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Craig F, Goldman A. Home management of the dying NICU patient. ACTA ACUST UNITED AC 2004; 8:177-83. [PMID: 15001154 DOI: 10.1016/s1084-2756(02)00223-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2002] [Accepted: 12/02/2002] [Indexed: 10/27/2022]
Abstract
Intensive aggressive medical therapy does not always result in cure. For some neonates it is a futile exercise that may prolong a short life of suffering. In this article, we will discuss the babies for whom aggressive therapy may not be appropriate, and how home centered palliative care can be effectively managed. We will outline the holistic multidisciplinary approach to care, with the parents as primary carers, empowered to make informed choices in the medical care of their dying baby. Symptom management will be discussed, based on the experience of an established palliative care team. We will also look at the practical and emotional preparation for death and bereavement support for the family. We hope that more families will be given the opportunity to spend time at home with their dying baby and that, through appropriate care and support, the memory of this time will be treasured.
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77
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Wiederkehr C, Basavaraj R, Sarrauste de Menthière C, Hermida L, Koch R, Schlecht U, Amon A, Brachat S, Breitenbach M, Briza P, Caburet S, Cherry M, Davis R, Deutschbauer A, Dickinson HG, Dumitrescu T, Fellous M, Goldman A, Grootegoed JA, Hawley R, Ishii R, Jégou B, Kaufman RJ, Klein F, Lamb N, Maro B, Nasmyth K, Nicolas A, Orr-Weaver T, Philippsen P, Pineau C, Rabitsch KP, Reinke V, Roest H, Saunders W, Schröder M, Schedl T, Siep M, Villeneuve A, Wolgemuth DJ, Yamamoto M, Zickler D, Esposito RE, Primig M. GermOnline, a cross-species community knowledgebase on germ cell differentiation. Nucleic Acids Res 2004; 32:D560-7. [PMID: 14681481 PMCID: PMC308789 DOI: 10.1093/nar/gkh055] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
GermOnline provides information and microarray expression data for genes involved in mitosis and meiosis, gamete formation and germ line development across species. The database has been developed, and is being curated and updated, by life scientists in cooperation with bioinformaticists. Information is contributed through an online form using free text, images and the controlled vocabulary developed by the GeneOntology Consortium. Authors provide up to three references in support of their contribution. The database is governed by an international board of scientists to ensure a standardized data format and the highest quality of GermOnline's information content. Release 2.0 provides exclusive access to microarray expression data from Saccharomyces cerevisiae and Rattus norvegicus, as well as curated information on approximately 700 genes from various organisms. The locus report pages include links to external databases that contain relevant annotation, microarray expression and proteome data. Conversely, the Saccharomyces Genome Database (SGD), S.cerevisiae GeneDB and Swiss-Prot link to the budding yeast section of GermOnline from their respective locus pages. GermOnline, a fully operational prototype subject-oriented knowledgebase designed for community annotation and array data visualization, is accessible at http://www.germonline.org. The target audience includes researchers who work on mitotic cell division, meiosis, gametogenesis, germ line development, human reproductive health and comparative genomics.
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78
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Goldman A, Rubin C, Gomez S, Palermo MS, Tasat DR. Functional age-dependent changes in bronchoalveolar lavage rat cells. Cell Mol Biol (Noisy-le-grand) 2004; 50 Online Pub:OL649-55. [PMID: 15579258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2004] [Accepted: 11/12/2004] [Indexed: 05/01/2023]
Abstract
Alveolar macrophages (AM) are located at the first line of non-specific defense against inhaled antigens in the lower respiratory tract and therefore represent the major effector cell in antimicrobial defense. Since children under 2 years are known to manifest increased susceptibility to lung infections we used a rat model to study functional capacities of the AM during different stages of development We analyzed several steps of the phagocytic process (adherence, chemotaxis and ingestion) as well as two different mechanisms of cytotoxicity [antibody dependent cellular cytotoxicity (ADCC) and cytotoxicity triggered by immune complex (ICC)] and tumor necrosis factor (TNF-alpha) secretion. We used young (4-6 weeks old), intermediate (16-25 weeks old) and adult (36-45 weeks old) rats. Adherence and phagocytic capacities of AM were lower in young rats compared to intermediate and adult animals. Chemotaxis towards the C5a complement component was low in the first two months of life, then it increased in the intermediate group and fell again in adults. Bronchoalveolar lavage (BAL) cells from young rats did not produce detectable TNF-alpha levels even when stimulated with phorbol 12-myristate 13-acetate (PMA). When we studied two different cytotoxic mechanisms we found that ICC markedly declines from youth to adulthood while ADCC showed a steady increase from youth to adulthood. In conclusion, our data show differences that may help to explain in part the enhanced susceptibility to pulmonary infections found in young children.
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79
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Goldman A, Graf C, Ramsay M, Leisegang F, Westwood ATR. Molecular diagnosis of cystic fibrosis in South African populations. S Afr Med J 2003; 93:518-9. [PMID: 12939925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023] Open
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80
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Hamada K, Suzaki Y, Goldman A, Ning YY, Goldsmith C, Palecanda A, Coull B, Hubeau C, Kobzik L. Allergen-independent maternal transmission of asthma susceptibility. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:1683-9. [PMID: 12574331 DOI: 10.4049/jimmunol.170.4.1683] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Maternal asthma is a risk factor for development of asthma in children, but mechanisms remain unclear. Offspring of asthmatic mother mice (sensitized and repeatedly exposed to OVA Ag) showed airway hyperresponsiveness and allergic pulmonary inflammation after an intentionally suboptimal OVA sensitization and exposure protocol that had little effect on normal offspring. Similar results were obtained when offspring of OVA-allergic mothers were exposed to an unrelated allergen, casein, indicating that the maternal effect is allergen independent and not transferred by OVA-specific Abs. Premating treatment with neutralizing anti-IL-4 Ab or reduction of maternal allergen exposure abrogated the maternal effect, showing a critical mechanistic role for IL-4 and suggesting an additional benefit of allergen avoidance.
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81
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Whitmore P, Nelligan S, Goldman A, Jones M, Burch M. Resourse implications of ECMO as a bridge to paediatric heart transplant. J Heart Lung Transplant 2003. [DOI: 10.1016/s1053-2498(02)00868-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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82
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Hamada K, Goldsmith CA, Suzaki Y, Goldman A, Kobzik L. Airway hyperresponsiveness caused by aerosol exposure to residual oil fly ash leachate in mice. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2002; 65:1351-1365. [PMID: 12227956 DOI: 10.1080/00984100290071586] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Particulate air pollution is associated with exacerbation of asthma and other respiratory disorders. This study sought to further characterize the pulmonary effects of residual oil fly ash (ROFA), an experimentally useful surrogate for combustion-derived particulates in ambient air. Mice were exposed to aerosols of the soluble leachate of residual oil fly ash (ROFA-s). Physiologic testing of airway function (non invasive plethysmography) showed increased Penh, an index of airway hyperresponsiveness (AHR), in a time- and dose-dependent manner after exposure to ROFA-s. BAL analysis showed a minor influx of neutrophils, which was maximal at 12 h after exposure and essentially resolved by the time point of maximal AHR (48 h after exposure). The AHR caused by ROFA-s was reproduced by a mixture of its major metal components (Ni, V, Zn, Co, Mn, Cu) but not by any individual metal alone. Systemic pretreatment of mice with the antioxidant dimethylthiourea abrogated ROFA-s-mediated AHR. Analysis of mice of varying ages showed that ROFA-s had no marked effect on airway responsiveness of 2-wk-old mice, in contrast to the AHR seen in 3- and 8-wk old mice. ROFA-s-mediated AHR was unchanged in neurokinin 1 receptor knockout mice and in mice treated with an neurokinin antagonist, arguing against a role for this mediator in ROFA-s-mediated effects. Data indicate that ROFA-s mediates AHR in mice through antioxidant-sensitive mechanisms that require multiple metal constituents. Maturational differences in susceptibility to ROFA-induced AHR may be useful for further studies of mechanisms of particle effects.
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83
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Sen S, Jaakola VP, Heimo H, Kivelä P, Scheinin M, Lundstrom K, Goldman A. Development of a scintiplate assay for recombinant human alpha(2B)-adrenergic receptor. Anal Biochem 2002; 307:280-6. [PMID: 12202245 DOI: 10.1016/s0003-2697(02)00041-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A high-throughput solid-phase platform for ligand-binding assays using microtiter plates (Scintiplates) has been developed using the scintillation proximity assay principle. The system has been developed using human alpha(2B)-adrenergic receptor (alpha(2B)-AR) expressed from Semliki Forest virus vectors in CHO cells. Alpha(2B)-AR bind natural (adrenaline and noradrenaline) and synthetic ligands with different affinities to mediate a variety of physiological and pharmacological responses. Antagonist radioligands were used for the binding experiments, and the values obtained for the binding constants with the Scintiplate system are in good agreement with those obtained by the traditional filter-binding assay system. The Scintiplate assay offers the advantages of a high-throughput format over the filter-binding assay and is amenable for screening many compounds rapidly for generation of leads.
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84
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Tuominen VU, Heikinheimo P, Baykov AA, Lahti R, Goldman A. Mechanism of pyrophosphatase catalysed hydrolysis of pyrophosphate by X-ray and neutron diffraction. Acta Crystallogr A 2002. [DOI: 10.1107/s0108767302087056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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85
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Leppanen VM, Bespalov M, Saarma M, Goldman A. Studies on the glial cell-line derived neurotrophic factor (GDNF) co-receptor α1. Acta Crystallogr A 2002. [DOI: 10.1107/s0108767302095806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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86
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Lehtio L, Leppanen VM, Kozarich J, Goldman A. Structure of pyruvate formate-lyase in complex with a natural substrate, pyruvate. Acta Crystallogr A 2002. [DOI: 10.1107/s0108767302089249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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87
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Nummelin H, Merckel M, El Tahir Y, Ollikka P, Skurnik M, Goldman A. Structural studies of a collagen binding fragment ofYersiniaadhesin YadA. Acta Crystallogr A 2002. [DOI: 10.1107/s0108767302096873] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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88
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Smith JH, Goldman A, Macrae D, Smith E, Cassidy J, Haynes SR, Bolton DT, Hamilton JRLH, Hasan A, De Leval M. Deliberate bridging to transplantation in the paediatric age group: initial UK results. Crit Care 2001. [PMCID: PMC3300235 DOI: 10.1186/cc984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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89
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Grech V, Goldman A. Acute respiratory distress syndrome due to cyanotic spell in an infant with tetralogy of Fallot. Pediatr Pulmonol 2001; 32:406-7. [PMID: 11596167 DOI: 10.1002/ppul.1151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Acute respiratory distress syndrome (ARDS) is characterized by fulminant respiratory failure due to noncardiac pulmonary edema. This can be triggered by a heterogeneous group of diseases. We report an unusual case of an infant who developed severe ARDS in association with a severe cyanotic attack due to tetralogy of Fallot.
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90
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Hunt A, Goldman A, Devine T, Phillips M. Transdermal fentanyl for pain relief in a paediatric palliative care population. Palliat Med 2001; 15:405-12. [PMID: 11591092 DOI: 10.1191/026921601680419456] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
This multicentre, observational study examined the efficacy of the therapeutic transdermal fentanyl system (TTS-fentanyl) in children requiring opioids for pain in life-threatening disease. Forty-one children receiving oral morphine (median dose 60 mg/day) transferred to transdermal fentanyl (median dose 25 micrograms/h according with the manufacturer's dose conversion guidelines). Twenty-six children completed the 15-day treatment phase, seven died due to disease progression and eight were withdrawn because of adverse events, inadequate analgesia or a change to parenteral opioids. After 15 days, the median fentanyl dose was 75 micrograms/h (range 25-250). No serious adverse events were attributed to fentanyl. There was a trend toward improved side-effects and convenience with fentanyl. Twenty-three of 26 parents (three missing) and 25 of 26 investigators considered transdermal fentanyl to be better than previous treatment. For all records available (at 15 days or on withdrawal if earlier), 75% (27/36) reported that fentanyl treatment was 'good' or 'very good'. The findings suggest that transdermal fentanyl is both effective and acceptable for children and their families.
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91
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Welch J, Millar D, Goldman A, Heenan P, Stark M, Eldon M, Clark S, Martin NG, Hayward NK. Lack of genetic and epigenetic changes in CDKN2A in melanocytic nevi. J Invest Dermatol 2001; 117:383-4. [PMID: 11511321 DOI: 10.1046/j.0022-202x.2001.01391.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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92
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Liitti S, Matikainen MT, Scheinin M, Glumoff T, Goldman A. Immunoaffinity purification and reconstitution of human alpha(2)-adrenergic receptor subtype C2 into phospholipid vesicles. Protein Expr Purif 2001; 22:1-10. [PMID: 11388793 DOI: 10.1006/prep.2001.1410] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Large quantities of correctly folded, pure alpha(2)-adrenergic receptor protein are needed for structural analysis. We report here the first efficient method to purify human alpha(2)-adrenergic receptor subtype C2 to homogeneity from recombinant yeast Saccharomyces cerevisiae by one-step purification using a monoclonal antibody column (specific for alpha(2)C2). We show that the adrenoceptor antagonist phentolamine stabilized the receptor during purification. We used a very effective chaotropic agent, NaSCN, to elute the receptor from the immunoaffinity column with an overall yield of 34% before reconstitution. Ligand binding of detergent-solubilized, immunoaffinity-purified receptors could not be demonstrated, but partial recovery of ligand binding activity was achieved when purified receptors were reconstituted into phospholipid vesicles. The reconstituted receptors still bound radioligand after storage on ice for 4 weeks. This purification procedure can be easily scaled-up and thus demonstrates the utility of a monoclonal antibody column and NaSCN elution to purify large quantities of G-protein-coupled receptors.
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MESH Headings
- Adrenergic alpha-2 Receptor Antagonists
- Amino Acid Sequence
- Antibodies, Monoclonal
- Blotting, Western
- Chromatography, Affinity/methods
- Chromatography, Gel
- Electrophoresis, Polyacrylamide Gel
- Ethylmaleimide/pharmacology
- Humans
- Ligands
- Liposomes/chemistry
- Liposomes/metabolism
- Molecular Sequence Data
- Phentolamine/metabolism
- Phosphatidylcholines/metabolism
- Protein Binding
- Protein Folding
- Receptors, Adrenergic, alpha-2/genetics
- Receptors, Adrenergic, alpha-2/isolation & purification
- Receptors, Adrenergic, alpha-2/metabolism
- Recombinant Proteins/isolation & purification
- Recombinant Proteins/metabolism
- Saccharomyces cerevisiae/cytology
- Saccharomyces cerevisiae/genetics
- Solubility
- Thiocyanates/pharmacology
- Yohimbine/metabolism
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93
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Zyryanov AB, Pohjanjoki P, Kasho VN, Shestakov AS, Goldman A, Lahti R, Baykov AA. The electrophilic and leaving group phosphates in the catalytic mechanism of yeast pyrophosphatase. J Biol Chem 2001; 276:17629-34. [PMID: 11279052 DOI: 10.1074/jbc.m100343200] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Binding of pyrophosphate or two phosphate molecules to the pyrophosphatase (PPase) active site occurs at two subsites, P1 and P2. Mutations at P2 subsite residues (Y93F and K56R) caused a much greater decrease in phosphate binding affinity of yeast PPase in the presence of Mn(2+) or Co(2+) than mutations at P1 subsite residues (R78K and K193R). Phosphate binding was estimated in these experiments from the inhibition of ATP hydrolysis at a sub-K(m) concentration of ATP. Tight phosphate binding required four Mn(2+) ions/active site. These data identify P2 as the high affinity subsite and P1 as the low affinity subsite, the difference in the affinities being at least 250-fold. The time course of five "isotopomers" of phosphate that have from zero to four (18)O during [(18)O]P(i)-[(16)O]H(2)O oxygen exchange indicated that the phosphate containing added water is released after the leaving group phosphate during pyrophosphate hydrolysis. These findings provide support for the structure-based mechanism in which pyrophosphate hydrolysis involves water attack on the phosphorus atom located at the P2 subsite of PPase.
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94
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Perrin A, Flaud JM, Keller F, Smith MAH, Rinsland CP, Devi VM, Benner DC, Stephen TM, Goldman A. The v(1)+v(3) Bands of the (16)O(17)O(16)O and (16)O(16)O(17)O Isotopomers of Ozone. JOURNAL OF MOLECULAR SPECTROSCOPY 2001; 207:54-59. [PMID: 11336520 DOI: 10.1006/jmsp.2001.8320] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Using 0.002 cm(-1) resolution Fourier transform absorption spectra of an (17)O enriched ozone sample, an extensive analysis of the v(1)+v(3) bands of the (16)O(17)O(16)O and (16)O(16)O(17)O isotopomers of ozone has been performed for the first time. The experimental rotational levels of the (101) vibrational states were satisfactorily reproduced using a Hamiltonian matrix that takes into account the observed rovibrational resonances. More precisely, for (16)O(17)O(16)O, as for the other C(2v)-type ozone isotopomers, it was necessary to account for the Coriolis type resonances linking the (101) rotational levels with the levels of the (200) and (002) vibrational states and the Darling-Dennison interaction coupling the levels of (200) with those of (002). For the C(s)-type isotopomer, namely (16)O(16)O(17)O, as for (16)O(16)O(18)O and (16)O(18)O(18)O, it proved necessary to also account for an additional DeltaK(a)&equals+/-2 resonance involving the rotational levels from (101) and (002) (J.-M. Flaud and R. Bacis, Spectrochimica Acta Part A 54, 3-16 (1998)). Using a Hamiltonian matrix which takes these resonances explicitly into account, precise vibrational energies and rotational and coupling constants were deduced, leading to the following band centers: v(0)(v(1)+v(3))=2078.3496 cm(-1) for (16)O(17)O(16)O and v(0)(v(1)+v(3))=2098.8631 cm(-1) for (16)O(16)O(17)O. Copyright 2001 Academic Press.
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95
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Hyytiä T, Halonen P, Salminen A, Goldman A, Lahti R, Cooperman BS. Ligand binding sites in Escherichia coli inorganic pyrophosphatase: effects of active site mutations. Biochemistry 2001; 40:4645-53. [PMID: 11294631 DOI: 10.1021/bi010049x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Type I soluble inorganic pyrophosphatases (PPases) are well characterized both structurally and mechanistically. Earlier we measured the effects of active site substitutions on pH--rate profiles for the type I PPases from both Escherichia coli (E-PPase) and Saccharomyces cerevisae (Y-PPase). Here we extend these studies by measuring the effects of such substitutions on the more discrete steps of ligand binding to E-PPase, including (a) Mg(2+) and Mn(2+) binding in the absence of added ligand; (b) Mg(2+) binding in the presence of either P(i) or hydroxymethylbisphosphonate (HMBP), a competitive inhibitor of E-PPase; and (c) P(i) binding in the presence of Mn(2+). The active site of a type I PPase has well-defined subsites for the binding of four divalent metal ions (M1--M4) and two phosphates (P1, P2). Our results, considered in light of pertinent results from crystallographic studies on both E-PPase and Y-PPase and parallel functional studies on Y-PPase, allow us to conclude the following: (a) residues E20, D65, D70, and K142 play key roles in the functional organization of the active site; (b) the major structural differences between the product and substrate complexes of E-PPase are concentrated in the lower half of the active site; (c) the M1 subsite is functionally isolated from the rest of the active site; and (d) the M4 subsite is an especially unconstrained part of the active site.
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96
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Merckel MC, Fabrichniy IP, Salminen A, Kalkkinen N, Baykov AA, Lahti R, Goldman A. Crystal structure of Streptococcus mutans pyrophosphatase: a new fold for an old mechanism. Structure 2001; 9:289-97. [PMID: 11525166 DOI: 10.1016/s0969-2126(01)00587-1] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Streptococcus mutans pyrophosphatase (Sm-PPase) is a member of a relatively uncommon but widely dispersed sequence family (family II) of inorganic pyrophosphatases. A structure will answer two main questions: is it structurally similar to the family I PPases, and is the mechanism similar? RESULTS The first family II PPase structure, that of homodimeric Sm-PPase complexed with metal and sulfate ions, has been solved by X-ray crystallography at 2.2 A resolution. The tertiary fold of Sm-PPase consists of a 189 residue alpha/beta N-terminal domain and a 114 residue mixed beta sheet C-terminal domain and bears no resemblance to family I PPase, even though the arrangement of active site ligands and the residues that bind them shows significant similarity. The preference for Mn2+ over Mg2+ in family II PPases is explained by the histidine ligands and bidentate carboxylate coordination. The active site is located at the domain interface. The C-terminal domain is hinged to the N-terminal domain and exists in both closed and open conformations. CONCLUSIONS The active site similiarities, including a water coordinated to two metal ions, suggest that the family II PPase mechanism is "analogous" (not "homologous") to that of family I PPases. This is a remarkable example of convergent evolution. The large change in C-terminal conformation suggests that domain closure might be the mechanism by which Sm-PPase achieves specificity for pyrophosphate over other polyphosphates.
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97
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Heikinheimo P, Tuominen V, Ahonen AK, Teplyakov A, Cooperman BS, Baykov AA, Lahti R, Goldman A. Toward a quantum-mechanical description of metal-assisted phosphoryl transfer in pyrophosphatase. Proc Natl Acad Sci U S A 2001; 98:3121-6. [PMID: 11248042 PMCID: PMC30617 DOI: 10.1073/pnas.061612498] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2000] [Accepted: 12/22/2000] [Indexed: 11/18/2022] Open
Abstract
The wealth of kinetic and structural information makes inorganic pyrophosphatases (PPases) a good model system to study the details of enzymatic phosphoryl transfer. The enzyme accelerates metal-complexed phosphoryl transfer 10(10)-fold: but how? Our structures of the yeast PPase product complex at 1.15 A and fluoride-inhibited complex at 1.9 A visualize the active site in three different states: substrate-bound, immediate product bound, and relaxed product bound. These span the steps around chemical catalysis and provide strong evidence that a water molecule (O(nu)) directly attacks PPi with a pK(a) vastly lowered by coordination to two metal ions and D117. They also suggest that a low-barrier hydrogen bond (LBHB) forms between D117 and O(nu), in part because of steric crowding by W100 and N116. Direct visualization of the double bonds on the phosphates appears possible. The flexible side chains at the top of the active site absorb the motion involved in the reaction, which may help accelerate catalysis. Relaxation of the product allows a new nucleophile to be generated and creates symmetry in the elementary catalytic steps on the enzyme. We are thus moving closer to understanding phosphoryl transfer in PPases at the quantum mechanical level. Ultra-high resolution structures can thus tease out overlapping complexes and so are as relevant to discussion of enzyme mechanism as structures produced by time-resolved crystallography.
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98
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Kapat A, Jaakola VP, Heimo H, Liitti S, Heikinheimo P, Glumoff T, Goldman A. Production and purification of recombinant human alpha 2C2 adrenergic receptor using Saccharomyces cerevisiae. BIOSEPARATION 2001; 9:167-72. [PMID: 11105246 DOI: 10.1023/a:1008150412294] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The objective is to generate milligram quantities of recombinant human alpha 2C2 adrenergic receptor for X-ray crystallographic studies. It has been cloned in Saccharomyces cerevisiae, and the production level is at best about 13 pmol/mg of membrane protein, as estimated by radio-ligand binding assay. The receptor is solubilized with sucrose monolaurate followed by immunoaffinity purification and reconstitution into phospholipid vesicles. The efficiency of solubilization and immuno-purification are 60% and 91%, respectively.
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99
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Diamond JA, Krakoff LR, Goldman A, Coplan N, Gharavi A, Martin K, Goldsmith R, Henzlova MJ, Machac J, Phillips RA. Comparison of two calcium blockers on hemodynamics, left ventricular mass, and coronary vasodilatory in advanced hypertension. Am J Hypertens 2001; 14:231-40. [PMID: 11281234 DOI: 10.1016/s0895-7061(00)01267-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Dihydropyridine and nondihydropyridine calcium channel blockers (CCB) differ in pharmacologic characteristics. Few clinical studies distinguish effects of CCB as monotherapy. We conducted a comprehensive comparison of two CCB on patients with moderate to severe hypertension. Thirty patients with pretreatment diastolic blood pressures > or = 100 mm Hg were randomly assigned to either nifedipine-GITS or verapamil-SR. Dose titration achieved a diastolic blood pressure of < or = 95 mm Hg or a decrease of > or = 15 mm Hg over 4 weeks. Clinic blood pressure (BP), 24-h ambulatory BP, exercise BP, left ventricular mass, systolic and diastolic function by echocardiography, and coronary flow reserve by split-dose thallium-201 imaging with adenosine were assessed at baseline, end of titration, 3 months and 6 months of treatment. Plasma renin activity, atrial natriuretic peptide, norepinephrine, and epinephrine were assayed. Both drugs caused similar reductions in clinic and 24-h ambulatory BP and similar reductions in left ventricular mass index. Compared to nifedipine-GITS, verapamil-SR produced a significantly lower resting and peak exercise heart rate. Nifedipine-GITS elicited a lower peak exercise systolic BP. At end titration nifedipine-GITS produced lower plasma atrial natriuretic peptide levels, no longer apparent by 6 months. Plasma norepinephrine was lower with verapamil-SR, also at end titration and at 3 months, but not at 6 months. Plasma epinephrine and plasma renin activity were unchanged by either drug. There was no difference for systolic or diastolic left ventricular function or coronary flow reserve between the two treatments. Once daily nifedipine-GITS and verapamil-SR are equally effective for reduction of arterial pressure in moderate to severe hypertension. Differences in their hemodynamic profiles and neurohormonal responses are consistent with preclinical pharmacologic characteristics. The clinical implications of their similarities and differences remain to be fully evaluated in outcome studies.
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Tuominen H, Heikinheimo P, Loo BM, Kataja K, Oker-Blom C, Uutela M, Jalkanen M, Goldman A. Expression and glycosylation studies of human FGF receptor 4. Protein Expr Purif 2001; 21:275-85. [PMID: 11237689 DOI: 10.1006/prep.2000.1375] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Fibroblast growth factor receptor subtype 4 (FGFR4) has been shown to have special activation properties and just one splicing form, unlike the other FGFRs. FGFR4 overexpression is correlated with breast cancer and therefore FGFR4 is a target for drug design. Our aim is to overexpress high amounts of homogeneous FGFR4 extracellular domain (FGFR4(ed)) for structural studies. We show that baculovirus-insect cell-expressed FGFR4(ed) is glycosylated on three (N88, N234, and N266) of the six possible N-glycosylation sites but is not O-glycosylated. The deglycosylated triple mutant was expressed and had binding properties similar to those of glycosylated FGFR4(ed), but was still heterogeneous. Large amounts of FGFR4(ed) have been produced into inclusion bodies in Escherichia coli and refolded at least partly correctly but the refolded E. coli-produced FGFR4(ed) still aggregates.
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