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51.
Differential effect of ultracentrifugation on apolipoprotein A-I-containing lipoprotein subpopulations 总被引:3,自引:0,他引:3
Two populations of apolipoprotein (apo) A-I-containing lipoprotein particles are found in high density lipoproteins (HDL): those that also contain apo A-II[Lp(A-I w A-II)] and those that do not [Lp(A-I w/o A-II)]. Lp(A-I w/o A-II) comprised two distinct particle sizes with mean hydrates Stokes diameter of 10.5 nm for Lp(A-I w/o A-II)1 and 8.5 nm for Lp(A-I w/o A-II)2. To study the effect of ultracentrifugation on these particles, Lp(A-I w/o A-II) and Lp(A-I w A-II) were isolated from the plasma and the ultracentrifugal HDL (d 1.063-1.21 g/ml fractions) of five normolipidemic and three hyperlipidemic subjects. The size subpopulations of these particles were studied by gradient polyacrylamide gel electrophoresis. Several consistent differences were detected between plasma Lp(A-I w/o A-II) and HDL Lp(A-I w/o A-II). First, in all subjects, the relative proportion of Lp(A-I w/o A-II)1 to Lp(A-I w/o A-II)2 isolated from HDL was reduced. Second, particles larger than Lp(A-I w/o A-II)1 and smaller than Lp(A-I w/o A-II)2 were considerably reduced in HDL. Third, a distinct population of particles with approximate Stokes diameter of 7.1 nm usually absent in plasma was detected in HDL Lp(A-I w/o A-II). Little difference in subpopulation distribution was detected between Lp(A-I w A-II) isolated from the plasma and HDL of the same subject. When plasma Lp(A-I w/o A-II) and Lp(A-I w A-II) were centrifuged, 14% and 4% of A-I were, respectively, recovered in the D greater than 1.21 g/ml fraction. Only 2% A-II was found in this density fraction. These studies show that the Lp(A-I w/o A-II) particles are less stable than Lp(A-I w A-II) particles upon ultracentrifugation. Among the various Lp(A-I w/o A-II) subpopulations, particles larger than Lp(A-I w/o A-II)1 and smaller than Lp(A-I w/o A-II)2 are most labile. 相似文献
52.
H K Wolf G R Dagenais J G Fodor R S Fynes S P Handa R B Haynes G A Klassen M G Myers N M Robitaille 《CMAJ》1988,139(6):507-512
Causal blood pressure measurements were recorded in two groups of men aged 40 to 64 years; of the 7024 men in metropolitan Saint John, NB, and the 4044 men in seven suburbs of Quebec who were asked, 5840 (83.1%) and 3097 (76.6%) respectively agreed to participate. Of the Saint John group 9.0% were taking antihypertensive drugs, as compared with only 3.3% of the Quebec group (p less than 0.0001). Among the treated subjects 33% in Saint John and 53% in Quebec still had a diastolic pressure greater than 95 mm Hg (p less than 0.01). Among the participants not taking antihypertensive drugs the systolic blood pressure increased with age, but the diastolic blood pressure increased only slightly up to 55 years of age and then decreased. On average the subjects in Saint John who were not being treated had a systolic pressure 6.2 mm Hg lower and a diastolic blood pressure 3.6 mm Hg lower than their Quebec counterparts (p less than 0.0001). This difference was observed in all the age groups and was not the result of the treatment of a greater proportion of the Saint John cohort. Despite the higher blood pressures and the smaller number receiving adequate treatment in the Quebec group, the rate of death due to coronary artery disease was 10% lower than that in the Saint John group. A bias in the data from Quebec may have influenced the magnitude of the differences between the two samples, but if present it should have underestimated the blood pressures in the Quebec group and therefore not have changed the outcome. 相似文献
53.
The structure of human erythrocytic carbonic anhydrase II has been refined by constrained and restrained structure–factor least-squares refinement at 2.0 Å resolution. The conventional crystallographic R value is 17.3%. Of 167 solvent molecules associated with the protein, four are buried and stabilize secondary structure elements. The zinc ion is ligated to three histidyl residues and one water molecule in a nearly tetrahedral geometry. In addition to the zinc-bound water, seven more water molecules are identified in the active site. Assuming that Glu-106 is deprotonated at pH 8.5, some of the hydrogen bond donor–acceptor relations in the active site can be assigned and are described here in detail. The Oγ1 atom of Thr-199 donates its proton to the Oε1 atom of Glu-106 and can function as a hydrogen bond acceptor only in additional hydrogen bonds. 相似文献
54.
55.
56.
Maria Anvret Margareta Blombäck Monika Lindstedt Elisabeth Söderlind Margareta Tapper-Persson Ann-Christine Thelander 《Human genetics》1992,89(2):147-154
Summary Twenty-five patients with von Willebrand's disease (vWD) type III were analysed with regard to blood coagulation variables and possible deletions. Nine of the probands and their families were further investigated with DNA linkage analyses. Different patterns of heredity can be suggested in our families with vWD type III, on the basis of blood coagulation analyses. The findings suggest homozygosity in five families and the possibility of compound heterozygosity or a new mutation in the proband in three families. The linkage analyses confirm the results of the coagulation analyses. The segregation of the von Willebrand factor (vWF) gene can be followed in the families, and carrier diagnosis can be made in several of the probands' relatives. The possibility of large deletions in the vWF gene of the probands and their parents was investigated with probes representing the whole vWF cDNA. No deletions were found.This study was approved by the Ethics Committee of the Karolinska Hospital (No. 84:1) 相似文献
57.
M. Lindner A. Wolf B. Moh P. Steinbach E. Kleihauer C. R. Bartram A. E. Kulozik 《Human genetics》1992,90(3):267-269
The cystic fibrosis transmembrane conductance regulator (CFTR) gene of 110 cystic fibrosis (CF) patients from the south-west of Germany was screened for 12 different mutations. This analysis resulted in an identification of 79% of all CF mutations and a complete genotype in 66% of the families. The most common mutation found was F508 (67%). Another 5 mutations accounted for a further 12.5% (4% G542X; 3% R553X; 3% N1303K; 2% 1717-1 GA; 0.5% G551D) whereas 6 mutations (R117H, A455E, I507, S549I, S549N, and R1162X) were not found. Fifty-four (49%) patients were AF508 homozygotes and 18 (16.5%) were compound heterozygotes for F508 and one of the rarer mutations. These frequencies differ slightly from those found in the north of Germany and considerably from those reported from the south of Europe, which seems to be consistent with a north to south decline of the relative abundance of F508. Two patients, age 6 and 25 years, were compound heterozygotes for G542X and N1303K. The clinical features of the 6 year old were characterised by severe gastrointestinal and as yet only mild pulmonary complications whereas the 25 year old manifested severe pulmonary and gastrointestinal symptoms indicating that the N1303K mutation of the C-terminal CFTR nucleotide binding fold significantly impairs protein function in both the pancreas and the lungs. 相似文献
58.
Regeneration of transgenic plants of Prunus armeniaca containing the coat protein gene of Plum Pox Virus 总被引:1,自引:0,他引:1
Margit Laimer da Câmara Machado Artur da Câmara Machado Veronika Hanzer Hans Weiss Ferdinand Regner Herta Steinkellner Diethard Mattanovich Regina Plail Elisabeth Knapp Birgit Kalthoff Hermann Katinger 《Plant cell reports》1992,11(1):25-29
Summary A system was developed which allows the transfer of foreign genes into apricot cultivars. We report the transformation and regeneration of Prunus armeniaca plants with Agrobacterium tumefaciens strain LBA 4404 containing various binary plasmids, pBinGUSint, carrying the marker gene ß-glucuronidase (GUS) and pBinPPVm, carrying the coat protein gene of Plum Pox Virus (PPV). The marker gene GUS was used for optical evaluation of the efficiency of the transformation system. The coat protein gene of PPV was used to introduce coat protein mediated resistance against one of the most important pathogens of stone fruit trees in Europe and the whole Mediterranean area. This is the first report of the successful integration of a viral coat protein gene into a fruit tree species, opening a new perspective on the control of the disease.Abbreviations GUS
ß-glucuronidase
- PPV
Plum Pox Virus
- BA
6-benzylaminopurine
- NPTII
neomycin phosphotransferase II
- CP
coat protein
- CaMV
Cauliflower Mosaic Virus
- P35S 35S
promoter
- MS
Murashige and Skoog
- PCR
polymerase chain reaction
- P/C/I
phenol/chloroform/isoamylalcohol
- RNase
ribonuclease
- dNTP
deoxyribonucleosidetriphosphate
- DMSO
dimethyl sulfoxide 相似文献
59.
We model the base compositional structure of the human and Escherichia coli genomes. Three particular properties are first quantified: (1) There is a significant tendency for any region of either genome to have a strand-symmetric base composition. (2) The variation in base composition from region to region, within each genome, is very much larger than expected from common homogeneous stochastic models. (3) A given local base composition tends to persist over a scale of at least kilobases (E. coli) or tens of kilobases (human). Multidomain stochastic models from the literature are reviewed and sharpened. In particular, quantitative measurements of the third property lead us to suggest a significant shift in the style of domain models, in which the variation of A+T content with position is modeled by a random walk with frequent small steps rather than with large quantum jumps. As an application, we suggest a way to reduce the amount of computation in the assembly of large sequences from sequences of randomly chosen fragments. 相似文献
60.
Assignment of genes encoding a unique cytokine (IL12) composed of two unrelated subunits to chromosomes 3 and 5. 总被引:14,自引:0,他引:14
D Sieburth E W Jabs J A Warrington X Li J Lasota S LaForgia K Kelleher K Huebner J J Wasmuth S F Wolf 《Genomics》1992,14(1):59-62
IL12 (formerly NKSF or CLMF) is a unique cytokine composed of two unrelated disulfide-linked subunits. The larger 40-kDa subunit (p40) is a member of the cytokine receptor family, and the smaller 35-kDa subunit (p35) is related to IL6 and GCSF. The chromosomal localization of these two subunits was determined by PCR analysis of DNA from rodent-human hybrids. More refined mapping was obtained by PCR analysis of hybrids containing translocation chromosomes and for p40, by analysis of radiation hybrids. The subunits map to different chromosomes: p40 (IL12B) to 5q31-q33 and p35 (IL12A) to 3p12-3q13.2. 相似文献