Comparison of surgical invasiveness, hidden blood loss, and clinical outcome between unilateral biportal endoscopic and minimally invasive transforaminal lumbar interbody fusion for lumbar degenerative disease: a retrospective cohort study.

BACKGROUND: Currently, hidden blood loss (HBL) has been paid more and more attention by spine surgeons. Simultaneously, it has been the effort of spine surgeons to explore more advantages of minimally invasive surgery. More and more articles have compared unilateral biportal endoscopic lumbar interbody fusion (BE-LIF) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). But so far, there is no HBL comparison between BE-LIF and MIS-TLIF. This study aims to compare the surgical invasiveness, hidden blood loss, and clinical outcome of BE-LIF and MIS-TLIF and to provide insight regarding minimally invasive surgery for lumbar degenerative disease (LDD). METHODS: We enrolled 103 eligible patients with LDD who underwent BE-LIF (n = 46) and MIS-TLIF (n = 57) during August 2020-March 2021. We collected data, including demographics, perioperative haematocrit, operative and postoperative hospital times, serum creatine kinase (CK) and C-reactive protein (CRP) levels, and hospitalization costs. Total and hidden blood loss was calculated. Clinical outcomes were assessed using a visual analogue scale (VAS) score for back and leg pain, Oswestry Disability Index (ODI), modified MacNab criteria, fusion rate, and complications. RESULTS: Basic demographics and surgical data were comparable. The CRP and CK levels were generally lower in the BE-LIF than in the MIS-TLIF group, especially CRP levels on postoperative day (POD) three and CK levels on POD one. True total blood loss, postoperative blood loss, and hidden blood loss were significantly reduced in the BE-LIF group compared with the MIS-TLIF group. Postoperative hospital times was statistically significantly shorter in the BE-LIF group. The VAS pain and ODI scores improved in both groups. At three days and one month, the VAS lower back pain scores were significantly better after BE-LIF. Clinical outcomes did not otherwise differ between groups. CONCLUSIONS: Compared with MIS-TLIF, BE-LIF has similar medium and short-term clinical outcomes. However, it is better regarding surgical trauma, early lower back pain, total and hidden blood loss, and recovery time. BE-LIF is an adequate option for selected LDD.

Transplantation of a vascularized pedicle of hemisected spinal cord to establish spinal cord continuity after removal of a segment of the thoracic spinal cord: A proof-of-principle study in dogs.

INTRODUCTION: Glial scar formation impedes nerve regeneration/reinnervation after spinal cord injury (SCI); therefore, removal of scar tissue is essential for SCI treatment. AIMS: To investigate whether removing a spinal cord and transplanting a vascularized pedicle of hemisected spinal cord from the spinal cord caudal to the transection can restore motor function, to aid in the treatment of future clinical spinal cord injuries. We developed a canine model. After removal of a 1-cm segment of the thoracic (T10-T11) spinal cord in eight beagles, a vascularized pedicle of hemisected spinal cord from the first 1.5 cm of the spinal cord caudal to the transection (cut along the posterior median sulcus of the spinal cord) was transplanted to bridge the transected spinal cord in the presence of a fusogen (polyethylene glycol, PEG) in four of the eight dogs. We used various forms of imaging, electron microscopy, and histologic data to determine that after our transplantation of a vascular pedicled hemisection to bridge the transected spinal cord, electrical continuity across the spinal bridge was restored. RESULTS: Motor function was restored following our transplantation, as confirmed by the re-establishment of anatomic continuity along with interfacial axonal sprouting. CONCLUSION: Taken together, our findings suggest that SCI patients-who have previously been thought to have irreversible damage and/or paralysis-may be treated effectively with similar operative techniques to re-establish electrical and functional continuity following SCI.

Single-molecule multiplexed profiling of protein-DNA complexes using magnetic tweezers.

Epigenetics, such as the dynamic interplay between DNA methylation and demethylation, play diverse roles in critical cellular events. Enzymatic activity at CpG sites, where cytosines are methylated or demethylated, is known to be influenced by the density of CpGs, methylation states, and the flanking sequences of a CpG site. However, how the relevant enzymes are recruited to and recognize their target DNA is less clear. Moreover, although DNA-binding epigenetic enzymes are ideal targets for therapeutic intervention, these targets have been rarely exploited. Single-molecule techniques offer excellent capabilities to probe site-specific protein-DNA interactions and unravel the dynamics. Here, we develop a single-molecule approach that allows multiplexed profiling of protein-DNA complexes using magnetic tweezers. When a DNA hairpin with multiple binding sites is unzipping, strand separation pauses at the positions bound by a protein. We can thus measure site-specific binding probabilities and dissociation time directly. Taking the TET1 CXXC domain as an example, we show that TET1 CXXC binds multiple CpG motifs with various flanking nucleotides or different methylation patterns in an AT-rich DNA. We are able to establish for the first time, at nanometer resolution, that TET1 CXXC prefers G/C flanked CpG motif over C/G, A/T, or T/A flanked ones. CpG methylation strengthens TET1 CXXC recruitment but has little effect on dissociation time. Finally, we demonstrate that TET1 CXXC can distinguish five CpG clusters in a CpG island with crowded binding motifs. We anticipate that the feasibility of single-molecule multiplexed profiling assays will contribute to the understanding of protein-DNA interactions.

Peg-Enhanced Behavioral Recovery After Sciatic Nerve Transection and Either Suturing Or Sleeve Conduit Deployment in Rats.

Polyethylene glycol (PEG) has previously been reported to improve outcomes of peripheral nerve microsuturing. However, recent studies have challenged this finding. Given its clinical importance, we investigated the potential of PEG as a facilitator of peripheral nerve restoration. The sciatic nerve of 144 rats was transected and submitted either to simple suturing (Group A), PEG-enhanced suturing (Group B), and insertion in an arterial sleeve conduit without PEG (Group C), or with PEG (Group D) in equal numbers. Behavioral recovery was assessed with the sciatic function index (SFI). Nerve impulse conduction was assessed with compound muscle action potentials (CMAPs). Histology comprised standard hematoxylin/eosin staining, electron microscopy and glial cell line-derived neurotrophic factor (GDNF) immunohistochemistry. Expression of GDNF was also assessed with western blotting. Results were evaluated at weeks 1, 4, and 8. PEG treatment significantly improved behavioral recovery and morphology of nerve restoration, particularly in the sleeve conduit group, relative to that of controls. In conclusion, PEG may improve outcomes of peripheral nerve reconstruction.

20(S)-Protopanaxatriol promotes the binding of P53 and DNA to regulate the antitumor network via multiomic analysis.

Although the tumor suppressor P53 is known to regulate a broad network of signaling pathways, it is still unclear how certain drugs influence these P53 signaling networks. Here, we used a comprehensive single-cell multiomics view of the effects of ginsenosides on cancer cells. Transcriptome and proteome profiling revealed that the antitumor activity of ginsenosides is closely associated with P53 protein. A miRNA-proteome interaction network revealed that P53 controlled the transcription of at least 38 proteins, and proteome-metabolome profiling analysis revealed that P53 regulated proteins involved in nucleotide metabolism, amino acid metabolism and "Warburg effect". The results of integrative multiomics analysis revealed P53 protein as a potential key target that influences the anti-tumor activity of ginsenosides. Furthermore, by applying affinity mass spectrometry (MS) screening and surface plasmon resonance fragment library screening, we confirmed that 20(S)-protopanaxatriol directly targeted adjacent regions of the P53 DNA-binding pocket and promoted the stability of P53-DNA interactions, which further induced a series of omics changes.

Reconstruction of the spinal cord of spinal transected dogs with polyethylene glycol.

BACKGROUND: Our study shows that a membrane sealant/fiber fusogen polyethylene glycol (PEG) applied immediately on a sharp section of the spinal cord can mend the cord and lead to exceptional levels of motor recovery, with some animals almost normal. MATERIALS AND METHODS: Before deploying such technology in man, long-term data in large mammals that exclude delayed complications (e.g., central pain), confirm the stability of motor recovery, and provide histological evidence of fiber regrowth are necessary. Here, we provide such evidence in dogs followed up over 6 months and in 2 cases up to 1 year along with imaging and histologic data. RESULTS: We show that dogs whose dorsal cord has been fully transected recover locomotion after immediate treatment with a fusogen (PEG). No pain syndrome ensued over the long term. Diffusion tensor imaging magnetic resonance and histological, including immunohistochemical, data confirmed the re-establishment of anatomical continuity along with interfacial axonal sprouting. CONCLUSIONS: This study proves that a form of irreversible spinal cord injury (SCI) can effectively be treated and points out a way to treat SCI patients.

Role of the Janus kinase 2/signal transducers and activators of transcription 3 pathway in the protective effect of remote ischemia preconditioning against cerebral ischemia-reperfusion injury in rats.

Remote ischemia preconditioning (RIPC) is a convenient and effective method for alleviating cerebral ischemia-reperfusion injury (CIRI). However, to date, the underlying mechanism has not been fully elucidated. The aim of this research was to explore the protective mechanism of RIPC on the brain after CIRI. Four groups of rats were included in this experiment: the sham group, the middle cerebral artery occlusion (MCAO) group, the RIPC group, and the AG490 group. As an inhibitor of Janus kinase 2 (JAK2), AG490 was used after MCAO in the AG490 group to explore the role of JAK2/signal transducers and activators of transcription 3 (STAT3) after CIRI. Brain tissue was collected for evaluation after 2 h of ischemia and 24 h of reperfusion. ELISA for interleukin (IL)-6, IL-1ß and tumor necrosis factor-α, western blot for phosphorylated-JAK2 and phosphorylated-STAT3, the neurological severity score and Longa scoring system for neurological deficit evaluation, triphenyltetrazolium chloride staining for cerebral infarction, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining for apoptotic cells in the brain tissue were performed. Neurological function in the RIPC group was notably better than that in the MCAO group. There were smaller infarction sizes and fewer apoptotic cells in the ischemic area in the RIPC group than in the MCAO group. In the RIPC group, the expression levels of IL-1ß, tumor necrosis factor-α, IL-6, and phosphorylated-JAK2 and phosphorylated-STAT3 were significantly lower than those in the MCAO group. The findings in the RIPC and AG490 groups were similar. The inflammatory response and apoptosis are two important processes involved in brain dysfunction after CIRI. The JAK2/STAT3 signaling pathway has an underlying relationship with these two processes. These findings suggest that RIPC can alleviate the damage to brain tissue by CIRI by regulating the JAK2/STAT3 signaling pathway negatively.

Single channel recording of a mitochondrial calcium uniporter.

Mitochondrial calcium uniporter (MCU) is the pore-forming subunit of the entire uniporter complex and plays an important role in mitochondrial calcium uptake. However, the single channel recording of MCU remains controversial. Here, we expressed and purified different MCU proteins and then reconstituted them into planar lipid bilayers for single channel recording. We showed that MCU alone from Pyronema omphalodes (pMCU) is active with prominent single channel Ca2+ currents. In sharp contrast, MCU alone from Homo sapiens (hMCU) is inactive. The essential MCU regulator (EMRE) activates hMCU, and therefore, the complex (hMCU-hEMRE) shows prominent single channel Ca2+ currents. These single channel currents are sensitive to the specific MCU inhibitor Ruthenium Red. Our results clearly demonstrate that active MCU can conduct large amounts of calcium into the mitochondria.

Leucine zipper-EF-hand containing transmembrane protein 1 (LETM1) forms a Ca2+/H+ antiporter.

Leucine zipper-EF-hand-containing transmembrane protein1 (LETM1) is located in the mitochondrial inner membrane and is defective in Wolf-Hirschhorn syndrome. LETM1 contains only one transmembrane helix, but it behaves as a putative transporter. Our data shows that LETM1 knockdown or overexpression robustly increases or decreases mitochondrial Ca2+ level in HeLa cells, respectively. Also the residue Glu221 of mouse LETM1 is identified to be necessary for Ca2+ flux. The mutation of Glu221 to glutamine abolishes the Ca2+-transport activity of LETM1 in cells. Furthermore, the purified LETM1 exhibits Ca2+/H+ anti-transport activity, and the activity is enhanced as the proton gradient is increased. More importantly, electron microscopy studies reveal a hexameric LETM1 with a central cavity, and also, observe two different conformational states under alkaline and acidic conditions, respectively. Our results indicate that LETM1 is a Ca2+/H+ antiporter and most likely responsible for mitochondrial Ca2+ output.

Fermentative production of enantiomerically pure S-1,2-propanediol from glucose by engineered E. coli strain.

The pure stereoisomers of 1,2-propanediol (1,2-PDO) could be used as starting materials to synthesize high value-added specialty chemicals and chiral pharmaceutical products. As the stereoisomers of 1,2-PDO cannot be obtained by traditional chemical synthesis processes, biotechnological processes have gained increasing attention. However, to our knowledge, the production of S-1,2-PDO directly from glucose has not been previously reported. In this study, we demonstrate a novel artificial pathway to convert L-lactic acid to S-1,2-PDO and its integration into the genome of Escherichia coli strain BW25113∆poxB with synchronous deletion of genes responsible for branch metabolic pathways from glucose. L-lactate production was increased by replacing the native D-lactate dehydrogenase with the L-lactate dehydrogenase from Bacillus coagulans. The methylglyoxal bypass pathway was blocked to avoid synthesis of a racemic mixture of D- and L-lactate and prevent the accumulation of methylglyoxal, a toxic intermediate. To further improve the yield of S-1,2-PDO, a novel cofactor regeneration system was introduced by combining pyruvate decarboxylase and acetaldehyde-CoA dehydrogenase II to simultaneously regenerate NADH and the CoA donor of acetyl-CoA for the lactate conversion pathway. Finally, 13.7 mM S-1,2-PDO with >99 % enantiomeric purity was directly produced from glucose by disrupting the major carbon-competing pathways and strengthening the lactate transformation pathway. This study demonstrates the first attempt to synthesize S-1,2-PDO by direct fermentation of glucose.