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Ferdinand Bohlmann Elena Tsankova Jasmin Jakupovic Robert M. King Harold Robinson 《Phytochemistry》1983,22(2):557-560
The investigation of Encelia canescens afforded, in addition to several known compounds, four new dimeric p-hydroxyacetophenone derivatives, two epimeric chromene dimers and two epimeric mixed dimers of euparin and encecalin. Furthermore, derivatives of tremetone and of encecalin were present. The structures were elucidated hy high field 1H NMR spectroscopy. 相似文献
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Sarcolemmal Na+-Ca2+ exchange during the development of genetically determined cardiomyopathy 总被引:1,自引:0,他引:1
N Makino G Jasmin R E Beamish N S Dhalla 《Biochemical and biophysical research communications》1985,133(2):491-497
The UM-X7.1 myopathic and control hamsters at 40, 120 and 280 days of age were employed for the examination of heart sarcolemmal Ca2+-transport activities. Na+-dependent Ca2+ uptake activities were significantly depressed in myopathic animals at 120 and 280 days of age in comparison to the control values. No difference in Na+-induced Ca2+ release activities was found between control and experimental sarcolemmal vesicles. ATP-dependent Ca2+ binding and Ca2+-stimulated, Mg2+ ATPase activities were depressed in the experimental animals at 120 and 280 days of age. Similar alterations in the sarcolemmal Na+-dependent Ca2+ exchange and Ca2+-pump activities were seen upon treating the control hamsters with 40 mg/kg isoproterenol for 24 hr. It is suggested that a depression in the sarcolemmal Ca2+ transport activities may contribute to the development of intracellular Ca2+ overload in the genetically determined cardiomyopathy in hamsters and such a defect may be due to excessive amount circulating catecholamines in these animals. 相似文献
5.
Ferdinand Bohlmann Cornelius Scheidges Laxmi N. Misra Jasmin Jakupovic 《Phytochemistry》1984,23(8):1795-1798
The investigation of three South African Vernonia species afforded minute amounts of five new glaucolides, two monoepoxides and three diepoxides. The structures were elucidated by 1H NMR spectroscopy. The roots of Vernonia sutherlandii contain, in addition to vernonataloide, bergamotene and santalene, minute amounts of the corresponding acetoxy derivatives. 相似文献
6.
The DNA replication origins of herpes simplex virus type 1 strain Angelotti 总被引:3,自引:0,他引:3 下载免费PDF全文
The nucleotide sequences of the origins of DNA replication (ori) of the S- and L-component (oriS, oriL) of the herpes simplex virus type 1 (HSV-1) standard genome were determined from HSV-1 strain Angelotti (ANG). In contrast to other HSV-1 strains, the ANG oriS sequence revealed an insertion of an TA-dinucleotide in an otherwise very conserved but imperfect palindromic sequence of 47 bp. The oriL sequence of the standard ANG genome was found to be identical to that of an ANG class II defective genome which exhibits a duplication of a 144 bp palindrome. A model is presented to explain the origination of the amplified ANG oriL sequences from the parental genome with a single copy of oriL via illegitimate recombination. Alignment of the ori sequences of HSV, adeno- and papovaviruses unveiled that the HSV ori region can be subdivided into two distinct sites of homology to the DNA initiation signals of papova- and adenoviruses, suggesting that the HSV origins of replication comprise elements for DNA replication by both, cellular and virus-encoded DNA polymerases. 相似文献
7.
M. Herve F. Sinoussi-Barre J.C. Chermann G. Herve C. Jasmin 《Biochemical and biophysical research communications》1983,116(1):222-229
The 21-tungsto-9-antimonate (TA, HPA 23), a polyoxotungstate, has shown a significant antiviral activity in vivo and in vitro. It inhibits viral and bacterial DNA polymerases. In this paper, several compounds of two polyoxotungstic families, tungstoantimonates and tungstoarsenates, have been used to specify the mechanism of polymerase inhibition. It has been demonstrated that the inhibitory activity of polyoxotungstates is not related to the occupation of their coordinative sites by cations, nor to the nature of these bound cations. Kinetic studies and binding assays have shown that polyoxotungstates bind to the polymerases in competition with the nucleic acid template. This result seems to be related to their polyanionic nature. Furthermore, the size and charge of these compounds may play a prominent part in their affinity for the polymerases. 相似文献
8.
The nucleoside triphosphate–ribonucleic acid nucleotidyltransferase (EC 2.7.7.6) of Agrobacterium tumefaciens (Smith and Townsend) Conn. Purification and properties of the enzyme from the tumorigenic strain B6806 下载免费PDF全文
U. C. Knopf 《The Biochemical journal》1974,143(3):511-520
The RNA nucleotidyltransferase (RNA polymerase) of the plant-tumorigenic bacterium Agrobacterium tumefaciens was purified. The method involves the disruption of the bacterial cells with glass beads in a Waring Blendor, treatment with DEAE-cellulose, fractionation with (NH(4))(2)SO(4), protamine sulphate precipitation, DEAE-cellulose column chromatography and either glycerol-gradient centrifugation or phosphocellulose chromatography. The subunit structure of the highly purified enzyme is similar to, although not identical with, the RNA nucleotidyltransferase of Escherichia coli. It can be described as beta', beta, chi(1) and alpha (mol.wts. 160000, 150000, 98000, and 41000+/-10% respectively). chi(1) is the temporary designation for a protein subunit, which might have the same functions as the sigma subunit in E. coli. The enzyme of A. tumefaciens is rifampicin-sensitive, has a temperature optimum in vitro of 41+/-1 degrees C and a pH optimum of 8.2+/-0.1. Mg(2+) and Mn(2+) are activators. The enzyme transcribes with different efficiencies artificial, viral, bacterial, plant and animal templates. 相似文献
9.
G. Mathé J. L. Amiel L. Schwarzenberg J. Choay P. Trolard M. Schneider M. Hayat J. R. Schlumberger Cl. Jasmin 《BMJ (Clinical research ed.)》1970,2(5702):131-136
Allogeneic bone marrow grafts carried out after previous administration of antilymphocytic serum alone were attempted in 16 patients. Of these, six had acute myeloblastic leukaemia, four acute lymphoblastic leukaemia, and one a blast cell crisis in polycythaemia vera. Ten of these patients were in an overt phase of the disease and resistant to chemotherapy, while nine had complete agranulocytosis. In five of these patients erythrocyte and leucocyte antigenic markers demonstrated the establishment of the graft. One patient had thalassaemia major, and four others had aplasia of the bone marrow, in one case due to chloramphenicol poisoning and in another to virus hepatitis. The grafts were successful in the last two patients and transformed their clinical condition.No signs of early acute secondary disease were noted in any of the patients, either when the donor had been given antilymphocytic serum or when he was untreated. The grafts had no adoptive immunotherapeutic effect on the acute leukaemia. These observations have clearly shown that antilymphocytic serum has an immunosuppressive effect in man when it is used alone. 相似文献
10.
Rajat Sethi Neel Bector Nobuakira Takeda Makoto Nagano Gaetan Jasmin Naranjan S. Dhalla 《Molecular and cellular biochemistry》1994,140(2):163-170
In order to explain the attenuated sympathetic support during the development of heart failure, the status of -adrenergic mechanisms in the failing myocardium was assessed by employing cardiomyopathic hamsters (155–170 days old) at moderate degree of congestive heart failure. The norepinephrine turnover rate was increased but the norepinephrine content was decreased in cardiomyopathic hearts. The number and the affinity of receptors in the sarcolemmal preparations were not changed in these hearts at moderate stage of congestive heart failure. While the basal adenylyl cyclase activity was not altered in sarcolemma, the stimulation of enzyme activity by NaF, forskolin, Gpp(NH)p or epinephrine was depressed in hearts from these cardiomyopathic hamsters. Since G-proteins are involved in modifying the adenylyl cyclase activity, the functional and bioactivities as well as contents of both Gs and Gi proteins were determined in the cardiomyopathic heart sarcolemma. The functional stimulation of adenylyl cyclase by cholera toxin, which activates Gs proteins, was markedly depressed whereas that by Pertussis toxin, which inhibits Gi proteins, was markedly augmented in cardiomyopathic hearts. The cholera toxin and pertussis toxin catalyzed ADP-ribosylation was increased by 37 and 126%, respectively; this indicated increased bioactivities of both Gs and Gi proteins in experimental preparations. The immunoblot analysis suggested 74 and 124% increase in Gs and Gi contents in failing hearts, respectively. These results suggest that depressed adenylyl cyclase activation in cardiomyopathic hamsters may not only be due to increased content and bioactivity of Gi proteins but the functional uncoupling of Gs proteins from the adenylyl cyclase enzyme may also be involved at this stage of heart failure. 相似文献