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21.
H?Bukulmez AL?Matthews CM?Sullivan C?Chen MJ?Kraay RC?Elston RW?Moskowitz VM?Goldberg ML?WarmanEmail author 《Arthritis research & therapy》2005,8(1):R25
In order to determine whether there is a genetic component to hip or knee joint failure due to idiopathic osteoarthritis (OA),
we invited patients (probands) undergoing hip or knee arthroplasty for management of idiopathic OA to provide detailed family
histories regarding the prevalence of idiopathic OA requiring joint replacement in their siblings. We also invited their spouses
to provide detailed family histories about their siblings to serve as a control group. In the probands, we confirmed the diagnosis
of idiopathic OA using American College of Rheumatology criteria. The cohorts included the siblings of 635 probands undergoing
total hip replacement, the siblings of 486 probands undergoing total knee replacement, and the siblings of 787 spouses. We
compared the prevalence of arthroplasty for idiopathic OA among the siblings of the probands with that among the siblings
of the spouses, and we used logistic regression to identify independent risk factors for hip and knee arthroplasty in the
siblings. Familial aggregation for hip arthroplasty, but not for knee arthroplasty, was observed after controlling for age
and sex, suggesting a genetic contribution to end-stage hip OA but not to end-stage knee OA. We conclude that attempts to
identify genes that predispose to idiopathic OA resulting in joint failure are more likely to be successful in patients with
hip OA than in those with knee OA. 相似文献
22.
Structure and regulation of the anthranilate synthase genes in Pseudomonas aeruginosa: II. Cloning and expression in Escherichia coli 总被引:7,自引:0,他引:7
Crawford IP; Wilde A; Yelverton EM; Figurski D; Hedges RW 《Molecular biology and evolution》1986,3(5):449-458
The genes for the large and small subunits of anthranilate synthase (trpE
and trpG, respectively) have been cloned from Pseudomonas aeruginosa PAC174
into E. coli by R-prime formation with the broad-host- range plasmid
R68.44. Sequential subcloning into plasmid vectors reduced the active
Pseudomonas DNA fragment to a length of 3.1 kb. We obtained evidence that
this region contains the promoter for its own expression and retains a
vestigial regulatory response to tryptophan scarcity or excess.
相似文献
23.
RW Dapson 《Biotechnic & histochemistry》2016,91(8):522-531
During the 1860’s, Hugo Schiff studied many reactions between amines and aldehydes, some of which have been used in histochemistry, at times without credit to Schiff. Much controversy has surrounded the chemical structures and reaction mechanisms of the compounds involved, but modern analytical techniques have clarified the picture. I review these reactions here. I used molecular modeling software to investigate dyes that contain primary amines representing eight chemical families. All dyes were known to perform satisfactorily for detecting aldehydes in tissue sections. The models verified the correct chemical structures at various points in their reactions and also determined how decolorization occurred in those with “leuco” forms. Decolorization in the presence of sulfurous acid can occur by either adduction or reduction depending on the dye. The final condensation product with aldehyde was determined to be either a C-sulfonic acid adduct on the carbonyl carbon atom or an aminal at the same atom. Based on the various outcomes, I have placed the dyes and their reactions into five categories. Because Hugo Schiff studied the reactions between aldehydes and amines with and without various acids or alcohol, it is only proper to call each of them Schiff reactions that used various types of Schiff reagents. 相似文献
24.
RW Dapson 《Biotechnic & histochemistry》2013,88(3):133-140
Although the mechanics of formalin fixation and antigen retrieval have been studied extensively and reviewed periodically, little attention has been directed toward conformational changes in target molecules. Formaldehyde changes the shape of tissue molecules by appending small hydroxymethyl groups to them. These adducts, in turn, can react with other tissue molecules to form crosslinks, or they can participate in a variety of reactions during tissue processing, including formation of imines, ethoxymethyl adducts, and further crosslinks. Under the influence of alcohol dehydration, fixed DNA may fragment and form a variety of depurination products. The situation becomes even more complex with short fixation times because under these conditions, the dehydrating agent used for tissue processing denatures macromolecules in other ways, most notably through rearrangement of molecular shape to move hydrophobic realms outward and hydrophilic areas inward (hydrophobic inversions). How tissue molecules are modified affects the outcome of immunohistochemical staining and prospects for restoration of antigenicity. Immunoreacitivity may be compromised because epitopes are either sterically hidden, but otherwise unaffected, or they have been altered more directly. Enzyme-based retrieval methods are best suited for the former because they literally snip the molecule apart to reveal the portions of interest. Heat-induced retrieval with buffers can demodify affected epitopes by removing adducts and breaking crosslinks. The choice of temperature and pH is usually critical for optimal retrieval. Effective temperatures are directly related to the strength of bonds-higher temperatures are needed to break stronger bonds. The pH of the retrieval solution determines the charge on the tissue molecule; the goal is to create a charge that causes the demodified molecule to assume a near natural conformation. Rational use of these concepts should lead to better control of immunohistochemical reactions. 相似文献
25.
In June 2008, the Biological Stain Commission sponsored A Seminar on Dyes and Staining the purpose of which was twofold: first, to show that very useful information applicable to biomedical dyes and staining is available from unrelated disciplines and second, to summarize modern thinking on how dyes, solvents, and tissues interact to produce selective staining. In this introduction to the papers from the symposium, we acknowledge that biomedical dye research has declined as newer technologies have gained importance. We should point out, however, that dyes and staining still are vitally important. Moreover, needs abound for innovative studies concerned with dye analysis, synthesis, and mode of action. Concepts and tools from unrelated fields hold promise for significant breakthroughs in many areas of interest. 相似文献
26.
Joel A Dave Nico C Gey van Pittius Albert D Beyers Mario RW Ehlers Gordon D Brown 《BMC microbiology》2002,2(1):30
Background
Exported proteases are commonly associated with virulence in bacterial pathogens, yet there is a paucity of information regarding their role in Mycobacterium tuberculosis. There are five genes (mycP1-5) present within the genome of Mycobacterium tuberculosis H37Rv that encode a family of secreted, subtilisin-like serine proteases (the mycosins). The gene mycP1 (encoding mycosin-1) was found to be situated 3700 bp (four ORF's) from the RD1 deletion region in the genome of the attenuated vaccine strain M. bovis BCG (bacille de Calmette et Guérin) and was selected for further analyses due to the absence of expression in this organism. 相似文献27.
Willey JS Lloyd SA Robbins ME Bourland JD Smith-Sielicki H Bowman LC Norrdin RW Bateman TA 《Radiation research》2008,170(3):388-392
Willey, J. S., Lloyd, S. A. J., Robbins, M. E., Bourland, J. D., Smith-Sielicki, H., Bowman, L. C., Norrdin, R. W. and Bateman, T. A. Early Increase in Osteoclast Number in Mice after Whole-Body Irradiation with 2 Gy X Rays. Radiat. Res. 170, 388-392 (2008).Bone loss is a consequence of exposure to high-dose radiotherapy. While damage to bone vasculature and reduced proliferation of bone-forming osteoblasts has been implicated in this process, the effect of radiation on the number and activity of bone-resorbing osteoclasts has not been characterized. In this study, we exposed mice to a whole-body dose of 2 Gy of X rays to quantify the early effects of radiation on osteoclasts and bone structural properties. Female C57BL/6 mice (13 weeks old) were divided into two groups: irradiated and nonirradiated controls. Animals were killed humanely 3 days after radiation exposure. Analysis of serum chemistry revealed a 14% increase in the concentration of tartrate resistant acid phosphatase (TRAP)-5b, a marker of osteoclast activity, in irradiated mice (P < 0.05). Osteoclast number (+44%; P < 0.05) and osteoclast surface (+213%; P < 0.001) were elevated in TRAP-stained histological sections of tibial metaphyses. No significant change was observed in osteoblast surface or osteocalcin concentration or in trabecular microarchitecture (i.e. bone volume fraction) as measured through microcomputed tomography (P > 0.05). This study provides definitive, quantitative evidence of an early, radiation-induced increase in osteoclast activity and number. Osteoclastic bone resorption may represent a contributor to bone atrophy observed after therapeutic irradiation. 相似文献
28.
29.
Norrdin RW Bay BK Drews MJ Martin RB Stover SM 《Journal of musculoskeletal & neuronal interactions》2001,1(4):357-362
An overload arthrosis occurs consistently in the palmar region of the metacarpal condyle of the equine fetlock (metacarpophalangeal) joint characterized by subchondral bone sclerosis, devitalization and mechanical failure leading to collapse of the overlying articular cartilage. Samples were selected of joints with mild, moderate, and severe subchondral sclerosis, in which cartilage collapse had not yet occurred. An additional group that had severe sclerosis with focal rarefaction suggesting impending collapse was also studied (n=5/group). Parasagittal slices were milled to 2.0 mm thickness and subjected to palmar forces 50 to 200% of those applied by the sesamoid bone at angles corresponding to early, mid and late stance support phases of the gait cycle. From contact radiographs in the loaded and unloaded samples, strains were determined by recognizing displacements in the trabecular patterns using texture correlation analysis. Failure did not occur in any of the samples. Strains were generally proportional to the forces applied and greatest at midstance. Strain patterns varied between samples and with the different loading positions. With increased subchondral bone sclerosis there was greater shear strain in overlying trabeculae. Strain patterns were not consistently different within the sclerotic bone at the site of failure. Focally higher strains at the surface were sometimes related to the edge of the platen which was molded to mimic the sesamoid bone in vivo. These results indicate that sclerotic thickening of subchondral bone transmits stresses to overlying trabeculae. No consistent strain pattern was recognized where devitalization and mechanical failure occurs. Focally higher strains related to the edge of the opposing sesamoid bone may play a role. 相似文献
30.
During preimplantation development in mammals, distinct epigenetic marks on oocyte and sperm DNA are remodeled to an embryonic pattern. A recent study examining global methylation of repetitive elements in various mammals showed that the reprogramming that occurs during normal preimplantation development is aberrant in cloned embryos. 相似文献