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31.
32.
Hb Grady and alpha thalassemia: a contribution to the problem of the number of Hb alpha structural loci in man. 总被引:2,自引:2,他引:0
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Hematological evaluation and data from chain synthesis analyses in six members of the family with two members having Hb Grady (i.e., and alpha chain variant with elongated chains due to an insertion of three amino acid residues [1]) indicate the presence of multiple nonallelic Hb alpha structural loci in the single Hb Grady heterozygote. The data support the earlier stated hypothesis that the Hb alpha Grady locus resulted from a crossing over between chromosomes of two tandemly repeated Hb alpha loci. The presence of an alpha thalassemia condition in one of the two Hb Grady heterozygotes increases the relative production of the alpha Grady chain by a factor of two. 相似文献
33.
Hemoglobin-A2-Coburg or alpha2delta2-116 Arg leads to His (G18) has been found in members of a family of Sicilian origin. The propositus is heterozygous for hemoglobin-A2-Coburg as well as for beta-thalassemia, and family data indicate that the gene for the delta-Coburg chain is in trans of the beta-thalassemia determinant. 相似文献
34.
In a three-hour bioassay, we tested the palatability and feeding preferences of Uresiphita maorialis (kōwhai moth) for Sophora tetraptera, Sophora microphylla and Sophora prostrata. Palatability tests showed no differences among the Sophora species. Feeding preferences, on the other hand, showed that S. tetraptera and S. microphylla leaves are preferred over S. prostrata leaves. Our results support our field observations in Wellington city parks and gardens showing that S. tetraptera and S. microphylla plants frequently have higher densities of larvae than S. prostrata. 相似文献
35.
36.
Two new taxa of Liagoraceae (Nemaliales) are described from Western Australia. Gloiotrichus fractalis gen. et sp. nov. has been collected from 3–20 m depths at the Houtman Abrolhos, Western Australia. Plants are calcified, extremely lubricous, and grow to 17 cm in length. Carpogonial branches are straight, 6 or 7 cells in length, arise from the basal or lower cells of cortical fascicles, and are occasionally compound. Branched sterile filaments of narrow elongate cells arise on the lower cells of the carpogonial branch prior to gonimoblast initiation, at first on the basal cells, then on progressively more distal cells. Following presumed fertilisation the carpogonium divides transversely, with both cells giving rise to gonimoblast filaments. The distal cells of the carpogonial branch then begin to fuse, with fusion progressing proximally until most of the cells of the carpogonial branch are included. As fusion extends, the filaments on the carpogonial branch are reduced to the basal 2 or 3 cells. The gonimoblast is compact and bears terminal carposporangia. Spermatangial clusters arise on subterminal cells of the cortex, eventually displacing the terminal cells. The sequence of pre- and post-fertilisation events occurring in the new genus separates it from all others included in the Liagoraceae, although it appears to have close affinities with the uncalcified genus Nemalion. Ganonema helminthaxis sp. nov. was collected from 12 m depths at Rottnest Island, Western Australia. Plants are uncalcified and mucilaginous, the axes consisting of a few (< 10) primary medullary filaments, each cell of which gives rise to a cortical fascicle at alternate forks of the pseudodichotomies borne on successive medullary cells. Subsidiary (adventitious) filaments and rhizoids comprise the bulk of the thallus. Carpogonial branches are straight, (3-)4(-6) cells in length, arise on the basal 1–4 cells of the cortical fascicles, and are frequently compound. Carposporophytes develop from the upper of two daughter cells formed by a transverse division of the fertilised carpogonium. Ascending and descending sterile filaments girdle the carpogonial branch cells and arise mostly on the supporting cell prior to fertilisation. Ganonema helminthaxis is the first completely non-calcified member of the genus, and its reproductive and vegetative morphology supports the recognition of Ganonema as a genus independent from Liagora. Liagora codii Womersley is a southern Australian species displaying features of Ganonema, to which it is transferred. 相似文献
37.
Boynton ZL Koon JJ Brennan EM Clouart JD Horowitz DM Gerngross TU Huisman GW 《Applied and environmental microbiology》1999,65(4):1524-1529
Poly(3-hydroxyalkanoates) (PHAs) are biodegradable thermoplastics which are accumulated by many bacterial species in the form of intracellular granules and which are thought to serve as reserves of carbon and energy. Pseudomonas putida accumulates a polyester, composed of medium-side-chain 3-hydroxyalkanoic acids, which has excellent film-forming properties. Industrial processing of PHA involves purification of the PHA granules from high-cell-density cultures. After the fermentation process, cells are lysed by homogenization and PHA granules are purified by chemical treatment and repeated washings to yield a PHA latex. Unfortunately, the liberation of chromosomal DNA during lysis causes a dramatic increase in viscosity, which is problematic in the subsequent purification steps. Reduction of the viscosity is generally achieved by the supplementation of commercially available nuclease preparations or by heat treatment; however, both procedures add substantial costs to the process. As a solution to this problem, a nuclease-encoding gene from Staphylococcus aureus was integrated into the genomes of several PHA producers. Staphylococcal nuclease is readily expressed in PHA-producing Pseudomonas strains and is directed to the periplasm, and occasionally to the culture medium, without affecting PHA production or strain stability. During downstream processing, the viscosity of the lysate from a nuclease-integrated Pseudomonas strain was reduced to a level similar to that observed for the wild-type strain after treatment with commercial nuclease. The nuclease gene was also functionally integrated into the chromosomes of other PHA producers, including Ralstonia eutropha. 相似文献
38.
Recent theory shows that: (i) competition between multiple species for multiple resources may generate oscillations and chaotic fluctuations in species abundances; and (ii) these non-equilibrium dynamics may favor a high biodiversity. These findings were based on Liebigs Law of the Minimum, which assumes that each species is limited by only one resource at a time. In reality, however, resources can have interactive effects on growth. Here, we investigate whether competition for interactively essential resources may generate oscillations and chaos as well. Our results show that competition for interactively essential resources may, indeed, exhibit dynamics of similar complexity. This illustrates the wide potential for non-equilibrium dynamics generated by multispecies competition, and suggests that competitive chaos may occur on a wide variety of different resource types. 相似文献
39.
Jolanda?HM?van Bilsen Josée?PA?Wagenaar-Hilbers Maarten?JF?van der Cammen Mariska?EA?van Dijk Willem?van Eden Marca?HM?WaubenEmail author 《Arthritis research & therapy》2002,4(4):R2
We have recently found that matrix metalloproteinases (MMPs) are targets for T-cell and B-cell reactivity in experimental
arthritis. In the present article, we investigate whether modulation of MMP-specific T-cell responses could influence the
course of adjuvant arthritis (AA). Lewis rats were treated nasally with MMP peptides prior to or after AA induction. Administration
of the MMP-10 or the MMP-16 peptide prior to AA induction reduced the arthritic symptoms. In contrast, administration of the
MMP-10 peptide after AA induction aggravated the arthritic symptoms. The present study shows the possible usefulness of MMP
peptides for immunotherapy. However, a clear understanding of proper timing of peptide administration is crucial for the development
of such therapies. 相似文献
40.
Venneman NG Huisman SJ Moschetta A vanBerge-Henegouwen GP van Erpecum KJ 《Biochimica et biophysica acta》2002,1597(2):221-228
[Ru(2,2'-bipyridine)(2)(4,4'-dicarboxy-2,2'-bipyridine)](2+) (RuBDc) is a very photostable probe that possesses favorable photophysical properties including long lifetime, high quantum yield, large Stokes' shift, and highly polarized emission. In the present study, we demonstrated the usefulness of this probe for monitoring the rotational diffusion of high-molecular-weight (MW) proteins. Using frequency-domain fluorometry with a high-intensity, blue light-emitting diode (LED) as the modulated light source, we compared the intensity and anisotropy decays of RuBDc conjugated to immunoglobulin G (IgG) and immunoglobulin M (IgM), which show a six-fold difference in MW We obtained slightly longer lifetimes for IgM (=428 ns in buffer) than IgG (=422 ns in buffer) in the absence and presence of glycerol, suggesting somewhat more efficient shielding of RuBDc from water in IgM than in IgG. The anisotropy decay data showed longer rotational correlation times for IgM (1623 and 65.7 ns in buffer) as compared to IgG (264 and 42.5 ns in buffer). Importantly, the ratio of the long rotational correlation times of IgM to IgG in buffer was 6.2, which is very close to that of MW of IgM to IgG (6.0). The shorter correlation times are most likely to be associated with domain motions within the proteins. The anisotropy decays reflect both the molecular size and shape of the immunoglobulins, as well as the viscosity. These results show that RuBDc can have numerous applications in studies of high-MW protein hydrodynamics and in fluorescence polarization immunoassays (FPI) of high-MW analytes. 相似文献