Showing papers by "Ludwig Maximilian University of Munich published in 1990"
TL;DR: Spectroscopy and spin-Polarized STM Reference LNS-ARTICLE-1990-002 provide new insights into the determinants of spin- polarization in the Higgs boson.
Abstract: Keywords: Surface Electronic and Atomic Structure ; Spectroscopy ; Spin-Polarized STM Reference LNS-ARTICLE-1990-002doi:10.1103/PhysRevB.42.9307 Record created on 2009-04-14, modified on 2017-05-12
1,123 citations
TL;DR: A complementary cDNA coding for KBF1 is isolated and the DNA binding and dimerization domain of the protein is identified, which suggests functional homologies between KBF2 and v-rel and the Drosophila maternal morphogen dorsal.
802 citations
TL;DR: In this article, a series of 10 samples of "arable land groundwater" was taken from different depths at these multilevel wells and isotope ratios of 15 N 14 N and 18 O 16 O in the nitrate were measured.
776 citations
TL;DR: By analysis of a temperature-sensitive yeast mutant, a heat-shock protein in the matrix of mitochondria, mitochondrial hsp70 (Ssc1p), is found to be involved both in translocation of nuclear-encoded precursor proteins across the mitochondrial membranes and in (re)folding of imported proteins in the Matrix.
Abstract: By analysis of a temperature-sensitive yeast mutant, a heat-shock protein in the matrix of mitochondria, mitochondrial hsp70 (Ssc1p), is found to be involved both in translocation of nuclear-encoded precursor proteins across the mitochondrial membranes and in (re)folding of imported proteins in the matrix.
715 citations
TL;DR: Of several symptoms thought to be related to gastrooesophageal reflux disease (GORD), only heartburn and acid regurgitation occurred in more of the patients with GORD (as determined by pH monitoring) than of those with normal pH monitoring.
703 citations
TL;DR: Long circulation time and high retention of the newly developed liposomes open up ways for the future systemic use as such stabilized drug carriers for the therapeutic applications in vivo.
694 citations
TL;DR: In this paper, a method is presented which allows a simple, selfconsistent solution of the Dirac equation for the deformed spinor fields of the nucleons and of the Klein-Gordon equation for deformed scalar and vector fields of mesons.
622 citations
TL;DR: Opening of potassium channels in coronary smooth muscle cells and the subsequent drop in intracellular calcium is probably the major cause of hypoxic and ischemic vasodilation in the mammalian heart.
Abstract: The function of the heart depends critically on an adequate oxygen supply through the coronary arteries Coronary arteries dilate when the intravascular oxygen tension decreases Hypoxic vasodilation in isolated, perfused guinea pig hearts can be prevented by glibenclamide, a blocker of adenosine triphosphate (ATP)-sensitive potassium channels, and can be mimicked by cromakalim, which opens ATP-sensitive potassium channels Opening of potassium channels in coronary smooth muscle cells and the subsequent drop in intracellular calcium is probably the major cause of hypoxic and ischemic vasodilation in the mammalian heart
596 citations
TL;DR: This study suggests two pathways of TNF alpha release: activation of host macrophages and stimulation of donor cells in the course of acute graft-versus-host disease.
574 citations
TL;DR: In this paper, the author looks at important new results emerging from recent research in gold chemistry and discusses the relationship between gold's unique position in the family of elements and its properties.
Abstract: Chemists today are increasingly fascinated by gold’s unique position in the family of elements. In this review, the author looks at important new results emerging from recent research in gold chemistry.
521 citations
TL;DR: A refined model of work-related socio-emotional distress substantially contributes to the explanation of high IHD incidence among blue-collar men.
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TL;DR: It is shown that adhering (or bound) vesicles can exhibit a large variety of different shapes and the notion of a contact angle governed by tension is found to be applicable only for a restricted subset of these shapes.
Abstract: A simple model for the adhesion of vesicles to interfaces and membranes is introduced and theoretically studied. It is shown that adhering (or bound) vesicles can exhibit a large variety of different shapes. The notion of a contact angle governed by tension is found to be applicable only for a restricted subset of these shapes. Furthermore, the vesicle undergoes a nontrivial adhesion transition from a free to a bound state. This transition is governed by the balance between the overall bending and adhesion energies, and occurs even in the absence of shape fluctuations.
TL;DR: Recent findings show that the sorting of proteins into the mitochondrial subcompartments and their folding and assembly follow principles already developed in prokaryotes.
Abstract: According to the endosymbiont hypothesis, mitochondria have lost the autonomy of their prokaryotic ancestors. They have to import most of their proteins from the cytosol because the mitochondrial genome codes for only a small percentage of the polypeptides that reside in the organelle. Recent findings show that the sorting of proteins into the mitochondrial subcompartments and their folding and assembly follow principles already developed in prokaryotes. The components involved may have structural and functional equivalents in bacteria.
TL;DR: Two chromatographically distinct forms of IκB were purified and found to be more basic and 3–8 kd larger than the α form, which could explain how NF-κB can be activated in response to various agents that signal via different intracellular messenger systems.
TL;DR: Theorem II and the dual of Theorem I holds and generalizes results of Gabriel on quotients of formal schemes to the case of non-cocommutative coalgebras.
Abstract: LetH be a Hopf algebra over a field with bijective antipode,A a rightH-comodule algebra,B the subalgebra ofH-coinvariant elements and can:A ⊗
B
A →A ⊗H the canonical map. ThenA is a faithfully flat (as left or rightB-module) Hopf Galois extension iffA is coflat asH-comodule and can is surjective (Theorem I). This generalizes results on affine quotients of affine schemes by Oberst and Cline, Parshall and Scott to the case of non-commutative algebras. The dual of Theorem I holds and generalizes results of Gabriel on quotients of formal schemes to the case of non-cocommutative coalgebras (Theorem II). Furthermore, in the dual situation, a normal basis theorem is proved (Theorem III) generalizing results of Oberst-Schneider, Radford and Takeuchi.
TL;DR: Use of Escherichia coli as an expression host has opened up new possibilities in antibody research and its applications and greatly facilitates rational engineering and random mutagenesis.
Abstract: Use of Escherichia coli as an expression host has opened up new possibilities in antibody research and its applications. It greatly facilitates rational engineering and random mutagenesis.
TL;DR: It is suggested that magnetic bacteria and their magnetofossils14 can contribute to the magnetic properties of soils.
Abstract: ENRICHMENT of the ferrimagnetic minerals magnetite and maghemite is frequently observed in the top layer of soil horizons1–5. Although both inorganic6,7and organic8,9processes are known to produce magnetite, magnetite in soils has been ascribed to an inorganic origin6. We report here the discovery of living magnetic bacteria, similar to those found in salt- and fresh-water sediments8,10–2, in the A horizon of a well developed soil profile in a typical meadow environment in southern Bavaria. The bacteria were detected in fresh samples using an optical microscope equipped with a rotating magnetic field13 and a volumetrically calibrated depression slide, permitting accurate counts of the volume density of the organisms. We suggest that magnetic bacteria and their magnetofossils14 can contribute to the magnetic properties of soils.
TL;DR: The atomic structure of ordered Cu adsorbate layers on Au(111) and Au(100) electrode surfaces and of the clean substrates was resolved in scanning tunneling microscopy images taken in situ, showing increasingly repulsive interactions between closely spaced Cu adatoms.
Abstract: The atomic structure of ordered Cu adsorbate layers on Au(111) and Au(100) electrode surfaces and of the clean substrates was resolved in scanning tunneling microscopy images taken in situ. For submonolayer coverages deposited from sulfuric acid solutions under potential control, various ordered structures were observed. The quasihexagonal arrangement of Cu atoms in these structures reflects increasingly repulsive interactions between closely spaced Cu adatoms. These structures differ from the pseudomorphic Cu adlayer formed under vacuum conditions, which demonstrates the structure-determining role of the coadsorbed anions.
TL;DR: Linkage between MHS and DNA markers from the GPI region of human chromosome 19 with a maximum log likelihood ratio (lod score) of 5.65 indicates that human and porcine MH are most probably due to mutations in homologous genes, and provides a potentially accurate and noninvasive method of diagnosis for MHS.
Abstract: MALIGNANT hyperthermia (MH) is an inherited human skeletal muscle disorder and is one of the main causes of death due to anaesthesia1. The reported incidence of MH varies from 1 in 12,000 in children to 1 in 40,000 in adults2,3. MH is triggered in susceptible people by all commonly used inhalational anaesthetics; it is characterized by a profoundly accelerated muscle metabolism, contractures, hyperthermia and tachycardia1,4,5. Susceptibility to MH (MHS) is predicted by contracture tests on muscle tissue obtained by biopsy6,7. An almost identical disorder known as porcine MH exists in pigs8,9. The genetics of the porcine syndrome have been extensively studied10; the locus controlling expression of porcine MH is genetically linked to the glucose phosphate isomerase locus (GPI)11. In man, GPI has been mapped to the q12–13.2 region of chromosome 19 (refs 10–12). We have now investigated genetic linkage in several extended Irish pedigrees in which MHS is segregating as an autosomal dominant trait. Here we show linkage between MHS and DNA markers from the GPI region of human chromosome 19 with a maximum log likelihood ratio (lod score) of 5.65 at the CYP2A locus. These results indicate that human and porcine MH are most probably due to mutations in homologous genes, and also provide a potentially accurate and noninvasive method of diagnosis for MHS.
TL;DR: It is concluded that the increase of Gi alpha is accompanied by a reduction of basal and guanine-nucleotide-stimulated adenylate cyclase activity, which might contribute to the reduced effects of endogenous catecholamines and exogenous cAMP-dependent positive inotropic agents in the former but not the latter condition.
Abstract: In myocardial membranes from hearts with dilated cardiomyopathy (DCM), there was a 37% increase of the Gi alpha-protein as measured by 32P-ADP-ribosylation of a approximately 40 kDa pertussis toxin substrate. Immunoblotting techniques also showed increased amounts of Gi alpha in DCM. In hearts with ischemic cardiomyopathy (ICM), Gi alpha was not altered compared with nonfailing myocardium (NF). Basal and Gpp(NH)p-stimulated adenylate cyclase activity was reduced in DCM but not in ICM. The number of beta-adrenoceptors was similarly reduced both in DCM and ICM compared with NF. Alterations of m-cholinoceptors or A1-adenosine receptors did not occur. Consistently, "indirect" negative inotropic effects of the m-cholinoceptor agonist carbachol and the A1-adenosine receptor agonist R-PIA were not different in ICM, DCM, and nonfailing myocardium. In ICM and DCM, there was a marked reduction of the positive inotropic responses to isoprenaline and milrinone. However, there was a further reduction in DCM compared with ICM. It is concluded that the increase of Gi alpha is accompanied by a reduction of basal and guanine-nucleotide-stimulated adenylate cyclase activity. Alterations of m-cholinoceptors and A1-adenosine receptors do not appear to be involved. The further decrease of the positive inotropic effects of isoprenaline and milrinone in DCM provides evidence that the increase of Gi alpha is functionally relevant in DCM but not ICM and hence might contribute to the reduced effects of endogenous catecholamines and exogenous cAMP-dependent positive inotropic agents in the former but not the latter condition.
TL;DR: The results indicate that cytochrome c oxidase deficient muscle fibres in normal skeletal muscle represent an age related phenomenon which probably results from cellular ageing and might be involved in the reduction of muscle mass and strength during senescence.
TL;DR: The history and present situation of the human microbiome, as well as some of the mechanisms behind its development, are reviewed in detail.
Abstract: INTRODUCTION .. . . 331 THE PRECURSOR PROTEINS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332 Targeting Signals 332 Translocation Competence 335 IMPORT RECEPTORS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . ... . . . . . . . . . . ...... . . . . . . . . . . . . . 337 MEMBRANE INSERTION OF PRECURSOR PROTEINS . ........ 340 A General Insertion Protein 340 Pathway of Apocytochrome c 342 Partial and Artificial Systems 342 TRANSLOCA TION CONTACT SITES . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . 343 COVALENT AND NONCOVALENT MODIFICATION OF IMPORTED PRECURSOR PROTEINS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345 Processing Enzymes 345 A Folding Machinery . ... . . ........ ...... ....... ....... . ......... 346 INTRAMITOCHONDRIAL SORTING . ...... . . ..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348 Conservative Sorting 348 N onconservative Sorting 349 SUMMARY AND PERSPECTIVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
TL;DR: MOM72 has a complementary function to that of MOM19, which acts as an import receptor for the majority of mitochondrial proteins studied so far but not for the ADP/ATP carrier.
TL;DR: The operon described, therefore, appears to comprise genes for redox carriers linking formate oxidation to proton reduction and for a hydrogenase of hitherto unique composition.
Abstract: Summary
An 8kb segment of DNA from the 58/59 min region of the E. coli chromosome, which complements the defect of a mutant devoid of hydrogenase 3 activity, has been sequenced. Eight open reading frames were identified which are arranged in a transcriptional unit; all open reading frames were transcribed and translated in vivo in a T7 promoter/polymerase system. Analysis of the amino acid sequences derived from the nucleic acid sequences revealed that one of them, open reading frame 5 (0RF5), exhibits significant sequence similarity to conserved regions of the large subunit from Ni/Fe hydrogenases. Two of the open reading frames (orf2, orf6) code for proteins apparently carrying iron-sulphur clusters of the 4Fe/4S ferredoxin type. The product of one of the open reading frames, orf7, displays extensive sequence similarity with protein G from the chloroplast electron transport chain. ORF3 and ORF4, on the other hand, are extremely hydrophobic proteins with nine and six putative transmembrane helices, respectively. Over a limited hydrophilic sequence stretch, bordered by putative transmembrane areas, ORF3 and ORF4 exhibit homology with subunits 4 and 1 of mitochondrial and plastid NADH-ubiquinol oxidoreductases, respectively. The operon described, therefore, appears to comprise genes for redox carriers linking formate oxidation to proton reduction and for a hydrogenase of hitherto unique composition.
TL;DR: It is reported here that 3′-truncated preS2/Ssequences in integrated HBV DNA of liver cell carcinomas encode a so far unidentified transcriptional trans-activation activity, indicating that trans- activation by integrated preS/S sequences is a possible mechanism for HBV-associated oncogenesis.
Abstract: Hepatitis B virus (HBV) is regarded as the main aetiologic factor in the development of human hepatocellular carcinoma (HCC), one of the most frequent fatal malignancies worldwide. Detection of integrated HBV sequences in the cellular DNA of almost all HCCs studied, and the recent finding that the integrated HBV open reading frame (orf) X encodes a transactivating activity, supports the notion that integrated HBV DNA could contribute to liver carcinogenesis by activation of cellular genes in trans. But not all HCCs seem to harbour a functional orf X. We report here that 3'-truncated preS2/S sequences in integrated HBV DNA of liver cell carcinomas encode a so far unidentified transcriptional trans-activation activity. This activity is also produced by an artificially 3'-truncated preS2/S gene of the wild-type HBV genome. Besides the simian virus 40 promoter of the reporter plasmid pSV2CAT, the promoter of the human c-myc oncogene can also be activated. These results, taken together with the fact that preS/S is the only HBV gene found to be integrated in almost every HBV-related HCC analysed so far, indicate that trans-activation by integrated preS2/S sequences is a possible mechanism for HBV-associated oncogenesis.
TL;DR: The uncoupling protein found in mitochondria from thermogenic brown adipose tissue is structurally very similar to two other mitochondrial carrier proteins transporting ADP/ATP and phosphate, respectively, further strengthening the evidence that the uncoupled protein has evolved from this family of mitochondrial Carrier proteins.
TL;DR: It is reported here that three previously identified zygotic genes buttonhead, empty spiracles and orthodenticle l5–17 may behave like gap genes that mediate bed function in the embryonic head.
Abstract: THE first phase of embryonic development in Drosophila consists of the elaboration and interpretation of maternally encoded information that specifies spatial pattern in the embryo1. The product of the maternal gene bicoid (bcd) is thought to organize the anterior pattern of the embryo2. Although the bed transcript is localized at the anterior pole of the egg3,4 the bed protein forms a stable concentration gradient through the anterior two thirds of the embryo5. The graded distribution of bed protein defines position along the anterior-posterior axis of the embryo6–8 through the spatially restricted activation of subordinate targets such as the gap gene hunchback(hb)7–11. In vitro manipulation of specific bcd protein binding sites has shown that the gradient of bed protein can in principle define more than one discrete domain of spatially restricted gene activation in the head of the embryo, depending on the affinity of the available binding sites for the bcd protein8.12. Genetic analysis has indicated the need for at least one additional zygotic segmentation gene to mediate bcd function in portions of the head that lie anterior to the hb domain2,12–14. The missing gene activity is expected to be activated in response to higher levels of bed protein than are required for hb activation12. We report here that three previously identified zygotic genes buttonhead (btd), empty spiracles (ems) and orthodenticle (otd) l5–17 may behave like gap genes that mediate bed function in the embryonic head.