46 research outputs found
Cervical spondylosis with spinal cord encroachment: should preventive surgery be recommended?
<p>Abstract</p> <p>Background</p> <p>It has been stated that individuals who have spondylotic encroachment on the cervical spinal cord without myelopathy are at increased risk of spinal cord injury if they experience minor trauma. Preventive decompression surgery has been recommended for these individuals. The purpose of this paper is to provide the non-surgical spine specialist with information upon which to base advice to patients. The evidence behind claims of increased risk is investigated as well as the evidence regarding the risk of decompression surgery.</p> <p>Methods</p> <p>A literature search was conducted on the risk of spinal cord injury in individuals with asymptomatic cord encroachment and the risk and benefit of preventive decompression surgery.</p> <p>Results</p> <p>Three studies on the risk of spinal cord injury in this population met the inclusion criteria. All reported increased risk. However, none were prospective cohort studies or case-control studies, so the designs did not allow firm conclusions to be drawn. A number of studies and reviews of the risks and benefits of decompression surgery in patients with cervical myelopathy were found, but no studies were found that addressed surgery in asymptomatic individuals thought to be at risk. The complications of decompression surgery range from transient hoarseness to spinal cord injury, with rates ranging from 0.3% to 60%.</p> <p>Conclusion</p> <p>There is insufficient evidence that individuals with spondylotic spinal cord encroachment are at increased risk of spinal cord injury from minor trauma. Prospective cohort or case-control studies are needed to assess this risk. There is no evidence that prophylactic decompression surgery is helpful in this patient population. Decompression surgery appears to be helpful in patients with cervical myelopathy, but the significant risks may outweigh the unknown benefit in asymptomatic individuals. Thus, broad recommendations for decompression surgery in suspected at-risk individuals cannot be made. Recommendations to individual patients must consider possible unique circumstances.</p
Alterations of renal phenotype and gene expression profiles due to protein overload in NOD-related mouse strains
BACKGROUND: Despite multiple causes, Chronic Kidney Disease is commonly associated with proteinuria. A previous study on Non Obese Diabetic mice (NOD), which spontaneously develop type 1 diabetes, described histological and gene expression changes incurred by diabetes in the kidney. Because proteinuria is coincident to diabetes, the effects of proteinuria are difficult to distinguish from those of other factors such as hyperglycemia. Proteinuria can nevertheless be induced in mice by peritoneal injection of Bovine Serum Albumin (BSA). To gain more information on the specific effects of proteinuria, this study addresses renal changes in diabetes resistant NOD-related mouse strains (NON and NOD.B10) that were made to develop proteinuria by BSA overload. METHODS: Proteinuria was induced by protein overload on NON and NOD.B10 mouse strains and histology and microarray technology were used to follow the kidney response. The effects of proteinuria were assessed and subsequently compared to changes that were observed in a prior study on NOD diabetic nephropathy. RESULTS: Overload treatment significantly modified the renal phenotype and out of 5760 clones screened, 21 and 7 kidney transcripts were respectively altered in the NON and NOD.B10. Upregulated transcripts encoded signal transduction genes, as well as markers for inflammation (Calmodulin kinase beta). Down-regulated transcripts included FKBP52 which was also down-regulated in diabetic NOD kidney. Comparison of transcripts altered by proteinuria to those altered by diabetes identified mannosidase 2 alpha 1 as being more specifically induced by proteinuria. CONCLUSION: By simulating a component of diabetes, and looking at the global response on mice resistant to the disease, by virtue of a small genetic difference, we were able to identify key factors in disease progression. This suggests the power of this approach in unraveling multifactorial disease processes
Inhibition of c-MYC expression through disruption of an RNA.protein interaction using antisense oligonucleotides
grantor:
University of TorontoThe proto-oncogene c-'myc' encodes a protein that regulates cellular proliferation and differentiation. Conditions that alter the stability of c-'myc' mRNA can lead to overexpression of the gene resulting in uncontrolled cell growth. Synthetic therapeutic agents, known as Antisense Oligonucleotides (ODN), can bind to target mRNA and inhibit its expression. A previously characterized protein, the coding region stability determinant-binding protein (CRD-BP), binds the coding region determinant (CRD) of c-' myc' mRNA and is believed to protect it from endonucleolytic cleavage. Accordingly, we hypothesized that ODNs directed towards the CRD of c-' myc' mRNA could prevent CRD-BP·RNA interactions, thus decreasing c-'myc' expression. Using an 'in vitro' gel shift assay we demonstrated that ODNs inhibit the CRD-BP·c-' myc' mRNA interaction. The most effective ODN, CRD-ODN4, exhibited a sequence-specific and concentration-dependent inhibition of the RNA·CRD-BP interaction. Up to 65% inhibition of protein expression and 45% inhibition of mRNA expression was observed with 200 nM of CRD-ODN4. Conversely, a 2 '-O-methyl ODN derivative targeting the translational initiation codon (ODN-AUG) reduced c-'myc' protein but increased mRNA levels 2-fold. Additionally, CRD-ODN4 was more effective at inhibiting K562 cell growth. The results observed both 'in vitro' and within cells support the hypothesis that CRD-ODN4 is capable of disrupting the interaction between CRD-BP and c-'myc' mRNA and this disruption decreases c-'myc' expression and functional effects in cells. (Abstract shortened by UMI.)M.Sc
Macroarthropod-microorganism interactions during the decomposition of Mediterranean shrub litter at different moisture levels
International audienc
Leaf Litter Consumption by Macroarthropods and Burial of their Faeces Enhance Decomposition in a Mediterranean Ecosystem
International audienceno abstrac
Chiropractic & Osteopathy BioMed Central Review
Cervical spondylosis with spinal cord encroachment: should preventive surgery be recommended
Plasticity in leaf litter traits partly mitigates the impact of thinning on forest floor carbon cycling
Myofibrillar tightly bound calcium in skeletal muscle fibers: a possible role of this cation in titin strands aggregation
In muscle cells, part of the calcium is tightly bound to the N1- and N2-line of the sarcomere but its physiological significance was unknown. In the present work we reported the ability of a recombinant titin fragment spanning titin domains Z9 to I1 to tightly bind calcium ions with a K-d of 0.049 +/- 0.004 nM. We further showed that calcium induced a spontaneous aggregation of the titin fragment and that the major aggregate is a tetramer. The implication of these findings on the organization of the six titin strands that emanate from the end of the thick filament within the I-band is discussed. (C) 2003 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved
Endogeic earthworms modify soil phosphorus, plant growth and interactions in a legume-cereal intercrop
Intercropping of legumes and cereals appears as an alternative agricultural practice to decrease the use of chemical fertilizers while maintaining high yields. A better understanding of the biotic and abiotic factors determining interactions between plants in such associations is required. Our study aimed to analyse the effect of earthworms on the legume-cereal interactions with a focus on the modifications induced by earthworms on the forms of soil phosphorus (P). In a glasshouse experiment we investigated the effect of an endogeic earthworm (Allolobophora chlorotica) on the plant biomass and on N and P acquisition by durum wheat (Triticum turgidum durum L.) and chickpea (Cicer arietinum L.) either grown alone or intercropped. The modifications of the different organic and inorganic P forms in the bulk soil were measured. There was no overyielding of the intercrop in the absence of earthworms. Earthworms had a strong influence on biomass and resource allocation between roots and shoots whereas no modification was observed in terms of total biomass production and P acquisition. Earthworms changed the interaction between the intercropped species mainly by reducing the competition for nutrients. Facilitation (positive plant-plant interactions) was only observed for the root biomass and P acquisition in the presence of earthworms. Earthworms decreased the amount of organic P extracted with NaOH (Po NaOH), while they increased the water soluble inorganic P (Pi H2O) content. In this experiment, earthworms could be seen as "troubleshooter" in plant-plant interaction as they reduced the competition between the intercropped species. Our study brings new insights into how earthworms affect plant growth and the P cycle