Assessment of Blood Clot Composition by Spectral Optical Coherence Tomography: An In Vitro Study / 신경중재치료의학

Purpose@#Optical coherence tomography (OCT) has the potential for in vivo clot composition characterization in difficult mechanical embolectomy cases. We performed an in vitro study to determine the OCT characteristics of red blood cells (RBCs) and fibrin rich clots. @*Materials and Methods@#Analogues of 5 compositions of clots (5% to 95% RBCs from Group A to E) were created from human blood. The blood mixture was injected into the bifurcation of a 3D printed bifurcated silicone tube. The OPTISTM Integrated System (St. Jude Medical Inc.) was used to identify the magnitude of OCT signals from different compositions of clots. Martius Scarlett Blue trichrome (MSB) staining was performed to confirm the composition of RBCs and fibrin in each clot. @*Results@#Group A and B showed less signal attenuation (less than 30%) from its surface to the inside, which indicated high penetration (low-back scattering). Group C indicated intermediate signal attenuation (60%) from its surface to inside the clots, in which signals were found even at the periphery of the clot. Group D and E were superficially signal rich with more signal attenuation (more than 80%) from its surface to the inside indicating low penetration (high-back scattering). Signal-free shadowing was shown in 3 clots in Group E. MSB staining indicated color change (from red in fibrin-rich clots to yellow in RBC-rich clots). @*Conclusion@#Different compositions of clots can be assessed using OCT. Fibrin-rich clots have homogeneous signals with high penetration, while RBC-rich clots can be recognized as superficially signal rich with low penetration.

Phospholipid composition of the outer membrane of Escherichia coli influences its susceptibility against antimicrobial peptide apidaecin 1b.

Proline-rich antimicrobial peptides (PrAMPs) kill bacteria in a multimodal mechanism by inhibiting the 70S ribosome (i.e., protein translation) as dominant lethal mechanism besides inhibition of several other proteins, such as chaperone DnaK. PrAMPs pass the outer membrane of Gram-negative bacteria, probably by a self-promoted uptake followed by a transporter-mediated uptake from the periplasm. Mutation of transporter protein SbmA is a well-studied resistance mechanism observed in vitro by resistance induction with PrAMPs. Here, we compared the membrane compositions of Escherichia coli BL21AI and BL21AI Apir, which was obtained by resistance induction with PrAMP apidaecin 1b. Lipid A was partially modified by phosphatidylethanolamine, 4-aminoarabinose, or both groups, but the relative contents of these and further unidentified species did not differ much between wild-type and resistant strains, indicating that resistance was not related to lipid A modifications. The same was true for 20 glycerophospholipids identified, i.e., 11 phosphatidylethanolamines and 9 phosphatidylglycerols. However, glycerophospholipids in BL21AI Apir contained much lower levels of cyclopropane-modified acyl groups, which probably alter the biophysical properties of the inner membrane and the inner leaflet of the outer membrane. Indeed, when cyclopropane-fatty-acyl-phospholipid synthase was knocked out in E. coli BW25113, the resulting BW25113 Δcfa was less susceptible against apidaecin 1b.

Transplantation of umbilical cord mesenchymal stem cells for treatment of autosomal dominant spinocerebellar ataxias in 12 cases / 中国组织工程研究

BACKGROUND: There is no study addressing transplantation of umbilical cord mesenchymal stem cells for the treatment of spinocerebellar ataxia.OBJECTIVE: To study the clinical effect of human umbilical cord stem cells transplantation in the treatment of autosomal dominant spinocerebellar ataxias. METHODS: Spinocerebellar ataxias patients selected from Stem Transplantation Center of the 455 Hospital of Chinese PLA were treated with umbilical cord mesenchymal stem cells transplantation via intrathecal injection. The number of umbilical cord mesenchymal stem cells was 107 per transplantation, once per week, for 4 weeks.RESULTS AND CONCLUSION: Both the total score of the International Cooperative Ataxia Rating Scale and Activities of Daily Living score were significantly decreased at 1 month after transplantation compared with before treatment (P < 0.05). The nerve function was significantly improved and the total effective rate was up to 16.7%. Experimental findings indicate that, transplantation of umbilical cord mesenchymal stem cells via intrathecal injection is a feasible and effective treatment to ameliorate the clinical efficacy of spinocerebellar ataxias patients and improve their quality of life.