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31.
Both kidneys were imaged ultrasono-graphically in each of 100 normal adult dogs. Small but significant differences were found in the dimensions of the left and right kidneys and in renal dimensions of male and female dogs of similar bodyweight. There was a statistically significant correlation between renal length and bodyweight (r = 0–84, P<0–001). The relationship between renal length and bodyweight was linear except at very low or very high bodyweights. There was also a statistically significant correlation between renal volume and bodyweight (r = 0–91, P<0–001), and the relationship remained linear even at extremes of bodyweight. Graphs could therefore be constructed for renal lengthy bodyweight and renal volume/bodyweight with 95 per cent confidence limits. 相似文献
32.
Antibodies to the core protein of lymphadenopathy-associated virus (LAV) in patients with AIDS 总被引:16,自引:0,他引:16
V S Kalyanaraman C D Cabradilla J P Getchell R Narayanan E H Braff J C Chermann F Barré-Sinoussi L Montagnier T J Spira J Kaplan 《Science (New York, N.Y.)》1984,225(4659):321-323
Lymphadenopathy-associated virus ( LAV ), a human T- lymphotrophic retrovirus isolated from a homosexual man with lymphadenopathy, has been causally associated with acquired immunodeficiency syndrome (AIDS). A sensitive and specific radioimmunoprecipitation test was developed for the detection of antibodies to the major core protein of LAV , p25 (molecular weight 25,000). Antibody to LAV p25 was found in the serum of 51 of 125 AIDS patients, 81 of 113 patients with lymphadenopathy syndrome, 0 of 70 workers at the Centers for Disease Control (some of whom had handled specimens from AIDS patients), and 0 of 189 random blood donors. Of a group of 100 homosexual men from San Francisco whose serum was obtained in 1978, only one had antibody to LAV p25; in contrast, of a group of 50 homosexual men in the same community whose serum was obtained in 1984, 12 had antibodies to LAV p25. 相似文献
33.
Lorenz KT Chandler DW Barr JW Chen W Barnes GL Cline JI 《Science (New York, N.Y.)》2001,293(5537):2063-2066
The preferred sense of product molecule rotation (clockwise or counterclockwise) in a bimolecular collision system has been measured. Rotationally inelastic collisions of nitric oxide (NO) molecules with Ar atoms were studied by combining crossed molecular beams, circularly polarized resonant multiphoton ionization probing, and velocity-mapped ion imaging detection. The observed sense of NO product rotation varies with deflection angle and is a strong function of the NO final rotational state. The largest preferences for sense of rotation are observed at the highest kinematically allowed product rotational states; for lower rotational states, the variation with deflection angle becomes oscillatory. Quantum calculations on the most recently reported NO-Ar potential give good agreement with the observed oscillation patterns in the sense of rotation. 相似文献
34.
Russell CA Jones TC Barr IG Cox NJ Garten RJ Gregory V Gust ID Hampson AW Hay AJ Hurt AC de Jong JC Kelso A Klimov AI Kageyama T Komadina N Lapedes AS Lin YP Mosterin A Obuchi M Odagiri T Osterhaus AD Rimmelzwaan GF Shaw MW Skepner E Stohr K Tashiro M Fouchier RA Smith DJ 《Science (New York, N.Y.)》2008,320(5874):340-346
Antigenic and genetic analysis of the hemagglutinin of approximately 13,000 human influenza A (H3N2) viruses from six continents during 2002-2007 revealed that there was continuous circulation in east and Southeast Asia (E-SE Asia) via a region-wide network of temporally overlapping epidemics and that epidemics in the temperate regions were seeded from this network each year. Seed strains generally first reached Oceania, North America, and Europe, and later South America. This evidence suggests that once A (H3N2) viruses leave E-SE Asia, they are unlikely to contribute to long-term viral evolution. If the trends observed during this period are an accurate representation of overall patterns of spread, then the antigenic characteristics of A (H3N2) viruses outside E-SE Asia may be forecast each year based on surveillance within E-SE Asia, with consequent improvements to vaccine strain selection. 相似文献
35.
Redesigning trypsin: alteration of substrate specificity 总被引:40,自引:0,他引:40
C S Craik C Largman T Fletcher S Roczniak P J Barr R Fletterick W J Rutter 《Science (New York, N.Y.)》1985,228(4697):291-297
A general method for modifying eukaryotic genes by site-specific mutagenesis and subsequent expression in mammalian cells was developed to study the relation between structure and function of the proteolytic enzyme trypsin. Glycine residues at positions 216 and 226 in the binding cavity of trypsin were replaced by alanine residues, resulting in three trypsin mutants. Computer graphic analysis suggested that these substitutions would differentially affect arginine and lysine substrate binding of the enzyme. Although the mutant enzymes were reduced in catalytic rate, they showed enhanced substrate specificity relative to the native enzyme. This increased specificity was achieved by the unexpected differential effects on the catalytic activity toward arginine and lysine substrates. Mutants containing alanine at position 226 exhibited an altered conformation that may be converted to a trypsin-like structure upon binding of a substrate analog. 相似文献
36.
In the presence of H2O2 as donor, horseradish peroxidase was used to catalyze the polymerization of seven monomeric phenols. Yields of humic acid (HA) polymers from meta phenols—resorcinol and phloroglucinol—were insignificant. Of the five ortho and para phenols—phenol, catechol, hydroquinone, pyrogallol and 1,2,4-trihydroxybenzene—all except hydroquinone inhibited the enzyme at high concentration. The kinetics of polymerization of the ortho and para compounds were complex and dependent on the concentration of both electron acceptor and donor.The percentage yield of HA before dialysis was far greater from pyrogallol than from catechol or hydroquinone. After dialysis, the yield of the catechol HA was higher than those of the hydroquinone and pyrogallol HAs. A higher molecular weight for the catechol HA over those of the hydroquinone and pyrogallol HAs was also indicated by the lowest E4/E6 ratio and highest free radical content.All of the synthetic HAs were relatively rich in free radicals, suggesting that their synthesis occurred via free radicals, i.r. and 13C NMR spectra showed that the HAs were molecularly complex polymers or mixtures of complex aromatic structures rich in phenolic OH groups and to a lesser extent in CO2H groups. The only HA which showed fine structure in the i.r. spectrum was the pyrogallol HA; the presence of aryl ethers was indicated. 13C NMR spectra showed that all synthetic HAs were highly aromatic, that aromatic rings of the initial phenols had been built into the HAs, but that molecular environments around phenolic OH groups had changed during the formation of the HAs. 相似文献
37.
N Barré E Camus G Borel R Aprelon 《Revue d'élevage et de médecine vétérinaire des pays tropicaux》1991,44(4):453-458
The examination of 458 domestic and wild hosts of the tick A. variegatum allowed to collect 8,581 larvae, 646 nymphs, 685 adults in 9 different animal species and to determine their preferential attachment sites. In another survey on 15 goats and 5 cattle, 12,345 larvae, 2,111 nymphs and 4,625 adults were counted on the anatomic sites. Immature ticks feed preferentially on the head, neck and limbs of birds, the limbs of mongoose and the limbs and ears of dogs, goats and cattle. Adults feed only on hosts of medium to large size and attach on ventral parts of the body, especially the groin, perineum, axillae and the dewlap of cattle. This tick species should be searched for on these sites when estimating its propagation in a threatened area or the evolution of its population during an eradication campaign. Moreover, the acaricide concentration on these sites must be optimal during systematic treatments. 相似文献
38.
39.
Clinical, clinicopathologic, and parasitologic observations of trypanosomiasis in dogs infected with North American Trypanosoma cruzi isolates 总被引:1,自引:0,他引:1
Nineteen purebred Beagles of various ages (4, 5, 13, and 47 weeks) were inoculated with North American Trypanosoma cruzi isolates obtained from an opossum (Tc-O), an armadillo (Tc-A), or a dog (Tc-D). Dogs were grouped on the basis of clinical outcome of infection. During the acute stage of disease, dogs of group 1 (n = 7 inoculated with Tc-O or Tc-A) died or were euthanatized because of the severity of disease. Dogs of group 2 (n = 5 inoculated with Tc-O or Tc-A) developed acute disease, but survived to develop chronic disease. Dogs of group 3 (n = 7 Tc-D-inoculated dogs) developed neither acute nor chronic disease. Dogs of group 4 (n = 4--2 dogs 13 weeks old and 2 dogs 47 weeks old) served as noninoculated controls. Clinical signs associated with severe acute myocarditis developed in dogs of groups 1 and 2 between postinoculation day (PID) 15 and 28. Generalized lymphadenopathy and lymphocytosis were observed in all dogs of groups 1, 2, and 3 between PID 14 and 17. Serum alanine transaminase and aspartate transaminase activities and urea nitrogen concentration were high, and glucose concentration was low prior to death of dogs in group 1. Serum activities of isoenzymes of creatine kinase were significantly (P less than 0.05) high in only 1 dog (group 1), whereas serum lactate dehydrogenase isoenzyme activities were not significantly high in any dog.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
40.
Neospora-like protozoan infection as a major cause of abortion in California dairy cattle 总被引:17,自引:0,他引:17
M L Anderson P C Blanchard B C Barr J P Dubey R L Hoffman P A Conrad 《Journal of the American Veterinary Medical Association》1991,198(2):241-244
Ninety-five aborted bovine fetuses received from California dairies over a 4.5-year period had histologic lesions of focal encephalitis. Protozoa that reacted with Neospora caninum antiserum were detected in the brain of 88 of these fetuses and in the heart of 1 fetus. Sarcocystis spp schizonts were seen in the vascular endothelium of 1 fetus. It was concluded that a Neospora-like cyst-forming coccidian may be a major cause of abortion in California dairy cattle. 相似文献