Twisted pair transmission line coil - a flexible, self-decoupled and robust element for 7 T MRI

OBJECTIVE

This study evaluates the performance of a twisted pair transmission line coil as a transceive element for 7 T MRI in terms of physical flexibility, robustness to shape deformations, and interelement decoupling.

METHODS

Each coil element was created by shaping a twisted pair of wires into a circle. One wire was interrupted at the top, while the other was interrupted at the bottom, and connected to the matching circuit. Electromagnetic simulations were conducted to determine the optimal number of twists per length (in terms of B₁+ field efficiency, SAR efficiency, sensitivity to elongation, and interelement decoupling properties) and for investigating the fundamental operational principle of the coil through fields streamline visualisation. A comparison between the twisted pair coil and a conventional loop coil in terms of B₁+ fields, maxSAR₁₀g, and stability of S₁₁ when the coil was deformed was performed. Experimentally measured interelement coupling between individual elements of multichannel arrays was also investigated.

RESULTS

Increasing the number of twists per length resulted in a more physically robust coil. Poynting vector streamline visualisation showed that the twisted pair coil concentrated most of the energy in the near field. The twisted pair coil exhibited comparable B₁+ fields and improved maxSAR₁₀g to the conventional coil but demonstrated exceptional stability with respect to coil deformation and a strong self-decoupling nature when placed in an array configuration.

DISCUSSION

The findings highlight the robustness of the twisted pair coil, showcasing its stability under shape variations. This coil holds great potential as a flexible RF coil for various imaging applications using multiple-element arrays, benefiting from its inherent decoupling.

NMR and MS reveal characteristic metabolome atlas and optimize esophageal squamous cell carcinoma early detection

Metabolic changes precede malignant histology. However, it remains unclear whether detectable characteristic metabolome exists in esophageal squamous cell carcinoma (ESCC) tissues and biofluids for early diagnosis. Here, we conduct NMR- and MS-based metabolomics on 1,153 matched ESCC tissues, normal mucosae, pre- and one-week post-operative sera and urines from 560 participants across three hospitals, with machine learning and WGCNA. Aberrations in 'alanine, aspartate and glutamate metabolism' proved to be prevalent throughout the ESCC evolution, consistently identified by NMR and MS, and reflected in 16 serum and 10 urine metabolic signatures in both discovery and validation sets. NMR-based simplified panels of any five serum or urine metabolites outperform clinical serological tumor markers (AUC = 0.984 and 0.930, respectively), and are effective in distinguishing early-stage ESCC in test set (serum accuracy = 0.994, urine accuracy = 0.879). Collectively, NMR-based biofluid screening can reveal characteristic metabolic events of ESCC and be feasible for early detection (ChiCTR2300073613).

MRI characterization of in vitro clots at 3T and 7T: A technical note

In acute ischemic stroke, the composition of the occlusive clot can be associated with the underlying pathophysiology and the response to treatment. For these reasons, it is important to characterize the clot composition from clinical scans. We examine the ability of 3T and 7T MRI to distinguish the composition of in vitro clots, using quantitative T1 and T2*, alternatively R2*, mapping. When comparing the two field strengths, we found a tradeoff between sensitivity for clot composition and confidence in the clot depiction associated with spatial resolution. The loss of sensitivity at 7T can be mitigated by combining the T1 and T2* signals.

Improved reproducibility of γ-aminobutyric acid measurement from short-echo-time proton MR spectroscopy by linewidth-matched basis sets in LCModel

γ-Aminobutyric acid (GABA), as the primary inhibitory neurotransmitter, is extremely important for maintaining healthy brain function, and deviations from GABA homeostasis are related to various brain diseases. Short-echo-time (short-TE) proton MR spectroscopy (1 H-MRS) has been employed to measure GABA concentration from various human brain regions at high magnetic fields. The aim of this study was to investigate the effect of spectral linewidth on GABA quantification and explore the application of an optimized basis-set preparation approach using a spectral-linewidth-matched (LM) basis set in LCModel to improve the reproducibility of GABA quantification from short-TE 1 H-MRS. In contrast to the fixed-linewidth basis-set approach, the LM basis-set preparation approach, where all metabolite basis spectra were simulated with a linewidth 4 Hz narrower than that of water, showed a smaller standard deviation of estimated GABA concentration from synthetic spectra with varying linewidths and lineshapes. The test-retest reproducibility was assessed by the mean within-subject coefficient of variation, which improved from 19.2% to 12.0% in the thalamus, from 27.9% to 14.9% in the motor cortex, and from 9.7% to 2.8% in the medial prefrontal cortex using LM basis sets at 7 T. We conclude that spectral linewidth has a large effect on GABA quantification from short-TE 1 H-MRS data and that using LM basis sets in LCModel can improve the reproducibility of GABA quantification.

[Quality Control Indexes for Oncology (2023 edition) and hot topics in breast surgery]

The National Health Commission of the People's Republic of China has formulated the Quality Control Indexes for Oncology (2023 edition), with the objective of improving medical quality scientifically, refined and standardized. Among these indexes, the rate of pretreatment clinical TNM staging and the coincidence rate of evaluation of pretreatment TNM staging lay national standards for patients to formulate rational and targeted treatment strategies. This article reviewed the literature and referred to Chinese Medical Association Clinical Practice Guide for Breast Surgery, and presented recommendations for the hot topics of breast surgery, such as pathological sampling of the breast specimen, sentinel lymph node biopsy for early-stage breast cancer, breast conserving surgery, axillary lymph node dissection, breast reconstruction surgery, endoscopic-assisted breast surgery, the principles of surgical treatment for metastatic breast cancer, neoadjuvant treatment for advanced disease, and surgical grade of breast surgery, which have been widely concerned in recent years, to help improve homogenization of breast cancer treatment in China.

Effect of circadian rhythm on NAD and other metabolites in human brain

Nicotinamide Adenine Dinucleotide (NAD) plays a central role in the master circadian clock of the brain (the suprachiasmatic nuclei, SCN) as demonstrated in many model organisms. NAD acts as an enzyme co-factor and substrate and its modulation was found to be tightly regulated to the periodicity of the cycles. However, in human brain, the effect of the circadian rhythm (CR) on the metabolism of the SCN and other brain regions is poorly understood. We conducted a magnetic resonance spectroscopy (MRS) study at a high magnetic field, measuring the occipital brain NAD levels and other metabolites in two different morning and afternoon diurnal states in 25 healthy participants. Salivary cortisol levels were determined to confirm that the experiment was done in two chronologically different physiological conditions, and a behavioral test of risk-taking propensity was administered. Overall, we found that the CR did not significantly affect NAD levels in the occipital brain region. The other brain metabolites measured, including lactate, were not significantly affected by the CR either, except for taurine. The CR did impact risk-taking behavior and salivary cortisol level, confirming that the participants were in two circadian different behavioral and physiological states in the morning and in the afternoon. Measurement of the CR effect on NAD and taurine levels in other brain regions might provide stronger effects.

Fast in vivo assay of creatine kinase activity in the human brain by 31 P magnetic resonance fingerprinting

A new and efficient magnetisation transfer 31 P magnetic resonance fingerprinting (MT-31 P-MRF) approach is introduced to measure the creatine kinase metabolic ratek CK between phosphocreatine (PCr) and adenosine triphosphate (ATP) in human brain. The MRF framework is extended to overcome challenges in conventional 31 P measurement methods in the human brain, enabling reduced acquisition time and specific absorption rate (SAR). To address the challenge of creating and matching large multiparametric dictionaries in an MRF scheme, a nested iteration interpolation method (NIIM) is introduced. As the number of parameters to estimate increases, the size of the dictionary grows exponentially. NIIM can reduce the computational load by breaking dictionary matching into subsolutions of linear computational order. MT-31 P-MRF combined with NIIM providesT 1 PCr ,T 1 ATP andk CK estimates in good agreement with those obtained by the exchange kinetics by band inversion transfer (EBIT) method and literature values. Furthermore, the test-retest reproducibility results showed that MT-31 P-MRF achieves a similar or better coefficient of variation (<12%) forT 1 ATP andk CK measurements in 4 min 15 s, than EBIT with 17 min 4 s scan time, enabling a fourfold reduction in scan time. We conclude that MT-31 P-MRF in combination with NIIM is a fast, accurate, and reproducible approach for in vivok CK assays in the human brain, which enables the potential to investigate energy metabolism in a clinical setting.

Optimizing the Combination of Cytotoxic Drugs Along with Radiotherapy as Effective Treatment for Extranodal NK/T-Cell Lymphoma

PURPOSE/OBJECTIVE(S)

The optimal combination of cytotoxic drugs along with radiotherapy (RT) is unknown. We undertook multidrug screening process to identify the most efficacious cytotoxic drugs, and appraise the efficacy of various drug combinations.

MATERIALS/METHODS

We reviewed 3105 patients who received 40 chemotherapy regimens with different combinations of nine drug classes and/or RT. Least absolute shrinkage and selection operator (LASSO) and multivariable Cox regression analyses were used to screen efficacious single drugs and identify optimal combinations for overall survival (OS). Inverse probability of treatment weighting (IPTW) and multivariable analyses were used to compare survival between treatment regimens.

RESULTS

Screening and validation revealed RT, asparaginase (ASP), and gemcitabine (GEM) to be the most efficacious single modality/drugs. RT remained an important component of first-line treatment, whereas ASP was a fundamental drug of non-anthracycline (ANT)-based regimens. Addition of RT to non-ANT-based or ASP/GEM-based regimens, or addition of an ASP-drug into ANT-based or GEM/PLA-based regimens, improved 5-year OS significantly. Use of ASP/GEM-based regimens led to significantly higher 5-year OS (79.9%) compared with ASP/ANT-based (69.2%, P = 0.001), ASP/MTX-based (63.5%, P = 0.011), or ASP/NOS-based (63.2%, P<0.001) regimens. The survival benefit of ASP/GEM-based regimens over other ASP-based regimens was substantial across risk-stratified and advanced-stage subgroups. The survival benefits of a combination of RT, ASP, and GEM were consistent after adjustment for confounding factors by IPTW.

CONCLUSION

These results suggest that combining ASP/GEM with RT for ENKTCL is an efficacious and feasible therapeutic option, and provides a rationale and strategy for developing combination therapies.

Risk factors for bloodstream infection in paediatric haematopoietic stem cell transplantation: a systematic review and meta-analysis

BACKGROUND

Haematopoietic stem cell transplantation (HSCT), a standard treatment for paediatric haematological diseases, is highly associated with bloodstream infection (BSI), which may increase mortality.

AIM

To explore the risk factors for BSI in paediatric HSCT recipients.

METHODS

Three English databases and four Chinese databases were searched from inception to March 17th, 2022. Eligible studies included randomized controlled trials, cohort studies, and case-control studies that enrolled HSCT recipients aged ≤18 years and reported BSI risk factors. Two reviewers independently screened studies, extracted data, and assessed the risk of bias. Using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE), certainty of body of evidence was assessed.

FINDINGS

Fourteen studies involving 4602 persons were included. The incidences of BSI and associated mortality in paediatric HSCT recipients were approximately 10-50% and 5-15%, respectively. Meta-analysis of all studies revealed that previous BSI before HSCT (relative effect (RE): 2.28; 95% confidence interval (CI) 1.19-4.34, moderate certainty) and receiving an umbilical cord blood transplant (RE: 1.55; 95% CI: 1.22-1.97, moderate certainty) were probably associated with an increased risk of BSI. Meta-analysis of studies with low risk of bias reassured that previous BSI before HSCT probably increased the risk of BSI (RE: 2.28; 95% CI: 1.19-4.34, moderate certainty), and revealed that steroid use (RE: 2.72; 95% CI: 1.31-5.64, moderate certainty) was likely a risk factor whereas autologous HSCT was probably a protective factor of BSI (RE: 0.65; 95% CI: 0.45-0.94, moderate certainty).

CONCLUSION

These findings could inform the management of paediatric HSCT recipients, helping identify who may benefit from prophylactic antibiotics.

Developmental changes in cerebral NAD and neuroenergetics of an antioxidant compromised mouse model of schizophrenia

Defects in essential metabolic regulation for energy supply, increased oxidative stress promoting excitatory/inhibitory imbalance and phospholipid membrane dysfunction have been implicated in the pathophysiology of schizophrenia (SZ). The knowledge about the developmental trajectory of these key pathophysiological components and their interplay is important to develop new preventive and treatment strategies. However, this assertion is so far limited. To investigate the developmental regulations of these key components in the brain, we assessed, for the first time, in vivo redox state from the oxidized (NAD+) and reduced (NADH) form of Nicotinamide Adenine Dinucleotide (NAD), energy and membrane metabolites, inhibitory and excitatory neurotransmitters by 31P and 1H MRS during the neurodevelopment of an SZ animal model with genetically compromised glutathione synthesis (gclm-KO mice). When compared to age-matched wild type (WT), an increase in NAD+/NADH redox ratio was found in gclm-KO mice until early adulthood, followed by a decrease in full adults as observed in patients. Especially, in early postnatal life (P20, corresponding to childhood), levels of several metabolites were altered in gclm-KO mice, including NAD+, NAD+/NADH, ATP, and glutamine + glutamate, suggesting an interactive compensation for redox dysregulation between NAD, energy metabolism, and neurotransmission. The identified temporal neurometabolic regulations under deficits in redox regulation provide insights into preventive treatment targets for at-risk individuals, and other neurodevelopmental disorders involving oxidative stress and energetic dysfunction.

High field brain proton magnetic resonance spectroscopy and volumetry in children with chronic, compensated liver disease - A pilot study

BACKGROUND

and rationale: There is increasing evidence that children or young adults having acquired liver disease in childhood display neurocognitive impairment which may become more apparent as they grow older. The molecular, cellular and morphological underpinnings of this clinical problem are incompletely understood.

AIM

Therefore, we used the advantages of highly-resolved proton magnetic resonance spectroscopy at ultra-high magnetic field to analyze the neurometabolic profile and brain morphometry of children with chronic, compensated liver disease, hypothesizing that with high field spectroscopy we would identify early evidence of rising brain glutamine and decreased myoinositol, such as has been described both in animals and humans with more significant liver disease.

METHODS

Patients (n = 5) and age-matched controls (n = 19) underwent 7T MR scans and short echo time ¹H MR spectra were acquired using the semi-adiabatic SPECIAL sequence in two voxels located in gray and white matter dominated prefrontal cortex, respectively. A 3D MP2RAGE sequence was also acquired for brain volumetry and T₁ mapping. Liver disease had to have developed at least 6 months before entering the study. Subjects underwent routine blood analysis and neurocognitive testing using validated methods within 3 months of MRI and MRS.

RESULTS

Five children currently aged 8-16 years with liver disease acquired in childhood were included. Baseline biological characteristics were similar among patients. There were no statistically significant differences between subjects and controls in brain metabolite levels or brain volumetry. Finally, there were minor neurocognitive fluctuations including attention deficit in one child, but none fell in the statistically significant range.

CONCLUSION

Children with chronic, compensated liver disease did not display an abnormal neurometabolic profile, neurocognitive abnormalities, or signal intensity changes in the globus pallidus. Despite the absence of neurometabolic changes, it is an opportunity to emphasize that it is only by developing the use of ¹H MRS at high field in the clinical arena that we will understand the significance and generalizability of these findings in children with CLD. Attention deficit was observed in one child. Healthy children displayed neurometabolic regional differences as previously reported in adult subjects.

Dipolectric antenna for high-field MRI

PURPOSE

To introduce the dipolectric antenna: a novel RF coil design for high-field MRI using a combination of a dipole antenna with a loop-coupled dielectric resonator antenna.

METHODS

Simulations in human voxel model Duke involving 8-, 16-, and 38-channel dipolectric antenna arrays for brain MRI were conducted. An 8-channel dipolectric antenna for occipital lobe MRI at 7 T was designed and constructed. The array was built of four dielectric resonator antennas (dielectric constant = 1070) and four segmented dipole antennas. In vivo MRI experiments were conducted in one subject, and the SNR performance was benchmarked against a commercial 32-channel head coil.

RESULTS

A 38-channel dipolectric antenna array provided the highest whole-brain SNR (up to a 2.3-fold SNR gain in the center of the Duke's head vs. an 8-channel dipolectric antenna array). Dipolectric antenna arrays driven in dipole-only mode (with dielectric resonators used as receive-only) yielded the highest transmit performance. The constructed 8-channel dipolectric antenna array provided up to threefold higher in vivo peripheral SNR when compared with a 32-channel commercial head coil.

CONCLUSION

Dipolectric antenna can be considered a promising approach to enhance SNR in human brain MRI at 7 T. This strategy can be used to develop novel multi-channel arrays for different high-field MRI applications.

Comparative effectiveness and safety of antibiotic prophylaxis during induction chemotherapy in children with acute leukaemia: a systematic review and meta-analysis

BACKGROUND

Bacterial infections are common during induction therapy in children and adolescents with acute leukaemia and may cause infection-related mortality.

AIM

To determine the efficacy and safety of prophylactic antibiotics in paediatric patients with acute leukaemia receiving induction chemotherapy.

METHODS

From three English databases and four Chinese databases, we searched for randomized controlled trials (RCTs) and cohort studies that compared prophylactic antibiotics to placebo, no prophylaxis, or that compared one antibiotic versus another in paediatric patients with acute leukaemia undergoing induction chemotherapy. Two reviewers independently screened the studies, extracted data, and assessed the risk of bias using Cochrane Risk of Bias 2 tool and Newcastle-Ottawa Scale, and the certainty of evidence using Grading of Recommendations Assessment, Development, and Evaluation (GRADE).

FINDINGS

Two RCTs and ten cohort studies were finally included. For children with acute lymphoblastic leukaemia, antibiotic prophylaxis, including levofloxacin, sulfamethoxazole-trimethoprim, or other antibiotics, probably reduced bacteraemia (risk ratio (RR): 0.44; 95% confidence interval (CI): 0.33-0.60; moderate certainty) without significantly increasing Clostridioides difficile infection (CDI) or invasive fungal infection. Levofloxacin reduced the CDI rate (RR: 0.08; 95% CI: 0.01-0.62; high certainty). Ciprofloxacin prophylaxis probably reduced infection-related mortality (RR: 0.12; 95% CI: 0.01-0.97; moderate certainty). In children with acute myeloid leukaemia, ciprofloxacin plus vancomycin may reduce febrile neutropenia (RR: 0.79; 95% CI: 0.66-0.94; low certainty). Individual studies indicated that prophylaxis increased antibiotic exposure but reduced non-preventive antibiotic exposure.

CONCLUSION

In children with acute leukaemia undergoing induction therapy, antibiotic prophylaxis may improve the bacterial infection and mortality.

Variability and magnitude of brain glutamate levels in schizophrenia: a meta and mega-analysis

Glutamatergic dysfunction is implicated in schizophrenia pathoaetiology, but this may vary in extent between patients. It is unclear whether inter-individual variability in glutamate is greater in schizophrenia than the general population. We conducted meta-analyses to assess (1) variability of glutamate measures in patients relative to controls (log coefficient of variation ratio: CVR); (2) standardised mean differences (SMD) using Hedges g; (3) modal distribution of individual-level glutamate data (Hartigan's unimodality dip test). MEDLINE and EMBASE databases were searched from inception to September 2022 for proton magnetic resonance spectroscopy (1H-MRS) studies reporting glutamate, glutamine or Glx in schizophrenia. 123 studies reporting on 8256 patients and 7532 controls were included. Compared with controls, patients demonstrated greater variability in glutamatergic metabolites in the medial frontal cortex (MFC, glutamate: CVR = 0.15, p < 0.001; glutamine: CVR = 0.15, p = 0.003; Glx: CVR = 0.11, p = 0.002), dorsolateral prefrontal cortex (glutamine: CVR = 0.14, p = 0.05; Glx: CVR = 0.25, p < 0.001) and thalamus (glutamate: CVR = 0.16, p = 0.008; Glx: CVR = 0.19, p = 0.008). Studies in younger, more symptomatic patients were associated with greater variability in the basal ganglia (BG glutamate with age: z = -0.03, p = 0.003, symptoms: z = 0.007, p = 0.02) and temporal lobe (glutamate with age: z = -0.03, p = 0.02), while studies with older, more symptomatic patients associated with greater variability in MFC (glutamate with age: z = 0.01, p = 0.02, glutamine with symptoms: z = 0.01, p = 0.02). For individual patient data, most studies showed a unimodal distribution of glutamatergic metabolites. Meta-analysis of mean differences found lower MFC glutamate (g = -0.15, p = 0.03), higher thalamic glutamine (g = 0.53, p < 0.001) and higher BG Glx in patients relative to controls (g = 0.28, p < 0.001). Proportion of males was negatively associated with MFC glutamate (z = -0.02, p < 0.001) and frontal white matter Glx (z = -0.03, p = 0.02) in patients relative to controls. Patient PANSS total score was positively associated with glutamate SMD in BG (z = 0.01, p = 0.01) and temporal lobe (z = 0.05, p = 0.008). Further research into the mechanisms underlying greater glutamatergic metabolite variability in schizophrenia and their clinical consequences may inform the identification of patient subgroups for future treatment strategies.

Apparent diffusion coefficients of 31P metabolites in the human calf muscle at 7 T

PURPOSE

In this study, we aimed to measure the apparent diffusion coefficients (ADCs) of major phosphorous metabolites in the human calf muscle at 7 T with a diffusion-weighted (DW)-STEAM sequence.

METHODS

A DW-STEAM sequence with bipolar gradients was implemented at 7 T, and DW MR spectra were acquired in three orthogonal directions in the human calf muscle of six healthy volunteers (TE/TM/TR = 15 ms/750 ms/5 s) at three b-values (0, 800, and 1200 s/mm²). Frequency and phase alignments were applied prior to spectral averaging. Averaged DW MR spectra were analyzed with LCModel, and ADCs of ³¹P metabolites were estimated.

RESULTS

Four metabolites (phosphocreatine (PCr), adenosine triphosphate (ATP), inorganic phosphate (Pi) and glycerol phosphorylcholine (GPC)) were quantified at all b-values with mean CRLBs below 10%. The ADC values of PCr, ATP, Pi, and GPC were (0.24 ± 0.02, 0.15 ± 0.04, 0.43 ± 0.14, 0.40 ± 0.09) × 10^-3 mm²/s, respectively.

CONCLUSION

The ADCs of four ³¹P metabolites were successfully measured in the human calf muscle at 7 T, among which those of ATP, Pi and GPC were reported for the first time in humans. This study paves the way to investigate ³¹P metabolite diffusion properties in health and disease on the clinical MR scanner.

Redox and Immune Signaling in Schizophrenia: New Therapeutic Potential

Redox biology and immune signaling play major roles in the body, including in brain function. A rapidly growing literature also suggests that redox and immune abnormalities are implicated in neuropsychiatric conditions such as schizophrenia, bipolar disorder, autism, and epilepsy. In this article we review this literature, its implications for the pathophysiology of schizophrenia, and the potential for development of novel treatment interventions targeting redox and immune signaling. Redox biology and immune signaling in the brain are complex and not fully understood; in addition, there are discrepancies in the literature, especially in patient-oriented studies. Nevertheless, it is clear that abnormalities arise in schizophrenia from an interaction between genetic and environmental factors during sensitive periods of brain development and these abnormalities disrupt local circuits and long-range connectivity. Interventions that correct these abnormalities may be effective in normalizing brain function in psychotic disorders, especially in early phases of illness.

In vivo magnetic resonance <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:msup><mml:mrow/> <mml:mrow><mml:mn>31</mml:mn></mml:mrow> </mml:msup> </mml:mrow> </mml:math> P-Spectral Analysis With Neural Networks: 31P-SPAWNN

PURPOSE

We have introduced an artificial intelligence framework, 31P-SPAWNN, in order to fully analyze phosphorus-31 ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics> <mml:mrow><mml:msup><mml:mrow/> <mml:mrow><mml:mn>31</mml:mn></mml:mrow> </mml:msup> </mml:mrow> <mml:annotation>$$ {}^{31} $$</mml:annotation></mml:semantics> </mml:math> P) magnetic resonance spectra. The flexibility and speed of the technique rival traditional least-square fitting methods, with the performance of the two approaches, are compared in this work.

THEORY AND METHODS

Convolutional neural network architectures have been proposed for the analysis and quantification of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics> <mml:mrow><mml:msup><mml:mrow/> <mml:mrow><mml:mn>31</mml:mn></mml:mrow> </mml:msup> </mml:mrow> <mml:annotation>$$ {}^{31} $$</mml:annotation></mml:semantics> </mml:math> P-spectroscopy. The generation of training and test data using a fully parameterized model is presented herein. In vivo unlocalized free induction decay and three-dimensional <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics> <mml:mrow><mml:msup><mml:mrow/> <mml:mrow><mml:mn>31</mml:mn></mml:mrow> </mml:msup> </mml:mrow> <mml:annotation>$$ {}^{31} $$</mml:annotation></mml:semantics> </mml:math> P-magnetic resonance spectroscopy imaging data were acquired from healthy volunteers before being quantified using either 31P-SPAWNN or traditional least-square fitting techniques.

RESULTS

The presented experiment has demonstrated both the reliability and accuracy of 31P-SPAWNN for estimating metabolite concentrations and spectral parameters. Simulated test data showed improved quantification using 31P-SPAWNN compared with LCModel. In vivo data analysis revealed higher accuracy at low signal-to-noise ratio using 31P-SPAWNN, yet with equivalent precision. Processing time using 31P-SPAWNN can be further shortened up to two orders of magnitude.

CONCLUSION

The accuracy, reliability, and computational speed of the method open new perspectives for integrating these applications in a clinical setting.

Glutathione in the nucleus accumbens regulates motivation to exert reward-incentivized effort

Emerging evidence is implicating mitochondrial function and metabolism in the nucleus accumbens in motivated performance. However, the brain is vulnerable to excessive oxidative insults resulting from neurometabolic processes, and whether antioxidant levels in the nucleus accumbens contribute to motivated performance is not known. Here, we identify a critical role for glutathione (GSH), the most important endogenous antioxidant in the brain, in motivation. Using proton magnetic resonance spectroscopy at ultra-high field in both male humans and rodent populations, we establish that higher accumbal GSH levels are highly predictive of better, and particularly, steady performance over time in effort-related tasks. Causality was established in in vivo experiments in rats that, first, showed that downregulating GSH levels through micro-injections of the GSH synthesis inhibitor buthionine sulfoximine in the nucleus accumbens impaired effort-based reward-incentivized performance. In addition, systemic treatment with the GSH precursor N-acetyl-cysteine increased accumbal GSH levels in rats and led to improved performance, potentially mediated by a cell-type-specific shift in glutamatergic inputs to accumbal medium spiny neurons. Our data indicate a close association between accumbal GSH levels and an individual’s capacity to exert reward-incentivized effort over time. They also suggest that improvement of accumbal antioxidant function may be a feasible approach to boost motivation.

γ-aminobutyric acid measurement in the human brain at 7 T: Short echo-time or Mescher-Garwood editing

The purposes of the current study were to introduce a Mescher-Garwood (MEGA) semi-adiabatic spin-echo full-intensity localization (MEGA-sSPECIAL) sequence with macromolecule (MM) subtraction and to compare the test-retest reproducibility of γ-aminobutyric acid (GABA) measurements at 7 T using the sSPECIAL and MEGA-sSPECIAL sequences. The MEGA-sSPECIAL editing scheme using asymmetric adiabatic and highly selective Gaussian pulses was used to compare its GABA measurement reproducibility with that of short echo-time (TE) sSPECIAL. Proton magnetic resonance spectra were acquired in the motor cortex (M1) and medial prefrontal cortex (mPFC) using the sSPECIAL (TR/TE = 4000/16 ms) and MEGA-sSPECIAL sequences (TR/TE = 4000/80 ms). The metabolites were quantified using LCModel with unsuppressed water spectra. The concentrations are reported in institutional units. The test-retest reproducibility was evaluated by scanning each subject twice. Between-session reproducibility was assessed using coefficients of variation (CVs), Pearson's r correlation coefficients, and intraclass correlation coefficients (ICCs). Intersequence agreement was evaluated using Pearson's r correlation coefficients and Bland-Altman plots. Regarding GABA measurements by sSPECIAL, the GABA concentrations were 0.92 ± 0.31 (IU) in the M1 and 1.56 ± 0.49 (IU) in the mPFC. This demonstrated strong between-session correlation across both regions (r = 0.81, p < 0.01; ICC = 0.82). The CVs between the two scans were 21.8% in the M1 and 10.2% in the mPFC. On the other hand, the GABA measurements by MEGA-sSPECIAL were 0.52 ± 0.04 (IU) in the M1 and 1.04 ± 0.24 (IU) in the mPFC. MEGA-sSPECIAL demonstrated strong between-session correlation across the two regions (r = 0.98, p < 0.001; ICC = 0.98) and lower CVs than sSPECIAL, providing 4.1% in the M1 and 5.8% in the mPFC. The MEGA-editing method showed better reproducibility of GABA measurements in both brain regions compared with the short-TE sSPECIAL method. Thus it is a more sensitive method with which to detect small changes in areas with low GABA concentrations. In GABA-rich brain regions, GABA measurements can be achieved reproducibly using both methods.

Dual-energy CT perfusion imaging for differentiating invasive thymomas, thymic carcinomas, and lymphomas in adults

AIM

To evaluate the role of dual-energy computed tomography perfusion (DECTP) imaging in differentiating invasive thymomas (ITs), thymic cancers (TCs), and lymphomas in adults.

MATERIALS AND METHODS

Ninety-five patients with solid masses in the prevascular mediastinum who underwent DECTP examinations were enrolled in this study. The perfusion parameters (blood flow, BF; blood volume, BV; mean transit time, MTT; permeability surface, PS) and spectral parameters (water concentration, WC; iodine concentration, IC; normalised iodine concentration, NIC; the slope of spectral radiodensity [Hounsfield units] curve, λ_HU) of the lesions were analysed.

RESULTS

There were no differences in the MTT or WC values among ITs, TCs, and lymphomas (all p>0.05). The IC, NIC, and λ_HU values in the optimal arterial and venous phases and PS values of TCs were higher than those of ITs and lymphomas (all p<0.05), and there were no differences between ITs and lymphomas (all p>0.05). The BF and BV values of lymphomas were lower than those of ITs and TCs (all p<0.05), and there were no differences between ITs and TCs (all p>0.05). The cut-off values for BF and BV used to differentiate lymphomas from ITs and TCs were 42.83 ml/min/100 g and 4.66 ml/100 g, respectively (area under the receiver operating characteristic curve: 0.847 and 0.839; sensitivity, 80.6% and 82.1%; specificity, 75% and 71.4%; accuracy, 78.9% and 81.1%).

CONCLUSIONS

The perfusion and spectral parameters of DECTP imaging help to identify ITs, TCs, and lymphomas, and BF and BV values help to differentiate lymphomas from ITs and TCs.

Bridging structural MRI with cognitive function for individual level classification of early psychosis via deep learning

INTRODUCTION

Recent efforts have been made to apply machine learning and deep learning approaches to the automated classification of schizophrenia using structural magnetic resonance imaging (sMRI) at the individual level. However, these approaches are less accurate on early psychosis (EP) since there are mild structural brain changes at early stage. As cognitive impairments is one main feature in psychosis, in this study we apply a multi-task deep learning framework using sMRI with inclusion of cognitive assessment to facilitate the classification of patients with EP from healthy individuals.

METHOD

Unlike previous studies, we used sMRI as the direct input to perform EP classifications and cognitive estimations. The proposed deep learning model does not require time-consuming volumetric or surface based analysis and can provide additionally cognition predictions. Experiments were conducted on an in-house data set with 77 subjects and a public ABCD HCP-EP data set with 164 subjects.

RESULTS

We achieved 74.9 ± 4.3% five-fold cross-validated accuracy and an area under the curve of 71.1 ± 4.1% on EP classification with the inclusion of cognitive estimations.

DISCUSSION

We reveal the feasibility of automated cognitive estimation using sMRI by deep learning models, and also demonstrate the implicit adoption of cognitive measures as additional information to facilitate EP classifications from healthy controls.

Morphological classification and clinical significance of medial malleolus based on computed tomography three-dimensional reconstruction

BACKGROUND

Internal malleolus fractures and postoperative functional limitations are serious complications of deltoid ligament repair, reconstruction, while studies on conducting beak. Anatomical structure classification of medial malleolus at home and abroad is reported rarely. Hence, this morphological study is mainly designed to investigate the anatomical morphological classification and clinical significance of medial malleolus based on computed tomography (CT) three-dimensional reconstruction.

MATERIALS AND METHODS

From October 2018 to January 2021, 373 patients who underwent CT examination of malleolus medialis joint in the Jiang'an Hospital of Traditional Chinese Medicine were observed. The medial malleolus was observed and classified; then, geometric parameters were measured according to different medial malleolus types.

RESULTS

According to the results of 373 cases, medial malleolus can be divided into four types: omega type (66%), radical sign type (16%), inverted triangle type (14%), and wave type (4%).

CONCLUSIONS

There are four main shapes: omega, inverted triangle, radical sign, and wave in the medial malleolus of all normal ankles. The measurement of medial malleolus parameters according to medial malleolus in different shapes was of importance to guide smooth operation of medial malleolus fixation and deltoid ligament reconstruction and epidemiological.

[Expression characteristics and functional analysis of ELK3 in gastric cancer]

OBJECTIVE

To explore the expression characteristics of ELK3 and its role in the occurrence, progression and prognosis of gastric cancer.

METHODS

We analyzed the expression characteristics of ELK3 in gastric cancer based on E-MTAB-6693 dataset and explored the prognostic value of ELK3 using Kaplan-Meier survival analysis and univariate and multivariate Cox regression analysis. Chip-Atlas, ChipBase, Genes Transcription Regulation Database, and hTFtarget were used for predicting the target genes of ELK3 and constructing the transcription regulation network. Functional enrichment analysis of the target genes was performed using R software. The proportions of infiltrating immune cells in gastric cancer were analyzed using Cibersort tool, and the Pearson coefficients between ELK3 and these cells were calculated. The expression profile of ELK3 was verified based on Gene Expression Profiling Interactive Analysis and Human Protein Atlas databases. We also collected 5 pairs of gastric cancer and adjacent tissue samples and detected the expression of ELK3 at both the mRNA and protein levels using RT-PCR and Western blotting.

RESULTS

In public datasets and clinical samples, ELK3 was highly expressed in gastric cancer (P < 0.05), and its expression increased with the progression of M stage, AJCC stage, and perineural invasion (P < 0.05). ELK3 expression was correlated with N stage, AJCC stage, Lauren classification, differentiation, pathological classification, and microsatellite status of gastric cancer (P < 0.05). A high expression of ELK3 was associated with significantly reduced overall survival and disease-free survival of the patients, and served as an independent prognostic factor of gastric cancer (P < 0.05). Comprehensive analysis identified 176 potential target genes of ELK3, and enrichment analysis showed that ELK3 may regulate Rap1, AMPK, chemokines, VEGF, TNF, and tumor PD-L1/PD-1 signaling (PP < 0.05). The expression of ELK3 was negatively correlated with regulatory T cells, follicular helper T cells, and CD8+T cells in gastric cancer (P < 0.05).

CONCLUSION

ELK3 acts as an oncogene in gastric cancer, and its high expression may promote the occurrence, progression and immune escape of gastric cancer.

Metabolic and transcriptomic profiles of glioblastoma invasion revealed by comparisons between patients and corresponding orthotopic xenografts in mice

The invasive behavior of glioblastoma, the most aggressive primary brain tumor, is considered highly relevant for tumor recurrence. However, the invasion zone is difficult to visualize by Magnetic Resonance Imaging (MRI) and is protected by the blood brain barrier, posing a particular challenge for treatment. We report biological features of invasive growth accompanying tumor progression and invasion based on associated metabolic and transcriptomic changes observed in patient derived orthotopic xenografts (PDOX) in the mouse and the corresponding patients’ tumors. The evolution of metabolic changes, followed in vivo longitudinally by ¹H Magnetic Resonance Spectroscopy (¹H MRS) at ultra-high field, reflected growth and the invasive properties of the human glioblastoma transplanted into the brains of mice (PDOX). Comparison of MRS derived metabolite signatures, reflecting temporal changes of tumor development and invasion in PDOX, revealed high similarity to spatial metabolite signatures of combined multi-voxel MRS analyses sampled across different areas of the patients’ tumors. Pathway analyses of the transcriptome associated with the metabolite profiles of the PDOX, identified molecular signatures of invasion, comprising extracellular matrix degradation and reorganization, growth factor binding, and vascular remodeling. Specific analysis of expression signatures from the invaded mouse brain, revealed extent of invasion dependent induction of immune response, recapitulating respective signatures observed in glioblastoma. Integrating metabolic profiles and gene expression of highly invasive PDOX provided insights into progression and invasion associated mechanisms of extracellular matrix remodeling that is essential for cell–cell communication and regulation of cellular processes. Structural changes and biochemical properties of the extracellular matrix are of importance for the biological behavior of tumors and may be druggable. Ultra-high field MRS reveals to be suitable for in vivo monitoring of progression in the non-enhancing infiltration zone of glioblastoma.

In vivo macromolecule signals in rat brain 1 H-MR spectra at 9.4T: Parametrization, spline baseline estimation, and T2 relaxation times

PURPOSE

Reliable detection and fitting of macromolecules (MM) are crucial for accurate quantification of brain short-echo time (TE) ¹ H-MR spectra. An experimentally acquired single MM spectrum is commonly used. Higher spectral resolution at ultra-high field (UHF) led to increased interest in using a parametrized MM spectrum together with flexible spline baselines to address unpredicted spectroscopic components. Herein, we aimed to: (1) implement an advanced methodological approach for post-processing, fitting, and parametrization of 9.4T rat brain MM spectra; (2) assess the concomitant impact of the LCModel baseline and MM model (ie, single vs parametrized); and (3) estimate the apparent T₂ relaxation times for seven MM components.

METHODS

A single inversion recovery sequence combined with advanced AMARES prior knowledge was used to eliminate the metabolite residuals, fit, and parametrize 10 MM components directly from 9.4T rat brain in vivo ¹ H-MR spectra at different TEs. Monte Carlo simulations were also used to assess the concomitant influence of parametrized MM and DKNTMN parameter in LCModel.

RESULTS

A very stiff baseline (DKNTMN ≥ 1 ppm) in combination with a single MM spectrum led to deviations in metabolite concentrations. For some metabolites the parametrized MM showed deviations from the ground truth for all DKNTMN values. Adding prior knowledge on parametrized MM improved MM and metabolite quantification. The apparent T₂ ranged between 12 and 24 ms for seven MM peaks.

CONCLUSION

Moderate flexibility in the spline baseline was required for reliable quantification of real/experimental spectra based on in vivo and Monte Carlo data. Prior knowledge on parametrized MM improved MM and metabolite quantification.

OTME-13. Integration of metabolic and transcriptional signatures of glioblastoma invasion reveals extracellular matrix reorganization and vasculature remodeling

Background

The invasive behavior of glioblastoma is considered highly relevant for recurrence. However, the invasion zone is difficult to visualize, typically lies outside the resected and irradiated area, and is protected by the blood brain barrier, posing a particular challenge for treatment. We present biological features of invasive growth accompanying tumor progression and invasion based on associated metabolic and transcriptomic changes in patient derived orthotopic xenografts (PDOX) and corresponding patients.

Methods

Patients with suspected glioblastoma were enrolled (NCT02904525) and underwent ¹H-MR spectroscopy and imaging (¹H-MRS/I, 7T). Tissue obtained at surgery was transplanted orthotopically into immune-compromised mice. Longitudinal follow-up was performed by ¹H-MRS/I (14.1T) on the injected and the contralateral side. The PDOX, the corresponding contralateral side, and the original human tumors underwent RNA-sequencing.

Results

The temporal changes of the metabolite profiles characterized the kinetics of invasive growth of PDOX, and were patient specific. Comparison of ¹H-MRS derived metabolite signatures, reflecting temporal changes of tumor development and invasion in PDOX, revealed high similarity to spatial metabolite signatures of combined multi-voxel analyses of the patients’ tumors. Associations between the metabolite profiles and the combined transcriptome of the xenografts and the host, reflected molecular signatures of invasion, comprising extracellular matrix degradation and reorganization, growth factor binding, and vascular remodeling.

Conclusion

Integrating metabolic profiles and gene expression of highly invasive PDOX allows in vivo monitoring of progression in the non-enhancing tumor infiltration zone and provides insights into the remodeling of the extracellular matrix that is essential for cell-cell communication and regulation of cellular processes. The changes of the structural and biochemical properties of the extracellular matrix are of importance for the biological behavior of the tumors and may be subjected to therapeutic targeting.

Timely N-Acetyl-Cysteine and Environmental Enrichment Rescue Oxidative Stress-Induced Parvalbumin Interneuron Impairments via MMP9/RAGE Pathway: A Translational Approach for Early Intervention in Psychosis

Research in schizophrenia (SZ) emphasizes the need for new therapeutic approaches based on antioxidant/anti-inflammatory compounds and psycho-social therapy. A hallmark of SZ is a dysfunction of parvalbumin-expressing fast-spiking interneurons (PVI), which are essential for neuronal synchrony during sensory/cognitive processing. Oxidative stress and inflammation during early brain development, as observed in SZ, affect PVI maturation. We compared the efficacy of N-acetyl-cysteine (NAC) and/or environmental enrichment (EE) provided during juvenile and/or adolescent periods in rescuing PVI impairments induced by an additional oxidative insult during childhood in a transgenic mouse model with gluthation deficit (Gclm KO), relevant for SZ. We tested whether this rescue was promoted by the inhibition of MMP9/RAGE mechanism, both in the mouse model and in early psychosis (EP) patients, enrolled in a double-blind, randomized, placebo-controlled clinical trial of NAC supplementation for 6 months. We show that a sequential combination of NAC+EE applied after an early-life oxidative insult recovers integrity and function of PVI network in adult Gclm KO, via the inhibition of MMP9/RAGE. Six-month NAC treatment in EP patients reduces plasma sRAGE in association with increased prefrontal GABA, improvement of cognition and clinical symptoms, suggesting similar neuroprotective mechanisms. The sequential combination of NAC+EE reverses long-lasting effects of an early oxidative insult on PVI/perineuronal net (PNN) through the inhibition of MMP9/RAGE mechanism. In analogy, patients vulnerable to early-life insults could benefit from a combined pharmacological and psycho-social therapy.

Association of Age, Antipsychotic Medication, and Symptom Severity in Schizophrenia With Proton Magnetic Resonance Spectroscopy Brain Glutamate Level: A Mega-analysis of Individual Participant-Level Data

Importance

Proton magnetic resonance spectroscopy (1H-MRS) studies indicate that altered brain glutamatergic function may be associated with the pathophysiology of schizophrenia and the response to antipsychotic treatment. However, the association of altered glutamatergic function with clinical and demographic factors is unclear.

Objective

To assess the associations of age, symptom severity, level of functioning, and antipsychotic treatment with brain glutamatergic metabolites.

Data Sources

The MEDLINE database was searched to identify journal articles published between January 1, 1980, and June 3, 2020, using the following search terms: MRS or magnetic resonance spectroscopy and (1) schizophrenia or (2) psychosis or (3) UHR or (4) ARMS or (5) ultra-high risk or (6) clinical high risk or (7) genetic high risk or (8) prodrome* or (9) schizoaffective. Authors of 114 1H-MRS studies measuring glutamate (Glu) levels in patients with schizophrenia were contacted between January 2014 and June 2020 and asked to provide individual participant data.

Study Selection

In total, 45 1H-MRS studies contributed data.

Data Extraction and Synthesis

Associations of Glu, Glu plus glutamine (Glx), or total creatine plus phosphocreatine levels with age, antipsychotic medication dose, symptom severity, and functioning were assessed using linear mixed models, with study as a random factor.

Main Outcomes and Measures

Glu, Glx, and Cr values in the medial frontal cortex (MFC) and medial temporal lobe (MTL).

Results

In total, 42 studies were included, with data for 1251 patients with schizophrenia (mean [SD] age, 30.3 [10.4] years) and 1197 healthy volunteers (mean [SD] age, 27.5 [8.8] years). The MFC Glu (F1,1211.9 = 4.311, P = .04) and Glx (F1,1079.2 = 5.287, P = .02) levels were lower in patients than in healthy volunteers, and although creatine levels appeared lower in patients, the difference was not significant (F1,1395.9 = 3.622, P = .06). In both patients and volunteers, the MFC Glu level was negatively associated with age (Glu to Cr ratio, F1,1522.4 = 47.533, P < .001; cerebrospinal fluid-corrected Glu, F1,1216.7 = 5.610, P = .02), showing a 0.2-unit reduction per decade. In patients, antipsychotic dose (in chlorpromazine equivalents) was negatively associated with MFC Glu (estimate, 0.10 reduction per 100 mg; SE, 0.03) and MFC Glx (estimate, -0.11; SE, 0.04) levels. The MFC Glu to Cr ratio was positively associated with total symptom severity (estimate, 0.01 per 10 points; SE, 0.005) and positive symptom severity (estimate, 0.04; SE, 0.02) and was negatively associated with level of global functioning (estimate, 0.04; SE, 0.01). In the MTL, the Glx to Cr ratio was positively associated with total symptom severity (estimate, 0.06; SE, 0.03), negative symptoms (estimate, 0.2; SE, 0.07), and worse Clinical Global Impression score (estimate, 0.2 per point; SE, 0.06). The MFC creatine level increased with age (estimate, 0.2; SE, 0.05) but was not associated with either symptom severity or antipsychotic medication dose.

Conclusions and Relevance

Findings from this mega-analysis suggest that lower brain Glu levels in patients with schizophrenia may be associated with antipsychotic medication exposure rather than with greater age-related decline. Higher brain Glu levels may act as a biomarker of illness severity in schizophrenia.

Contribution of macromolecules to brain 1 H MR spectra: Experts' consensus recommendations

Proton MR spectra of the brain, especially those measured at short and intermediate echo times, contain signals from mobile macromolecules (MM). A description of the main MM is provided in this consensus paper. These broad peaks of MM underlie the narrower peaks of metabolites and often complicate their quantification but they also may have potential importance as biomarkers in specific diseases. Thus, separation of broad MM signals from low molecular weight metabolites enables accurate determination of metabolite concentrations and is of primary interest in many studies. Other studies attempt to understand the origin of the MM spectrum, to decompose it into individual spectral regions or peaks and to use the components of the MM spectrum as markers of various physiological or pathological conditions in biomedical research or clinical practice. The aim of this consensus paper is to provide an overview and some recommendations on how to handle the MM signals in different types of studies together with a list of open issues in the field, which are all summarized at the end of the paper.

Twenty-year changes in mortality rates and underlying causes of death in patients with rheumatoid arthritis-associated interstitial lung disease

Objectives: Despite recent advances in the treatment of rheumatoid arthritis (RA), few population-based studies have assessed the mortality rates and the underlying causes of death (UCDs) among patients with RA and RA-associated interstitial lung disease (RA-ILD). This study evaluated the trends in mortality rates, demographic characteristics, and UCDs among patients with RA-ILD.Method: Using data from death certificates (1999-2018) from the US Centers for Disease Control and Prevention Multiple Cause of Death files, we explored the trends in mortality rates and UCD for patients with RA and RA-ILD. Moreover, we examined the crude and age-standardized mortality rates (ASMRs) for such patients.Results: Among patients with RA or RA-ILD, ASMR variation decreased over 20 years. The ASMR ratio of RA-ILD to RA decreased by 5.84%. The ASMR for RA and RA-ILD stratified by gender or age group also decreased. The change in the ASMR ratio of RA-ILD to RA trended downwards in women and upwards in men. Arthropathies and ILD were the most frequent UCDs for RA-ILD, while arthropathies and ischaemic heart disease were the most frequent UCDs for RA.Conclusions: Although RA and RA-ILD presented a downward trend in mortality, RA combined with ILD may reduce life expectancy. Specifically, the mortality rate for patients with RA-ILD remained relatively stable during the study period when ILD was the UCD, suggesting the need for active prevention, early diagnosis, and effective management of RA-ILD.

Effect of lncRNA AK023948 on rats with postmenopausal osteoporosis via PI3K/AKT signaling pathway

OBJECTIVE

To investigate the effect of long non-coding ribonucleic acid (lncRNA) AK023948 (AK0) on rats with postmenopausal osteoporosis via the phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) signaling pathway.

MATERIALS AND METHODS

Firstly, postmenopausal osteoporosis rat models were established to obtain osteoblasts. The phosphorylation level of AKT was analyzed by controlling the expression of AK0 gene in osteoblasts. Finally, XTT was used to analyze the proliferation of osteoblasts and the messenger ribonucleic acid (mRNA) expression level of caspase in AK0 gene knockout (KO) rat model.

RESULTS

In the bone tissue of postmenopausal osteoporosis rats, the levels of phospho-PI3K (p-PI3K), p-Akt, and p-phosphoinositide-dependent kinase-1(PDK1) were significantly decreased (p<0.05). In rat model osteoblasts, the overexpression of AK0 gene upregulated the phosphorylation level of AKT, while the interference with small interfering RNA (siRNA) in AK0 gene decreased that of AKT. Knocking out AK0 gene led to the down-regulation of phosphorylation level of AKT in cells. Moreover, if the AK0 gene was re-expressed in the KO rat model cells, the phosphorylation level of AKT was restored to a certain extent, but still lower than that after the overexpression of AK0 gene. Although the proliferation rate of osteoblasts in estrogen deficiency-related osteoporosis rats was low, the growth rate of osteoblasts with AK0 KO was remarkably lower than that in blank control group (p<0.05). It was also found that there was a certain correlation between AK0 gene and osteoblast apoptosis.

CONCLUSIONS

LncRNA AK0 can regulate the phosphorylation level of AKT in osteoblasts of rats with estrogen deficiency-related osteoporosis through the PI3K/AKT signaling pathway, thus regulating the proliferation of osteoblasts. It is speculated that lncRNA AK0 may be an important factor in regulating the PI3K/AKT signaling pathway.

Effect of miR-133 on apoptosis of trophoblasts in human placenta tissues via Rho/ROCK signaling pathway

OBJECTIVE

The aim of this study was to explore the role of micro ribonucleic acid (miR)-133 in the apoptosis of human placental trophoblasts through the Ras homolog gene family (Rho)/Rho-associated coiled-coil forming protein kinase (ROCK) signaling pathway.

PATIENTS AND METHODS

The plasma samples were collected from 30 patients with pre-eclampsia (PE) undergoing treatment and 30 healthy subjects (control group) who received physical examination in our hospital. The Reverse Transcription-Polymerase Chain Reaction (RT-PCR) was utilized to measure the expression of miR-133 in PE patients and healthy people. Meanwhile, blood pressure, urine protein content, liver function, and kidney function were detected in patients of both groups as well. Subsequently, the placental trophoblasts were extracted and transfected with inhibitors and miRNA mimics to suppress and overexpress miR-133, respectively. The transfection efficiency was determined by RT-PCR. The levels of interleukin-6 (IL-6), IL-1, and tumor necrosis factor-alpha (TNF-α) were measured in both groups. The terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) assay was performed to determine the apoptosis of trophoblasts. Next, the RT-PCR and Western blotting were carried out to detect the expressions of the Rho/ROCK pathway. Furthermore, the influence of miR-133 on the apoptosis of trophoblasts in human placenta tissues through Rho/ROCK was comprehensively observed.

RESULTS

In vivo experiments demonstrated that the urinary protein content, miR-133 level, systolic blood pressure, diastolic blood pressure, and liver function and renal function indexes were significantly elevated in pre-eclampsia (PE) patients in comparison with normal subjects (p<0.05). After transfection of mimics and inhibitors, the expression of miR-133 was remarkably up- and down-regulated, respectively. The content of the inflammatory factors in miR-133 mimics group was overtly higher than the other two groups. The TUNEL staining results showed that the number of apoptotic cells significantly increased and decreased in the miR-133 mimics group and miR-133 inhibitors group, respectively. Subsequent experiments indicated that the expressions of apoptosis gene Caspase3, pathway gene, and protein ROCKI were notably up-regulated in miR-133 mimics group. However, they were evidently down-regulated in miR-133 inhibitors group than in the control group. In addition, a consistent trend was observed in the protein expression level.

CONCLUSIONS

MiR-133 participates in the development and progression of PE through the Rho/ROCK signaling pathway, which may affect the apoptosis of trophoblasts in the placenta tissues.

[The Breast Cancer Cohort Study in Chinese Women: research design and preliminary results of clinical multi-center cohort]

Objective: The incidence of breast cancer in Chinese women continues to rise. The large breast cancer cohort studies in China are relatively scarce. There are many bottlenecks in the construction of large clinical cohort for breast cancer diagnosis, treatment, and prognoses, such as inconsistent standards, high rates of lost follow-up, repeated construction, and inability to share. To better solving the difficulties and problems faced by large-scale clinical cohort research in China, this project will cooperate with several tertiary A hospitals to establish a breast cancer cohort in Chinese women. It also provides a data platform and technical support for breast cancer multi-center clinical cohort research. Methods: Based on the evidence-based medicine and expert opinion and consensus, we established a breast cancer cohort standardized indicator set-recording baseline information, diagnosis and treatment-related information of the enrolled patients, and collecting biological specimens. According to the technical specification of long-term follow-up for the endpoint, data management, and data security and in the large population-based cohort study, a standardized follow-up system for the diagnosis, treatment, and prognosis of breast cancer prospective cohorts is formed. Results: Based on standardized data sets and the computer discipline's advantage from the University of Science and Technology Beijing, we integrate the new information technology methods, including dynamic information collection terminals and social networks. Thus, the quality of control programs on compliance and intelligence data was improved, and a Chinese women breast cancer cohort database was developed. By February 2020, 12 147 patients were included in the clinical cohort database. Biological specimens'resources in cohort construction were collected and cooperated with Shandong University to research the multi-center quality control system and shared evaluation system of biobanks. Building an open and shared biobank network and forming a full chain of breast cancer research platform. Conclusion: With the implementation of the "13(th) Five-Year Plan" precision medicine research, this study provides a research foundation for precision diagnosis and treatment of breast cancer and provides data support for the country to formulate relevant medical policies.

Brain NAD Is Associated With ATP Energy Production and Membrane Phospholipid Turnover in Humans

The brain requires a large amount of energy, mostly derived from the metabolism of glucose, which decreases substantially with age and neurological diseases. While mounting evidence in model organisms illustrates the central role of brain nicotinamide adenine dinucleotide (NAD) for maintaining energy homeostasis, similar data are sparse in humans. This study explores the correlations between brain NAD, energy production and membrane phospholipid metabolism by 31-phosphorous magnetic resonance spectroscopy (³¹P-MRS) across 50 healthy participants including a young (mean age 27.1-year-old) and middle-aged (mean age 56.4-year-old) group. The analysis revealed that brain NAD level and NAD⁺/NADH redox ratio were positively associated with ATP level and the rate of energy production, respectively. Moreover, a metabolic network linking NAD with membrane phospholipid metabolism, energy production, and aging was identified. An inverted trend between age and NAD level was detected. These results pave the way for the use of ³¹P-MRS as a powerful non-invasive tool to support the development of new therapeutic interventions targeting NAD associated phospho-metabolic pathways in brain aging and neurological diseases.

Circ-ZNF609 promotes carcinogenesis of gastric cancer cells by inhibiting miRNA-145-5p expression

OBJECTIVE

To elucidate the expression pattern and biological function of circular RNA ZNF609 (circ-ZNF609) in gastric cancer (GC).

PATIENTS AND METHODS

Circ-ZNF609 expression in GC tissues and adjacent normal tissues (ANT) was determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The regulatory effect of circ-ZNF609 on growth and metastasis of GC cells was evaluated through the Cell Counting Kit-8 (CCK-8), colony formation and transwell invasion assay, respectively. GC cell apoptosis influenced by circ-ZNF609 was examined by flow cytometry. The binding between circ-ZNF609 and miRNA-145-5p was verified by the Dual-Luciferase reporter gene assay. Finally, a series of rescue experiments were conducted to explore the mechanism of the circ-ZNF609/miRNA-145-5p axis in regulating GC progression.

RESULTS

QRT-PCR data revealed a higher level of circ-ZNF609 in GC tissues relative to ANT. Identically, circ-ZNF609 was highly expressed in GC cell lines relative to controls. The knockdown of circ-ZNF609 in BGC823 and MGC803 cells suppressed proliferative and invasive abilities. MiRNA-145-5p was predicted to be the target gene of circ-ZNF609 by bioinformatics, and further verified by the Dual-Luciferase reporter gene assay. Rescue experiments showed that miRNA-145-5p knockdown partially reversed the regulatory effect of circ-ZNF609 on growth and metastasis of GC cells.

CONCLUSIONS

Circ-ZNF609 promotes proliferative and invasive abilities of gastric cancer cells by inhibiting miRNA-145-5p expression as a ceRNA, thus accelerating gastric cancer progression.

MMP9/RAGE pathway overactivation mediates redox dysregulation and neuroinflammation, leading to inhibitory/excitatory imbalance: a reverse translation study in schizophrenia patients

Various mechanisms involved in schizophrenia pathophysiology, such as dopamine dysregulation, glutamate/NMDA receptor dysfunction, neuroinflammation or redox imbalance, all appear to converge towards an oxidative stress "hub" affecting parvalbumine interneurones (PVI) and their perineuronal nets (PNN) (Lancet Psychiatry. 2015;2:258-70); (Nat Rev Neurosci. 2016;17:125-34). We aim to investigate underlying mechanisms linking oxidative stress with neuroinflammatory and their long-lasting harmful consequences. In a transgenic mouse of redox dysregulation carrying a permanent deficit of glutathione synthesis (gclm-/-), the anterior cingulate cortex presented early in the development increased oxidative stress which was prevented by the antioxidant N-acetylcysteine (Eur J Neurosci. 2000;12:3721-8). This oxidative stress induced microglia activation and redox-sensitive matrix metalloproteinase 9 (MMP9) stimulation, leading to the receptor for advanced glycation end-products (RAGE) shedding into soluble and nuclear forms, and subsequently to nuclear factor-kB (NF-kB) activation and secretion of various cytokines. Blocking MMP9 activation prevented this sequence of alterations and rescued the normal maturation of PVI/PNN, even if performed after an additional insult that exacerbated the long term PVI/PNN impairments. MMP9 inhibition thus appears to be able to interrupt the vicious circle that maintains the long-lasting deleterious effects of the reciprocal interaction between oxidative stress and neuroinflammation, impacting on PVI/PNN integrity. Translation of these experimental findings to first episode patients revealed an increase in plasma soluble RAGE relative to healthy controls. This increase was associated with low prefrontal GABA levels, potentially predicting a central inhibitory/excitatory imbalance linked to RAGE shedding. This study paves the way for mechanistically related biomarkers needed for early intervention and MMP9/RAGE pathway modulation may lead to promising drug targets.

Glutamine-to-glutamate ratio in the nucleus accumbens predicts effort-based motivated performance in humans

Substantial evidence implicates the nucleus accumbens in motivated performance, but very little is known about the neurochemical underpinnings of individual differences in motivation. Here, we applied ¹H magnetic resonance spectroscopy (¹H-MRS) at ultra-high-field in the nucleus accumbens and inquired whether levels of glutamate (Glu), glutamine (Gln), GABA or their ratios predict interindividual differences in effort-based motivated task performance. Given the incentive value of social competition, we also examined differences in performance under self-motivated or competition settings. Our results indicate that higher accumbal Gln-to-Glu ratio predicts better overall performance and reduced effort perception. As performance is the outcome of multiple cognitive, motor and physiological processes, we applied computational modeling to estimate best-fitting individual parameters related to specific processes modeled with utility, effort and performance functions. This model-based analysis revealed that accumbal Gln-to-Glu ratio specifically relates to stamina; i.e., the capacity to maintain performance over long periods. It also indicated that competition boosts performance from task onset, particularly for low Gln-to-Glu individuals. In conclusion, our findings provide novel insights implicating accumbal Gln and Glu balance on the prediction of specific computational components of motivated performance. This approach and findings can help developing therapeutic strategies based on targeting metabolism to ameliorate deficits in effort engagement.

Magnetic resonance spectroscopy in the rodent brain: Experts' consensus recommendations

In vivo MRS is a non-invasive measurement technique used not only in humans, but also in animal models using high-field magnets. MRS enables the measurement of metabolite concentrations as well as metabolic rates and their modifications in healthy animals and disease models. Such data open the way to a deeper understanding of the underlying biochemistry, related disturbances and mechanisms taking place during or prior to symptoms and tissue changes. In this work, we focus on the main preclinical 1H, 31P and 13C MRS approaches to study brain metabolism in rodent models, with the aim of providing general experts' consensus recommendations (animal models, anesthesia, data acquisition protocols). An overview of the main practical differences in preclinical compared with clinical MRS studies is presented, as well as the additional biochemical information that can be obtained in animal models in terms of metabolite concentrations and metabolic flux measurements. The properties of high-field preclinical MRS and the technical limitations are also described.

Cannabis use decreases prefrontal glutamate levels in early psychosis

Recent evidences have consistently reported lower glutamate (Glu) levels in various brain regions, including the medial prefrontal cortex (mPFC), in chronic schizophrenia but findings in the early (EP) or in the prodromal phase of the disorder are equivocal. Although regular cannabis use has been associated with an increased risk of subsequent psychosis and with a perturbed Glu signalling, to date, the critical question of whether or not Glu abnormalities exist in EP and are related to cannabis use remains unanswered. Magnetic resonance spectroscopy was used to measure [GlumPFC] of 35 EP subjects (18 of whom were regular cannabis users) and 33 healthy controls (HC). For correlative analysis, neuropsychological performances were scored by a comprehensive cognitive battery. [GlumPFC] was lower in EP users comparing to both HC and EP non-users (P = 0.001 and P = 0.01, respectively), while no differences were observed between HC and EP non-users. In EP users Glu declined with age (r = −0.46; P = 0.04) but this relationship was not observed in non-users. Among neuropsychological profiles, working memory was the only domain that differentiates patients depending on their cannabis use, with users having poorer performances. In summary, our research revealed that cannabis use in EP is associated with Glu decreased levels, which are normally not seen in the early phase of the disorder. This finding is in line with previous 1H-MRS studies in cannabis users without a psychotic disorder and sheds light for the role of cannabis use in the progression of the disease.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Metabolite concentration changes associated with positive and negative BOLD responses in the human visual cortex: A functional MRS study at 7 Tesla

Negative blood oxygenation-level dependent (BOLD) signal observed during task execution in functional magnetic resonance imaging (fMRI) can be caused by different mechanisms, such as a blood-stealing effect or neuronal deactivation. Electrophysiological recordings showed that neuronal deactivation underlies the negative BOLD observed in the occipital lobe during visual stimulation. In this study, the metabolic demand of such a response was studied by measuring local metabolite concentration changes during a visual checkerboard stimulation using functional magnetic resonance spectroscopy (fMRS) at 7 Tesla. The results showed increases of glutamate and lactate concentrations during the positive BOLD response, consistent with previous fMRS studies. In contrast, during the negative BOLD response, decreasing concentrations of glutamate, lactate and gamma-aminobutyric acid (GABA) were found, suggesting a reduction of glycolytic and oxidative metabolic demand below the baseline. Additionally, the respective changes of the BOLD signal, glutamate and lactate concentrations of both groups suggest that a local increase of inhibitory activity might occur during the negative BOLD response.

Advanced single voxel 1 H magnetic resonance spectroscopy techniques in humans: Experts' consensus recommendations

Conventional proton MRS has been successfully utilized to noninvasively assess tissue biochemistry in conditions that result in large changes in metabolite levels. For more challenging applications, namely, in conditions which result in subtle metabolite changes, the limitations of vendor-provided MRS protocols are increasingly recognized, especially when used at high fields (≥3 T) where chemical shift displacement errors, B0 and B1 inhomogeneities and limitations in the transmit B1 field become prominent. To overcome the limitations of conventional MRS protocols at 3 and 7 T, the use of advanced MRS methodology, including pulse sequences and adjustment procedures, is recommended. Specifically, the semiadiabatic LASER sequence is recommended when TE values of 25-30 ms are acceptable, and the semiadiabatic SPECIAL sequence is suggested as an alternative when shorter TE values are critical. The magnetic field B0 homogeneity should be optimized and RF pulses should be calibrated for each voxel. Unsuppressed water signal should be acquired for eddy current correction and preferably also for metabolite quantification. Metabolite and water data should be saved in single shots to facilitate phase and frequency alignment and to exclude motion-corrupted shots. Final averaged spectra should be evaluated for SNR, linewidth, water suppression efficiency and the presence of unwanted coherences. Spectra that do not fit predefined quality criteria should be excluded from further analysis. Commercially available tools to acquire all data in consistent anatomical locations are recommended for voxel prescriptions, in particular in longitudinal studies. To enable the larger MRS community to take advantage of these advanced methods, a list of resources for these advanced protocols on the major clinical platforms is provided. Finally, a set of recommendations are provided for vendors to enable development of advanced MRS on standard platforms, including implementation of advanced localization sequences, tools for quality assurance on the scanner, and tools for prospective volume tracking and dynamic linear shim corrections.

Improved off-resonance phase behavior using a phase-inverted adiabatic half-passage pulse for 13 C MRS in humans at 7 T

In vivo ¹³ C MRS at high field benefits from an improved SNR and spectral resolution especially when using surface coils in combination with adiabatic pulses, such as the adiabatic half-passage (AHP) pulse for ¹³ C excitation. However, the excitation profile of the AHP pulse is asymmetric relative to the carrier frequency, which could lead to asymmetric excitation of the spectral lines relative to the center of the spectrum. In this study, a pulse-acquire sequence was designed for adiabatic ¹³ C excitation with a symmetric bandwidth, utilizing a combination of two AHP pulses with inverted phases in alternate scans. Magnetization and phase behavior as a function of frequency offset and RF amplitude of the B₁ field, as well as the steady-state transverse magnetization response to off-resonance, were simulated. Excitation properties of the combined pulse sequence were studied by ²³ Na imaging and ¹³ C spectroscopy in vitro on a phantom and in vivo on the human calf at 7 T. Simulations demonstrated symmetric transverse magnetization and phase with respect to positive and negative frequency offsets when using two AHP pulses with inverted phases in alternate scans, thereby minimizing baseline distortion and achieving symmetric T₁ weighting, as confirmed by in vitro measurements. The intensities of the lipid peaks at 15, 30, 62, 73, and 130 ppm were in agreement with those theoretically predicted using two AHP pulses with inverted phases in alternate scans. We conclude that using two phase-inverted AHP pulses improves the symmetry of the ¹³ C excitation profile and phase response to off-resonance effects at 7 T in comparison with using a single AHP pulse.