Di-Huang-Yin-Zi regulates P53/SLC7A11 signaling pathway to improve the mechanism of post-stroke depression

ETHNOPHARMACOLOGICAL RELEVANCE

Post-stroke depression (PSD) is a condition characterized by a profoundly depressed mood and diminished interest following a stroke. Di-Huang-Yin-Zi (DHYZ), a traditional Chinese herbal preparation, gained widespread use and shown favorable outcomes in PSD treatment. However, the combination mechanisms of this formula for PSD remain unclear.

AIM OF STUDY

This study aimed to assess the therapeutic effects of DHYZ extract on rats with PSD and further investigate its underlying mechanism.

MATERIALS AND METHODS

The active components of DHYZ extract were quantified by the high-performance liquid chromatography-ultraviolet (HPLC-UV). Neurofunctional and depressive-like behavioral tests were performed to assess the neuroprotective effects of DHYZ extract after establishing a PSD rat model. Brain tissue damage volume was assessed using TTC staining, and transmission electron microscopy (TEM) was used to observe the ultrastructural changes of neurons in the prefrontal cortex region, while cell apoptosis was evaluated through TUNEL assay in the prefrontal cortex region of the brain. The effect of DHYZ on ferroptosis markers includes Fe2+, malondialdehyde (MDA), reactive oxygen species (ROS), and glutathione (GSH) were determined in the brain tissue. Moreover, the expression of key proteins or mRNA levels of the P53/SLC7A11 signaling pathway were detected using Western blot or PCR, respectively. Additionally, P53-constructed overexpression vectors were injected to increase the level of P53. In this series of experiments, ferroptosis markers and key factors of the P53/SLC7A11 signaling pathway were evaluated.

RESULTS

DHYZ extract could increase the sucrose preference of SPT, but decrease the duration of immobility of FST and cortical infarct volume of PSD rats. A TEM study revealed that DHYZ extract improved synaptic ultrastructure in the cortical region of PSD rats. Furthermore, DHYZ treatment effectively decreased ROS and MDA levels, inhibiting the expression of ferroptosis-related markers such as Fe2+, SLC7A11, and GPX4. Additionally, DHYZ promoted the ubiquitination of P53, thus inhibiting its degradation. Notably, AAV-mediated overexpression of P53 reversed the effects of DHYZ on neuroprotection and ferroptosis inhibition in PSD rats.

CONCLUSIONS

Our results demonstrated that DHYZ extract alleviates the symptoms and enhances the functional capability of PSD rats, mainly by suppressing the ferroptosis through the P53/SLC7A11/GPX4 pathway.

Morroniside improves the symptoms of post-stroke depression in mice through the BDNF signaling pathway mediated by MiR-409-3p

BACKGROUND

Post-stroke depression (PSD) is a common psychiatric symptom after a stroke. Morroniside, an iridoid glycoside found in Cornus officinalis, has garnered significant attention for its potential to alleviate symptoms associated with depression.

PURPOSE

This study aims to highlight the potential use of morroniside in the treatment of PSD and elucidate the underlying molecular mechanisms.

METHODS

To establish a reliable PSD model, male C57BL/6 mice were subjected to brief MCAO in conjunction with CUMS. Post-morroniside administration, neuronal viability, and hippocampal cell apoptosis were evaluated by Nissl staining and TUNEL detection, respectively. Depression-like behaviors were evaluated using SPT, TST, and FST. The Longa score and cylinder test were used to evaluate the effect of morroniside on motor function. Furthermore, to investigate the underlying molecular mechanisms, bioinformatic analysis and the dual luciferase assay were performed to investigate the MiR-409-3p-BDNF interaction. In addition, subsequent to MiR-409-3p overexpression via AAV virus, we assessed mRNA expression and protein levels of key components within the BDNF/TrkB signaling pathway using RT-qPCR, immunohistochemistry, and western blot analysis.

RESULTS

The observed decrease in apoptosis and amelioration of depression-like behaviors strongly indicate the potential of morroniside as a therapeutic agent for PSD. Furthermore, the upregulation of key proteins within the BDNF/TrkB signaling pathway in the cortex suggests that morroniside activates this pathway. Through bioinformatics analysis, MiR-409-3p was identified and found to bind to the BDNF gene, resulting in the inhibition of BDNF expression. Importantly, we demonstrate that morroniside mitigates this inhibitory effect of MiR-409-3p on BDNF, thereby facilitating the activation of the BDNF/TrkB signaling pathway.

CONCLUSION

The findings suggest that morroniside demonstrates the ability to improve PSD symptoms through the BDNF/TrkB signaling pathway mediated by MiR-409-3p. These results emphasize the importance of the BDNF signaling pathway in improving PSD symptoms and provide a possible mechanism for morroniside to treat PSD.

Targeting XPO1 Combined with Radiotherapy to Enhance Systemic Anti-tumor Effects in Non-Small Cell Lung Cancer

PURPOSE/OBJECTIVE(S)

The combination of radiation and radiosensitizing chemotherapeutic agents have shown promising anti-tumor effects in NSCLC. Acting as an oncogenic driver, XPO1 is frequently overexpressed and/or mutated in lung cancer. Thus, suppression of XPO1-mediated nuclear export presents a unique therapeutic strategy. We hypothesize that XPO1 inhibition combined with radiotherapy (XRT) may remodel the tumor immune microenvironment (TIME) and reduce radioresistance, thus enhance systemic anti-tumor effects.

MATERIALS/METHODS

Herein, we optimized a small molecule inhibitor, WJ01024, which can bind to XPO1 and antagonize its activity to inhibit nuclear export. In the C57BL/6 mouse subcutaneous tumor model, we evaluated the ability of different treatment regimens containing oral WJ01014 single or combined with XRT (one fractions of 15 Gy) in tumor control and tumor recurrence inhibition. The effects of each treatment regimen on the alterations of immunophenotypes, including the quantification, activation, proliferative capacity, exhaustion marker expression, and memory status, were evaluated by flow cytometry.

RESULTS

In our study, we found that the overexpression of XPO1 was associated with poor prognosis and survival in radioresistant patients with NSCLC. The combination therapy of WJ01024 and XRT resulted in an increase of apoptosis and a decrease of proliferation compared to monotherapy, which was closely correlated with tumor regression and improved survival in the C57BL/6 mouse subcutaneous tumor model. Notably, we found that WJ01024 were shown to enhance the therapeutic effect of XRT by remodeling TIME. Compared with XRT, the addition of WJ01024 increased the infiltration and proliferation of radiation-stimulated CD8+ T cells, which especially promoted the production of interferon-γ and granzyme B. Moreover, the combination therapy also reversed the immunosuppressive effect of radiation on the percentage of Tregs and exhausted T cells in mouse xenografts. Thus, the TIME was significantly improved in combination therapy. Strikingly, mechanistic studies suggested that the activation of cyclic GMP-AMP synthase/stimulator of interferon genes (cGAS/STING) signaling pathway is required to reshape TIME and produce synergistic anti-tumor effect with the combination of WJ01024 and XRT.

CONCLUSION

Our findings suggest that WJ01024 might be a potential synergistic treatment for radiotherapy to control the proliferation of NSCLC cells, promote tumor regression and prolong survival in mouse model of NSCLC by activating cGAS/STING signaling, and this in turn potentiate the immune microenvironment.

A binary pulsar in a 53-minute orbit

Spider pulsars are neutron stars that have a companion star in a close orbit. The companion star sheds material to the neutron star, spinning it up to millisecond rotation periods, while the orbit shortens to hours. The companion is eventually ablated and destroyed by the pulsar wind and radiation1,2. Spider pulsars are key for studying the evolutionary link between accreting X-ray pulsars and isolated millisecond pulsars, pulsar irradiation effects and the birth of massive neutron stars3-6. Black widow pulsars in extremely compact orbits (as short as 62 minutes7) have companions with masses much smaller than 0.1 M⊙. They may have evolved from redback pulsars with companion masses of about 0.1-0.4 M⊙ and orbital periods of less than 1 day8. If this is true, then there should be a population of millisecond pulsars with moderate-mass companions and very short orbital periods9, but, hitherto, no such system was known. Here we report radio observations of the binary millisecond pulsar PSR J1953+1844 (M71E) that show it to have an orbital period of 53.3 minutes and a companion with a mass of around 0.07 M⊙. It is a faint X-ray source and located 2.5 arcminutes from the centre of the globular cluster M71.

The Importance of Marital Status in the Morbidity and Prognosis of Lung Metastasis in Newly Diagnosed Ovarian Cancer

Objective: The study aimed to evaluate the risk factors for the morbidity and prognosis of lung metastases (LM) in patients with newly diagnosed ovarian cancer (OC), and further explore the important role of marital status. Materials and methods: Based on the Surveillance, Epidemiology, and End Results (SEER) dataset, OC patients from 2010 and 2019 were retrospectively analyzed. Logistic regression analysis and Kaplan-Meier method were applied to evaluate the vital factors of incidence and survival outcome in LM population. Cox regression analysis was performed to identify risk factors for the prognosis of OC patients with LM. The predictive potential was showed by two established nomograms and examined by the concordance index (C-index), calibration curves, the area under the curve (AUC), decision curve analyses (DCAs) and clinical impact curves (CICs). Results: There are 25,202 eligible OC patients were enrolled in the study, the morbidity of LM at 5.61%. Multivariable logistic regression models illustrated that chemotherapy (P<0.01), surgical treatment of bilateral or more areas (P<0.01), T stage (P<0.01), N1 stage (P<0.01), bone metastasis (P<0.01), brain metastasis (P<0.01) and liver metastasis (P<0.01) were all significantly connected with LM in OC. Multivariable Cox regression analyses illustrated that unmarried, radiotherapy, elder people and positive cancer antigen 125 (CA-125) were significantly associated with shorter survival time, while chemotherapy made contributions to improve survival. Our study found that marital relationships promoted LM and was associated with the better prognosis, while unmarried patients had the opposite results. With the further development of our research, the cross-action of social, economic and psychological factors together determined the great impact of marital status on the morbidity and prognosis of OC patients combined with LM. Finally, the stability of the models was proved by internal verification. Conclusion: The population-based cohort study provides references for guiding clinical screening and individualized treatment of OC patients with LM. Under the influence of society and economy, marital status is closely related to the morbidity and prognosis of OC, which can be an important direction to explore the risk of OC lung metastasis in the future.

The new exploration of pure total flavonoids extracted from Citrus maxima (Burm.) Merr. as a new therapeutic agent to bring health benefits for people

The peel and fruit of Citrus varieties have been a raw material for some traditional Chinese medicine (TCM). Pure total flavonoids from Citrus maxima (Burm.) Merr. (PTFC), including naringin, hesperidin, narirutin, and neohesperidin, have been attracted increasing attention for their multiple clinical efficacies. Based on existing in vitro and in vivo research, this study systematically reviewed the biological functions of PTFC and its components in preventing or treating liver metabolic diseases, cardiovascular diseases, intestinal barrier dysfunction, as well as malignancies. PTFC and its components are capable of regulating glycolipid metabolism, blocking peroxidation and persistent inflammation, inhibiting tumor progression, protecting the integrity of intestinal barrier and positively regulating intestinal microbiota, while the differences in fruit cultivation system, picking standard, manufacturing methods, delivery system and individual intestinal microecology will have impact on the specific therapeutic effect. Thus, PTFC is a promising drug for the treatment of some chronic diseases, as well as continuous elaborate investigations are necessary to improve its effectiveness and bioavailability.

Optimising diffusion-weighted imaging of the thyroid gland using dedicated surface coil

AIM

To assess the feasibility of applying field-of-view (FOV) optimised and constrained undistorted single-shot (FOCUS) diffusion-weighted imaging (DWI) in the thyroid gland by comparing its image quality with conventional DWI (C-DWI) qualitatively and quantitatively using a dedicated surface coil exclusively designed for the thyroid gland at 3 T magnetic resonance imaging (MRI).

MATERIALS AND METHODS

In this prospective study, 32 healthy volunteers who had undergone 3 T the thyroid gland MRI with FOCUS-DWI and C-DWI were enrolled. Two independent reviewers assessed the overall image quality, artefacts, sharpness, and geometric distortion based on a five-point Likert scale. The signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and apparent diffusion coefficient (ADC) were quantified for both sequences. Interobserver agreement, qualitative scores, and quantitative parameters were compared between two sequences.

RESULTS

Agreement between the two readers was good for FOCUS-DWI (κ = 0.714-0.778) and moderate to good for C-DWI (κ = 0.525-0.672) in qualitative image quality assessment. Qualitatively, image quality (overall image quality, artefacts, sharpness, and geometric distortion) was significantly better in FOCUS-DWI than that in the C-DWI (all p<0.05); however, quantitatively, FOCUS-DWI had significantly lower SNRs (p<0.001) and CNRs (p=0.012) compared with C-DWI. The ADC value on FOCUS-DWI was significantly higher than that on C-DWI (p<0.001).

CONCLUSION

FOCUS-DWI depicted the thyroid gland with significantly better image quality qualitatively and less ghost artefacts, but had significantly lower SNR and CNR quantitatively, compared with C-DWI, suggesting that both DWI sequences have advantages and could be chosen for different purposes.

Exploring the Pharmacological Mechanism of the Effective Chinese Medicines Against Gynecological Cancer Based on Meta-Analysis Combined With Network Pharmacology Analysis

This meta-analysis plus network pharmacology aimed to investigate whether traditional Chinese medicine (TCM) combined with chemotherapy is associated with more beneficial efficacy data in the treatment of gynecological cancer (GC). A total of 11 randomized controlled trials (RCTs) consisting of 863 GC patients were included. Results showed a better ORR (RR: 1.42, 95% CI: 1.18–1.71; I² = 21.4%; p = 0.282), DCR (RR: 1.13, 95% CI: 1.03–1.25; I² = 0.0%; p = 0.492), PD (RR: 0.27, 95% CI: 0.11–0.65, p = 0.003; I² = 0.0%, p = 0.930), and QOL (SMD: 0.85, 95% CI: 0.38–1.33, p = 0.005) and higher proportions of CD3⁺ T (WMD: 5.65, 95% CI: 4.23–7.08, p = 0.000; I² = 68.3%, p = 0.004), CD4⁺ T (WMD: 6.97, 95% CI: 5.35–8.59, p = 0.000; I² = 83.4%, p = 0.000), and the CD4⁺/CD8⁺ T ratio (WMD: 0.32, 95% CI: 0.23–0.42, p = 0.000; I² = 78.0%, p = 0.000). The number of adverse events (AEs) was significantly lower in the TCM + chemotherapy group. The active components and targets of 19 high-frequency Chinese medicines obtained from the meta-analysis were screened and explored in network pharmacology analysis. Also, a regulatory network of active components and targets, a core network and key genes, a diagram of protein interaction, network topology analysis, and gene body GO function and KEGG pathway enrichment analysis were performed. A total of 120 active components were identified. NPM1 and HSPA8 are the most critical target proteins in the core network of protein interaction. HSP90AA1 is the most important target protein in the TCM group. KEGG enrichment analysis showed that it was highly significant in the lipid and atherosclerotic pathways. Therefore, moderate evidence revealed that TCM plus chemotherapy has obvious advantages over chemotherapy alone in terms of tumor responses, QOL, peripheral blood lymphocyte levels, and fewer AEs in the treatment of GC. The potential important targets and core genes were displayed.

Driving Influences of the Doppler Flash Observed by SuperDARN HF Radars in Response to Solar Flares

Sudden enhancement in high-frequency absorption is a well-known impact of solar flare-driven Short-Wave Fadeout (SWF). Less understood, is a perturbation of the radio wave frequency as it traverses the ionosphere in the early stages of SWF, also known as the Doppler flash. Investigations have suggested two possible sources that might contribute to it's manifestation: first, enhancements of plasma density in the D-and lower E-regions; second, the lowering of the F-region reflection point. Our recent work investigated a solar flare event using first principles modeling and Super Dual Auroral Radar Network (SuperDARN) HF radar observations and found that change in the F-region refractive index is the primary driver of the Doppler flash. This study analyzes multiple solar flare events observed across different SuperDARN HF radars to determine how flare characteristics, properties of the traveling radio wave, and geophysical conditions impact the Doppler flash. In addition, we use incoherent scatter radar data and first-principles modeling to investigate physical mechanisms that drive the lowering of the F-region reflection points. We found, (a) on average, the change in E- and F-region refractive index is the primary driver of the Doppler flash, (b) solar zenith angle, ray's elevation angle, operating frequency, and location of the solar flare on the solar disk can alter the ionospheric regions of maximum contribution to the Doppler flash, (c) increased ionospheric Hall and Pedersen conductance causes a reduction of the daytime eastward electric field, and consequently reduces the vertical ion-drift in the lower and middle latitude ionosphere, which results in lowering of the F-region ray reflection point.

An early transition to magnetic supercriticality in star formation

Magnetic fields have an important role in the evolution of interstellar medium and star formation^1,2. As the only direct probe of interstellar field strength, credible Zeeman measurements remain sparse owing to the lack of suitable Zeeman probes, particularly for cold, molecular gas³. Here we report the detection of a magnetic field of +3.8 ± 0.3 microgauss through the H I narrow self-absorption (HINSA)^4,5 towards L1544^6,7—a well-studied prototypical prestellar core in an early transition between starless and protostellar phases^8–10 characterized by a high central number density¹¹ and a low central temperature¹². A combined analysis of the Zeeman measurements of quasar H I absorption, H I emission, OH emission and HINSA reveals a coherent magnetic field from the atomic cold neutral medium (CNM) to the molecular envelope. The molecular envelope traced by the HINSA is found to be magnetically supercritical, with a field strength comparable to that of the surrounding diffuse, magnetically subcritical CNM despite a large increase in density. The reduction of the magnetic flux relative to the mass, which is necessary for star formation, thus seems to have already happened during the transition from the diffuse CNM to the molecular gas traced by the HINSA. This is earlier than envisioned in the classical picture where magnetically supercritical cores capable of collapsing into stars form out of magnetically subcritical envelopes^13,14.

An analysis of Zeeman measurements reveals that the reduction of magnetic flux relative to mass, which is necessary for star formation, seems to have occurred earlier than previously thought.

A bimodal burst energy distribution of a repeating fast radio burst source

The event rate, energy distribution and time-domain behaviour of repeating fast radio bursts (FRBs) contain essential information regarding their physical nature and central engine, which are as yet unknown^1,2. As the first precisely localized source, FRB 121102 (refs. ^3-5) has been extensively observed and shows non-Poisson clustering of bursts over time and a power-law energy distribution^6-8. However, the extent of the energy distribution towards the fainter end was not known. Here we report the detection of 1,652 independent bursts with a peak burst rate of 122 h^-1, in 59.5 hours spanning 47 days. A peak in the isotropic equivalent energy distribution is found to be approximately 4.8 × 10³⁷ erg at 1.25 GHz, below which the detection of bursts is suppressed. The burst energy distribution is bimodal, and well characterized by a combination of a log-normal function and a generalized Cauchy function. The large number of bursts in hour-long spans allows sensitive periodicity searches between 1 ms and 1,000 s. The non-detection of any periodicity or quasi-periodicity poses challenges for models involving a single rotating compact object. The high burst rate also implies that FRBs must be generated with a high radiative efficiency, disfavouring emission mechanisms with large energy requirements or contrived triggering conditions.

A novel micro-tensile system for full-field deformation measurement of thin films

We propose a novel micro-tensile system fit for mechanical property characterization of low-dimensional materials. The micro-tensile system was integrated with a micro-tensile apparatus driven by a piezoelectric transducer (PZT) and an optical microscope. The displacement provided by the PZT actuator was amplified by a lever structure on the micro-tensile apparatus. A stalloy was designed to transmit the displacement and reduce the mechanical resistance to the PZT actuator. Quantitative analysis was conducted for the designed apparatus. A calibration experiment was performed based on the micro-scale digital image correlation under the optical microscope. To validate the feasibility, the PET film specimen with a V-notch was tested by the proposed system. The results indicate that the proposed micro-tensile system is reliable and powerful.

Gamma-Ray Observation of the Cygnus Region in the 100-TeV Energy Region

We report observations of gamma-ray emissions with energies in the 100-TeV energy region from the Cygnus region in our Galaxy. Two sources are significantly detected in the directions of the Cygnus OB1 and OB2 associations. Based on their positional coincidences, we associate one with a pulsar PSR J2032+4127 and the other mainly with a pulsar wind nebula PWN G75.2+0.1, with the pulsar moving away from its original birthplace situated around the centroid of the observed gamma-ray emission. This work would stimulate further studies of particle acceleration mechanisms at these gamma-ray sources.

Caspase inhibition prolongs inflammation by promoting a signaling complex with activated RIPK1

Activation of inflammation by lipopolysaccharide (LPS) is an important innate immune response. Here we investigated the contribution of caspases to the LPS-mediated inflammatory response and discovered distinctive temporal roles of RIPK1 in mediating proinflammatory cytokine production when caspases are inhibited. We propose a biphasic model that differentiates the role of RIPK1 in early versus late phase. The early production of proinflammation cytokines stimulated by LPS with caspase inhibition is mediated by the NF-κB pathway that requires the scaffold function of RIPK1 but is kinase independent. Autocrine production of TNFα in the late phase promotes the formation of a novel TNFR1-associated complex with activated RIPK1, FADD, caspase-8, and key mediators of NF-κB signaling. The production of proinflammatory cytokines in the late phase can be blocked by RIPK1 kinase inhibitor Nec-1s. Our study demonstrates a mechanism by which the activation of RIPK1 promotes its own scaffold function to regulate the NF-κB–mediated proinflammatory cytokine production that is negatively regulated by caspases to restrain inflammatory signaling.

Diagnostic efficacy of contrast-enhanced ultrasound versus MRI Liver Imaging Reporting and Data System (LI-RADS) for categorising hepatic observations in patients at risk of hepatocellular carcinoma

AIM

To investigate the diagnostic efficacy of the contrast-enhanced ultrasound Liver Imaging Reporting and Data System (CEUS LI-RADS) for categorising hepatic observations in patients at risk of hepatocellular carcinoma (HCC) compared with magnetic resonance imaging (MRI) LI-RADS.

MATERIALS AND METHODS

CEUS and MRI data were analysed retrospectively according to the LI-RADS scheme. Follow-up results and pathological findings served as the reference standard. Receiver operating characteristic (ROC) curve analysis was used to reveal the area under the curve (AUC). The sensitivity, specificity, accuracy, and positive (PPV) and negative predictive values (NPV) of LR-5 for determining HCC were calculated. The intra-observer agreement of CEUS LI-RADS was also evaluated.

RESULTS

Eighty-four patients with 86 liver observations were enrolled. Forty-two observations were classified as LR-5 by CEUS and MRI, respectively. Based on the reference standard, 53 nodules were HCC. The AUCs were 0.876 for CEUS and 0.873 for MRI, without a significant difference (Z=0.050, p=0.960). The sensitivity, specificity, PPV, NPV, and accuracy of LR-5 was 75.47%, 93.94%, 95.24%, 70.45%, 82.56% with CEUS and 73.58%, 90.9%, 92.86%, 68.18%, 80.23% with MRI, respectively. There was a significant difference in specificity between CEUS and MRI (p=0.006). There was almost perfect agreement for arterial phase hyperenhancement (k=0.870), substantial agreement for washout (k=0.765) and CEUS LI-RADS category (k=0.787).

CONCLUSION

The CEUS LI-RADS scheme is an effective diagnostic tool for HCC with substantial intra-observer reliability. The diagnostic performance of CEUS LI-RADS for determining HCC was comparable to MRI LI-RADS, and the specificity of CEUS LR-5 was significantly higher.

Tafolecimab, a novel potential long-acting PCSK9 monoclonal antibody: efficacy and safety in healthy and hypercholesterolemia subjects

Background

LDL cholesterol (LDL-C) is a well-established risk factor for cardiovascular disease. PCSK9 binds LDL receptors, targeting them for degradation. The dosing intervals for currently available PCSK9 monoclonal antibodies are once every 2 or 4 weeks. Tafolecimab, a novel recombinant human PCSK9 monoclonal antibody, was found to have higher affinity with PCSK9 and show longer LDL-C reduction compared to evolocumab in preclinical studies.

Purposes

The objectives for the SAD and MAD studies were to investigate the safety and efficacy of tafolecimab and explore the optimal dosing schedule.

Methods

The phase 1 study was a randomized, placebo-controlled, double-blind, single-ascending dose study (SAD) in Chinese healthy subjects, who were randomized 3:1 to tafolecimab and placebo (n=58). SAD subjects received tafolecimab subcutaneously at 25/75/150/300/450/600mg, or intravenously at 75/450mg, monitored up to day 84. The phase 2 study was a randomized, double-blind, placebo-controlled, repeated-dosing, multiple ascending dose (MAD) study in patients with hypercholesterolemia, who were randomized 4:1 to tafolecimab and placebo (n=60). MAD subjects received tafolecimab subcutaneously at 75/140mg every 2 weeks, 300/420mg every 4weeks, 450/600mg every 6 weeks up to day 84 or 98 with 3 months follow-up.

Results

In the SAD, the maximum mean reduction in LDL-C ranged from 52.2% to 72.1% and was achieved as early as 5 days (figure 1a). The duration of LDL-C reduction was tafolecimab dose dependent. In the MAD, the mean LDL-C concentrations were reduced by tafolecimab for each dose at 12 weeks relative to baseline (ranging from 54.30% to 72.26%; p&lt;0.001). Particularly, a 56.52% (−72.50%, −40.54%) reduction of LDL-C was observed in the cohort of 600mg Q6W. The effect sustained till week 14 (8 weeks after the last dose) where there was still a 43.46% (−60.96%, −25.96%) reduction from baseline (figure 1b). The mean reduction of Lp(a) at week 12 ranged from 24.04% to 50.59% relative to baseline. Tafolecimab reduced the other lipids when comparing with placebo. The pharmacokinetics/pharmadynamics (LDL-C) profiles of tafolecimab were well characterised and support the potential dosing interval of 6–8 weeks subcutaneously.

Both healthy and hypercholesterolemia subjects are generally tolerable to tafolecimab. Reported treatment-emergent adverse events (TEAEs) were: tafolecimab 23 (52.3%) vs. placebo 8 (57.1%); tafolecimab 34 (70.8%) vs. placebo 9 (75.0%) in the SAD and MAD respectively. There were no serious TEAEs or events leading to death or treatment discontinuation in both SAD and MAD.

Conclusions

Tafolecimab was well tolerated in both healthy and hypercholesterolemia in Chinese subjects, and improved lipid profile including LDL-C, Lp(a) and other lipids. The sustained effects on LDL-C suggests the potential of tafolecimab as a long-lasting PCSK9 inhibitor with dosing interval of 6–8 weeks or beyond.

Figure 1. LDL-C: Percent change from baseline

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Innovent Biologics (Suzhou), China

Efficacy of sonothrombolysis using acoustically activated perflutren nanodroplets versus perflutren microbubbles

Background

The use of intermittent high mechanical index (HMI) ultrasound impulses in combination with intravenously administered microbubbles (MB) has been shown to dissolve arterial and microvascular thrombi. The recent development of liquid droplets with nanoscale diameter from commercially available microbubbles may optimize thrombus permeation and subsequent thrombus dissolution.

Methods

Thrombi were formed from fresh porcine arterial whole blood mixed with thrombin, and placed in a vascular system mimicking branching epicardial coronary circulation (Figure 1A) at 37 Celsius and flow rate. A diagnostic ultrasound system with a tissue mimicking phantom was placed on top of the thrombus to simulate transthoracic echocardiography. Thrombus treatment consisted of a 10-minute infusion of either diluted nanodroplets (ND) or MB (same concentration) with intermittent HMI fundamental multipulse (3 usec pulse duration; FUS) or single pulse harmonic (HUS) impulses. All treatments were randomized and compared with HMI impulses alone. Efficacy was evaluated by percentage thrombus dissolution (%TD). Transmission electron microscopy (TEM) of residual thrombi after treatment was performed to examine for droplet permeation and resultant formed microbubble size.

Results

A relatively monodisperse nanodroplets size distribution was formed from microbubble cooled compression (mean diameter was 147±54 nm). A total of 60 porcine arterial thrombi were tested, 20 in each MB and ND treated group (20 control). Overall, there was a significant difference in %TD between ND treated thrombi (combining HUS and FUS HMI treated groups) versus MB treated thrombi and control (p&lt;0.0001 and p=0.02, respectively; ANOVA, Figure 1B). The highest %TD was seen in the FUS HMI treated ND group (mean 51±17%; Figure 1B). TEM of the DND treated group demonstrated significant expansion (diameters of 6 microns; Figure 1 C) of acoustically activated droplets embedded within the thrombi.

Conclusion

ND in combination with intermittent HMI ultrasound resulted in significantly greater thrombolysis compared to MB. In-vivo studies on nanodroplet mediated sonothrombolysis for vascular and microvascular thrombi should be performed with this modification of a commercially available microbubble.

Figure 1

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Theodore F. Hubbard Foundation

Performance of IOTA ADNEX model in evaluating adnexal masses in a gynecological oncology center in China

OBJECTIVE

To evaluate the diagnostic accuracy of the International Ovarian Tumor Analysis (IOTA) Assessment of Different NEoplasias in the adneXa (ADNEX) model in the preoperative diagnosis of adnexal masses using data from a gynecological oncology center in China.

METHODS

This was a single-center, retrospective diagnostic accuracy study based on ultrasound data collected prospectively, between May and December 2017, from 278 patients with at least one adnexal (ovarian, paraovarian or tubal) mass. Clinical and pathologic information, serum CA 125 level and ultrasonographic findings were collected. All patients underwent surgery and the histopathological diagnosis was used as reference standard. The final diagnosis was classified into five tumor types according to the ADNEX model: benign ovarian tumor, borderline ovarian tumor (BOT), Stage-I ovarian cancer (OC), Stages-II-IV OC and ovarian metastasis. Receiver-operating characteristics (ROC) curve analysis was used to evaluate the diagnostic accuracy of the ADNEX model, with and without inclusion of CA 125 level in the model.

RESULTS

Of the 278 women included, 203 (73.0%) had a benign ovarian tumor and 75 (27.0%) had a malignant ovarian tumor, including 18 (6.5%) with BOT, 17 (6.1%) with Stage-I OC, 32 (11.5%) with Stages-II-IV OC and eight (2.9%) with ovarian metastasis. The performance of the IOTA ADNEX model was good for discriminating between benign and malignant tumors, with an area under the ROC curve (AUC) of 0.94 (95% CI, 0.91-0.97) when CA 125 was included in the model and AUC of 0.93 (95% CI, 0.90-0.96) without CA 125. The AUC values of the model including CA 125 ranged between 0.61 and 0.99 for distinguishing between the different types of tumor, and it showed excellent performance in discriminating between a benign ovarian tumor and Stages-II-IV OC, with an AUC of 0.99 (95% CI, 0.97-1.00). The performance of the model was less effective at distinguishing between BOT and Stage-I OC and between Stages-II-IV OC and ovarian metastasis, with AUC values of 0.61 (95% CI, 0.43-0.77) and 0.78 (95% CI, 0.62-0.90), respectively. Although inclusion of CA 125 did not alter the performance of the ADNEX model in discriminating between benign and malignant lesions (AUC of 0.94 and 0.93 with and without CA 125 level, respectively; P = 0.54), the inclusion of CA 125 in the model improved its performance in discriminating between Stage-I OC and Stages-II-IV OC (AUC increased from 0.81 to 0.92; P = 0.04) and between Stages-II-IV OC and metastatic cancer (AUC increased from 0.58 to 0.78; P = 0.01).

CONCLUSIONS

The IOTA ADNEX model showed good to excellent performance in distinguishing between benign and malignant adnexal masses and between the different types of ovarian tumor in a Chinese setting. Based on our findings, the ADNEX model has high value in clinical practice and can aid in the preoperative diagnosis of patients with an adnexal mass. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

HuR, TTP, and miR-133b expression in NSCLC and their association with prognosis

OBJECTIVE

This study sought to explore HuR, Thrombotic Thrombocytopenic Purpura (TTP), and microRNA 133b (miR-133b) expression levels in non-small cell lung cancer (NSCLC) patients and assess the relationship of expression with disease prognosis.

PATIENTS AND METHODS

One hundred and ten paraffin-embedded and 33 fresh flash-frozen NSCLC samples, together with matched tumor adjacent normal tissue controls, were collected from patients between January 2013 and July 2015 in Yidu Central Hospital of Weifang. Twenty-nine patients provided both paraffin-embedded and fresh frozen tissues. HuR and TTP protein expression levels were measured in 110 paraffin-embedded tumors and matched controls using immunohistochemistry, while miR-133b levels were measured using Real-time fluorescent quantitative PCR.

RESULTS

Follow-up parameters included treatment response, relapse events, post-relapse treatment, disease free survival (DFS), and overall survival (OS). HuR expression was significantly different between tumor and matched controls (p < 0.0001). Cytoplasmic expression levels of HuR and TTP correlated with pTNM staging (p < 0.05). No significant correlation was observed between HuR and TTP expression and other clinical pathological factors (gender, age, tumor size, pathological subtype, differentiation status, lymph node metastasis, distant metastasis, and tumor invasiveness). MiR-133b expression correlated with tumor size (p = 0.015) and differentiation status (p = 0.013) in paraffin-embedded sections, but was only correlated with pTNM staging (p = 0.032) in frozen tissue samples. No significant difference in DFS nor OS was observed between 68 HuR-positive and 42 HuR-negative patients (DFS, Log Rank p = 0.712; OS, Log Rank p = 0.220). However, DFS and OS were significantly different between miR-133b high-expression and low-expression patients (DFS, Log Rank p = 0.048 < 0.05; OS, Log Rank p = 0.025 < 0.05). This indicates that miR-133b levels may have prognostic value.

CONCLUSIONS

HuR expression was negatively correlated with TTP expression in NSCLC tissues. MiR-133b levels were downregulated in normal tissues compared to both paraffin and frozen tumor samples, and correlated with both HuR and TTP expression, which may affect the prognosis of NSCLC patients.

Survival prediction with score model based on clinical characteristics in advanced HCC patients receiving oxaliplatin-containing regimens

A score model based on clinical characteristics in advanced hepatocellular carcinoma (HCC) patients treated with systemic chemotherapy of oxaliplatin-containing regimens was established to evaluate progression-free survival (PFS) and overall survival (OS). Thirty HCC patients eligible for radical resection were involved in the retrospective study, and these were divided into the good response group (complete response (CR)/partial response (PR) and the poor response group (stable disease (SD)/progression disease (PD). The median PFS and OS were compared in the two groups. PFS and OS combined with clinical characteristics were evaluated by univariate and multivariate analyses. The score model was defined with 1 score for each characteristic, and score model cut-off values were determined by the receiver operating characteristic curve (ROC) which describes treatment response. The median PFS was 10 and 2 months (p<0.001), and the median OS was 13 and 4 months (p=0.011) for the CR/PR and SD/PD groups, respectively. The score of 1 was the optimal cutoff value, with sensitivity ranging from 52.6 to 63.2% and specificity from 81.8 to 100% (AUC= 0.773, p=0.014). The median PFS for good and poor response groups was 9 months and 1month (p<0.001) and the median OS was 22 and 3months at p<0.001, respectively. Patients with scores above 1 had poor response, with median 3 months OS and 1 month PFS, and patients with scores of 0 and 1 established good response, with median 22 months OS and 9 months PFS, respectively.

The effect of neonatal maternal separation on short-chain fatty acids and airway inflammation in adult asthma mice

BACKGROUND

To investigate neonatal maternal separation (NMS) effects on airway inflammation of asthma and potential mechanism using a mouse model.

METHODS

80 Balb/c neonatal male mice were randomly assigned to NMS and non-NMS groups. Feces were collected on PND21, 28, 35 and 42 to analyze microbiota and short-chain fatty acids (SCFAs). Non-NMS group were then divided into control (group A) and asthma groups (group B), while NMS group was assigned to NMS+asthma (group C) and NMS+SCFAs+asthma groups (group D). Inflammatory cells and eosinophils (EOS) in bronchoalveolar lavage fluid (BALF) were assessed. Pathological changes and cytokines in lung tissue were observed. Protein expression of Occludin and E-cadherin in airway epithelial was examined.

RESULTS

The number of S', diversity index H' and dominance index D', as well as content butyric acid in NMS group C were significantly lower than non-NMS group B (p<0.05). Mice in group C had a higher level of inflammatory cells and EOS compared with group A, B and D. EOS moderate infiltration was found in mice of group B, C and D. Mice in group C had significantly higher levels of cytokines and showed slightly increased bronchial epithelium goblet cells and a small amount of visceral secretions. Occludin and E-cadherin expression in lung in B, C and D groups was depressed, and protein level in group C was significantly lower than group B and D.

CONCLUSIONS

NMS is associated with exacerbated inflammation of adult asthma by changing intestinal microflora resulting in butanoic acid decline and airway epithelial barrier damage.

ABIN-1 heterozygosity sensitizes to innate immune response in both RIPK1-dependent and RIPK1-independent manner

ABIN-1 (encoded by the gene Tnip1) is a ubiquitin-binding protein that can interact with ubiquitin-editing enzyme A20 (encoded by the gene TNFAIP3) to restrain the activation of necroptosis and NF-κB activation. Genetic variants in the genes Tnip1 and TNFAIP3 are both strongly associated with susceptibility to autoimmune chronic inflammatory diseases such as psoriasis vulgaris and systemic lupus erythematosus (SLE) in humans. Here we investigated the mechanism by which ABIN-1 regulated innate immune responses. We show that ABIN-1 heterozygosity sensitizes cells to antiviral response by mediating NF-κB-dependent and RIPK1-independent expression of pattern recognition molecules, including TLR3, RIG-I, and MDA5, in MEFs. Furthermore, we demonstrate that increased interaction of ABIN-1 and A20 with prolonged poly(I:C) stimulation of WT cells leads to A20-dependent reduction of ABIN-1 protein. Finally, we show that ABIN-1 heterozygosity sensitizes innate immune response of Abin-1^+/- mice in vivo by promoting the production of proinflammatory cytokines, which can be blocked upon inhibition of RIPK1 kinase. Inhibition of RIPK1 kinase activity in vivo partially reduces the expression of MDA5, RIG-I, and caspase-11 in Abin-1^+/- mice but not in WT mice. Thus, we conclude that ABIN-1 is a suppressor of innate immune response and the interaction of ABIN-1 with A20 controls innate immunity response through the NF-κB pathway and in both RIPK1 kinase activity-independent and dependent manner.

Complication Follow-up With Ultrasonographic Analyses of 91 Cases With Donor Gallbladder Preservation in Living Donor Liver Transplantation of Left Lateral Sectionectomies

BACKGROUND

Preserving the donor's gallbladder during living donor liver transplantation (LDLT) is a better method for liver transplantation surgery, but not enough is known about gallbladder complications after the operation.

METHODS

We retrospectively investigated postsurgical donor gallbladder complications in clinical LDLT with gallbladder preservation. The feasibility of retaining the gallbladder during liver graft procurement is discussed. Ninety-one donors with retained gallbladder after LDLT with the hepatic left lateral sectionectomy (from June 2013 to October 2015) were retrospectively analyzed. Donors were followed for 12.6 to 40.7 months after surgery (median 26.1 months). Sonography was used to evaluate gallbladder characteristics before and after surgery.

RESULTS

Gallbladder function had recovered to almost normal 1 month after transplantation. Four donors (4.40%) experienced gallbladder enlargement that resolved after 3 days. Thickening of the gallbladder wall in 31 donors (34.07%) was restored within 2 to 75 days. Biliary sludge appeared in 9 donors (9.89%); 6 of them recovered within 3 to 34 days. Three (3.30%) and 1 donor (1.10%) suffered gallstone and gallbladder polyps, respectively, which persisted until the last follow-up.

CONCLUSION

The rate of postoperative complications of the gallbladder in donors was relative low. Preserving the gallbladder in liver transplantation donors during liver graft procurement is feasible and safe.

A comparison of the biomechanical stability of pedicle-lengthening screws and traditional pedicle screws: an in vitro instant and fatigue-resistant pull-out test

Aims

The aim of this study was to compare the peak pull-out force (PPF) of pedicle-lengthening screws (PLS) and traditional pedicle screws (TPS) using instant and cyclic fatigue testing.

Materials and Methods

A total of 60 lumbar vertebrae were divided into six groups: PLS submitted to instant pull-out and fatigue-resistance testing (groups A1 and A2, respectively), TPS submitted to instant pull-out and fatigue-resistance testing (groups B1 and B2, respectively) and PLS augmented with 2 ml polymethylmethacrylate, submitted to instant pull-out and fatigue-resistance testing (groups C1 and C2, respectively). The PPF and normalized PPF (PPFn) for bone mineral density (BMD) were compared within and between all groups.

Results

In all groups, BMD was significantly correlated with PPF (r = 0.83, p < 0.001). The PPFn in A1 was significantly less than in B1 (p = 0.006) and C1 (p = 0.002). The PPFn of A2 was significantly less than in B2 (p < 0.001) and C2 (p < 0.001). The PPFn in A1, B1, and C1 was significantly greater than in A2 (p = 0.002), B2 (p = 0.027), and C2 (p = 0.003). There were no significant differences in PPFn between B1 and C1, or between B2 and C2.

Conclusion

Pedicle lengthening screws with cement augmentation can provide the same fixation stability as traditional pedicle screws and may be a viable clinical option. Cite this article: Bone Joint J 2018;100-B:516-21.

Family History of Melanoma and Lifetime Patterns of Daytime Hours Spent Outdoors in Melanoma-prone Families

Longer daytime hours spent outdoors reflect higher ultraviolet radiation exposure, which is a modifiable risk factor of melanoma. Among individuals of melanoma-prone families, we sought to describe lifetime patterns for hours spent outdoors, and to investigate whether having an affected family member with melanoma from an older generation was associated with patterning. Methods: Information on hours spent outdoors on weekdays, weekends, and holidays beginning at age 10 was obtained from individuals from melanoma-prone families. We determined time-weighted average hours outdoors for warmer months, colder months, and the entire year. K-means for longitudinal data was used to identify lifetime patterns. We created a variable to indicate whether there was an existing melanoma in a prior generation of an individual's family. Multinomial logistic regression models were used to examine the association between family history of melanoma and lifetime patterns of daytime hours spent outdoors, adjusting for covariates. Results: We analyzed 2540 individuals from 669 families ascertained across 15 countries, and four lifetime patterns were identified. Three patterns began with moderate hours that (B) decreased slowly (n = 1014); (C) decreased sharply until age 20 and then remained low (n = 572); or (D) increased at age 20 and remained high (n = 173). One pattern, (A) began with few hours that decreased at age 20 then remained very low (n = 781). Compared to individuals with the high (D) pattern, individuals with an existing melanoma in a prior family generation were more likely to have the low (A) pattern (OR = 1.92, 95% CI: 1.34–2.76), the moderate and slowly decreasing (B) pattern (OR = 1.72, 95% CI: 1.15–2.57), or the sharply decreasing (C) pattern (OR = 2.01, 95% CI: 1.40–2.87). Similar associations were observed separately in warmer and colder months. Examining lifetime patterns of hours spent outdoors during holidays, we noticed a stronger relationship with family history of melanoma in warmer months than in colder months. Conclusions: As expected, the diagnosis of a melanoma in a prior generation may impact family members' awareness of UVR exposure leading to reduced daytime hours spent outdoors.

SPATA2 regulates the activation of RIPK1 by modulating linear ubiquitination

Stimulation of cells with TNFα leads to the formation of the TNF-R1 signaling complex (TNF-RSC) to mediate downstream cellular fate decision. Activation of the TNF-RSC is modulated by different types of ubiquitination and may lead to cell death, including apoptosis and necroptosis, in both RIPK1-dependent and RIPK1-independent manners. Spata2 (spermatogenesis-associated 2) is an adaptor protein recruited into the TNF-RSC to modulate the interaction between the linear ubiquitin chain assembly complex (LUBAC) and the deubiquitinase CYLD (cylindromatosis). However, the mechanism by which Spata2 regulates the activation of RIPK1 is unclear. Here, we report that Spata2-deficient cells show resistance to RIPK1-dependent apoptosis and necroptosis and are also partially protected against RIPK1-independent apoptosis. Spata2 deficiency promotes M1 ubiquitination of RIPK1 to inhibit RIPK1 kinase activity. Furthermore, we provide biochemical evidence for the USP domain of CYLD and the PUB domain of the SPATA2 complex preferentially deubiquitinating the M1 ubiquitin chain in vitro. Spata2 deficiency also promotes the activation of MKK4 and JNK and cytokine production independently of RIPK1 kinase activity. Spata2 deficiency sensitizes mice to systemic inflammatory response syndrome (SIRS) induced by TNFα, which can be suppressed by RIPK1 inhibitor Nec-1s. Thus, Spata2 can regulate inflammatory response and cell death in both RIPK1-dependent and RIPK1-independent manners.

Small molecule probes for cellular death machines

The past decade has witnessed a significant expansion of our understanding about the regulated cell death mechanisms beyond apoptosis. The application of chemical biological approaches had played a major role in driving these exciting discoveries. The discovery and use of small molecule probes in cell death research has not only revealed significant insights into the regulatory mechanism of cell death but also provided new drug targets and lead drug candidates for developing therapeutics of human diseases with huge unmet need. Here, we provide an overview of small molecule modulators for necroptosis and ferroptosis, two non-apoptotic cell death mechanisms, and discuss the molecular pathways and relevant pathophysiological mechanisms revealed by the judicial applications of such small molecule probes. We suggest that the development and applications of small molecule probes for non-apoptotic cell death mechanisms provide an outstanding example showcasing the power of chemical biology in exploring novel biological mechanisms.

USP25 regulates Wnt signaling by controlling the stability of tankyrases

Here, Xu et al. identified USP25, a ubiquitin-specific protease, as a positive regulator of Wnt–β-catenin signaling. They found that USP25 directly interacted with tankyrases to promote their deubiquitination and stabilization, and USP25 deficiency could promote the degradation of tankyrases and consequent stabilization of Axin to antagonize Wnt signaling. Their findings provide new insights into the molecular mechanism that regulates the turnover of tankyrases and the Wnt–β catenin pathway.

Aberrant activation of the Wnt signaling pathway plays an important role in human cancer development. Wnt signaling is negatively regulated by Axin, a scaffolding protein that controls a rate-limiting step in the destruction of β-catenin, the central activator of the Wnt pathway. In Wnt-stimulated cells, Axin is rapidly modified by tankyrase-mediated poly(ADP-ribosyl)ation, which promotes the proteolysis of Axin and consequent stabilization of β-catenin. Thus, regulation of the levels and activity of tankyrases is mechanistically important in controlling Wnt signaling. Here, we identify ubiquitin-specific protease 25 (USP25) as a positive regulator of Wnt/β-catenin signaling. We found that USP25 directly interacted with tankyrases to promote their deubiquitination and stabilization. We demonstrated that USP25 deficiency could promote the degradation of tankyrases and consequent stabilization of Axin to antagonize Wnt signaling. We further characterized the interaction between TNKS1 and USP25 by X-ray crystal structure determination. Our results provide important new insights into the molecular mechanism that regulates the turnover of tankyrases and the possibility of targeting the stability of tankyrases by antagonizing their interaction with USP25 to modulate the Wnt/β-catenin pathway.

USP14 regulates autophagy by suppressing K63 ubiquitination of Beclin 1

Xu et al. show that USP14 regulates autophagy by controlling K63 ubiquitination of Beclin 1. Activation of USP14 by Akt-mediated phosphorylation provides a mechanism for Akt to negatively regulate autophagy by promoting K63 deubiquitination.

The ubiquitin–proteasome system (UPS) and autophagy are two major intracellular degradative mechanisms that mediate the turnover of complementary repertoires of intracellular proteomes. Simultaneously activating both UPS and autophagy might provide a powerful strategy for the clearance of misfolded proteins. However, it is not clear whether UPS and autophagy can be controlled by a common regulatory mechanism. K48 deubiquitination by USP14 is known to inhibit UPS. Here we show that USP14 regulates autophagy by negatively controlling K63 ubiquitination of Beclin 1. Furthermore, we show that activation of USP14 by Akt-mediated phosphorylation provides a mechanism for Akt to negatively regulate autophagy by promoting K63 deubiquitination. Our study suggests that Akt-regulated USP14 activity modulates both proteasomal degradation and autophagy through controlling K48 and K63 ubiquitination, respectively. Therefore, regulation of USP14 provides a mechanism for Akt to control both proteasomal and autophagic degradation. We propose that inhibition of USP14 may provide a strategy to promote both UPS and autophagy for developing novel therapeutics targeting neurodegenerative diseases.

The segment-dependent changes in lumbar intervertebral space height during flexion-extension motion

Objectives

Many studies have investigated the kinematics of the lumbar spine and the morphological features of the lumbar discs. However, the segment-dependent immediate changes of the lumbar intervertebral space height during flexion-extension motion are still unclear. This study examined the changes of intervertebral space height during flexion-extension motion of lumbar specimens.

Methods

First, we validated the accuracy and repeatability of a custom-made mechanical loading equipment set-up. Eight lumbar specimens underwent CT scanning in flexion, neural, and extension positions by using the equipment set-up. The changes in the disc height and distance between adjacent two pedicle screw entry points (DASEP) of the posterior approach at different lumbar levels (L3/4, L4/5 and L5/S1) were examined on three-dimensional lumbar models, which were reconstructed from the CT images.

Results

All the vertebral motion segments (L3/4, L4/5 and L5/S1) had greater changes in disc height and DASEP from neutral to flexion than from neutral to extension. The change in anterior disc height gradually increased from upper to lower levels, from neutral to flexion. The changes in anterior and posterior disc heights were similar at the L4/5 level from neutral to extension, but the changes in anterior disc height were significantly greater than those in posterior disc height at the L3/4 and L5/S1 levels, from neutral to extension.

Conclusions

The lumbar motion segment showed level-specific changes in disc height and DASEP. The data may be helpful in understanding the physiologic dynamic characteristics of the lumbar spine and in optimising the parameters of lumbar surgical instruments.

Cite this article: M. Fu, Q. Ye, C. Jiang, L. Qian, D. Xu, Y. Wang, P. Sun, J. Ouyang. The segment-dependent changes in lumbar intervertebral space height during flexion-extension motion. Bone Joint Res 2017;6:245–252. DOI: 10.1302/2046-3758.64.BJR-2016-0245.R1.

Down-regulation of N-acetylglucosamine-1-phosphate transferase (WecA) enhanced the sensitivity of Mycobacterium smegmatis against rifampin

AIMS

To construct a conditional N-acetylglucosamine-1-phosphate transferase (WecA) knockdown strain of Mycobacterium smegmatis and to investigate the biological effect of WecA on mycobacterial growth, morphology and susceptibilities against anti-tuberculosis drugs.

METHODS AND RESULTS

Mycobacterium smegmatis wecA knockdown strain was constructed by using a tetracycline-inducible expression vector pMind and the expression of WecA was regulated by antisense RNA. The results of growth curves and the colony formation unit curves showed that the growth rate of WecA down-regulation strain was decreased and the amount of live bacterial cells dropped. In addition, the wecA knockdown strain exhibited dramatically morphological alterations through scanning electron microscopy observation. The susceptibility of WecA low-expression strain to anti-tuberculosis drugs was detected by using a rapid resazurin microtitre assay as well as a traditional agar dilution method. Notably, the wecA knockdown strain was more sensitive to rifampin, compared with the wecA normal-expression strain. In addition, the sensitivity of wild type Myco. smegmatis mc(2) 155 strain against rifampin was also enhanced in the presence of a low concentration of tunicamycin, a natural WecA inhibitor.

CONCLUSIONS

Down-regulation of WecA enhanced the sensitivity of Myco. smegmatis against rifampin.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results provided a possibility of combined application of rifampin together with tunicamycin or other WecA inhibitors, which could be a new approach for the treatment of tuberculosis.

Impact of pedicle-lengthening osteotomy on spinal canal volume and neural foramen size in three types of lumbar spinal stenosis

Objectives

Pedicle-lengthening osteotomy is a novel surgery for lumbar spinal stenosis (LSS), which achieves substantial enlargement of the spinal canal by expansion of the bilateral pedicle osteotomy sites. Few studies have evaluated the impact of this new surgery on spinal canal volume (SCV) and neural foramen dimension (NFD) in three different types of LSS patients.

Methods

CT scans were performed on 36 LSS patients (12 central canal stenosis (CCS), 12 lateral recess stenosis (LRS), and 12 foraminal stenosis (FS)) at L4-L5, and on 12 normal (control) subjects. Mimics 14.01 workstation was used to reconstruct 3D models of the L4-L5 vertebrae and discs. SCV and NFD were measured after 1 mm, 2 mm, 3 mm, 4 mm, or 5 mm pedicle-lengthening osteotomies at L4 and/or L5. One-way analysis of variance was used to examine between-group differences.

Results

In the intact state, SVC and NFD were significantly larger in the control group compared with the LSS groups (P<0.05). After lengthening at L4, the percentage increase in SCV (per millimetre) was LRS>CCS>FS>Control. After lengthening at L5 and L4-L5, the percentage increase in SCV (per millimetre) was LRS>FS>CCS>Control. After lengthening at L4 and L4-L5, the percentage increase in NFD (per millimetre) was FS>CCS>LRS>Control. After lengthening at L5, the percentage increase in NFD (per millimetre) was CCS>LRS>control>FS.

Conclusions

LRS patients are the most suitable candidates for treatment with pedicle-lengthening osteotomy. Lengthening L4 pedicles produced larger percentage increases in NFD than lengthening L5 pedicles (p < 0.05). Lengthening L4 pedicles may be the most effective option for relieving foraminal compression in LSS patients.

Cite this article: P. Li, L. Qian, W. D. Wu, C. F. Wu, J. Ouyang. Impact of pedicle-lengthening osteotomy on spinal canal volume and neural foramen size in three types of lumbar spinal stenosis. Bone Joint Res 2016;5:239–246. DOI: 10.1302/2046-3758.56.2000469.