Anterior Lumbar Interbody Fusion (ALIF) or Transforaminal Lumbar Interbody Fusion (TLIF) for Fusion Surgery in L5/S1 - What Is the Best Way to Restore a physiological Alignment?

STUDY DESIGN: A retrospective single center cohort study with prospective collected data from an institutional spine registry. OBJECTIVES: To determine whether restoration of lordosis L5/S1 is possible with both anterior lumbar interbody fusion (ALIF) and transforaminal lumbar interbody fusion (TLIF) and to find out which technique is superior to recreate lordosis in L5/S1. METHODS: Seventy-seven patients with ALIF and seventy-nine with TLIF L5/S1 were included. Operation time, estimated blood loss), and complications were evaluated. Segmental lordosis L5/S1 and L4/5, overall lordosis, and proximal lordosis (L1 to L4) were measured in X-rays before and after surgery. Oswesery disability index and EQ-5D were assessed before surgery, and 3 and 12 months after surgery. RESULTS: Mean operation time was 176.9 minutes for ALIF and 195.7 minutes for TLIF (p = 0.048). Estimated blood loss was 249.2 cc for ALIF and 362.9 cc for TLIF (p = 0.005). In terms of complications, only a difference in dural tears were found (TLIF 6, ALIF none; p = 0.014). Lordosis L5/S1 increased in the ALIF group (15.8 to 24.6°; p < 0.001), whereas no difference was noted in the TLIF group (18.4 to 19.4°; p = 0.360). Clinical results showed significant improvement in the Oswesery disability index (ALIF: 43 to 21.9, TLIF: 45.2 to 23.0) and EQ-5D (ALIF: 0.494 to 0.732, TLIF: 0.393 to 0.764) after 12 months in both groups, without differences between the groups. CONCLUSION: ALIF and TLIF are comparable methods for performing fusion at L5/S1, with good clinical outcomes and comparable rates of complications. However, there is only a limited potential for recreating lordosis at L5/S1 with a TLIF.

Phospholipase A2 of Microbiota as Pathogenetic Determinant to Induce Inflammatory States in Ulcerative Colitis: Therapeutic Implications of Phospholipase A2 Inhibitors.

BACKGROUND: Attack by commensal microbiota is one component of induction of inflammatory episodes in ulcerative colitis (UC). In UC, the mucus layer is intrinsically devoid of phosphatidylcholine (PC) resulting in low hydrophobicity which facilitates bacterial invasion. Colonic ectophospholipase-carrying bacterial strains are likely candidates to further thinning the PC mucus barrier and to precipitate inflammatory episodes. OBJECTIVE: To evaluate the effect of phospholipase A2 (PLA2) inhibitors on inflammation in a genetic UC mouse model. METHODS: As PLA2 inhibitor, we applied the bile acid-phospholipid conjugate ursodeoxycholate-lysophosphatidylethanolamide (UDCA-LPE) or as control 5% Tween 80 by oral gavage to intestine-specific kindlin 2 knockout mice. RESULTS: Luminal UDCA-LPE reduced the PLA2 activity in stool by 36 ± 8%. Concomitantly no inflammatory phenotype was observed when compared to kindlin 2(-/-) mice not treated with UDCA-LPE. The improvement was documented in regard to stool consistency, calprotectin levels in stool, and macroscopic/endoscopic as well as histologic features of the mucosa. The pattern of colonic microbiota distribution obtained in the UC phenotype mice was reversed by UDCA-LPE to the control mice pattern. CONCLUSION: The inhibition of the bacterial ectophospholipase A2 activity improves mucosal inflammation in a genetic mouse model of UC. It is assumed that the remaining mucus PC shield is better preserved when luminal PLA2 is suppressed.

Cellular Uptake of Gold Nanoparticles and Their Behavior as Labels for Localization Microscopy.

Gold nanoparticles (GNPs) enhance the damaging absorbance effects of high-energy photons in radiation therapy by increasing the emission of Auger-photoelectrons in the nm-µm range. It has been shown that the incorporation of GNPs has a significant effect on radiosensitivity of cells and their dose-dependent clonogenic survival. One major characteristic of GNPs is also their diameter-dependent cellular uptake and retention. In this article, we show by means of an established embodiment of localization microscopy, spectral position determination microscopy (SPDM), that imaging with nanometer resolution and systematic counting of GNPs becomes feasible, because optical absorption and plasmon resonance effects result in optical blinking of GNPs at a size-dependent wavelength. To quantify cellular uptake and retention or release, SPDM with GNPs that have diameters of 10 and 25 nm was performed after 2 h and after 18 h. The uptake of the GNPs in HeLa cells was either achieved via incubation or transfection via DNA labeling. On average, the uptake by incubation after 2 h was approximately double for 10 nm GNPs as compared to 25 nm GNPs. In contrast, the uptake of 25 nm GNPs by transfection was approximately four times higher after 2 h. The spectral characteristics of the fluorescence of the GNPs seem to be environment-dependent. In contrast to fluorescent dyes that show blinking characteristics due to reversible photobleaching, the blinking of GNPs seems to be stable for long periods of time, and this facilitates their use as an appropriate dye analog for SPDM imaging.

A method for the efficient cellular uptake and retention of small modified gold nanoparticles for the radiosensitization of cells.

Gold nanoparticles (GNP) enhance the absorbance of photons thereby increasing emission of Auger-/photoelectrons in the nm-µm range. Yet, a major disadvantage is their diameter-dependent cellular uptake with an optimum of ~50 nm which may not offer optimal radiosensitization. A method was developed to enhance the uptake of small GNP. GNP (10nm) were linked to DNA and transferred into HeLa cells by transient transfection (GNP-DT). Treatment of cells with GNP-DT resulted in a strong perinuclear focal accumulation, whereas this was dimmer and sparser for GNP-T (lacking DNA) and close to background levels in GNP-treated cells. Only GNP-DT showed a significant radiosensitizing effect (p=0.005) on clonogenic survival using clinically relevant megavolt x-rays. Our novel method markedly increases the uptake/retention and alters the localization of small GNP in cells compared to unmodified GNP. This work finally enables studying the radiosensitizing effects of differentially sized GNP. FROM THE CLINICAL EDITOR: In an effort to increase the radiosensitization of HeLa cells, his paper discusses a transient transfection-based method to enhance gold nanoparticle intracellular delivery.