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1.
From six to 89 months after surgery 82 patients who had been treated by radical surgery (118 excisions) for intractable hidradenitis suppurativa were reviewed. Local recurrence rates varied greatly with the disease site, being low after axillary (3%) and perianal surgery (0%) and high after inguinoperineal (37%) and submammary (50%) excision. Recurrence results from inadequate excision or an unusually wide distribution of apocrine glands, but physical factors such as obesity, local pressure, and skin maceration played a part in a few patients. Recurrence due to inadequate surgery tended to be the most troublesome. At follow up 75 (91%) of the patients were pleased with the results of their operation. A quarter of the patients developed disease at a new anatomical site after operation. Radical surgery gives good symptomatic control of severe hidradenitis suppurativa of the axilla, inguinoperineal, and perianal regions but is less satisfactory for submammary disease. 相似文献
2.
The effects of ethylene and auxin on the morphology and anatomy of root organ cultures of Pinus mugo Turra var. mugo were investigated to test the hypothesis that changes in root morphology associated with formation of ectomycorrhizae may be related to ethylene produced by ectomycorrhizal fungi or by host plant roots in response to fungus-produced auxin. Morphological changes characteristic of mycorrhizal infection include dichotomous branching of lateral roots, inhibition of root hair formation and enlargement of cortical cells. Lateral roots on non-mycorrhizal root organ cultures, grown in a defined medium, underwent dichtotomous branching while root hair formation was inhibited in response to the ethylene released by 50 and 100 μ M ethephon (2-chloroethylphosphonic acid), but no effect on cortical cell dimensions was observed. The auxin, naphthaleneacetic acid (1 and 10 μ M ) also stimulated dichotomous branching and inhibited root hair formation, but to a lesser extent and with a greater lag time than ethephon. Auxin-stimulated ethylene production by root organ cultures was demonstrated. This appeared to be responsible, at least in part, for the auxin-induced dichotomous branching since the ethylene action inhibitor, silver thiosulfate (0.1 m M ) inhibited the response to auxin by 35%. 相似文献
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L-Lactate dehydrogenase (L-LDH, E.C. 1.1.1.27) is encoded by two or three
loci in all vertebrates examined, with the exception of lampreys, which
have a single LDH locus. Biochemical characterizations of LDH proteins have
suggested that a gene duplication early in vertebrate evolution gave rise
to Ldh-A and Ldh-B and that an additional locus, Ldh-C arose in a number of
lineages more recently. Although some phylogenetic studies of LDH protein
sequences have supported this pattern of gene duplication, others have
contradicted it. In particular, a number of studies have suggested that
Ldh-C represents the earliest divergence among vertebrate LDHs and that it
may have diverged from the other loci well before the origin of
vertebrates. Such hypotheses make explicit statements about the
relationship of vertebrate and invertebrate LDHs, but to date, no closely
related invertebrate LDH sequences have been available for comparison. We
have attempted to provide further data on the timing of gene duplications
leading to multiple vertebrate LDHs by determining the cDNA sequence of the
LDH of the tunicate Styela plicata. Phylogenetic analyses of this and other
LDH sequences provide strong support for the duplications giving rise to
multiple vertebrate LDHs having occurred after vertebrates diverged from
tunicates. The timing of these LDH duplications is consistent with data
from a number of other gene families suggesting widespread gene duplication
near the origin of vertebrates. With respect to the relationships among
vertebrate LDHs, our data are not consistent with previous claims that
Ldh-C represented the earliest divergence. However, the precise
relationships among some of the main lineages of vertebrate LDHs were not
resolved in our analyses.
相似文献
5.
Paul DW Kirk Aviva Witkover Alan Courtney Alexandra M Lewin Robin Wait Michael PH Stumpf Sylvia Richardson Graham P Taylor Charles RM Bangham 《Retrovirology》2011,8(1):1-9
Background
A new subgroup of HIV-1, designated Group P, was recently detected in two unrelated patients of Cameroonian origin. HIV-1 Group P phylogenetically clusters with SIVgor suggesting that it is the result of a cross-species transmission from gorillas. Until today, HIV-1 Group P has only been detected in two patients, and its degree of adaptation to the human host is largely unknown. Previous data have shown that pandemic HIV-1 Group M, but not non-pandemic Group O or rare Group N viruses, efficiently antagonize the human orthologue of the restriction factor tetherin (BST-2, HM1.24, CD317) suggesting that primate lentiviruses may have to gain anti-tetherin activity for efficient spread in the human population. Thus far, three SIV/HIV gene products (vpu, nef and env) are known to have the potential to counteract primate tetherin proteins, often in a species-specific manner. Here, we examined how long Group P may have been circulating in humans and determined its capability to antagonize human tetherin as an indicator of adaptation to humans.Results
Our data suggest that HIV-1 Group P entered the human population between 1845 and 1989. Vpu, Env and Nef proteins from both Group P viruses failed to counteract human or gorilla tetherin to promote efficient release of HIV-1 virions, although both Group P Nef proteins moderately downmodulated gorilla tetherin from the cell surface. Notably, Vpu, Env and Nef alleles from the two HIV-1 P strains were all able to reduce CD4 cell surface expression.Conclusions
Our analyses of the two reported HIV-1 Group P viruses suggest that zoonosis occurred in the last 170 years and further support that pandemic HIV-1 Group M strains are better adapted to humans than non-pandemic or rare Group O, N and P viruses. The inability to antagonize human tetherin may potentially explain the limited spread of HIV-1 Group P in the human population. 相似文献6.
Current status of antisense DNA methods in behavioral studies 总被引:4,自引:0,他引:4
The antisense DNA method has been used successfully to block the expression
of specific genes in vivo in neuronal systems. An increasing number of
studies in the last few years have shown that antisense DNA administered
directly into the brain can modify various kinds of behaviors. These
findings strongly suggest that the antisense DNA method can be used as a
powerful tool to study causal relationships between molecular processes in
the brain and behavior. In this article we review the current status of the
antisense method in behavioral studies and discuss its potentials and
problems by focusing on the following four aspects; (i) optimal application
paradigms of antisense DNA methods in behavioral studies; (ii) efficiencies
of different administration methods of antisense DNA used in behavioral
studies; (iii) determination of specificity of behavioral effects of
antisense DNA; and (iv) discrepancies between antisense DNA effects on
behaviors and those on protein levels of the targeted gene.
相似文献
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Chanyarat Paungfoo-Lonhienne Thierry G.A. Lonhienne Stephen R. Mudge Peer M. Schenk Michael Christie Bernard J. Carroll Susanne Schmidt 《Plant physiology》2010,153(2):799-805
Phosphorus (P) enters roots as inorganic phosphate (Pi) derived from organic and inorganic P compounds in the soil. Nucleic acids can support plant growth as the sole source of P in axenic culture but are thought to be converted into Pi by plant-derived nucleases and phosphatases prior to uptake. Here, we show that a nuclease-resistant analog of DNA is taken up by plant cells. Fluorescently labeled S-DNA of 25 bp, which is protected against enzymatic breakdown by its phosphorothioate backbone, was taken up and detected in root cells including root hairs and pollen tubes. These results indicate that current views of plant P acquisition may have to be revised to include uptake of DNA into cells. We further show that addition of DNA to Pi-containing growth medium enhanced the growth of lateral roots and root hairs even though plants were P replete and had similar biomass as plants supplied with Pi only. Exogenously supplied DNA increased length growth of pollen tubes, which were studied because they have similar elongated and polarized growth as root hairs. Our results indicate that DNA is not only taken up and used as a P source by plants, but ironically and independent of Pi supply, DNA also induces morphological changes in roots similar to those observed with P limitation. This study provides, to our knowledge, first evidence that exogenous DNA could act nonspecifically as signaling molecules for root development.Phosphorus (P) is an essential macronutrient that limits plant growth in many situations due to a low availability in soils (for review, see Schachtman et al., 1998; Raghothama, 1999; Vance et al., 2003; Lambers et al., 2008). P enters plant roots as orthophosphates (Pi) via active transport across the plasma membrane (Smith et al., 2003; Park et al., 2007; Xu et al., 2007). Concentrations of Pi in soil solution are generally very low (<10 μm; Bieleski, 1973) and plants have evolved root specializations to access P from inorganic and organic sources (Raghothama, 1999; Hinsinger, 2001; López-Bucio et al., 2003; Vance et al., 2003; Lambers et al., 2008). Roots exude enzymes and chemicals to mobilize P directly from soil compounds or indirectly via enhanced activity of soil microbes, and form symbioses with P-mobilizing mycorrhizal fungi (Schachtman et al., 1998; Raghothama, 1999; Bucher, 2007).However, similar to other nutrients, notably nitrogen, research on P nutrition of plants has focused on inorganic sources although organic P (Porg) in soil can account for 40% to 80% of the total P pool of mineral and organic soils, respectively (Bower, 1945; Raghothama, 1999; Vance et al., 2003). Porg compounds in soils are derived from plant residues, soil biota, and from synthesis by soil microbes (Jencks et al., 1964). Soil Porg is composed primarily of phospholipids, nucleic acids, and phytin (Dyer and Wrenshall, 1941). Phytic acid (inositol hexaphosphate) and its salts phytate, account for a large proportion of the Porg pool of soils (Anderson, 1980). Nucleic acids (RNA, DNA) represent approximately 1% to 2% of the soil Porg pool (Dalal, 1977). It can be released from prokaryotic and eukaryotic cells after death and protected against nuclease degradation by its adsorption on soil colloids and sand particles (Pietramellara et al., 2009).Although Porg can be a substantial constituent of the soil P pool, its contribution to the P nutrition of plants is poorly understood. Porg can be converted to Pi via root-exuded enzymes (Tarafdar and Claassen, 1988; Marschner, 1995; Vance et al., 2003). Secretion of nucleolytic enzymes and breakdown of nucleic acid were considered the reason for the observed growth of axenic Arabidopsis (Arabidopsis thaliana) and wheat (Triticum aestivum) on nucleic acid substrates as the sole P source (Chen et al., 2000; Richardson et al., 2000).Whether plants take up intact DNA has not been reported. We recently showed that roots take up protein, possibly via endocytosis (Paungfoo-Lonhienne et al., 2008). We hypothesized that roots may take up DNA by a similar process and grew Arabidopsis in the presence of phosphorothioate oligonucleotides (S-DNA) labeled with Cy3-fluorescent dye. S-DNA has a sulfur backbone and cannot be digested by plant nucleases, allowing tracking DNA of known size into cells (Spitzer and Eckstein, 1988). We examined if S-DNA of 25 nucleotides in length enters root hairs and pollen tubes as both types of cells are strongly elongated and have similar polarized growth (Schiefelbein et al., 1993; Hepler et al., 2001). We also assessed if addition of DNA to the growth medium affects the morphology of roots and pollen tubes. Here, we present evidence that plants take up DNA and demonstrate that the presence of DNA in the growth medium enhances lateral branching of roots, and the length of root hairs and pollen tubes, irrespective of Pi supply. 相似文献
10.
Parchman TL Gompert Z Mudge J Schilkey FD Benkman CW Buerkle CA 《Molecular ecology》2012,21(12):2991-3005
Pine cones that remain closed and retain seeds until fire causes the cones to open (cone serotiny) represent a key adaptive trait in a variety of pine species. In lodgepole pine, there is substantial geographical variation in serotiny across the Rocky Mountain region. This variation in serotiny has evolved as a result of geographically divergent selection, with consequences that extend to forest communities and ecosystems. An understanding of the genetic architecture of this trait is of interest owing to the wide-reaching ecological consequences of serotiny and also because of the repeated evolution of the trait across the genus. Here, we present and utilize an inexpensive and time-effective method for generating population genomic data. The method uses restriction enzymes and PCR amplification to generate a library of fragments that can be sequenced with a high level of multiplexing. We obtained data for more than 95,000 single nucleotide polymorphisms across 98 serotinous and nonserotinous lodgepole pines from three populations. We used a Bayesian generalized linear model (GLM) to test for an association between genotypic variation at these loci and serotiny. The probability of serotiny varied by genotype at 11 loci, and the association between genotype and serotiny at these loci was consistent in each of the three populations of pines. Genetic variation across these 11 loci explained 50% of the phenotypic variation in serotiny. Our results provide a first genome-wide association map of serotiny in pines and demonstrate an inexpensive and efficient method for generating population genomic data. 相似文献