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Simonsen KW, Kaa E, Nielsen E, Rollmann D. Narcotics at street level in Denmark. A prospective investigation from 1995 to 2000. Forensic Sci Int 2003; 131:162-70. [PMID: 12590056 DOI: 10.1016/s0379-0738(02)00419-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This article describes an investigation of illicit drugs at street level in six selected police districts in different regions of Denmark. The investigation was carried out during a 6-year period from 1995 to 2000. During the period, a total of 1244 samples were examined, as about 200 samples were seized each year. A total of 94% of the seized samples were familiar drugs: heroin base, heroin hydrochloride, cocaine hydrochloride and amphetamine sulphate. Only 2% of the samples contained designer drugs. From having constituted 53% of the samples in 1995, the frequency of heroin base fell during the period to 27% of the samples in 2000. The frequency of heroin hydrochloride was unchanged. In the same period, the frequency of cocaine hydrochloride increased from 10% of the samples in 1995 to about 25% of the samples in 2000. Apart from a few exceptions, cocaine had the same extension in all regions of Denmark after 1996. Amphetamine was more frequent in the west of Denmark, while heroin hydrochloride was more frequent in central Denmark. The purity of heroin base was lower in the period 1997-1999 than in the other years. During the entire period, the purity of cocaine hydrochloride and amphetamine sulphate fell, while the purity of heroin hydrochloride was unchanged. No significant differences between the various regions of Denmark were detected during the period in the purity of heroin hydrochloride, heroin base, cocaine hydrochloride or amphetamine sulphate. MDMA was the most frequent designer drug, but other types of designer drugs such as MDA and MDE and the less common PMA, PMMA and MBDB were also found.
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Keijsper J, Polm LH, Van Koten G, Vrieze K, Nielsen E, Stam CH. Ruthenium carbonyl 1,4-diaza-1,3-butadiene (R-DAB) complexes. Reactivity of Ru2(CO)5(R-DAB) toward molecular hydrogen. Molecular structure of H2Ru4(CO)8(R-DAB)2, containing an unique linear chain of four ruthenium atoms. Organometallics 2002. [DOI: 10.1021/om00130a014] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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103
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Nielsen E. [The excavation of Odense's St. Jørgensgård. Preliminary results]. DANSK MEDICINHISTORISK ARBOG 2001; 12:39-51. [PMID: 11629291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
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104
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Nielsen E, Severin F, Hyman AA, Zerial M. In vitro reconstitution of endosome motility along microtubules. Methods Mol Biol 2001; 164:133-46. [PMID: 11217603 DOI: 10.1385/1-59259-069-1:133] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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105
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Lyngsoe M, Lundby L, Nielsen E. In virgin territory — With cancer nursing as baggage. Eur J Cancer 2001. [DOI: 10.1016/s0959-8049(01)81974-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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106
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Nielsen E, Christoforidis S, Uttenweiler-Joseph S, Miaczynska M, Dewitte F, Wilm M, Hoflack B, Zerial M. Rabenosyn-5, a novel Rab5 effector, is complexed with hVPS45 and recruited to endosomes through a FYVE finger domain. J Cell Biol 2000; 151:601-12. [PMID: 11062261 PMCID: PMC2185588 DOI: 10.1083/jcb.151.3.601] [Citation(s) in RCA: 342] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Rab5 regulates endocytic membrane traffic by specifically recruiting cytosolic effector proteins to their site of action on early endosomal membranes. We have characterized a new Rab5 effector complex involved in endosomal fusion events. This complex includes a novel protein, Rabenosyn-5, which, like the previously characterized Rab5 effector early endosome antigen 1 (EEA1), contains an FYVE finger domain and is recruited in a phosphatidylinositol-3-kinase-dependent fashion to early endosomes. Rabenosyn-5 is complexed to the Sec1-like protein hVPS45. hVPS45 does not interact directly with Rab5, therefore Rabenosyn-5 serves as a molecular link between hVPS45 and the Rab5 GTPase. This property suggests that Rabenosyn-5 is a closer mammalian functional homologue of yeast Vac1p than EEA1. Furthermore, although both EEA1 and Rabenosyn-5 are required for early endosomal fusion, only overexpression of Rabenosyn-5 inhibits cathepsin D processing, suggesting that the two proteins play distinct roles in endosomal trafficking. We propose that Rab5-dependent formation of membrane domains enriched in phosphatidylinositol-3-phosphate has evolved as a mechanism for the recruitment of multiple effector proteins to mammalian early endosomes, and that these domains are multifunctional, depending on the differing activities of the effector proteins recruited.
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107
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Nielsen E. [Hantavirus disease during pregnancy]. Ugeskr Laeger 2000; 162:5218-9. [PMID: 11043050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Hantavirus infection is known to occur in mice and rats without symptoms. In contrast, an infection with Hantavirus in humans gives influenzalike symptoms and acute renal failure. The treatment is symptomatic, but treatment with dialysis can be necessary for a while. A case of Hantavirus infection in Denmark in a 30 week pregnant woman is reported.
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108
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Breinholt V, Hossaini A, Svendsen GW, Brouwer C, Nielsen E. Estrogenic activity of flavonoids in mice. The importance of estrogen receptor distribution, metabolism and bioavailability. Food Chem Toxicol 2000; 38:555-64. [PMID: 10942316 DOI: 10.1016/s0278-6915(00)00046-6] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The in vivo estrogenic potential of the flavonoids apigenin, kaempferol, genistein and equol was investigated in immature female mice. Genistein and equol, administered by gavage for 4 consecutive days [post-natal day (PND) 17-20, 100 mg/kg body weight], was found to significantly increase uterine weights and the overall uterine concentration of estrogen receptor alpha (ERalpha). In kaempferol- and equol-exposed mice the cytosolic ERalpha concentration was significantly increased as compared to the solvent control, which is speculated to result in an increased sensitivity of the uterus to subsequently encountered estrogens. Oral administration of equol, genistein, biochanin A and daidzein to 6-week-old female mice revealed a great variation in their systemic bioavailability. The urinary recovery of equol was thus over 90% of a single gavage administered dose, whereas the urinary recoveries of biochanin A, genistein and daidzein were 16, 11 and 3%, respectively. Most of the metabolites were either hydroxylated or dehydrogenated forms of the parent compounds. The in vitro estrogenic potency of some of the metabolites was greater than that of the parent compounds, whereas others were of similar or lower potency. Bioavailability, metabolism, the ability to alter ERalpha distribution in the uterus and the estrogenic potential of parent compound and metabolites may thus contribute to the differences in in vivo estrogenicity of dietary flavonoids.
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Gordi T, Nielsen E, Yu Z, Westerlund D, Ashton M. Direct analysis of artemisinin in plasma and saliva using coupled-column high-performance liquid chromatography with a restricted-access material pre-column. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2000; 742:155-62. [PMID: 10892594 DOI: 10.1016/s0378-4347(00)00156-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A previously established HPLC system with post-column derivatization for the analysis of artemisinin was coupled to an ADS (alkyl-diol silica) pre-column, allowing direct and repetitive injection of protein-rich fluids such as plasma. The limit of quantitation for 100 microl of plasma was 10 ng/ml (CV=10.5%) while concentrations down to 2 ng/ml could be quantified for 1.00 ml saliva samples (CV=11.1%). The system was linear in the tested range of 10-2000 ng/ml for plasma and 2-240 ng/ml for saliva samples, respectively. This paper introduces coupled column HPLC as a simplified method for the routine analysis of artemisinin in biological fluids.
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Sönnichsen B, De Renzis S, Nielsen E, Rietdorf J, Zerial M. Distinct membrane domains on endosomes in the recycling pathway visualized by multicolor imaging of Rab4, Rab5, and Rab11. J Cell Biol 2000; 149:901-14. [PMID: 10811830 PMCID: PMC2174575 DOI: 10.1083/jcb.149.4.901] [Citation(s) in RCA: 831] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Two endosome populations involved in recycling of membranes and receptors to the plasma membrane have been described, the early and the recycling endosome. However, this distinction is mainly based on the flow of cargo molecules and the spatial distribution of these membranes within the cell. To get insights into the membrane organization of the recycling pathway, we have studied Rab4, Rab5, and Rab11, three regulatory components of the transport machinery. Following transferrin as cargo molecule and GFP-tagged Rab proteins we could show that cargo moves through distinct domains on endosomes. These domains are occupied by different Rab proteins, revealing compartmentalization within the same continuous membrane. Endosomes are comprised of multiple combinations of Rab4, Rab5, and Rab11 domains that are dynamic but do not significantly intermix over time. Three major populations were observed: one that contains only Rab5, a second with Rab4 and Rab5, and a third containing Rab4 and Rab11. These membrane domains display differential pharmacological sensitivity, reflecting their biochemical and functional diversity. We propose that endosomes are organized as a mosaic of different Rab domains created through the recruitment of specific effector proteins, which cooperatively act to generate a restricted environment on the membrane.
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Thomsen J, Mirz F, Wetke R, Astrup J, Bojsen-Møller M, Nielsen E. Intracranial sarcoma in a patient with neurofibromatosis type 2 treated with gamma knife radiosurgery for vestibular schwannoma. THE AMERICAN JOURNAL OF OTOLOGY 2000; 21:364-70. [PMID: 10821550 DOI: 10.1016/s0196-0709(00)80046-0] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
OBJECTIVE To discuss the possible relationship between stereotactic radiation therapy and the development of a meningosarcoma. STUDY DESIGN Retrospective case review. PATIENT A 19-year-old woman with bilateral vestibular schwannomas (neurofibromatosis type 2). One large tumor was removed totally by the translabyrinthine approach; the other smaller tumor was treated with stereotactic radiation (SRT). Six years after SRT, a malignant tumor (meningosarcoma) developed at the exact site of radiation. The patient subsequently died of this tumor. OUTCOME MEASURE On the basis of literature surveys, the possibility and risk of postirradiation neoplasia after SRT is discussed. Furthermore, the possible causal association between SRT and the development of the meningosarcoma in this case is evaluated. CONCLUSION On the basis of statistical considerations, the development of the reported mesenchymal sarcoma was most likely caused by the stereotactic radiation therapy.
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112
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Thomsen JL, Felby S, Theilade P, Nielsen E. [Alcoholic ketoacidosis]. Ugeskr Laeger 2000; 162:1859-61. [PMID: 10765690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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113
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Nielsen E, Severin F, Backer JM, Hyman AA, Zerial M. Rab5 regulates motility of early endosomes on microtubules. Nat Cell Biol 1999; 1:376-82. [PMID: 10559966 DOI: 10.1038/14075] [Citation(s) in RCA: 430] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The small GTPase Rab5 regulates membrane docking and fusion in the early endocytic pathway. Here we reveal a new role for Rab5 in the regulation of endosome interactions with the microtubule network. Using Rab5 fused to green fluorescent protein we show that Rab5-positive endosomes move on microtubules in vivo. In vitro, Rab5 stimulates both association of early endosomes with microtubules and early-endosome motility towards the minus ends of microtubules. Moreover, similarly to endosome membrane docking and fusion, Rab5-dependent endosome movement depends on the phosphatidylinositol-3-OH kinase hVPS34. Thus, Rab5 functionally links regulation of membrane transport, motility and intracellular distribution of early endosomes.
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Nielsen E. Handbook for administration of cytostatic agents in order to obtain uniformity in dealing with these. Eur J Cancer 1999. [DOI: 10.1016/s0959-8049(99)80594-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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115
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Sanz P, Calvo A, Tobella L, Salazar S, Daher V, Castillo S, Nielsen E, Smok G, Csendes A, Serra I. [Chromosome anomaly and flow cytometry in gallbladder adenocarcinoma]. Rev Med Chil 1998; 126:1301-10. [PMID: 10349172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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116
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Ashbury FD, Cameron C, Mercer SL, Fitch M, Nielsen E. One-on-one peer support and quality of life for breast cancer patients. PATIENT EDUCATION AND COUNSELING 1998; 35:89-100. [PMID: 10026552 DOI: 10.1016/s0738-3991(98)00035-4] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The Canadian Cancer Society's Reach to Recovery program provides one-on-one support for breast cancer patients that is delivered by breast cancer survivors. Professionally-led social support programs have generally been found to influence positively the quality of life of cancer patients. However, there is a lack of evidence on the benefits of one-on-one peer support programs. An evaluation of the Reach to Recovery program was completed in 1995 to determine if cancer patients who received the program were satisfied with the program and to determine if participation in Reach to Recovery affected the quality of life of program participants compared to patients who did not receive the program. We found that Reach to Recovery program participants were generally satisfied with the program they received and that the program has incremental benefits to the quality of life of patients with breast cancer. Peer-led, volunteer breast cancer support programs can be effective in enhancing the quality of life of breast cancer patients.
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Bundgaard H, von Oettingen G, Larsen KM, Landsfeldt U, Jensen KA, Nielsen E, Cold GE. Effects of sevoflurane on intracranial pressure, cerebral blood flow and cerebral metabolism. A dose-response study in patients subjected to craniotomy for cerebral tumours. Acta Anaesthesiol Scand 1998; 42:621-7. [PMID: 9689265 DOI: 10.1111/j.1399-6576.1998.tb05292.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Studies concerning the cerebrovascular effects of sevoflurane in patients with space-occupying lesions are few. This study was carried out as a dose-response study comparing the effects of increasing sevoflurane concentration (1.5% (0.7 MAC) to 2.5% (1.3 MAC)) on cerebral blood flow (CBF), intracranial pressure (ICP), cerebrovascular resistance (CVR), metabolic rate of oxygen (CMRO2) and CO2-reactivity in patients subjected to craniotomy for supratentorial brain tumours. METHODS Anaesthesia was induced with propofol/fentanyl/atracurium and maintained with 1.5% sevoflurane in air/oxygen at normocapnia. Blood pressure was maintained constant by ephedrine. In group 1 (n = 10), the patients received continuously 1.5% sevoflurane. Subdural ICP, CBF and CMRO2 were measured twice at 30-min intervals. In group 2 (n = 10), sevoflurane concentration was increased from 1.5% to 2.5% after CBF1. CBF2 was measured after 20 min during 2.5% sevoflurane. Finally, CO2-reactivity was studied in both groups. RESULTS In group 1, no time-dependent alterations in CBF, CVR, ICP and CMRO2 were found. In group 2, an increase in sevoflurane from 1.5% to 2.5% resulted in an increase in CBF from 29 +/- 10 to 34 +/- 12 ml 100 g-1 min-1 and a decrease in CVR from 2.7 +/- 0.9 to 2.3 +/- 1.2 mmHg ml-1 min 100 g (P < 0.05), while ICP and CMRO2 were unchanged. CO2-reactivity was maintained at 1.5% and 2.5% sevoflurane. CONCLUSION Sevoflurane is a cerebral vasodilator in patients with cerebral tumours. Sevoflurane increases CBF and decreases CVR in a dose-dependent manner. CO2-reactivity is preserved during 1.5% and 2.5% sevoflurane.
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Forlani G, Scainelli D, Nielsen E. [delta]1-Pyrroline-5-Carboxylate Dehydrogenase from Cultured Cells of Potato (Purification and Properties). PLANT PHYSIOLOGY 1997; 113:1413-1418. [PMID: 12223682 PMCID: PMC158265 DOI: 10.1104/pp.113.4.1413] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
[delta]1-Pyrroline-5-carboxylate (P5C) dehydrogenase (EC 1.5.1.12), the second enzyme in the proline catabolic pathway and a catalyst for the oxidation of P5C to glutamate, was purified from cultured potato (Solanum tuberosum L. var Desiree) cells. Homogeneous enzyme preparations were obtained by a three-step procedure that used anion-exchange, adsorption, and substrate elution chromatography. A 1600-fold purification was achieved, with a recovery of one-third of the initial activity. The purified enzyme was characterized with respect to structural, kinetic, and biochemical properties. It appeared to be an [alpha]-4 tetramer with subunits of an apparent molecular mass of about 60 kD and had a mildly acidic isoelectric point value. Potato P5C dehydrogenase had Michaelis constant values of 0.11 and 0.46 mM for NAD+ and P5C, respectively. Although NAD+ was the preferred electron acceptor, NADP+ also yielded an unusually high rate, and thus was found to serve as a substrate. Maximal activity was observed at pH values in the 7.3 to 8.3 range, and was progressively inhibited by chloride ions, a finding that strengthens recent suggestions that hyperosmotic stress negatively modulates in vivo proline oxidation.
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Akita M, Nielsen E, Keegstra K. Identification of protein transport complexes in the chloroplastic envelope membranes via chemical cross-linking. J Cell Biol 1997; 136:983-94. [PMID: 9060464 PMCID: PMC2132478 DOI: 10.1083/jcb.136.5.983] [Citation(s) in RCA: 165] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/1996] [Revised: 01/09/1997] [Indexed: 02/03/2023] Open
Abstract
Transport of cytoplasmically synthesized proteins into chloroplasts uses an import machinery present in the envelope membranes. To identify the components of this machinery and to begin to examine how these components interact during transport, chemical cross-linking was performed on intact chloroplasts containing precursor proteins trapped at a particular stage of transport by ATP limitation. Large cross-linked complexes were observed using three different reversible homobifunctional cross-linkers. Three outer envelope membrane proteins (OEP86, OEP75, and OEP34) and one inner envelope membrane protein (IEP110), previously reported to be involved in protein import, were identified as components of these complexes. In addition to these membrane proteins, a stromal member of the hsp100 family, ClpC, was also present in the complexes. We propose that ClpC functions as a molecular chaperone, cooperating with other components to accomplish the transport of precursor proteins into chloroplasts. We also propose that each envelope membrane contains distinct translocation complexes and that a portion of these interact to form contact sites even in the absence of precursor proteins.
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Nielsen E, Akita M, Davila-Aponte J, Keegstra K. Stable association of chloroplastic precursors with protein translocation complexes that contain proteins from both envelope membranes and a stromal Hsp100 molecular chaperone. EMBO J 1997; 16:935-46. [PMID: 9118955 PMCID: PMC1169694 DOI: 10.1093/emboj/16.5.935] [Citation(s) in RCA: 241] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Cytoplasmically synthesized precursors interact with translocation components in both the outer and inner envelope membranes during transport into chloroplasts. Using co-immunoprecipitation techniques, with antibodies specific to known translocation components, we identified stable interactions between precursor proteins and their associated membrane translocation components in detergent-solubilized chloroplastic membrane fractions. Antibodies specific to the outer envelope translocation components OEP75 and OEP34, the inner envelope translocation component IEP110 and the stromal Hsp100, ClpC, specifically co-immunoprecipitated precursor proteins under limiting ATP conditions, a stage we have called docking. A portion of these same translocation components was co-immunoprecipitated as a complex, and could also be detected by co-sedimentation through a sucrose density gradient. ClpC was observed only in complexes with those precursors utilizing the general import apparatus, and its interaction with precursor-containing translocation complexes was destabilized by ATP. Finally, ClpC was co-immunoprecipitated with a portion of the translocation components of both outer and inner envelope membranes, even in the absence of added precursors. We discuss possible roles for stromal Hsp100 in protein import and mechanisms of precursor binding in chloroplasts.
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Christensen A, Lange P, Nielsen E. SURGERY AND RADIOTHERAPY FOR INVASIVE CANCER OF THE CERVIX. SURGICAL TREATMENT. Acta Obstet Gynecol Scand 1996; 43:59-87. [PMID: 14154707 DOI: 10.3109/00016346409156825] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Steentoft A, Worm K, Pedersen CB, Sprehn M, Mogensen T, Sørensen MB, Nielsen E. Drugs in blood samples from unconscious drug addicts after the intake of an overdose. Int J Legal Med 1996; 108:248-51. [PMID: 8721424 DOI: 10.1007/bf01369819] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
This investigation includes whole blood samples from 53 drug addicts found unconscious in the Copenhagen area with evidence of a heroin overdose. Heroin/morphine was detected in 85% of the patients and other opioids in 11%. One or more benzodiazepines, most often diazepam, were detected in 75% of the patients. A blood alcohol concentration higher than 1.00 mg/g was detected in 57% of the patients. Methadone was detected in seven patients, ketobemidone in four, amphetamine in five and cocaine in one. This investigation showed widespread multi-drug abuse and heroin/morphine alone was detected in only one patient. As indicators of heroin intake, 6-mono-acetylmorphine (MAM) and morphine were detected in this investigation.
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Lübeck J, Soll J, Akita M, Nielsen E, Keegstra K. Topology of IEP110, a component of the chloroplastic protein import machinery present in the inner envelope membrane. EMBO J 1996. [DOI: 10.1002/j.1460-2075.1996.tb00797.x] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Lübeck J, Soll J, Akita M, Nielsen E, Keegstra K. Topology of IEP110, a component of the chloroplastic protein import machinery present in the inner envelope membrane. EMBO J 1996; 15:4230-8. [PMID: 8861951 PMCID: PMC452148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Proteins from both the inner and outer envelope membranes are engaged in the recognition and translocation of precursor proteins into chloroplasts. A 110 kDa protein of the chloroplastic inner envelope membrane was identified as a component of the protein import apparatus by two methods. First, this protein was part of a 600 kDa complex generated by cross-linking of precursors trapped in the translocation process. Second, solubilization with detergents of chloroplasts containing trapped precursors resulted in the identification of a complex containing both radiolabeled precursor and IEP110. Trypsin treatment of intact purified chloroplasts was used to study the topology of IEP110. The protease treatment left the inner membrane intact while simultaneously degrading domains of inner envelope proteins exposed to the intermembrane space. About 90 kDa of IEP110 was proteolitically removed, indicating that large portions protrude into the intermembrane space. Hydropathy analysis of the protein sequence deduced from the isolated cDNA clone in addition to Western blot analysis using an antiserum of IEP110 specific to the N-terminal 20 kDa, suggests that the N-terminus serves to anchor the protein in the membrane. We speculate that IEP110 could be involved in the formation of translocation contact sites due to its specific topology.
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Thomsen JL, Theilade P, Felby S, Nielsen E. [Alcoholic ketoacidosis]. Ugeskr Laeger 1995; 157:7156-7. [PMID: 8545935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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126
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Thomsen JL, Felby S, Theilade P, Nielsen E. Alcoholic ketoacidosis as a cause of death in forensic cases. Forensic Sci Int 1995; 75:163-71. [PMID: 8586340 DOI: 10.1016/0379-0738(95)01783-6] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Forensic pathologists are familiar with alcohol abusers, who are found dead and in whom the cause of death cannot be ascertained. In order to examine the possible role of ketoacidosis for the cause of death in this group of alcohol abusers, the concentrations of ketone bodies (acetone, acetoacetate, D-beta-hydroxybutyrate) were determined in post mortem blood specimens. Determination of the ketone body concentrations were made by a coupled enzymatic head-space gas chromatographic method. The material consisted of blood specimens from 131 deceased persons and was divided into three groups: Group 1: controls, 79 cases of non alcohol abusers; group 2: 35 cases of alcohol abusers with known causes of death and group 3: 17 cases of alcohol abusers without ascertainable cause of death. The geometric means for the sum of the ketone body concentrations in blood were: controls, 109 mumol/l; alcohol abusers with known causes of death, 152 mumol/l; and alcohol abusers without known cause of death, 590 mumol/l. The limit value between the controls and the group of alcoholics with unascertainable cause of death was by logistic regression found to be 531 mumol/l (343-1224 mumol/l). The term 'ketoalcoholic death' is, therefore, suggested, when the measured post mortem blood ketone body concentration in an alcoholic with otherwise unknown cause of death exceeds 531 mumol/l.
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Elphinstone RD, Hearn DJ, Cogger LL, Murphree JS, Singer H, Sergeev V, Mursula K, Klumpar DM, Reeves GD, Johnson M, Ohtani S, Potemra TA, Sandahl I, Nielsen E, Persson M, Opgenoorth H, Newell PT, Feldstein YI. Observations in the vicinity of substorm onset: Implications for the substorm process. ACTA ACUST UNITED AC 1995. [DOI: 10.1029/94ja02938] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Felby S, Nielsen E. Congener production in blood samples during preparation and storage. BLUTALKOHOL 1995; 32:50-8. [PMID: 7880489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The possibility of congener production in blood during storage was studied. The material consisted of 216 blood specimens in which ethanol was not detected. We divided the specimens into two groups, A and B. Group A: 97 specimens were stored at 4 degrees C until alcohol analysis, and only exposed shortly to room temperature during the aseptic preparation for analysis. Group B: 119 specimens were stored at 17 degrees C until alcohol analysis were performed, and the handling during preparation was not aseptic. All specimens were subsequently stored at 4 degrees C. After three to twelve months of storage the blood specimens were analyzed for congeners. None of the forensic important congeners (n-propanol, isobutanol, or butanol-2) were detected in Group A, whereas in Group B n-propanol was detected in fourteen of the specimens, isobutanol in sixteen, and butanol-2 in two specimens.
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Faunø P, Suomalainen O, Rehnberg V, Hansen TB, Krøner K, Soimakallio S, Nielsen E. Prophylaxis for the prevention of venous thromboembolism after total knee arthroplasty. A comparison between unfractionated and low-molecular-weight heparin. J Bone Joint Surg Am 1994; 76:1814-8. [PMID: 7989386 DOI: 10.2106/00004623-199412000-00007] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We compared the efficacy and safety of low-molecular-weight heparin with that of low-dose unfractionated heparin in the prevention of venous thromboembolism after total knee arthroplasty in a prospective, randomized, multicenter trial. One hundred and eighty-five patients were randomly assigned to two groups: ninety-two received low-molecular-weight heparin (forty milligrams of enoxaparin the evening before the operation and once a day subsequently) and ninety-three received unfractionated heparin (5000 international units the evening before the operation and three times a day thereafter). The prophylaxis was continued until bilateral ascending venography was performed six to nine days after the operation or, if venography was not done, until the eighth postoperative day. Venography revealed a prevalence of deep-vein thrombosis of 27 per cent (twenty-five of ninety-three patients) in the group that received unfractionated heparin and 23 per cent (twenty-one of ninety-two patients) in the group that received low-molecular-weight heparin. The difference was not significant (p = 0.6). Five patients (5 per cent) who received unfractionated heparin and 3 patients (3 per cent) who received low-molecular-weight heparin had a deep-vein thrombosis in the proximal veins. Two patients who received unfractionated heparin and one who received low-molecular-weight heparin had clinical symptoms suggestive of a pulmonary embolism. None of these three patients had a positive ventilation-perfusion scan. There were no deaths, major bleeding episodes, or wound hematomas necessitating operative intervention or discontinuation of the anticoagulation in the series.(ABSTRACT TRUNCATED AT 250 WORDS)
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Forlani G, Parisi B, Nielsen E. 5-enol-Pyruvyl-Shikimate-3-Phosphate Synthase from Zea mays Cultured Cells (Purification and Properties). PLANT PHYSIOLOGY 1994; 105:1107-1114. [PMID: 12232268 PMCID: PMC159438 DOI: 10.1104/pp.105.4.1107] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The shikimate pathway enzyme 5-enol-pyruvyl-shikimate-3-phosphate (EPSP) synthase (3-phosphoshikimate-1-carboxyvinyl transferase, EC 2.5.1.19) was purified from cultured maize (Zea mays L. var Black Mexican Sweet) cells. Homogeneous enzyme preparations were obtained by a four-step procedure using ammonium sulfate fractionation, anion- and cation-exchange chromatography, and substrate elution from a cellulose phosphate column. The last step resulted in two well-separated activities of about the same molecular weight. A 2000- to 3000-fold purification, with an overall recovery of one-fourth of the initial activity, was achieved. Both EPSP synthase isoforms were characterized with respect to structural, kinetic, and biochemical properties. Only slight differences are seen in molecular mass, activation energy, and apparent affinities for the two substrates. A more pronounced difference was found between their thermal inactivation rates. Two EPSP synthase isoforms were also elucidated in crude homogenates by anion-exchange fast protein liquid chromatography. This allowed us to follow their expression during a culture growth cycle. One form was found at substantial levels throughout, whereas the other increased in exponentially growing cells and declined in late-logarithmic phase. The analysis of highly purified plastid preparations demonstrated a plastidial localization of both proteins. Possible functional roles for maize EPSP synthase isozymes, with regard to the dual-pathway hypothesis and to the recent findings on defense-related aromatic biosynthesis in higher plants, are discussed.
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131
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Felby S, Nielsen E. Determination of ketone bodies in postmortem blood by head-space gas chromatography. Forensic Sci Int 1994; 64:83-8. [PMID: 8175092 DOI: 10.1016/0379-0738(94)90216-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A method describing determination of the physiological ketone bodies: acetone, acetoacetate, and D-beta-hydroxybutyrate in postmortem blood by head-space gas chromatography. The method involves enzymic dehydrogenation of D-beta-hydroxybutyrate into acetoacetate and quantitative conversion of acetoacetate into acetone. The recoveries of acetone, acetoacetate and D-beta-hydroxybutyrate were 94-100%, 88-104% and 83-91%, respectively.
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132
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Felby S, Nielsen E. The postmortem blood alcohol concentration and the water content. BLUTALKOHOL 1994; 31:24-32. [PMID: 8142086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Determination of blood alcohol concentration and water content were performed on blood specimens from 71 bodies. Two blood specimens were sampled from each body. First-specimens (short-time-specimens) were sampled from 0 to 9.6 hours postmortem, in mean 2.1 hours. Second-specimens (long-time-specimens) were sampled from 8.0 to 229.9 hours postmortem. The relation between the blood alcohol concentration and the blood water content in the two blood specimens (first and second) is described by a multiple regression equation. The equation gave as result: if the body had no signs of putrefaction, the difference in water content between the short-time-specimens and the long-time-specimens has a significant influence on the blood alcohol concentration. This was not the case if the body had visible signs of putrefaction. Then other factors influence the blood alcohol concentration more than the water content. Our study also indicates that if a blood alcohol determination is performed on whole blood, and the blood specimen was sampled shortly after death from a case of bleeding shock, a correction of the blood alcohol concentration should be done if the blood water content is higher than 82%.
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Madsen OD, Karlsen C, Nielsen E, Lund K, Kofod H, Welinder B, Rehfeld JF, Larsson LI, Steiner DF, Holst JJ. The dissociation of tumor-induced weight loss from hypoglycemia in a transplantable pluripotent rat islet tumor results in the segregation of stable alpha- and beta-cell tumor phenotypes. Endocrinology 1993; 133:2022-30. [PMID: 8404649 DOI: 10.1210/endo.133.5.8404649] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We previously established pluripotent transformed rat islet cell lines, MSL-cells, of which certain clones have been used to study processes of islet beta-cell maturation, including the transcriptional activation of the insulin gene induced by in vivo passage. Thus, successive sc transplantation in NEDH rats resulted in stable hypoglycemic insulinoma tumor lines, such as MSL-G2-IN. Occasionally, hypoglycemia as well as severe weight loss were observed in the early tumor passages of MSL-G and the subclone, NHI-5B, which carry the transfected neomycin and human insulin genes as unique clonal markers. By selective transplantation, it was possible to segregate stable anorectic normoglycemic tumor lines, MSL-G-AN and NHI-5B-AN, from both clones. These tumors cause an abrupt onset of anorexia when they reach a size of 400-500 mg (< 0.3% of total body weight), and the observed weight loss parallels that of starved rats until death results from cachexia. After tumor resection, animals immediately resume normal feeding behavior. Comparative studies of hormone release and mRNA content in anorectic lines, MSL-G-AN and NHI-5B-AN, vs. those in the insulinoma line, MSL-G2-IN, revealed selective glucagon gene expression in both of the anorectic tumors, whereas insulin and islet amyloid polypeptide gene expression were confined to the insulinoma. Both tumor phenotypes produced cholecystokinin and gastrin in variable small amounts, making it unlikely that these hormones contribute to the anorectic phenotype. Tumor necrosis factor (cachectin) was not produced by any of the tumors. Proglucagon was processed as in the fetal islet to products representative of both pancreatic alpha-cell and intestinal L-cell phenotypes, with glucagon and Glp-1 (7-36)amide as the major extractable products. In contrast to the administration of cholecystokinin, neither glucagon, Glp-1 (7-36)amide, nor their combination, affected feeding behavior in fasted mice, suggesting the presence of a hitherto unidentified anorectic substance released from the glucagonoma. We conclude 1) that glucagonomas and insulinomas can be derived from a common clonal origin of pluripotent MSL cells, thus supporting the existence of a cell lineage relationship between islet alpha- and beta-cell during ontogeny; and 2) that our glucagonomas release an anorexigenic substance(s) of unknown nature that causes a severe weight loss comparable to that reported in animals carrying tumor necrosis factor-producing experimental tumors.
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Sanz P, Calvo A, Tobella L, Nielsen E, Salazar S, Daher V, Castillo S, Molina G, López F, Morales B. [Chromosome aberrations in gallbladder adenocarcinoma]. Rev Med Chil 1993; 121:1342-3. [PMID: 8191147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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135
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Felby S, Nielsen E. Postmortem blood alcohol concentration. BLUTALKOHOL 1993; 30:244-50. [PMID: 8373563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The relation between the blood alcohol concentration and the vitreous humor alcohol concentration, blood propanol-1 concentration, and the signs of putrefaction of the body was described by a multiple regression equation. The calculations showed that the blood alcohol concentration increased 0.79/1000 when the vitreous humor alcohol concentration increased 1.00/1000, and that a blood propanol-1 content and signs of putrefaction had a significant influence on the postmortem ethanol concentration. The postmortem blood alcohol concentration increased 0.01/1000 in mean when the blood propanol-1 concentration increased 1 mg/kg, and increased 0.05/1000 when the body showed sign of putrefaction. The variance of the blood alcohol concentration between blood within the same body was independent of the ethanol concentration level. The pooled standard deviation was 0.05/1000.
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Rhodes CJ, Thorne BA, Lincoln B, Nielsen E, Hutton JC, Thomas G. Processing of proopiomelanocortin by insulin secretory granule proinsulin processing endopeptidases. J Biol Chem 1993; 268:4267-75. [PMID: 8382698 PMCID: PMC4295213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
A lysed preparation of isolated insulin secretory granules efficiently cleaved murine proopiomelanocortin (mPOMC) at physiologically important Lys-Arg processing sites. This processing was mostly attributed to an activity that co-eluted with the proinsulin processing type-II endopeptidase from anion exchange chromatography (Lys-Arg-directed; Davidson, H. W., Rhodes, C. J., and Hutton, J. C. (1988) Nature 333, 93-96). The principal peptide hormone products generated by the insulin secretory granule lysate were identified by specific radioimmunoassay and NH2-terminal microsequencing analysis of high performance liquid chromatography-separated products as alpha-melanocyte-stimulating hormone, corticotropin-like intermediate, gamma-lipotropin, beta-endorphin-(1-31), 18-kDa NH2-terminal fragment and, to a lesser extent, adrenocorticotrophin and beta-lipotropin. This processing had an acidic pH optimum (pH 5-5.5) and was Ca(2+)-dependent (K0.5 activation = 5-80 microM). With increasing Ca2+ concentrations there was an increase in the extent to which mPOMC was processed. The in vitro processing of mPOMC by the insulin secretory granule endopeptidase activity reported here is in excellent agreement with the in vivo processing of this prohormone by a combination of PC2 and PC3, candidates of prohormone endpeptidase, in gene transfer studies with cells that express the regulated secretory pathway (Thomas, L., Leduc, R., Thorne, B. A., Smeekens, S. S., Steiner, D. F., and Thomas, G. (1991) Proc. Natl. Acad. Sci. U.S.A. 88, 5297-5301).
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Rhodes C, Thorne B, Lincoln B, Nielsen E, Hutton J, Thomas G. Processing of proopiomelanocortin by insulin secretory granule proinsulin processing endopeptidases. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)53605-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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139
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Insunza A, González F, Guzmán E, Nielsen E, Gómez C, Castillo S, Valdés A. [Potter syndrome caused by bilateral renal agenesis and duodenal atresia]. REVISTA CHILENA DE OBSTETRICIA Y GINECOLOGIA 1993; 58:477-480. [PMID: 7991875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A case of Potter syndrome secondary to renal agenesia and duodenal atresia with anular pancreas is presented. The karyotype was 47 XY-21. We discuss the antenatal diagnosis and the perinatal management.
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140
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Bennett DL, Bailyes EM, Nielsen E, Guest PC, Rutherford NG, Arden SD, Hutton JC. Identification of the type 2 proinsulin processing endopeptidase as PC2, a member of the eukaryote subtilisin family. J Biol Chem 1992; 267:15229-36. [PMID: 1634553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Enzymological studies have implicated two Ca(2+)-dependent endopeptidases in the conversion of proinsulin to insulin; a type 1 activity which cleaves on the C-terminal side of Arg31-Arg32 and a type 2 activity which cleaves C-terminally to Lys64-Arg65 in the proinsulin sequence. The possibility that these enzymes are related to the recently discovered family of mammalian subtilisin-like gene products (furin, PC2, and PC3) and the yeast propheromone-converting enzyme (KEX-2), was investigated. Degenerate oligonucleotide primers flanking the putative catalytic domain within this gene family were used in a polymerase chain reaction to amplify related sequences from rat insulinoma cDNA. One major product of 700 base pairs was obtained which was greater than 99% identical to the corresponding rat PC2 sequence. This cDNA was subcloned into the bacterial expression vector pGEX-3X to generate a recombinant protein for antibody production. Western blot analysis showed the immunoreactivity was prominent in neuroendocrine tissues as a 65-kDa protein. It was concentrated in secretory granule-enriched fractions of insulinoma tissue, where it was present as a readily solubilized monomeric protein. Deglycosylation studies using endoglycosidase H and N-glycanase showed that the 65-kDa protein was comprised of approximately 9% carbohydrate, consistent with the presence of three consensus sequences for N-linked glycosylation in rat PC2. The immunoreactivity co-eluted with the type 2 proinsulin endopeptidase on gel filtration and ion-exchange chromatography and the antisera specifically immunoprecipitated type 2 activity from insulin granule extracts. N-terminal sequence analysis of the immunoreactive protein gave two sequences which corresponded to residues 109-112 and 112-119 of rat PC2. This indicated that posttranslational processing of PC2 itself occurs C-terminally to basic amino acids to produce the mature enzyme. It is concluded that PC2 is the type 2 endopeptidase involved in proinsulin conversion. Localization of PC2 immunoreactivity to other tissues of the diffuse neuroendocrine system suggests that the type 2 endopeptidase also functions in the processing of precursor forms of other prohormones and polypeptide neurotransmitters.
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Bennett D, Bailyes E, Nielsen E, Guest P, Rutherford N, Arden S, Hutton J. Identification of the type 2 proinsulin processing endopeptidase as PC2, a member of the eukaryote subtilisin family. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)42170-9] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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142
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Vidal P, Nielsen E, Welinder BS. Effect of glycation on the heterogeneity of human serum albumin analysed by reversed-phase high-performance liquid chromatography in a solvent containing formic acid. JOURNAL OF CHROMATOGRAPHY 1992; 573:201-6. [PMID: 1601952 DOI: 10.1016/0378-4347(92)80120-f] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Non-enzymic glycation of human serum albumin (HSA) induces a change in its charge heterogeneity that may account for its particular renal clearance in patients with early diabetic nephropathy. A new high-performance liquid chromatographic analysis for the study of HSA heterogeneity is described based on a high content of formic acid in the mobile phase combined with a concave gradient of isopropanol. Under these conditions, native HSA was separated into three individual components (I, II and III). When glycated HSA was analysed, it was found that although the present method is not suitable for the separation of glycated from non-glycated HSA, it shows the effect of glycation in producing changes in HSA heterogeneity that are different from those reported on surface change. This finding suggests an additional factor (probably conformational changes) that is contributing to the heterogeneity of glycated HSA.
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Thorleifson LH, Wyatt PH, Shilts WW, Nielsen E. Hudson Bay lowland Quaternary stratigraphy: Evidence for early Wisconsinan glaciation centered in Quebec. GEOLOGICAL SOCIETY OF AMERICA SPECIAL PAPERS 1992. [DOI: 10.1130/spe270-p207] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
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144
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Nielsen E, You Y, Forney J. Cysteine residue periodicity is a conserved structural feature of variable surface proteins from Paramecium tetraurelia. J Mol Biol 1991; 222:835-41. [PMID: 1762150 DOI: 10.1016/0022-2836(91)90573-o] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The DNA sequences of the entire coding regions of the A and C type variable surface protein genes from Paramecium tetraurelia, stock 51 have been determined. The 8151 nucleotide open reading frame of the A gene contains several tandem repeats of 210 nucleotides within the central portion of the molecule as well as a periodic structure defined by cysteine residues. The 6699 nucleotide open reading frame of the C gene does not contain any identifiable tandem repeats or internal similarity but maintains a periodicity based on the cysteine residue spacing. The deduced amino acid sequences encoded by the two genes are most similar within the 600 amino-terminal and 600 carboxyl-terminal amino acid residues, the central portions show only limited sequence similarity. We conclude that internal repeats are not a conserved feature of variable surface proteins in Paramecium and discuss the possible importance of the regular pattern of cysteine residues.
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145
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Nielsen E, Welinder BS, Madsen OD. Chromogranin-B, a putative precursor of eight novel rat glucagonoma peptides through processing at mono-, di-, or tribasic residues. Endocrinology 1991; 129:3147-56. [PMID: 1954895 DOI: 10.1210/endo-129-6-3147] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Chromogranin-B (CgB), a secretory granule protein, is normally synthesized in a variety of neuroendocrine tissues, including the pancreatic islet alpha-cells. We have demonstrated that rat CgB is expressed and extensively processed by limited proteolysis in a transplantable glucagonoma tumor line. Eight peptides (fragments 1-8) purified by HPLC from acidic tumor extracts were partially sequenced and showed homology to CgB amino acid sequences deduced from rat, mouse, and human cDNA. Similar peptides were not found in insulinomas of common origin. The determined amino acid sequence represents approximately 35% of the rat precursor CgB. Ten of a total of 231 sequenced residues deviated from the published rat cDNA sequence. The differences were clustered in 3 fragments, suggesting allelic polymorphism. Five of the 8 peptides could be derived from the precursor by processing at paired basic amino acids, but processing N-terminally at a single basic residue was also seen. One peptide equivalent to the previously reported C-terminal CgB (CCB) is released by processing at a tribasic segment. Fragment 1 containing the N-terminal sequence Ala-Pro-Val-Asp represents the actual N-terminus of CgB after removal of the putative signal peptide sequence. All processing sites used in glucagonoma tissue to derive the 8 isolated fragments were conserved between murine and human CgB. At least 3 dibasic sites present in rat, but not human, CgB sequence were actually not used. A previously reported CgB-derived pituitary peptide, GAWK, was further processed at a conserved internal dibasic site to yield fragment 6, indicating alternative processing in different tissues. The small undecapeptide, fragment 7, is 100% conserved among murine and human CgB and, thus, may have an important biological function. We conclude that CgB is extensively processed in glucagonoma tissue by limited proteolysis as prohormones at conserved basic residues. The proglucagon-converting enzymes present in transformed alpha-cells are likely candidates to be involved in tissue-specific CgB processing. Distinct biological activities of any of the CgB-derived fragments remain to be identified.
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Nielsen E. Family physicians agree with Surgeon General. PENNSYLVANIA MEDICINE 1991; 94:10. [PMID: 1852456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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147
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Nielsen E, Welinder B, Madsen OD. Protein HMG-17 is hyper-expressed in rat glucagonoma. Single-step isolation and sequencing. EUROPEAN JOURNAL OF BIOCHEMISTRY 1990; 192:81-6. [PMID: 2169420 DOI: 10.1111/j.1432-1033.1990.tb19198.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
High-mobility-group protein 17 (HMG-17) was identified by reversed-phase high-performance liquid chromatography analysis as a major component in acidic extracts of transplantable rat glucagonoma tissue but not in insulinoma tissue of similar origin. The peptide was purified in a single step and the entire sequence of 89 amino acids was determined. Rat HMG-17 has a molecular mass of 9238 Da and shows strong similarity to human, bovine (94.4%) and chicken (88.8%) HMG-17. Six of the seven residues which vary among the mammalian sequences are located within a short segment (positions 64-83) present in the acidic, non-DNA-binding C-terminal part of HMG-17. This region shows least similarity to the otherwise related proteins HMG-14 and H6 (a trout HMG protein). Interestingly, four of the six variable positions are Asp in rat HMG-17 which results in an overall net increase in the negative charge of the C-terminal region. The nature of selective hyper-expression of HMG-17 in glucagon but not in insulin-producing tumor tissue remains to be clarified.
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Breum L, Astrup A, Andersen T, Lammert O, Nielsen E, Garby L, Quaade F. The effect of long-term dexfenfluramine treatment on 24-hour energy expenditure in man. A double-blind placebo controlled study. Int J Obes (Lond) 1990; 14:613-21. [PMID: 2228396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In order to investigate the effect of long-term treatment with dexfenfluramine (dF) on 24-hour energy expenditure (EE), 10 obese females were studied in a double-blind design. Shortly before and 4 weeks after cessation of a 13 months treatment period with either dF (30 mg/day) or placebo (PL) the 24-hour EE was measured. The measurements were performed using a 24 m3 direct heat sink calorimeter with continuous real time measurements of evaporative and sensible heat losses. The patients performed a standardized program of exercise, rest and meals. The measurements were performed at 24 degrees C and at a humidity between 3 and 11 g/m3. Discontinuation of dF treatment did not change energy expenditure significantly from placebo, neither when expressed in kJ/kg lean body mass nor in kJ/kg body weight. After cessation of treatment total 24-hour EE decreased likewise nonsignificantly by 2.9 percent in the dF group and by 4.0 percent in the PL group. EE measured over 24 hours was subdivided into day and night periods and into resting energy expenditure as well as a measurement of the heat losses over a period of 3 hours after a meal. This subdivision of the EE showed similar nonsignificant differences. The conclusion is therefore that dF possesses no significant thermogenic effect during long-term administration in human obese subjects.
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149
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Garby L, Lammert O, Nielsen E. Negligible effects of previous moderate physical activity and changes in environmental temperature on whole body electrical impedance. Eur J Clin Nutr 1990; 44:545-6. [PMID: 2401285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Several studies have shown that the predictive power of various linear combinations of anthropometric data (body weight, height, sex, age, etc.) to estimate fat free mass is improved after inclusion of measurements of electrical impedance (see eg Khaled et al., 1988). Published algorithms are based on measurements performed under fairly standardized conditions with the subjects at stationary conditions of rest, of environmental temperature and of body fluids. Use of the method under less standardized conditions raises the question of possible effects of deviations from these standard conditions. Hydration and dehydration by 1-2 l of fluid increased or decreased, respectively, the electrical resistance by about 14 per cent and the effects persisted for more than 1 h (Khaled et al., 1988). A change in environmental temperature by 21 degrees C from 35 degrees C to 14 degrees C (with almost constant relative humidity) during 90 min caused an increase in the resistance of about 9 per cent (Caton et al., 1988). The perturbations used in the studies quoted above are fairly drastic and not likely to occur under reasonably controlled field conditions. Therefore, we report here results of measurements of whole body electrical impedance before, during and after a period of 10 degrees C increased environmental temperature and before and after a 5-min period of light to moderate physical exercise.
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150
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Ryttig KR, Lammert O, Nielsen E, Garby L, Poulsen K. The effect of a soluble dietary fibre supplement on 24-hour energy expenditure during a standardized physical activity programme. Int J Obes (Lond) 1990; 14:451-5. [PMID: 2166716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Twenty-four hour energy expenditure during a standard physical activity programme was investigated in 19 healthy volunteers in a randomized, double-blind, cross-over design, after supplementation with a soluble dietary fibre amounting 7 g/day for 2 weeks. Energy intake and food fibre intake were kept constant during the treatment period. Twenty-four hour energy expenditure decreased insignificantly during fibre treatment (1.3 +/- 1.7 per cent). The dietary fibre supplement also had no significant effect on body weight, faecal energy loss or heart rate. Systolic blood pressure was insignificantly reduced during both placebo and fibre treatment (P = 0.09). There was, however, no difference between the groups after treatment.
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