BACKGROUND The enteric nervous system(ENS)is situated along the entire gastrointestinal tract and is divided into myenteric and submucosal plexuses in the small and large intestines.The ENS consists of neurons,glial c...BACKGROUND The enteric nervous system(ENS)is situated along the entire gastrointestinal tract and is divided into myenteric and submucosal plexuses in the small and large intestines.The ENS consists of neurons,glial cells,and nerves assembled into ganglia,surrounded by telocytes,interstitial cells of Cajal,and connective tissue.Owing to the complex spatial organization of several interconnections with nerve fascicles,the ENS is difficult to examine in conventional histological sections of 3-5μm.AIM To examine human ileum full-thickness biopsies using X-ray phase-contrast nanotomography without prior staining to visualize the ENS.METHODS Six patients were diagnosed with gastrointestinal dysmotility and neuropathy based on routine clinical and histopathological examinations.As controls,fullthickness biopsies were collected from healthy resection ileal regions after hemicolectomy for right colon malignancy.From the paraffin blocks,4-μm thick sections were prepared and stained with hematoxylin and eosin for localization of the myenteric ganglia under a light microscope.A 1-mm punch biopsy(up to 1 cm in length)centered on the myenteric plexus was taken and placed into a Kapton®tube for mounting in the subsequent investigation.X-ray phase-contrast tomography was performed using two custom-designed laboratory setups with micrometer resolution for overview scanning.Subsequently,selected regions of interest were scanned at a synchrotron-based end-station,and high-resolution slices were reported.In total,more than 6000 virtual slices were analyzed from nine samples.RESULTS In the overview scans,the general architecture and quality of the samples were studied,and the myenteric plexus was localized.High-resolution scans revealed details,including the ganglia,interganglional nerve fascicles,and surrounding tissue.The ganglia were irregular in shape and contained neurons and glial cells.Spindle-shaped cells with very thin cellular projections could be observed on the surface of the ganglia,which appeared to build a network.In the patients,there were no alterations in the general architecture of the myenteric ganglia.Nevertheless,several pathological changes were observed,including vacuolar degeneration,autophagic activity,the appearance of sequestosomes,chromatolysis,and apoptosis.Furthermore,possible expulsion of pyknotic neurons and defects in the covering cellular network could be observed in serial slices.These changes partly corresponded to previous light microscopy findings.CONCLUSION The analysis of serial virtual slices could provide new information that cannot be obtained by classical light microscopy.The advantages,disadvantages,and future possibilities of this method are also discussed.展开更多
Biodegradable magnesium(Mg)alloys can revolutionize osteosynthesis,because they have mechanical properties similar to those of the bone,and degrade over time,avoiding the need of removal surgery.However,they are not y...Biodegradable magnesium(Mg)alloys can revolutionize osteosynthesis,because they have mechanical properties similar to those of the bone,and degrade over time,avoiding the need of removal surgery.However,they are not yet routinely applied because their degradation behavior is not fully understood.In this study we have investigated and quantified the degradation and osseointegration behavior of two biodegradable Mg alloys based on gadolinium(Gd)at high resolution.Mg-5Gd and Mg-10Gd screws were inserted in rat tibia for 4,8 and 12 weeks.Afterward,the degradation rate and degradation homogeneity,as well as bone-to-implant interface,were studied with synchrotron radiation micro computed tomography and histology.Titanium(Ti)and polyether ether ketone(PEEK)were used as controls material to evaluate osseointegration.Our results showed that Mg-5Gd degraded faster and less homogeneously than Mg-10Gd.Both alloys gradually form a stable degradation layer at the interface and were surrounded by new bone tissue.The results were correlated to in vitro data obtained from the same material and shape.The average bone-to-implant contact of the Mg-xGd implants was comparable to that of Ti and higher than for PEEK.The results suggest that both Mg-xGd alloys are suitable as materials for bone implants.展开更多
基金Supported by the Development Foundation of Region Skane,No.REGSKANE-818781 and No.2018-Projekt0024the Foundation Skane University Hospital,No.2020-0000028.
文摘BACKGROUND The enteric nervous system(ENS)is situated along the entire gastrointestinal tract and is divided into myenteric and submucosal plexuses in the small and large intestines.The ENS consists of neurons,glial cells,and nerves assembled into ganglia,surrounded by telocytes,interstitial cells of Cajal,and connective tissue.Owing to the complex spatial organization of several interconnections with nerve fascicles,the ENS is difficult to examine in conventional histological sections of 3-5μm.AIM To examine human ileum full-thickness biopsies using X-ray phase-contrast nanotomography without prior staining to visualize the ENS.METHODS Six patients were diagnosed with gastrointestinal dysmotility and neuropathy based on routine clinical and histopathological examinations.As controls,fullthickness biopsies were collected from healthy resection ileal regions after hemicolectomy for right colon malignancy.From the paraffin blocks,4-μm thick sections were prepared and stained with hematoxylin and eosin for localization of the myenteric ganglia under a light microscope.A 1-mm punch biopsy(up to 1 cm in length)centered on the myenteric plexus was taken and placed into a Kapton®tube for mounting in the subsequent investigation.X-ray phase-contrast tomography was performed using two custom-designed laboratory setups with micrometer resolution for overview scanning.Subsequently,selected regions of interest were scanned at a synchrotron-based end-station,and high-resolution slices were reported.In total,more than 6000 virtual slices were analyzed from nine samples.RESULTS In the overview scans,the general architecture and quality of the samples were studied,and the myenteric plexus was localized.High-resolution scans revealed details,including the ganglia,interganglional nerve fascicles,and surrounding tissue.The ganglia were irregular in shape and contained neurons and glial cells.Spindle-shaped cells with very thin cellular projections could be observed on the surface of the ganglia,which appeared to build a network.In the patients,there were no alterations in the general architecture of the myenteric ganglia.Nevertheless,several pathological changes were observed,including vacuolar degeneration,autophagic activity,the appearance of sequestosomes,chromatolysis,and apoptosis.Furthermore,possible expulsion of pyknotic neurons and defects in the covering cellular network could be observed in serial slices.These changes partly corresponded to previous light microscopy findings.CONCLUSION The analysis of serial virtual slices could provide new information that cannot be obtained by classical light microscopy.The advantages,disadvantages,and future possibilities of this method are also discussed.
基金This research was carried out within the SynchroLoad project(BMBF project number 05K16CGA)which is funded by the Rontgen-Ångstrom Cluster(RÅC)a bilateral research collaboration of the Swedish government and the German Federal Ministry of Education and Research(BMBF)+1 种基金We also acknowledge the project MgBone(BMBF project number 05K16CGB)Swedish Research Council 2015-06109.Additionally,we acknowledge provision of beamtime by PETRA III DESY within the long-term Proposal II-20170009 and beamtimes related to following IDs:11001978,11003288,11003440,11003773,11003950,11004016,11004263,11005553,and 11005842。
文摘Biodegradable magnesium(Mg)alloys can revolutionize osteosynthesis,because they have mechanical properties similar to those of the bone,and degrade over time,avoiding the need of removal surgery.However,they are not yet routinely applied because their degradation behavior is not fully understood.In this study we have investigated and quantified the degradation and osseointegration behavior of two biodegradable Mg alloys based on gadolinium(Gd)at high resolution.Mg-5Gd and Mg-10Gd screws were inserted in rat tibia for 4,8 and 12 weeks.Afterward,the degradation rate and degradation homogeneity,as well as bone-to-implant interface,were studied with synchrotron radiation micro computed tomography and histology.Titanium(Ti)and polyether ether ketone(PEEK)were used as controls material to evaluate osseointegration.Our results showed that Mg-5Gd degraded faster and less homogeneously than Mg-10Gd.Both alloys gradually form a stable degradation layer at the interface and were surrounded by new bone tissue.The results were correlated to in vitro data obtained from the same material and shape.The average bone-to-implant contact of the Mg-xGd implants was comparable to that of Ti and higher than for PEEK.The results suggest that both Mg-xGd alloys are suitable as materials for bone implants.
