bitter-Suermann H, Wright JR. Long-term survival of Wistar-Furth islet allografts in Lewis rats is associated with spontaneously tolerated orthotopic liver allografts. Transplant Proc 1994; 26:723-4. [PMID: 8171625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- X Wan
- Department of Pathology, Izaak Walton Killam (IWK) Children's Hospital, Halifax, Nova Scotia, Canada
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763
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Zhiqiang M, Mingliang T, Shun T, Jian Z, Yang X, Yu W, Chunyi X, Yuheng Z. Modulation structure in Bi2(La1-xCa1+x)CuO6.5+ delta and (Bi2-xPbx)LaCaCuO6.5+ delta systems. Phys Rev B Condens Matter 1994; 49:6265-6269. [PMID: 10011612 DOI: 10.1103/physrevb.49.6265] [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: 11/07/2022]
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764
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Yu W, Stroud D. Vortex motion and vortex-friction coefficient in triangular Josephson-junction arrays. Phys Rev B Condens Matter 1994; 49:6174-6184. [PMID: 10011599 DOI: 10.1103/physrevb.49.6174] [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] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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765
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Abstract
Connexin43 is the major protein of gap junctions in heart and smooth muscle including the myometrium. Molecular cloning of the connexin43 gene reveals a similar organization to that exhibited by other connexin genes: the 5' untranslated region is interrupted by an 8.5 kilobase intron. The promoter region preceding the first exon contains a TATA box and AP-1 and AP-2 sites. In addition, a series of half-palindromic oestrogen response elements is present in this region. When this promoter is linked to the reporter gene luciferase, it drives the expression of luciferase constitutively in HeLa cells transfected with this luciferase-connexin43 promoter fusion construct. When the same cells are cotransfected with oestrogen receptor cDNA, an upregulation of luciferase expression by oestrogen occurs in a cell-specific manner.
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Affiliation(s)
- W Yu
- Department of Biochemistry and Molecular Biology, University of Miami, School of Medicine, Florida 33101
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766
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Abstract
Studies have shown that low-level laser irradiation increases the proliferation of fibroblasts in cell culture. The mechanism of action is unknown. Basic fibroblast growth factor (bFGF) is a multifunctional polypeptide that has been detected in most tissues and which supports cell proliferation and differentiation. The purpose of this study was to determine whether laser irradiation (660 nm) can stimulate production of bFGF from fibroblast cells in cell culture. Our study showed that fibroblasts irradiated with laser energy at 2.16 J/cm2 demonstrated increased cell proliferation and enhanced production of bFGF, whereas fibroblasts irradiated with laser energy at 3.24 J/cm2 neither demonstrated increased cell proliferation or an enhanced release of bFGF as compared to the control group. These results provide direct evidence that the proliferation of fibroblasts as a result of stimulation by low level laser irradiation may be associated with the autocrine production of bFGF from fibroblasts.
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Affiliation(s)
- W Yu
- Department of Surgery, Rochester General Hospital, NY
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767
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Abstract
In this study, we characterize from Saccharomyces cerevisiae: 1) a protein that has immunological similarities to human chorionic gonadotropin (hCG), and 2) a binding site for this hCG-like protein which also binds hCG and human luteinizing hormone (hLH). Saccharomyces cerevisiae chorionic gonadotropin-like protein (ScCGLP) was purified in several steps. This protein when analyzed by SDS-PAGE, under nondenaturing conditions, produced two bands, one at 110-kDa, and another at 57.5-kDa. Under denaturing conditions, only the 57.5-kDa band appeared. This 57.5-kDa band also reacted in a Western blot, using a polyclonal antibody directed against hCG. Purified ScCGLP reacted in the following hCG immunoassays: 1) polyclonal rabbit anti-hCG equilibrium assay, 2) carboxyl-tail hCG equilibrium assay, 3) two equilibrium assays using monoclonal antibodies, and 4) free alpha-chain subunit equilibrium assay using a monoclonal antibody. Characterization of hCG/hLH binding sites in Saccharomyces cerevisiae was performed, and the ability of the ScCGLP to displace I125-hCG was also shown. Human CG and hLH were able to compete for I125-hCG binding to Saccharomyces cerevisiae blastospores (Kds of approximately 10(-8) M), while ScCGLP competed with higher affinity (Kd = 9.41 x 10(-10) M). The hCG-like immunoactivity was also present in Saccharomyces growth media, as well as in all brands of commercial beer studied.
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Affiliation(s)
- O Caticha
- Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City
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768
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Abstract
Growth factors are a group of hormone-like polypeptides that have been shown to play a central role in different phases of wound healing. The expression of these growth factors in early wound healing has not been quantified, and the pattern and distribution of these growth factors in early wound healing has not been described completely. Furthermore the quantity and pattern of distribution of these growth factors have not been investigated in early wounds produced by various methods of surgical incision. Comparison of the rate of healing between the CO2 laser wound and the scalpel wound has produced conflicting results. The present immunohistochemical study uses polyclonal antibodies specific for epidermal growth factor (EGF), platelet-derived growth factor (PDGF), transforming growth factor beta (TGF-beta), and basic fibroblast growth factor (bFGF) to observe the pattern and distribution of these growth factors in rat skin wound and elucidate whether there are differences in the expression of these growth factors which might account for the delayed healing of the CO2 laser wounds compared to the scalpel as has been observed by some authors. Our results indicate that EGF, TGF-beta, PDGF, and bFGF are expressed and distributed in same areas of the early skin wound. The area of expression of these growth factors was associated with presence of wound inflammatory cells and wound fibroblasts.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- W Yu
- Department of Surgery, Rochester General Hospital, University of Rochester, New York 14621
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769
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Abstract
A method is described to facilitate extensive abdominal surgery in diabetic rats using temporary renal subcapsular islet isografts. The procedure is performed in three stages--each separated by 2 wk. After each rat is made diabetic (Step 1), an isogenic islet transplant is performed beneath the left renal capsule (Step 2). Step 3 is the operative procedure, followed by a left nephrectomy. Finally, it is shown how the islet isograft can be excised from the nephrectomy specimen and "recycled" into another diabetic rat (Step 2). Using this three step process, it is possible to decrease the mortality rate following orthotropic liver transplantation in diabetic rats from 100% to about 30%. This procedure can also be used to facilitate other extensive surgical procedures in diabetic rats.
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Affiliation(s)
- H Yang
- Department of Pathology, Izaak Walton Killam Children's Hospital, Dalhousie University Faculty of Medicine, Halifax, Nova Scotia, Canada
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770
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Yu W, Wan X, Wright JR, Coddington D, Bitter-Suermann H. Heterotopic liver transplantation in rats: effect of intrahepatic islet isografts and split portal blood flow on liver integrity after auxiliary liver isotransplantation. Surgery 1994; 115:108-17. [PMID: 8284751] [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: 01/29/2023]
Abstract
BACKGROUND Auxiliary heterotopic liver grafts atrophy in the absence of portal venous inflow; evidence suggests that an islet-derived hepatotrophic factor may exist in the portal drainage. Here we examine the effects of intrahepatic islet isografts in maintaining hepatocyte integrity in Wistar Furth rats with one of several types of arterialized auxiliary liver isografts. METHODS In type 1 procedures the auxiliary liver was interposed into the recipient infrarenal vena cava and perfused through the graft portal vein with caval blood. In type 2 procedures the donor infrahepatic vena cava was anastomosed end-to-side to the recipient vena cava and the recipient portal vein was diverted to the graft portal vein. Both types of auxiliary grafts were arterialized; bile duct drainage was through the duodenum. Syngeneic islets were isolated and embolized into the portal veins of one half of the donor type 1 or native type 2 livers (1500 to 1700 islets). Finally, we performed six type 3 procedures in which a type 2 procedure was performed except that the portal blood flow was split so that the portal vein receiving the splenic, gastric, pancreatic, and duodenal drainage supplied the native liver and that the common mesenteric vein supplied the auxiliary graft with equivalent portal blood flow. Atrophy in heterotopic and native livers were compared for the three models after 3 months. RESULTS Intrahepatic islets in type 1 auxiliary liver isografts without portal venous inflow did not prevent graft atrophy. Conversely, native livers deprived of portal venous inflow in our type 2 procedures, regardless of the presence of intrahepatic islet isografts, atrophied relative to auxiliary liver grafts in which portal venous inflow was provided by diverting the recipient's portal vein to the graft. In type 3 recipients atrophy was greater in the native livers than in the grafts. CONCLUSIONS The results of our study suggest that islet-derived factors are not sufficient to prevent hepatocellular atrophy in auxiliary rat liver transplantation models and that a potent hepatotrophic factor may exist in the venous drainage of the bowel distal to the duodenum.
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Affiliation(s)
- W Yu
- Department of Surgery, Dalhousie University Faculty of Medicine, Halifax, Nova Scotia, Canada
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771
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Zhiqiang M, Hongguang Z, Mingliang T, Sun T, Yang X, Yu W, Jian Z, Chunyi X, Yuheng Z. Influence of the incommensurate-modulation structure on the Raman spectra for La- and Pb-doped Bi2Sr2CuOy systems. Phys Rev B Condens Matter 1993; 48:16135-16138. [PMID: 10008186 DOI: 10.1103/physrevb.48.16135] [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]
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772
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May J, White G, Waugh R, Yu W, Harris J. Transluminal placement of a prosthetic graft-stent device for treatment of subclavian artery aneurysm. J Vasc Surg 1993; 18:1056-9. [PMID: 8264035] [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: 01/29/2023]
Abstract
A 78-year-old man was seen with an expanding 5 cm false aneurysm of the right subclavian artery. This was treated by an intraluminal graft-stent device introduced through the brachial artery via a 16 F sheath. The graft was constructed from two polytetrafluoroethylene patches of 0.4 mm thickness and anchored in the subclavian artery by an 8 mm stainless steel stent. The procedure was monitored by an image intensifier. Completion arteriography and postoperative duplex scanning confirmed normal flow through the subclavian artery with no communication between the lumen and the aneurysmal sac. The patient recovered without complication.
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Affiliation(s)
- J May
- Department of Vascular Surgery, Royal Prince Alfred Hospital, University of Sydney, NSW, Australia
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773
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Cupane A, Leone M, Vitrano E, Cordone L, Hiltpold UR, Winterhalter KH, Yu W, Di Iorio EE. Structure-dynamics-function relationships in Asian elephant (Elephas maximus) myoglobin. An optical spectroscopy and flash photolysis study on functionally important motions. Biophys J 1993; 65:2461-72. [PMID: 8312484 PMCID: PMC1225987 DOI: 10.1016/s0006-3495(93)81311-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
In this work we report the thermal behavior (10-300 K) of the Soret band lineshape of deoxy and carbonmonoxy derivatives of Asian elephant (Elephas maximus) and horse myoglobins together with their carbon monoxide recombination kinetics after flash photolysis; the results are compared to analogous data relative to sperm whale myoglobin. The Soret band profile is modeled as a Voigt function that accounts for the coupling with high and low frequency vibrational modes, while inhomogeneous broadening is taken into account with suitable distributions of purely electronic transition frequencies. This analysis makes it possible to isolate the various contributions to the overall lineshape that; in turn, give information on structural and dynamic properties of the systems studied. The optical spectroscopy data point out sizable differences between elephant myoglobin on one hand and horse and sperm whale myoglobins on the other. These differences, more pronounced in deoxy derivatives, involve both the structure and dynamics of the heme pocket; in particular, elephant myoglobin appears to be characterized by larger anharmonic contributions to soft modes than the other two proteins. Flash photolysis data are analyzed as sums of kinetic processes with temperature-dependent fractional amplitudes, characterized by discrete pre-exponentials and either discrete or distributed activation enthalpies. In the whole temperature range investigated the behavior of elephant myoglobin appears to be more complex than that of horse and sperm whale myoglobins, which is in agreement with the increased anharmonic contributions to soft modes found in the former protein. Thus, to satisfactorily fit the time courses for CO recombination to elephant myoglobin five distinct processes are needed, only one of which is populated over the whole temperature range investigated. The remarkable convergence and complementarity between optical spectroscopy and flash photolysis data confirms the utility of combining these two experimental techniques in order to gain new and deeper insights into the functional relevance of protein fluctuations.
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Affiliation(s)
- A Cupane
- Istituto di Fisica, Università di Palermo, Italy
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774
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Yu W, Vath JE, Huberty MC, Martin SA. Identification of the facile gas-phase cleavage of the Asp-Pro and Asp-Xxx peptide bonds in matrix-assisted laser desorption time-of-flight mass spectrometry. Anal Chem 1993; 65:3015-23. [PMID: 8256865 DOI: 10.1021/ac00069a014] [Citation(s) in RCA: 160] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Abundant ions corresponding to the gas-phase cleavage of the Asp-Pro and Asp-Xxx bonds of peptides in the process of matrix-assisted laser desorption were observed using a time-of-flight mass spectrometer equipped with both linear and reflector mass analyzers. Peptides containing the N-terminal sequence, Asp-Pro ... from an endoproteinase Asp-N digest yielded one peak in the molecular ion region in the linear mode and two equally abundant peaks in the reflector mode TOF mass spectra. The lower molecular masses in the reflector mode mass spectra could be eliminated by removing the Asp residue or derivatizing its side-chain carboxyl group. The observed mass differences did not correspond to any amino acid; however, by lowering the potential of the reflector to correct for the energy loss the mass difference was determined to be 115 Da, i.e., Asp. The extent and rate of this decomposition was compared with that obtained using a four-sector tandem mass spectrometer in the MS/MS mode of operation without and with a collision gas at collision cell potentials of 3.0 and 9.86 kV. These data suggest the Asp-Pro peptide bond is more labile than other peptide bonds in the gas phase. Abundant metastable decomposition of internal Asp-Pro bonds was also observed in larger peptides and proteins. Based on these latter data, a mechanism for this gas-phase cleavage is proposed.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- W Yu
- Structural Biochemistry Department, Genetics Institute, Inc., Andover, Massachusetts 01810
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775
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Lawen JG, Yu W, Cook HW, Wright JR. The failure of donor essential fatty acid deficiency to prevent renal allograft rejection in rats. Transplantation 1993; 56:1269-70. [PMID: 8249137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- J G Lawen
- Department of Urology, Dalhousie University Faculty of Medicine, Halifax, Nova Scotia, Canada
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776
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Abstract
The utility of matrix-assisted laser desorption time-of-flight (MALD-TOF) mass spectrometry for the analysis of recombinant glycopeptides is discussed and compared to information which may be obtained by fast atom bombardment mass spectrometry (FABMS) and tandem mass spectrometry (MS/MS). MALD-TOF appears to be 10-100 times more sensitive than FAB MS for the analysis of underivatized glycopeptides, providing qualitative site-specific information regarding the carbohydrate microheterogeneity without the extensive isolation and derivatization procedures required to obtain similar information by FAB MS. Analysis of a digest mixture in the positive and negative ion mode of MALD-TOF indicated that, in mixtures, sialylated glycopeptides are preferentially detected in the negative ion mode. The determination of the molecular masses of a glycopeptide with MALD-TOF prior to and after treatment with a variety of specific glycosidases, often without removal of the buffers, coupled to a comparison of molecular mass information available from a carbohydrate database facilitates the assignment of a carbohydrate composition. The vast majority of the molecular ion signal observed in the linear mode for sialylated glycopeptides are metastable ions. Reflector mass spectra reveal a shift to lower mass consistent with the loss of most of the neuraminic acid residues. The loss of Hex and HexNAc residues is also observed. Sequential lowering of the reflector potential reveals structurally significant fragment ions representing the carbohydrate and peptide portions of the molecule.
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Affiliation(s)
- M C Huberty
- Structural Biochemistry Department, Genetics Institute, Inc., Andover, Massachusetts 01810
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777
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Lu MH, Yu W, Du WH, Chen FT, Wang CH, Zhou ZG, Wan YJ. [Immunohistochemical localization of CEA,EMA and keratin in salivary mucoepidermal carcinoma]. Shanghai Kou Qiang Yi Xue 1993; 2:149-51. [PMID: 15159829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Localizations of CEA,EMA and keration in 19 cases of mucoepidermal carcinomas were investigated using the indirect immunoperoxidase technique.The results showed CEA was negative in normal salivary glands and showed faint reaction in glands near carcinoma tissue.Keratin and EMA were localized in some myoepithelial cells.The positive rates in carcinoma tissue were 78.9%,89.5% and 84.2%,respectively.The positive rates and staining intensity of CEA and EMA in carcinoma tissue gradually decreased with the decline of tumor differentitation,but that of keratin showed no variation.the author consider that CEA and EMA could become good indices in clinically diagnosing mucoepithelial carcinoma and determining tumor differentiation type cell in mucoepidermal carcinoma and have a potential to multiply express the tumor elements of epithelium and/or mesenchyma.
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Affiliation(s)
- M H Lu
- Department of Pathology,Xuzhou First Hospital. Jiangsu 221002,China
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778
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Wang Z, Yu W, Cai Y. Treatment of xenophonia in male youths by extralaryngeal massage and language training. J TRADIT CHIN MED 1993; 13:221-2. [PMID: 8246602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Z Wang
- Zhanjiang Second People's Hospital, Guangdong
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779
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Abstract
We have proposed that microtubules (MTs) destined for axons and dendrites are nucleated at the centrosome within the cell body of the neuron, and are then released for translocation into these neurites (Baas, P. W., and H. C. Joshi. 1992. J. Cell Biol. 119:171-178). In the present study, we have tested the capacity of the neuronal centrosome to act as a generator of MTs for relocation into other regions of the neuron. In cultured sympathetic neurons undergoing active axonal outgrowth, MTs are present throughout the cell body including the region around the centrosome, but very few (< 10) are directly attached to the centrosome. These results indicate either that the neuronal centrosome is relatively inactive with regard to MT nucleation, or that most of the MTs nucleated at the centrosome are rapidly released. Treatment for 6 h with 10 micrograms/ml nocodazole results in the depolymerization of greater than 97% of the MT polymer in the cell body. Within 5 min after removal of the drug, hundreds of MTs have assembled in the region of the centrosome, and most of these MTs are clearly attached to the centrosome. A portion of the MTs are not attached to the centrosome, but are aligned side-by-side with the attached MTs, suggesting that the unattached MTs were released from the centrosome after nucleation. In addition, unattached MTs are present in the cell body at decreasing levels with increasing distance from the centrosome. By 30 min, the MT array of the cell body is indistinguishable from that of controls. The number of MTs attached to the centrosome is once again diminished to fewer than 10, suggesting that the hundreds of MTs nucleated from the centrosome after 5 min were subsequently released and translocated away from the centrosome. These results indicate that the neuronal centrosome is a highly potent MT-nucleating structure, and provide strong indirect evidence that MTs nucleated from the centrosome are released for translocation into other regions of the neuron.
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Affiliation(s)
- W Yu
- Department of Anatomy, University of Wisconsin Medical School, Madison 53706
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780
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Yu W, Xie YZ, Jiang M, Zheng WF, Wang LH, Wang YZ, Xing SZ. CT detection of wrist bone erosion in rheumatoid arthritis. Chin Med J (Engl) 1993; 106:509-13. [PMID: 8243122] [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: 01/29/2023] Open
Abstract
A correlative radiographic and CT study of the wrists of 30 patients with rheumatoid arthritis (RA) was reported. The results showed that sensitivity of CT in detecting wrist erosion is superior to that of conventional radiograph. Accordingly, wrist CT scanning is useful for early diagnosis of RA.
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Affiliation(s)
- W Yu
- Department of Radiology, PUMC Hospital, Beijing
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781
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Zhiqiang M, Chenggao F, Lei S, Zhen Y, Li Y, Yu W, Yuheng Z. Multiple Bi2Sr2-xBaxCuOy microstructures and the effect of element doping (Ba,La,Pb) on the 2:2:0:1 phase. Phys Rev B Condens Matter 1993; 47:14467-14475. [PMID: 10005798 DOI: 10.1103/physrevb.47.14467] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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782
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783
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Di Iorio EE, Yu W, Calonder C, Winterhalter KH, De Sanctis G, Falcioni G, Ascoli F, Giardina B, Brunori M. Protein dynamics in minimyoglobin: is the central core of myoglobin the conformational domain? Proc Natl Acad Sci U S A 1993; 90:2025-9. [PMID: 8446624 PMCID: PMC46013 DOI: 10.1073/pnas.90.5.2025] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The kinetics of CO binding to the horse myoglobin fragment Mb-(32-139), the so-called "mini-Mb," were investigated by laser flash photolysis in 0.1 M phosphate buffer and in buffer with 75% (vol/vol) glycerol. The reaction displays complex time courses that can be approximated satisfactorily only with a sum of five exponentials. The features of the kinetic components and a comparison of the deoxy-minus-carbonyl difference spectra of mini-Mb and horse Mb obtained under equilibrium conditions, with the kinetic difference spectra resulting from the global analysis of the traces recorded between 400 and 450 nm, show that CO binding to mini-Mb is accompanied by large structural changes. In view of the fact that mini-Mb is an approximation of the Mb-(31-105) fragment encoded by the central exon of the Mb gene, this finding is particularly relevant. On the basis of our data and previous reports [De Sanctis, G., Falcioni, G., Giardina, B., Ascoli, F. & Brunori, M. (1988) J. Mol. Biol. 200, 725-733; De Sanctis, G., Falcioni, G., Grelloni, F., Desideri, A., Polizo, F., Giardina, B., Ascoli, F. & Brunori, M. (1992) J. Mol. Biol. 222, 637-643], we propose that the protein fragment encoded by the central exon of the Mb gene is the domain responsible for ligand-linked conformational transitions, while the two terminal fragments dampen the amplitude of the structural changes that accompany ligand binding, thus rendering the protein stable and kinetically more efficient in its physiological function.
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Affiliation(s)
- E E Di Iorio
- Laboratorium für Biochemie I, Eidgenössische Technische Hochschule (ETH), Zurich, Switzerland
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784
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Yu W, do Egito E, Barratt G, Fessi H, Devissaguet J, Puisieux F. A novel approach to the preparation of injectable emulsions by a spontaneous emulsification process. Int J Pharm 1993. [DOI: 10.1016/0378-5173(93)90115-v] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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785
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Abstract
The purpose of this study was to investigate the functional state of the cerebral cortex during Qigong meditation with flash visual evoked potentials (F-VEPs) recorded from the occipital scalp in four groups of adults. The first group included 14 subjects who had exercised in Neiyang Gong for 0.5-5.5 years. The second group was composed of 12 subjects who had practiced Neiyang Gong for only 0.5-3 months. Eleven subjects who had never practiced Qigong before made up the third group and served as control. Eleven Qigong practitioners constituted the fourth group. It was found that F-VEP amplitudes were increased in the first group and decreased in the fourth group with the exception of one subject during Qigong meditation. No significant changes were found in the second group and controls. The results were discussed and it is shown that Qigong mediation may have either facilitative or inhibitory effects on the visual cortex depending on the Qigong methods practiced by different individuals.
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Affiliation(s)
- W Zhang
- Oigong Institute of Shanghai Academy of Traditional Chinese Medicine, Shanghai College of Traditional Chinese Medicine, China
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786
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787
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788
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Yu W, Wan X, Wright JR, Coddington D, Bitter-Suermann H. The effect of intrahepatic islet isografts on liver integrity following heterotopic auxiliary liver isotransplantation in rats. Transplant Proc 1992; 24:2920-1. [PMID: 1466000] [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: 12/27/2022]
Affiliation(s)
- W Yu
- Department of Surgery, Dalhousie University Faculty of Medicine, Halifax, Nova Scotia, Canada
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789
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Yu W, Zhang D, Spreitzer RJ. Sequences of the Chlamydomonas reinhardtii Chloroplast Genes Encoding tRNA and Ribosomal Protein L20. Plant Physiol 1992; 100:1079-80. [PMID: 16653025 PMCID: PMC1075674 DOI: 10.1104/pp.100.2.1079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Affiliation(s)
- W Yu
- Department of Biochemistry, University of Nebraska, Lincoln, Nebraska 68583
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790
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Abstract
Short-term use (less than 1 year) or oral contraceptives has been associated with increased to slightly decreased risks of epithelial ovarian cancer in several studies. To determine what might account for a statistically significant 40% reduction in risk associated with as little as 3 to 6 months of use, a finding previously reported from the Cancer and Steroid Hormone Study, and to consider the implications for mechanisms of pathogenesis, the authors compared numerous characteristics of short-term users of oral contraceptives (41 cases, 412 controls) with those of never users (242 cases, 1,517 controls). The reduced risk among short-term users was consistently restricted to women who stopped using oral contraceptives for medical reasons, which were essentially side effects; there was little evidence of a protective effect among women who stopped for nonmedical reasons. Factors such as age, parity, family history of ovarian cancer, estrogen dose, history of sterilization, and latency (interval from first use) could not account for the finding. These analyses suggest that short-term use of oral contraceptives has little to no effect per se on reducing the risk of epithelial ovarian cancer and that side effects resulting in cessation of oral contraceptive use shortly after it was begun may be indicative of factors that are protective against the disease.
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Affiliation(s)
- T P Gross
- Office of Epidemiology and Biostatistics, Food and Drug Administration, Rockville, MD
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791
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Yu W. [Normal radiographic appearance of the distal ends of the radius and ulna--a correlative radiographic and histologic slab study of the wrists in 50 infants]. Zhongguo Yi Xue Ke Xue Yuan Xue Bao 1992; 14:163-7. [PMID: 1394732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Based on a correlative radiographic and histologic slab study of the wrists in 50 infants who died of unrelated diseases, the author's chief conclusions are as follow: 1) On the wrist radiograph of the infant, bone bark in the Ranvier's groove may appear as a "thorn-like" bony process on the margins of the metaphysis of the radius and ulna. 2) The radiographic appearance of the provisional zone of calcification at the distal ends of the radius and ulna are variable on radiographs of normal wrists, and familiarity with these variations precludes incorrect diagnosis. 3) The locations of the partially convex part of the provisional zone of calcification on the radiograph of the wrist correspond to where the vessels in the epiphyseal cartilage are located.
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792
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Yu W, Harris EB, Hebboul SE, Garland JC, Stroud D. Fractional Shapiro steps in ladder Josephson arrays. Phys Rev B Condens Matter 1992; 45:12624-12627. [PMID: 10001312 DOI: 10.1103/physrevb.45.12624] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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793
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Abstract
Photosynthesis-deficient mutants of the green alga Chlamydomonas reinhardtii were previously shown to arise from nonsense mutations within the chloroplast rbcL gene, which encodes the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (EC 4.1.1.39). Photosynthesis-competent revertants of these nonsense mutants have often been found to be stably heteroplasmic, giving rise to both mutant and revertant cells during mitotic or meiotic divisions under nonselective growth conditions. It was proposed that the stable heteroplasmicity might arise from a balanced polymorphism of suppressor and wild-type alleles of a tRNA gene maintained within the polyploid chloroplast genome. In the present study, we have focused on determining the molecular basis for the heteroplasmicity of one such revertant, named R13-3C, which was recovered from the 18-7G amber (UAG) mutant. Restriction-enzyme analysis and DNA sequencing showed that the amber mutation is still present in the rbcL gene of the revertant strain. In contrast, DNA sequencing of the suspected tRNA(Trp) gene of the revertant revealed a mutation that would change its CCA anticodon to amber-specific CUA. This mutation was found to be heteroplasmic, being present in only 70% of the tRNA(Trp) gene copies. Under nonselective conditions, the suppressor mutation was lost from cells that also lost the revertant phenotype. We conclude that stable heteroplasmicity can arise as a balanced polymorphism of organellar alleles. This observation suggests that additional tRNA suppressors may be identified due to their heteroplasmic nature within polyploid genomes.
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Affiliation(s)
- W Yu
- Department of Biochemistry, University of Nebraska, Lincoln 68583-0718
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794
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Abstract
Analyses of tumor size and breast cancer stage were used to determine whether biased detection of breast cancer could have materially influenced estimates of risk associated with use of oral contraceptives. In a population-based case-control study conducted from 1980-1982, surveillance for breast cancer by breast exams, but not mammography, was found to be strongly linked to use of oral contraceptives. Tumors were slightly smaller and less likely to be late-stage (TNM stage III or IV) in patients who had used oral contraceptives. The net effect of any diagnostic bias on advancing the date of cancer diagnosis, whether from breast exams or other sources, was estimated to be less than 8 weeks. This corresponds to spuriously increasing the risk of early-occurring breast cancer in oral contraceptive users by at most 2.4% (relative risk = 1.024).
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Affiliation(s)
- J J Schlesselman
- Department of Preventive Medicine & Biometrics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814
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795
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Abstract
Biotinylated deoxyadenosine triphosphate (dATP) (Bio-7-dATP) and 3H deoxythymidine triphosphate (dTTP) labeled adenovirus DNA were hybridized in situ to thin sections of Lowicryl K4M-embedded and whole-mount extracted HeLa cells infected with adenovirus. The biotinylated probe was detected by exposing the extracted cells or sections to antibodies against biotin followed by colloidal gold-conjugated secondary antibodies and then critical-point dried while 3H-dTTP labeled probe by electron microscopic autoradiography. On Lowicryl K4M sections, gold particles and silver grains were mainly restricted in the nucleus. Furthermore, whole-mount results suggested that replicating adenovirus DNA is localized on the nuclear matrix of its host cell. In this paper, the described non-radioactive procedures for hybrid detection offered several advantages: a) rapid signal detection; b) superior morphological preservation and spatial resolution; c) precise localization; and d) on Lowicryl K4M sections, signal to noise equivalent to radiolabeling.
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Affiliation(s)
- R Jiao
- Department of Biology, Peking University, Beijing, People's Republic of China
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796
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Abstract
Treatment of purified frog virus 3 (FV3) with nonionic detergent and high salt released an endoribonucleolytic activity and confirmed earlier findings of a virion-associated endonuclease. This observation, coupled with evidence implicating host and viral message destabilization in herpesvirus and poxvirus biogenesis, raised the question of what role, if any, mRNA degradation plays in FV3 replication. To answer this question, Northern analyses of mock- and virus-infected cells were performed using probes for representative host and viral messages. These studies demonstrated that the steady state level of host messages progressively declined during the course of productive FV3 infection, whereas the steady state level of viral messages was not affected. To determine whether the decline in the steady state level of host mRNA was due to virus-induced degradation or to normal turnover coupled to virus-mediated transcriptional shut-off, actin mRNA levels were examined in mock- and virus-infected cells in the presence and absence of actinomycin D. Under these conditions, actin mRNA levels declined more quickly in actinomycin D-treated, virus-infected cells, than in mock-infected cells incubated in the presence of actinomycin D suggesting that the decline in the steady state level of actin mRNA was due to degradation. However, although it appears as if host message degradation is responsible for virus-mediated translational shut-off, the ability of heat-inactivated FV3 to block cellular translation without destabilizing cellular messages indicates that message degradation is not required for translational inhibition. As noted above, the degradation of early FV3 messages was not involved in controlling the transition from early to late gene expression. Furthermore, the presence of abundant, but nontranslated, early messages late in infection, coupled with the inefficient translation of late messages in vitro supported earlier suggestions that FV3 gene expression is controlled, at least in part, at the translational level. Taken together, these results suggest that FV3 regulates gene expression in a unique manner and may be a good model to examine the mechanics of translational control.
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Affiliation(s)
- V G Chinchar
- Department of Microbiology, University of Mississippi Medical Center, Jackson 39216
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797
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Gow BS, Legg MJ, Yu W, Kukongviriyapan U, Lee LL. Does vibration cause poststenotic dilatation in vivo and influence atherogenesis in cholesterol-fed rabbits? J Biomech Eng 1992; 114:20-5. [PMID: 1491582 DOI: 10.1115/1.2895443] [Citation(s) in RCA: 13] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Arterial post-stenotic dilatation (PSD) is a fusiform swelling immediately down-stream to a stenosis. It is characterized by the presence of turbulent blood flow and wall vibration which has been claimed by others to be causal by producing structural weakening. We tested the hypothesis that vibration causes PSD in vivo by attaching electromagnetic and pneumatic vibrators to the aortic wall in chronic rabbits. We also observed whether mechanical vibration of the aorta in vivo influenced the distribution of oil-red-O lesions during one percent dietary cholesterol feeding. Low mass vibration gauges were developed to measure the vibration. Electromechanical vibrators having a ceramic magnet slug within a coil supplied with 50 Hz were glued to the aorta of chronic rabbits and the vibration maintained for an average of 8 weeks. Despite greater amounts of energy imparted to the wall there was no dilatation or difference in oil-red-O staining from the controls. Five weeks vibration at 100 Hz and an amplitude equal to the normal diameter pulse also produced no dilatation. We conclude that vibration does not cause PSD in vivo and suggest that its cause is likely to involve the vascular muscle stimulated by the effect of turbulent flow on the endothelium.
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Affiliation(s)
- B S Gow
- Department of Physiology, University of Sydney, NSW, Australia
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798
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Abstract
A cDNA expression library from Schizosaccharomyces pombe was transformed into Saccharomyces cerevisiae to screen for genes capable of conferring cadmium resistance to S. cerevisiae cells. The cDNA library was cloned into the S. cerevisiae expression vector pDB20 which is designed to express cDNAs via the constitutively-expressed promoter of the gene for alcohol dehydrogenase I (ADH1). Terminator and polyadenylation signals are also provided by the ADH1 gene. Cadmium resistant colonies were shown to arise by a recombination event leading to the exchange of the S. pombe DNA with the chromosomal ADH1 gene and a consequent dramatic increase in the ADH1 gene expression due to the high copy number of the plasmid. The overexpression of ADH1 effectively buffered the cells for cadmium ions by formation of Cd-ADH.
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Affiliation(s)
- W Yu
- University of Utah Medical Center, School of Medicine, Salt Lake City 84132
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799
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Yu W, Spreitzer RJ. Sequences of trnR-ACG and petD that contain a tRNA-like element within the chloroplast genome of Chlamydomonas reinhardtii. Nucleic Acids Res 1991; 19:957. [PMID: 2017378 PMCID: PMC333740 DOI: 10.1093/nar/19.4.957] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- W Yu
- Department of Biochemistry, University of Nebraska, Lincoln 68583-0718
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800
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Yu W, Coddington D, Bitter-Suermann H. Use of crystalloids prior to storage in University of Wisconsin solution is deleterious in liver preservation. Transplant Proc 1991; 23:664-5. [PMID: 1990640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- W Yu
- Department of Surgery, Dalhousie University, Halifax, Nova Scotia, Canada
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