Record High Iodate Anion Capture by a Redox-Active Cationic Polymer Network.

As a critical radioactive anionic contaminant, traditional adsorbents primarily remove iodate (IO3 -) through ion exchange or hard acid-hard base interactions, but suffer from limited affinity and capacity. Herein, employing the synergistic effect of ion exchange and redox, we successfully synthesized a redox-active cationic polymer network (SCU-CPN-6, [C9H10O2N5 ⋅ Cl]n) by merging guanidino groups with ion-exchange capability and phenolic groups with redox ability via a Schiff base reaction. SCU-CPN-6 exhibits a groundbreaking adsorption capacity of 896 mg/g for IO3 -. The inferior adsorption capacities of polymeric networks containing only redox (~0 mg/g) or ion exchange (232 mg/g) fragments underscore the synergistic "1+1>2" effect of the two mechanisms. Besides, SCU-CPN-6 shows excellent uptake selectivity for IO3 - in the presence of high concentrations of SO4 2-, Cl-, and NO3 -. Meanwhile, a high distribution coefficient indicates its exemplary deep-removal performance for low IO3 - concentration. The synergic strategy not only presents a breakthrough solution for the efficient removal of IO3 - but also establishes a promising avenue for the design of advanced adsorbents for diverse applications.

Efficacy of cell-free DNA methylation-based blood test for colorectal cancer screening in high-risk population: a prospective cohort study.

BACKGROUND: Although colonoscopy is the standard screening test for colorectal cancer (CRC), its use is limited by a poor compliance rate, the need for extensive bowel preparation, and the risk of complications. As an alternative, an FDA-approved stool-based DNA test, Cologuard, has demonstrated satisfactory detection performance for CRC, but its compliance rate remains suboptimal, primarily attributable to individuals' reluctance to provide stool samples. METHODS: We developed a noninvasive blood-based CRC test, ColonSecure, based on cell-free DNA containing cancer-specific CpG island methylation patterns. We initially screened publicly available datasets for differentially methylated CpG sites in CRC with prediction potential. Subsequently, we performed two sequential bisulfite-free methylation sequencing on blood samples obtained from CRC patients and non-cancer controls. Through rigorous evaluation of each marker and machine learning-assisted feature selection, we identified 149 hypermethylated markers from over 193,000 CpG sites. These markers were then utilized to construct the ColonSecure model, enabling accurate CRC detection. RESULTS: We validated the efficacy of our cell-free DNA methylation-based blood test for CRC screening with 3493 high-risk individuals identified from 114,136 urban residents. The ColonSecure test identified 89 out of 103 CRC patients diagnosed by the follow-up colonoscopy, outperforming CEA, CRP, and CA19-9 (with a sensitivity of 86.4% compared to 45.6%, 39.8%, and 25.2% for CEA, CRP, and CA19-9 respectively; an AUROC of 0.956 compared to an AUROC of < 0.77 for other methods). CONCLUSION: Our observations emphasize the potential of our multiple cfDNA methylation marker-based test for CRC screening in high-risk populations.

An Aryl-ether-linked Covalent Organic Framework Modified with Thioamide Groups for Selective Extraction of Palladium from Strong Acid Solutions.

Efficient adsorption of palladium ions from acid nuclear waste solution is crucial for ensuring the safety of vitrification process for radioactive waste. However, the limited stability and selectivity of most current adsorbents hinder their practical applications under strong acid and intense radiation conditions. Herein, to address these limitations, we designed and synthesized an aryl-ether-linked covalent organic framework (COF-316-DM) grafted dimethylthiocarbamoyl groups on the pore walls. This unique structure endows COF-316-DM with high stability and exceptional palladium capture capacity. The robust polyarylether linkage enables COF-316-DM to withstand irradiation doses of 200 or 400 kGy of ß/γ ray. Furthermore, COF-316-DM demonstrates fast adsorption kinetics, high adsorption capacity (147 mg g-1 ), and excellent reusability in 4 M nitric acid. Moreover, COF-316-DM exhibits remarkable selectivity for palladium ions in the presence of 17 interference ions, simulating high level liquid waste scenario. The superior adsorption performance can be attributed to the strong binding affinity between the thioamide groups and Pd2+ ions, as confirmed by the comprehensive analysis of FT-IR and XPS spectra. Our findings highlight the potential of COFs with robust linkers and tailored functional groups for efficient and selective capture of metal ions, even in harsh environmental conditions.

Interaction analysis of high-risk pathological features on adjuvant chemotherapy survival benefit in stage II colon cancer patients: a multi-center, retrospective study.

BACKGROUND: We aimed to analyze the benefit of adjuvant chemotherapy in high-risk stage II colon cancer patients and the impact of high-risk factors on the prognostic effect of adjuvant chemotherapy. METHODS: This study is a multi-center, retrospective study, A total of 931 patients with stage II colon cancer who underwent curative surgery in 8 tertiary hospitals in China between 2016 and 2017 were enrolled in the study. Cox proportional hazard model was used to assess the risk factors of disease-free survival (DFS) and overall survival (OS) and to test the multiplicative interaction of pathological factors and adjuvant chemotherapy (ACT). The additive interaction was presented using the relative excess risk due to interaction (RERI). The Subpopulation Treatment Effect Pattern Plot (STEPP) was utilized to assess the interaction of continuous variables on the ACT effect. RESULTS: A total of 931 stage II colon cancer patients were enrolled in this study, the median age was 63 years old (interquartile range: 54-72 years) and 565 (60.7%) patients were male. Younger patients (median age, 58 years vs 65 years; P < 0.001) and patients with the following high-risk features, such as T4 tumors (30.8% vs 7.8%; P < 0.001), grade 3 lesions (36.0% vs 22.7%; P < 0.001), lymphovascular invasion (22.1% vs 6.8%; P < 0.001) and perineural invasion (19.4% vs 13.6%; P = 0.031) were more likely to receive ACT. Patients with perineural invasion showed a worse OS and marginally worse DFS (hazardous ratio [HR] 2.166, 95% confidence interval [CI] 1.282-3.660, P = 0.004; HR 1.583, 95% CI 0.985-2.545, P = 0.058, respectively). Computing the interaction on a multiplicative and additive scale revealed that there was a significant interaction between PNI and ACT in terms of DFS (HR for multiplicative interaction 0.196, p = 0.038; RERI, -1.996; 95%CI, -3.600 to -0.392) and OS (HR for multiplicative interaction 0.112, p = 0.042; RERI, -2.842; 95%CI, -4.959 to -0.725). CONCLUSIONS: Perineural invasion had prognostic value, and it could also influence the effect of ACT after curative surgery. However, other high-risk features showed no implication of efficacy for ACT in our study. TRIAL REGISTRATION: This study is registered on ClinicalTrials.gov, NCT03794193 (04/01/2019).

Colonic stem cells from normal tissues adjacent to tumor drive inflammation and fibrosis in colorectal cancer.

BACKGROUND: In colorectal cancer (CRC), the normal tissue adjacent to tumor (NAT) communicates actively with the tumor. Adult stem cells from the colon play a crucial role in the development of the colonic epithelium. In the tumor microenvironment, however, it is unclear what changes have occurred in colonic stem cells derived from NAT. METHODS: Using an intestinal stem cell culture system, we cultured colonic cells from NAT and paired CRC tissue, as well as cells from healthy tissue (HLT). Clonogenicity and differentiation ability were used to compare the function of clones from NAT, HLT and CRC tissues. RNA high-throughput sequencing of these clones was used to identify the molecular characteristics of NAT-derived clones. Coculture of clones from HLT and CRC was used to assess molecular changes. RESULTS: We found that the morphological characteristics, clonogenic ability, and differentiation ability of NAT-derived clones were consistent with those of HLT-derived clones. However, NAT-derived clones changed at the molecular level. A number of genes were specifically activated in NAT. NAT-derived clones enriched pathways related to inflammation and fibrosis, including epithelial mesenchymal transition (EMT) pathway and TGF-beta signaling pathway. Our results also confirmed that NAT-derived clones could recruit fibroblasts in mice. In addition, HLT-derived clones showed high expression of FOSB when cocultured with tumor cells. CONCLUSIONS: Our results demonstrate that colonic stem cells from NAT in the tumor microenvironment undergo changes at the molecular level, and these molecular characteristics can be maintained in vitro, which can induce fibrosis and an inflammatory response. Video Abstract.

GEMIN4, a potential therapeutic targets for patients with basal-like subtype breast cancer.

BACKGROUND: Basal-like breast cancer (BLBC) takes up about 10-20% of all breast cancer(BC), what's more, BLBC has the lowest survival rate among all BC subtypes because of lacks of efficient treatment methods. We aimed to explore the molecules that can be used as diagnostic maker for BLBC at early stage and provide optimized treatment strategies for BLBC patients in this study. METHODS: Apply weighted gene co-expression network analysis (WGCNA) to identify gene modules related to BLBC;The functional enrichment of candidate genes related to BLBC in the red module of Go data package and KEGG analysis;Overlapping cross analysis of URGs and WGCNA to identify candidate genes in each BC subtype;Divide BCBL patients into high-risk and low-risk groups, and analyze the two groups of overall survival (OS) and relapse free survival (RFS);Screening of GEMIN4 dependent cell lines; QRT PCR was used to verify the expression of GEMIN4 transfected with siRNA; CCK8 was used to determine the effect of GEMIN4 on cell viability; Positive cell count detected by BrdU staining;GO and KEGG enrichment analysis of GEMIN4. RESULTS: The "red module" has the highest correlation with BLBC, with 913 promising candidate genes identified from the red module;913 red module candidate genes related to BLBC participated in multiple GO terms, and KEGG enrichment analysis results mainly enriched in estrogen signaling pathways and pathways in cancer;There are 386 overlapping candidate genes among the 913 "red module" genes identified by 1893 common URG and WGCNA;In BLBC patients, 9 highly expressed genes are associated with OS. Five highly expressed genes are associated with RFS. Kaplan Meier survival analysis suggests that high GEMIN4 expression levels are associated with poor prognosis in BLBC patients;The GEMIN4 gene dependency score in HCC1143 and CAL120 cell lines is negative and low; Si-GEMIN4-1 can significantly reduce the mRNA expression of GEMIN4; Si-GEMIN4 can inhibit cell viability; Si-GEMIN4 can reduce the number of positive cells;GO enrichment analysis showed that GEMIN4 is associated with DNA metabolism processes and adenylate binding; KEGG pathway enrichment analysis shows that GEMIN4 is related to ribosome biogenesis in eukaryotes. CONCLUSION: We hypothesized that GEMIN4 may be the potential target for the treatment of BLBC.

Dynamic perturbation analysis of fractional order differential quasiperiodic Mathieu equation.

The paper investigates the influence of parameters on the stability of fractional order differential quasiperiodic Mathieu equations. First, we use the perturbation method to obtain approximate expressions (i.e., transition curves) for the stability and unstable region boundaries of the equation. After obtaining the approximate expression of the transition curve, we use Lyapunov's first method to analyze the stability of the fractional order differential quasiperiodic Mathieu system, thereby obtaining the conditions for the stability of the fractional order differential quasiperiodic Mathieu equation system. Second, by comparing the approximate expressions of the transition curve of the steady-state periodic solution of the quasiperiodic Mathieu oscillator under different parameter conditions, we obtained the conclusion that the fractional order differential term exists in the form of equivalent stiffness and equivalent damping in the fractional order differential quasiperiodic Mathieu system. By comparison, we have summarized the general forms of equivalent linear damping and equivalent stiffness of the system. Through this general form, we can define an approximate expression for the thickness of unstable regions to better study the characteristics of fractional order differential quasiperiodic Mathieu systems. Finally, the influence of the parameters of the fractional order differential quasiperiodic Mathieu equation on the transition curve of the equation was intuitively analyzed through numerical simulation, to analyze the stability changes in the equation.

The safety and prognosis of radical surgery in colorectal cancer patients over 80 years old.

OBJECTIVE: The purpose of this study was to assess the safety and feasibility of radical surgery and to investigate prognostic factors influencing in colorectal cancer (CRC) patients over the age of 80. METHODS: Between January 2010 and December 2020, 372 elderly CRC patients who underwent curative resection at the National Cancer Center were enrolled in the study. Preoperative clinical characteristics, perioperative outcomes, and postoperative pathological features were all collected. RESULTS: A total of 372 elderly patients with colorectal cancer were included in the study, including 226 (60.8%) men and 146 (39.2%) women. A total of 219 (58.9%) patients had a BMI < 24 kg/m2, and 153 (41.1%) patients had a BMI ≥ 24 kg/m2. The mean operation time and intraoperative blood loss were 152.3 ± 58.1 min and 67.6 ± 35.4 ml, respectively. The incidence of overall postoperative complications was 28.2% (105/372), and the incidence of grade 3-4 complications was 14.7% (55/372). In the multivariable Cox regression analysis, BMI ≥ 24 kg/m2 (HR, 2.30, 95% CI, 1.27-4.17; P = 0.006) and N1-N2 stage (HR: 2.97; 95% CI, 1.48-5.97; P = 0.002) correlated with worse CSS. CONCLUSION: The findings of this study showed that radical resection for CRC is safe and feasible for patients over the age of 80. After radical resection, BMI and N stage were independent prognostic factors for elderly CRC patients.

Robust arterial spin labeling MRI measurement of pharmacologically induced perfusion change in rat kidneys.

Kidney diseases such as acute kidney injury, diabetic nephropathy and chronic kidney disease (CKD) are related to dysfunctions of the microvasculature in the kidney causing a decrease in renal blood perfusion (RBP). Pharmacological intervention to improve the function of the microvasculature is a viable strategy for the potential treatment of these diseases. The measurement of RBP is a reliable biomarker to evaluate the efficacy of pharmacological agents' actions on the microvasculature, and measurement of RBP responses to different pharmacological agents can also help elucidate the mechanism of hemodynamic regulation in the kidney. Magnetic resonance imaging (MRI) with flow-sensitive alternating inversion recovery (FAIR) arterial spin labeling (ASL) has been used to measure RBP in humans and animals. However, artifacts caused by respiratory and peristaltic motions limit the potential of FAIR ASL in drug discovery and kidney research. In this study, the combined anesthesia protocol of inactin with a low dose of isoflurane was used to fully suppress peristalsis in rats, which were ventilated with an MRI-synchronized ventilator. FAIR ASL data were acquired in eight axial slices using a single-shot, gradient-echo, echo-planar imaging (EPI) sequence. The artifacts in the FAIR ASL RBP measurement due to respiratory and peristaltic motions were substantially eliminated. The RBP responses to fenoldopam and L-NAME were measured, and the increase and decrease in RBP caused by fenoldopam and L-NAME, respectively, were robustly observed. To further validate FAIR ASL, the renal blood flow (RBF) responses to the same agents were measured by an invasive perivascular flow probe method. The pharmacological agent-induced responses in RBP and RBF are similar. This indicates that FAIR ASL has the sensitivity to measure pharmacologically induced changes in RBP. FAIR ASL with multislice EPI can be a valuable tool for supporting drug discovery, and for elucidating the mechanism of hemodynamic regulation in kidneys.

How inclusive leadership paves way for psychological well-being of employees during trauma and crisis: A three-wave longitudinal mediation study.

AIMS: Nurses are at the forefront of public health emergencies facing psychological pressures ensuing from the loss of patients and potential risk of infection while treating the infected. This study examines whether inclusive leadership has a causal relationship with psychological distress and to assess the mediation effect of psychological safety on this relationship in the long run. The hypotheses are developed and interpreted with the help of theoretical underpinnings from job demands resources theory and the theory of shattered assumptions. DESIGN: Three-wave longitudinal study. METHODS: Questionnaire was used to carry out three waves of data collection from 405 nurses employed at five hospitals in Wuhan during the COVID-19 outbreak between the months of January-April 2020. Partial least square structural equation modelling (PLS-SEM) was used to analyze data while controlling for age, gender, education, experience, and working hours. RESULTS: Results supported the hypothesized relationships where inclusive leadership indicated significant inverse causal relationship with psychological distress and a positive causal relationship with psychological safety. Mediation effect of psychological safety was found significant, while the model explained 73.9% variance in psychological distress. CONCLUSION: Inclusive leadership, through its positive and supportive characteristics, can pave way for such mechanisms that improve the psychological safety of employees in the long run and curbs psychological distress. IMPACT: This is the first longitudinal study to examine the relationship between inclusive leadership and psychological distress in health care and also examines the mediating mechanism of psychology safety. There is scarcity of empirical research on factors that determine and affect behavioural mechanism of healthcare workers during traumatic events and crisis. Clinical leaders and healthcare policy makers must invest in and promote inclusive and supportive environment characterized with open and accessible leaders at workplace to improve psychological safety; it helps reduce levels of psychological distress.

fMRI study of olfactory processing in mice under three anesthesia protocols: Insight into the effect of ketamine on olfactory processing.

Functional magnetic resonance imaging (fMRI) is a valuable tool for studying neural activations in the central nervous system of animals due to its wide spatial coverage and non-invasive nature. However, the advantages of fMRI have not been fully realized in functional studies in mice, especially in the olfactory system, possibly due to the lack of suitable anesthesia protocols with spontaneous breathing. Since mice are widely used in biomedical research, it is desirable to evaluate different anesthesia protocols for olfactory fMRI studies in mice. Dexmedetomidine (DEX) as a sedative/anesthetic has been introduced to fMRI studies in mice, but it has a limited anesthesia duration. To extend the anesthesia duration, DEX has been combined with a low dose of isoflurane (ISO) or ketamine (KET) in previous functional studies in mice. In this report, olfactory fMRI studies were performed under three anesthesia protocols (DEX alone, DEX/ISO, and DEX/KET) in three different groups of mice. Isoamyl-acetate was used as an odorant, and the odorant-induced neural activations were measured by blood oxygenation-level dependent (BOLD) fMRI. BOLD fMRI responses were observed in the olfactory bulb (OB), anterior olfactory nuclei (AON), and piriform cortex (Pir). Interestingly, BOLD fMRI activations were also observed in the prefrontal cortical region (PFC), which are most likely caused by the draining vein effect. The response in the OB showed no adaptation to either repeated odor stimulations or continuous odor exposure, but the response in the Pir showed adaptation during the continuous odor exposure. The data also shows that ISO suppresses the olfactory response in the OB and AON, while KET enhances the olfactory response in the Pir. Thus, DEX/KET should be an attractive anesthesia for olfactory fMRI in mice.

Application of Pharmacokinetic-Pharmacodynamic Modeling to Inform Translation of In Vitro NaV1.7 Inhibition to In Vivo Pharmacological Response in Non-human Primate.

PURPOSE: This work describes a staged approach to the application of pharmacokinetic-pharmacodynamic (PK-PD) modeling in the voltage-gated sodium ion channel (NaV1.7) inhibitor drug discovery effort to address strategic questions regarding in vitro to in vivo translation of target modulation. METHODS: PK-PD analysis was applied to data from a functional magnetic resonance imaging (fMRI) technique to non-invasively measure treatment mediated inhibition of olfaction signaling in non-human primates (NHPs). Initial exposure-response was evaluated using single time point data pooled across 27 compounds to inform on in vitro to in vivo correlation (IVIVC). More robust effect compartment PK-PD modeling was conducted for a subset of 10 compounds with additional PD and PK data to characterize hysteresis. RESULTS: The pooled compound exposure-response facilitated an early exploration of IVIVC with a limited dataset for each individual compound, and it suggested a 2.4-fold in vitro to in vivo scaling factor for the NaV1.7 target. Accounting for hysteresis with an effect compartment PK-PD model as compounds advanced towards preclinical development provided a more robust determination of in vivo potency values, which resulted in a statistically significant positive IVIVC with a slope of 1.057 ± 0.210, R-squared of 0.7831, and p value of 0.006. Subsequent simulations with the PK-PD model informed the design of anti-nociception efficacy studies in NHPs. CONCLUSIONS: A staged approach to PK-PD modeling and simulation enabled integration of in vitro NaV1.7 potency, plasma protein binding, and pharmacokinetics to describe the exposure-response profile and inform future study design as the NaV1.7 inhibitor effort progressed through drug discovery.

Holothuria Leucospilota Polysaccharides Ameliorate Hyperlipidemia in High-Fat Diet-Induced Rats via Short-Chain Fatty Acids Production and Lipid Metabolism Regulation.

Holothuria leucospilota polysaccharides (HLP) are expected to become potential resources for the treatment of hyperlipidemia because of their various bioactivities. In the study, the treatment of HLP on improving hyperlipidemia in rats was explored. Oral administration of HLP at 100 or 200 mg/kg body weight effectively alleviated serum lipid levels and liver histological abnormalities in high-fat-diet rats. HLP regulated abnormal mRNA, lipogenesis-related hormones and inflammatory cytokines (tumor necrosis factor-α, interleukin-6 and interleukin-12) levels. HLP improved the ability of gut microbiota to produce short-chain fatty acids (SCFAs). SCFAs have been found to ameliorate liver lesions. Therefore, HLP alleviated hyperlipidemia by improving the levels of SCFAs to regulate lipid metabolism. These results indicated that HLP could be used as beneficial polysaccharides to alleviate hyperlipidemia.

fMRI study of the role of glutamate NMDA receptor in the olfactory adaptation in rats: Insights into cellular and molecular mechanisms of olfactory adaptation.

Olfactory adaptation, characterized by attenuation of response to repeated odor stimulations or continuous odor exposure, is an intrinsic feature of olfactory processing. Adaptation can be induced by either "synaptic depression" due to depletion of neurotransmitters, or "enhanced inhibition" onto principle neurons by local inhibitory interneurons in olfactory structures. It is not clear which mechanism plays a major role in olfactory adaptation. More importantly, molecular sources of enhanced inhibition have not been identified. In this study, olfactory responses to either repeated 40-s stimulations with interstimulus intervals (ISI) of 140-s or 30-min, or a single prolonged 200-s stimulus were measured by fMRI in different naïve rats. Olfactory adaptations in the olfactory bulb (OB), anterior olfactory nucleus (AON), and piriform cortex (PC) were observed only with repeated 40-s odor stimulations, and no olfactory adaptations were detected during the prolonged 200-s stimulation. Interestingly, in responses to repeated 40-s odor stimulations in the PC, the first odor stimulation induced positive activations, and odor stimulations under adapted condition induced negative activations. The negative activations suggest that "sparse coding" and "global inhibition" are the characteristics of olfactory processing in PC, and the global inhibition manifests only under an adapted condition, not a naïve condition. Further, we found that these adaptations were NMDA receptor dependent; an NMDA receptor antagonist (MK801) blocked the adaptations. Based on the mechanism that glutamate NMDA receptor plays a role in the inhibition onto principle neurons by interneurons, our data suggest that the olfactory adaptations are caused by enhanced inhibition from interneurons. Combined with the necessity of the interruption of odor stimulation to observe the adaptations, the molecular source for the enhanced inhibition is most likely an increased glutamate release from presynaptic terminals due to glutamate over-replenishment during the interruption of odor stimulation. Furthermore, with blockage of the adaptations, the data reveal that orbital, medial & prefrontal, and cingulate cortices (OmPFC) are involved in the olfactory processing.

Evaluation of an fMRI USPIO-based assay in healthy human volunteers.

PURPOSE: To present the testretest and contrast dose effect results of cerebral blood volume (CBV) functional MRI (fMRI) in healthy human volunteers using ferumoxytol (Feraheme), an ultrasmall-superparamagnetic iron oxide (USPIO) nanoparticle. MATERIALS AND METHODS: This was an open-label, two-period, fixed-sequence study in healthy young volunteers. In eight subjects, using a 3 Tesla field strength system, blood oxygen level dependent (BOLD) and CBV fMRI were acquired in response to a visual black-and-white checkboard stimulation paradigm using an escalating ferumoxytol dose design (250, 350, and 510 mg iron). Multiple outcome measures were analyzed including absolute percent signal change (|PSC|, primary endpoint), its contrast-to-noise ratio (CNR) and corresponding z-score, percent CBV change (ΔCBV) and respective CNR, concentration of Fe, and baseline CBV. RESULTS: The |PSC| in the visual cortex increased with ferumoxytol dose and was up to 3 × higher than BOLD fMRI. Test-retest reliability was comparable for BOLD and CBV fMRI. Intraclass correlation coefficients (ICCs) for |PSC| were 0.3 (one-sided 95% lower confidence limit = 0.00), 0.81 (0.47), 0.48 (0.00), and 0.3 (0.00) for BOLD and the 250-, 350-, and 510-mg doses of ferumoxytol, respectively. For ΔCBV, ICCs were 0.77 (0.37), 0.48 (0.00), and 0.49 (0.00) for 250 mg, 350 mg, and 510 mg, respectively. CONCLUSION: This work demonstrates that CBV fMRI techniques and endpoints are dose dependent, robust and have good test-retest repeatability. It also confirms previous findings that USPIO enhances sensitivity of fMRI stimulus-response endpoints. LEVEL OF EVIDENCE: 1 J. MAGN. RESON. IMAGING 2017;46:124-133.

fMRI study of olfaction in the olfactory bulb and high olfactory structures of rats: Insight into their roles in habituation.

Cerebral blood volume (CBV) fMRI with ultrasmall superparamagnetic iron oxide particles (USPIO) as a contrast agent was used to investigate olfactory processing in rats. fMRI data were acquired in sixteen 0.75-mm coronal slices covering the olfactory bulb (OB) and higher olfactory regions (HOR), including the anterior olfactory nucleus and piriform cortex. For each animal, multiple consecutive fMRI measurements were made during a 3-h experiment session, with each measurement consisting of a baseline period, an odorant stimulation period, and a recovery period. Two different stimulation paradigms with a stimulation period of 40s or 80s, respectively, were used to study olfactory processing. Odorant-induced CBV increases were robustly observed in the OB and HOR of each individual animal. Olfactory adaptation, which is characterized by an attenuation of responses to continuous exposure or repeated stimulations, has different characteristics in the OB and HOR. For adaptation to repeated stimuli, while it was observed in both the OB and HOR, CBV responses in the HOR were attenuated more significantly than responses in the OB. In contrast, within each continuous 40-s or 80-s odor exposure, CBV responses in the OB were stable and did not show adaptation, but the CBV responses in the HOR were state dependent, with no adaptation during initial exposures, but significant adaptation during following exposures. These results support previous reports that HOR plays a more significant role than OB in olfactory habituation. The technical approach presented in this study should enable more extensive fMRI studies of olfactory processing in rats.

Functional imaging of olfaction by CBV fMRI in monkeys: insight into the role of olfactory bulb in habituation.

Cerebral blood volume (CBV) fMRI with superparamagnetic iron oxide nanoparticles (USPIO) as contrast agent was used to investigate the odorant-induced olfaction in anesthetized rhesus monkeys. fMRI data were acquired in 24 axial slices covering the entire brain, with isoamyl-acetate as the odor stimulant. For each experiment, multiple fMRI measurements were made during a 1- or 2-h period, with each measurement consisting of a baseline period, a stimulation period, and a recovery period. Three different stimulation paradigms with a stimulation period of 1 min, 2 min, or 8 min, respectively, were used to study the olfactory responses in the olfactory bulb (OB). Odorant-induced CBV increases were observed in the OB of each individual monkey. The spatial and temporal activation patterns were reproducible within and between animals. The sensitivity of CBV fMRI in OB was comparable with the sensitivities reported in previous animal fMRI studies. The CBV responses during the 1-min, 2-min, or 8-min odor stimulation period were relatively stable, and did not show attenuation. The amplitudes of CBV response to the repeated stimuli during the 1- or 2-h period were also stable. The stable CBV response in the OB to both continuous and repeated odor stimuli suggests that the OB may not play a major role in olfactory habituation. The technical approach described in this report can enable more extensive fMRI studies of olfactory processing in OB of both humans and non-human primates.

Qualification of fMRI as a biomarker for pain in anesthetized rats by comparison with behavioral response in conscious rats.

fMRI can objectively measure pain-related neural activities in humans and animals, providing a valuable tool for studying the mechanisms of nociception and for developing new analgesics. However, due to its extreme sensitivity to subject motion, pain fMRI studies are performed in animals that are immobilized, typically with anesthesia. Since anesthesia could confound the nociceptive processes, it is unknown how well nociceptive-related neural activities measured by fMRI in anesthetized animals correlate with nociceptive behaviors in conscious animals. The threshold to vocalization (VT) in response to an increasing noxious electrical stimulus (NES) was implemented in conscious rats as a behavioral measure of nociception. The antinociceptive effect of systemic (intravenous infusion) lidocaine on NES-induced fMRI signals in anesthetized rats was compared with the corresponding VT in conscious rats. Lidocaine infusion increased VT and suppressed the NES-induced fMRI signals in most activated brain regions. The temporal characteristics of the nociception signal by fMRI and by VT in response to lidocaine infusion were highly correlated with each other, and with the pharmacokinetics (PK) of lidocaine. These results indicate that the fMRI activations in these regions may be used as biomarkers of acute nociception in anesthetized rats. Interestingly, systemic lidocaine had no effect on NES-induced fMRI activations in the primary somatosensory cortex (S1), a result that warrants further investigation.

Clinical characteristics and prognosis analysis of postoperative patients with stage I-III colon cancer based on SEER database.

PURPOSE: To identify the relevant factors affecting the prognosis and survival time of colon cancer and construct a survival prediction model. METHODS: Data on postoperative stage I-III colon cancer patients were obtained from the Surveillance, Epidemiology, and End Results database. We used R project to analyze the data. Univariate and multivariate Cox regression analyses were performed for independent factors correlated with overall survival from colon cancer. The C-index was used to screen the factors that had the greatest influence in overall survival after surgery in colon cancer patients. Receiver operating characteristic (ROC) curve was made according to the Risk score and calculated to validate the predictive accuracy of the model. In addition, we used decision curve analysis (DCA) to evaluate the clinical benefits and utility of the nomogram. We created a model survival curve to determine the difference in prognosis between patients in the low-risk group and those in the high-risk group. RESULTS: Univariate and multifactor COX analyses showed that the race, Grade, tumor size, N-stage and T-stage were independent risk factors affecting survival time of patients. The analysis of ROC and DCA showed the nomogram prediction model constructed based on the above indicators has good predictive effects. CONCLUSION: Overall, the nomogram constructed in this study has good predictive effects. It can provide a reference for future clinicians to evaluate the prognosis of colon cancer patients.