Current strategies for treatment of intervertebral disc degeneration: substitution and regeneration possibilities

Background: Intervertebral disc degeneration has an annual worldwide socioeconomic impact masked as low back pain of over 70 billion euros. This disease has a high prevalence over the working age class, which raises the socioeconomic impact over the years. Acute physical trauma or prolonged intervertebral disc mistreatment triggers a biochemical negative tendency of catabolic-anabolic balance that progress to a chronic degeneration disease. Current biomedical treatments are not only ineffective in the long-run, but can also cause degeneration to spread to adjacent intervertebral discs. Regenerative strategies are desperately needed in the clinics, such as: minimal invasive nucleus pulposus or annulus fibrosus treatments, total disc replacement, and cartilaginous endplates decalcification. Main Body: Herein, it is reviewed the state-of-the-art of intervertebral disc regeneration strategies from the perspective of cells, scaffolds, or constructs, including both popular and unique tissue engineering approaches. The premises for cell type and origin selection or even absence of cells is being explored. Choice of several raw materials and scaffold fabrication methods are evaluated. Extensive studies have been developed for fully regeneration of the annulus fibrosus and nucleus pulposus, together or separately, with a long set of different rationales already reported. Recent works show promising biomaterials and processing methods applied to intervertebral disc substitutive or regenerative strategies. Facing the abundance of studies presented in the literature aiming intervertebral disc regeneration it is interesting to observe how cartilaginous endplates have been extensively neglected, being this a major source of nutrients and water supply for the whole disc. Conclusion: Severalinnovative avenues for tackling intervertebral disc degeneration are being reported â from acellular to cellular approaches, but the cartilaginous endplates regeneration strategies remain unaddressed. Interestingly, patient-specific approaches show great promise in respecting patient anatomy and thus allow quicker translation to the clinics in the near future.The authors would like to acknowledge the support provided by the Portuguese Foundation for Science and Technology (FCT) through the project EPIDisc (UTAP-EXPL/BBBECT/0050/2014), funded in the Framework of the “International Collaboratory for Emerging Technologies, CoLab”, UT Austin|Portugal Program. The FCT distinctions attributed to J. Miguel Oliveira (IF/00423/2012 and IF/01285/ 2015) and J. Silva-Correia (IF/00115/2015) under the Investigator FCT program are also greatly acknowledged.info:eu-repo/semantics/publishedVersio

CMS physics technical design report : Addendum on high density QCD with heavy ions

Peer reviewe

In situ study of the autecology of the closely related, co-occurring sandy beach amphipods <i>Bathyporeia pilosa</i> and <i>Bathyporeia sarsi</i>

Population dynamics and zonation of the amphipods Bathyporeia pilosa and B. sarsi, co-occurring on some beaches, were studied through monthly sampling of eight cross-shore transects along the Belgian coast (October 2003-October 2004). Their biomass and production were assessed for the first time. Abundance and biomass of B. pilosa were ten times higher along western ultra-dissipative transects than along slightly more reflective, eastern transects. For B. sarsi (less prominent), differences between the two westernmost transects (2-5x higher) and all others were observed, whereas P/B ratio was comparable for all. B. pilosa could reach two times higher abundance and biomass and higher levels of production (max B. sarsi = 7,580 g m-2 y-1; max B. pilosa = 16,040 g m-2 y-1), while the species was nearly absent from the eastern transects. Continuous reproduction and recruitment with three relative peaks of the latter (February, July, October) were observed. Fecundity showed parallel temporal variation for both species, peaking in February and September-October. Interestingly, the July relative "recruitment" peak could not be explained by relative abundance of gravid females or fecundity, but was probably caused by adult mortality. Both species displayed comparable gonad production (B. pilosa: Pg = 0.73 mg/ind year; B. sarsi: Pg = 0.71 mg/ind year), but B. pilosa produced fewer yet larger embryos. Peak abundances were found at 436 +/- 25 SD cm (B. pilosa) and 357 +/- 40 SD cm (B. sarsi) above MLLWS, corresponding to a 40-62 m cross-shore distance between the peaks of both species. The occupied cross-shore range was larger for B. sarsi than for B. pilosa (35-54 m), for females than for males (15-23 m), and for adults than for juveniles of B. pilosa (5-8 m). Both species displayed many comparable life history features. Differences in abundance and biomass may be related to beach morphodynamics and zonation

<i>In situ</i> study of the autecology of two closely related, co-occurring sandy beach amphipods

Population dynamics and zonation of the amphipods Bathyporeia pilosa and B. sarsi, co-occurring on some Belgian beaches, were studied through monthly sampling of eight cross-shore transects (October 2003-October 2004). Their biomass and production were assessed for the first time. Abundance and biomass of B. pilosa were ten times higher along western ultra-dissipative transects than along slightly more reflective, eastern transects. For B. sarsi, (less prominent) differences between the two westernmost transects (2-5x higher) and all others were observed, whereas P/B ratio was comparable for all. Bathyporeia pilosa could reach two times higher abundance and biomass and higher levels of production (max. B. sarsi = 7580 mg*m-2*y-1; max. B. pilosa = 16040 mg*m-2*y-1), while nearly absent along eastern transects. Continuous reproduction and recruitment with three relative peaks of the latter (February, July, October) were observed. Fecundity showed parallel temporal variation for both species, peaking in February and September-October. Interestingly, the July relative recruitment peak could not be explained by relative abundance of gravid females or fecundity, but is probably caused by adult mortality. Both species displayed comparable gonad production (B. pilosa: Pg = 0.73 mg/ind*year; B. sarsi: Pg = 0.71 mg/ind*year), but B. pilosa produced fewer yet larger embryos. Peak abundances were found at 436 + 25 SD cm (B. pilosa) and 357 + 40 SD cm (B. sarsi) above MLLWS, corresponding to a 40-62 m cross-shore distance between the peaks of both species. The occupied cross-shore range was larger for B. sarsi than for B. pilosa (35-54 m), for females than for males (15-23 m), and for adults than for juveniles of B. pilosa (5-8 m). Both species displayed many comparable life history features. Differences in abundance and biomass may be related to beach morphodynamics and zonation

Competition and sediment-related responses explaining segregated zonation of two closely related, co-occurring key species on sandy beaches?

To address their role in promoting and/or maintaining observed cross-shore segregation of the co-occurring amphipods Bathyporeia pilosa and B. sarsi, sediment preferences and tolerances were investigated through lab experiments. Preferences were investigated in both allotopic and syntopic conditions, in order to investigate possible avoidance (as a proxy for interspecific competition). Selection of grain size showed no significant differences between the species, nor did the presence of the other species affect the selection. Both species avoided the finest (63-125 μm) and coarsest (>500 μm) grain sizes. Potential niche width with regard to grain size, as established from our experiments, was larger than the occupied width, as observed from field data. Selection of level of fines did not show any difference between species or condition (allo- vs. syntopy) either, while the highest abundance of B. pilosa occurred in 5% fines, whereas that of B. sarsi occurred in the absence of fines. Mortality of animals forced to survive in a single given sediment, was significantly higher in B. sarsi and both species had low mortality levels at a grain size best resembling natural beach sediment (255-350 μm). Thus, whereas preferences of both species are largely comparable, tolerances are not. Conclusively, no clear evidence for interspecific competition could be found, disallowing full explanation of observed segregation. Other possibly determining (abiotic and biotic) factors should be investigated to understand cross-shore segregation, as observed in these closely related yet coexisting species of sandy beach macrofauna