Prediction of biochemical nonresolution in patients with chronic drug-induced liver injury: A large multicenter study.

BACKGROUND AND AIMS: To clarify high-risk factors and develop a nomogram model to predict biochemical resolution or biochemical nonresolution (BNR) in patients with chronic DILI. APPROACH AND RESULTS: Retrospectively, 3655 of 5326 patients with chronic DILI were enrolled from nine participating hospitals, of whom 2866 underwent liver biopsy. All of these patients were followed up for over 1 year and their clinical characteristics were retrieved from electronic medical records. The endpoint was BNR, defined as alanine aminotransferase or aspartate aminotransferase >1.5× upper limit of normal or alkaline phosphatase >1.1× ULN, at 12 months from chronic DILI diagnosis. The noninvasive high-risk factors for BNR identified by multivariable logistic regression were used to establish a nomogram, which was validated in an independent external cohort. Finally, 19.3% (707 of 3655) patients presented with BNR. Histologically, with the increase in liver inflammation grades and fibrosis stages, the proportion of BNR significantly increased. The risk of BNR was increased by 21.3-fold in patients with significant inflammation compared to none or mild inflammation (p < 0.001). Biochemically, aspartate aminotransferase and total bilirubin, platelets, prothrombin time, sex, and age were associated with BNR and incorporated to construct a nomogram model (BNR-6) with a concordance index of 0.824 (95% CI, 0.798-0.849), which was highly consistent with liver histology. These results were successfully validated both in the internal cohort and external cohort. CONCLUSIONS: Significant liver inflammation is a robust predictor associated with biochemical nonresolution. The established BNR-6 model provides an easy-to-use approach to assess the outcome of chronic DILI.

Laparoscopic antireflux surgery or PPIs in the management of reflux-related esophageal stricture.

BACKGROUND: Gastroesophageal reflux disease (GERD) is often associated with esophageal stricture, particularly benign esophageal stricture. We aimed to evaluate the effects of balloon catheter dilation (BD) combined with laparoscopic fundoplication (LF) surgery and proton pump inhibitors (PPIs) in patients with reflux-induced esophageal strictures. METHODS: We retrospectively analyzed 116 patients with reflux-induced benign esophageal strictures who underwent balloon dilatation therapy combined with PPIs (BD-PPIs group, n = 58) and balloon dilatation combined with LF (BD-LF group, n = 58). Patients were followed up for 24 months. The outcomes of the patients were monitored, including clinical success, symptom improvement, adverse events, and the frequency of esophagitis. RESULTS: At the latest follow-up, the rate of clinical success was higher in BD-LF group than in BD-PPIs group (80.4% vs. 57.7%, P = 0.011). The patients in the BD-PPIs group required more dilation sessions to achieve successful dilation, as compared to those in the BD-LF group (2.1 ± 1.2 vs. 0.7 ± 0.8, P < 0.001). The DeMeester score, number of reflux episodes for which pH was < 4, and lower esophageal sphincter pressure were significantly better in the BD-LF group than in the BD-PPIs group (all P < 0.001). The incidence of reflux esophagitis was higher in the BD-PPIs group than in the BD-LF group, at 24 months (58.8% vs. 18.2%, P = 0.003). CONCLUSIONS: Balloon dilatation with concomitant LF is effective and safe for esophageal stricture secondary to GERD. Moreover, antireflux surgery techniques, such as Nissen or Toupet procedure, should be added for reflux-induced benign esophageal stricture.

MDM2-Mediated Ubiquitination of RXRß Contributes to Mitochondrial Damage and Related Inflammation in Atherosclerosis.

A novel function of retinoid X receptor beta (RXRß) in endothelial cells has been reported by us during the formation of atherosclerosis. Here, we extended the study to explore the cellular mechanisms of RXRß protein stability regulation. In this study, we discovered that murine double minute-2 (MDM2) acts as an E3 ubiquitin ligase to target RXRß for degradation. The result showed that MDM2 directly interacted with and regulated RXRß protein stability. MDM2 promoted RXRß poly-ubiquitination and degradation by proteasomes. Moreover, mutated MDM2 RING domain (C464A) or treatment with an MDM2 inhibitor targeting the RING domain of MDM2 lost the ability of MDM2 to regulate RXRß protein expression and ubiquitination. Furthermore, treatment with MDM2 inhibitor alleviated oxidized low-density lipoprotein-induced mitochondrial damage, activation of TLR9/NF-κB and NLRP3/caspase-1 pathway and production of pro-inflammatory cytokines in endothelial cells. However, all these beneficial effects were reduced by the transfection of RXRß siRNA. Moreover, pharmacological inhibition of MDM2 attenuated the development of atherosclerosis and reversed mitochondrial damage and related inflammation in the atherosclerotic process in LDLr-/- mice, along with the increased RXRß protein expression in the aorta. Therefore, our study uncovers a previously unknown ubiquitination pathway and suggests MDM2-mediated RXRß ubiquitination as a new therapeutic target in atherosclerosis.

Altered hippocampal-prefrontal functional network integrity in adult macaque monkeys with neonatal hippocampal lesions.

The dorsolateral prefrontal cortex (DLPFC) and ventral lateral prefrontal cortex (VLPFC) play critical but different roles in working memory (WM) processes. Resting-state functional MRI (rs-fMRI) was employed to investigate the effects of neonatal hippocampal lesions on the functional connectivity (FC) between the hippocampus (H) and the DLPFC and VLPFC and its relation to WM performance in adult monkeys. Adult rhesus monkeys with neonatal H lesions (Neo-H, n = 5) and age- and gender-matched sham-operated monkeys (Neo-C, n = 5) were scanned around 10 years of age. The FC of H-DLPFC and H-VLPFC in Neo-H monkeys was significantly altered as compared to controls, but also switched from being positive in the Neo-C to negative in the Neo-H. In addition, the altered magnitude of FC between right H and bilateral DLPFC was significantly associated with the extent of the hippocampal lesions. In particular, the effects of neonatal hippocampal lesion on FC appeared to be selective to the left hemisphere of the brain (i.e. asymmetric in the two hemispheres). Finally, FC between H and DLPFC correlated with WM task performance on the SU-DNMS and the Obj-SO tasks for the control animals, but only with the H-VLPFC and SU-DNMS task for the Neo-H animals. In conclusion, the present rsfMRI study revealed that the neonatal hippocampal lesions significantly but differently altered the integrity in the functional connectivity of H-DLPFC and H-VLPFC. The similarities between the behavioral, cognitive and neural alterations in Neo-H monkeys and Schizophrenia (SZ) patients provide a strong translational model to develop new therapeutic tools for SZ.

Endoscopic cardial constriction with band ligation in the treatment of refractory gastroesophageal reflux disease: a preliminary feasibility study.

BACKGROUND: Gastroesophageal reflux disease (GERD) is a common digestive disease, could cause extra-esophageal symptoms. Peroral endoscopic cardial constriction with band ligation (PECC-b) is a minimally invasive method for the treatment of GERD in recent years. The goals of this study were to evaluate the clinical efficacy of PECC-b to treat gastroesophageal reflux-related symptoms. METHODS: A retrospective study of patients undergoing PECC-b between January 2017 and December 2018 at a single institution was conducted. All patients confirmed GERD by endoscopy, esophageal PH-impedance monitoring, esophageal manometry and symptom questionnaires. The outcome measures included reflux-related scores, patients' satisfaction and drug independence after 12 months following surgery. RESULTS: A total of 68 patients, with follow-up of 12 months post surgery, were included in the final analysis. The symptom scores were all significantly decreased as compared with preoperation (P < 0.05). The esophageal symptom scores showed a better improvement than extra-esophageal symptoms (P < 0.001). Fifty-three (77.9%) patients achieved complete drug therapy independence and 52 (76.5%) patients were completely or partially satisfied with the symptom relief following surgery. CONCLUSIONS: The PECC-b is a safe, effective and recommended approach for the control of GERD-related symptoms. Further multicenter prospective studies are required to confirm these outcomes.

Preparation and Evaluation of a Self-Nanoemulsifying Drug Delivery System Loaded with Heparin Phospholipid Complex.

A self-nanoemulsifying drug delivery system (SNEDDS) was developed to enhance the absorption of heparin after oral administration, in which heparin was compounded with phospholipids to achieve better fat solubility in the form of heparin-phospholipid (HEP-Pc) complex. HEP-Pc complex was prepared using the solvent evaporation method, which increased the solubility of heparin in n-octanol. The successful preparation of HEP-Pc complex was confirmed by differential scanning calorimetry (DSC), Fourier-transform infrared (FT-IR) spectroscopy, NMR, and SEM. A heparin lipid microemulsion (HEP-LM) was prepared by high-pressure homogenization and characterized. HEP-LM can enhance the absorption of heparin after oral administration, significantly prolong activated partial thromboplastin time (APTT) and thrombin time (TT) in mice, and reduce fibrinogen (FIB) content. All these outcomes indicate that HEP-LM has great potential as an oral heparin formulation.

[Predictive analysis of quality markers of Coptidis Rhizoma based on network pharmacology and multivariate statistical analysis].

Coptidis Rhizoma, as a bulk medicinal material, is in great demand in clinical practice. Its quality is uneven in the market due to the mixture of genuine, counterfeit and adulterants. Therefore, it is particularly important to establish a quality control system for Coptidis Rhizoma. Based on the concept of Chinese medicine quality marker(Q-marker), the potential quality markers of Coptidis Rhizoma were analyzed and predicted from the perspective of chemistry and pharmacology. The sources of the Q-markers of Coptidis Rhizoma were identified by literature retrieval. The potential Q-markers were then screened through the visualization of the "components-targets-pathways" network. High performance liquid chromatography(HPLC) was used to establish a multi-indicator qualitative and quantitative control method featuring fingerprints for 10 batches of Coptidis Rhizoma. A supervised mode of orthogonality partial least squares method-discriminant analysis(OPLS-DA) was used to screen the main marker components that caused differences between groups. The literature review results showed that the alkaloids were the main source of Coptidis Rhizoma Q-markers.The fingerprints of 13 common peaks were successfully established, and berberine, palmatine, berberine and epiberberine were selected as Q-markers of Coptidis Rhizoma, and their contents were determined.Based on the concept of the Q-marker of traditional Chinese medicine, the four components can be selected as the Q-marker of Coptidis Rhizoma after comprehensive consideration. The results of this study are not only conducive to the quality evaluation of Coptidis Rhizoma on the market, but also provide a reference for the overall quality control of Coptidis Rhizoma and lay foundation for the future exploration of the mechanism of Coptidis Rhizoma.

Differential expression of the Hsf family in cassava under biotic and abiotic stresses.

Heat shock transcription factors (Hsfs) are important regulators of biotic and abiotic stress responses in plants. Currently, the Hsf gene family is not well understood in cassava, an important tropical crop. In the present study, 32 MeHsf genes were identified from the cassava genome database, which were divided into three types based on functional domain and motif distribution analyses. Analysis of the differential expression of the genes belonging to the Hsf family in cassava was carried out based on published cassava transcriptome data from tissues/organs (leaf blade, leaf midvein, lateral buds, organized embryogenic structures, friable embryogenic callus, fibrous roots, storage roots, stem, petiole, shoot apical meristem, and root apical meristem) under abiotic stress (cold, drought) or biotic stress (mealybugs. cassava brown streak disease, cassava bacterial blight). The results show the expression diversity of cassava Hsfs genes in various tissues/organs. The transcript levels of MeHsfB3a, MeHsfA6a, MeHsfA2a, and MeHsfA9b were upregulated by abiotic and biotic stresses, such as cold, drought, cassava bacterial blight, cassava brown streak disease, and mealybugs, indicating their potential roles in mediating the response of cassava plants to environment stresses. Further interaction network and co-expression analyses suggests that Hsf genes may interact with Hsp70 family members to resist environmental stresses in cassava. These results provide valuable information for future studies of the functional characterization of the MeHsf gene family.

Treatment With Wheat Root Exudates and Soil Microorganisms From Wheat/Watermelon Companion Cropping Can Induce Watermelon Disease Resistance Against Fusarium oxysporum f. sp. niveum.

Companion cropping with wheat (Triticum aestivum L.) can enhance watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] wilt disease resistance against Fusarium oxysporum f. sp. niveum. However, the mechanism of resistance induction remains unknown. In this study, the effects of microbial community dynamics and the interactions between wheat and watermelon plants, particularly the effect of wheat root exudates on watermelon resistance against F. oxysporum f. sp. niveum, were examined using a plant-soil feedback trial and plant tissue culture approach. The plant-soil feedback trial showed that treating watermelon with soil from wheat/watermelon companion cropping decreased watermelon wilt disease incidence and severity, increased lignin biosynthesis- and defense-related gene expression, and increased ß-1,3-glucanase activity in watermelon roots. Furthermore, soil microbes can contribute to increasing disease resistance in watermelon plants. Tissue culture experiments showed that both exogenous addition of wheat root exudates and companion cropping with wheat increased host defense gene expression, lignin and total phenols, and increased ß-1,3-glucanase activity in watermelon roots. In conclusion, both root exudates from wheat and the related soil microorganisms in a wheat/watermelon companion cropping system played critical roles in enhancing resistance to watermelon wilt disease induced by F. oxysporum f. sp. niveum.

Deficiency of unc-51 like kinase 1 (Ulk1) protects against mice traumatic brain injury (TBI) by suppression of p38 and JNK pathway.

Unc-51 like autophagy activating kinase 1 (Ulk1) is a serine/threonine kinase that plays a key role in regulating autophagy processes. We attempted to investigate the effects of Ulk1 on traumatic brain injury (TBI) progression by using wild type (WT) mice and Ulk1-knockout (KO) mice suffered with or not TBI. The results were verified using LPS-treated primary astrocyte (AST). Here, Ulk1 was over-expressed in hippocampus of WT mice after TBI, as well as in lipopolysaccharide (LPS)-stimulated AST. Ulk1-deletion improved cognitive ability and hippocampus histological changes in TBI mice. Nissl and neuronal nuclei (NeuN) staining indicated that Ulk1-deletion increased the number of surviving neurons in hippocampus of TBI mice. Ulk1-ablation alleviated neuroinflammation, as evidenced by the reduced expression of hippocampus pro-inflammatory cytokines in TBI mice. TBI-induced apoptosis was also ameliorated by Ulk1-ablation, as proved by the reduced number of TUNEL-staining cells, and cleaved Caspase-3 and poly (ADP-ribose) polymerase (PARP) expressions. Moreover, Ulk1-knockout suppressed TBI-stimulated activation of astrocytes and microglia cells. Additionally, hippocampus autophagy induced by TBI was attenuated by Ulk1-knockout. Further, TBI-activated p38/c-Jun N-terminal Kinase (JNK) pathway was repressed by Ulk1-deletion in hippocampus of mice. The findings above were confirmed in LPS-stimulated AST with or without Ulk1 siRNA transfection. Intriguingly, pre-treatment of p38 or JNK activator markedly abolished the anti-inflammation, anti-apoptosis and anti-autophagy effects of Ulk1-knockdown on LPS-incubated AST. In conclusion, our results demonstrated that Ulk1 might be a potential target for developing therapeutic strategy against TBI in future.

Generic ledipasvir-sofosbuvir for patients with chronic hepatitis C: A real-life observational study.

BACKGROUND & AIMS: Few patients from developing countries can afford brand name direct-acting antiviral agents for treating hepatitis C virus (HCV) infection, and controversy regarding the bioequivalence of generics exists. This study aimed to observe the safety and efficacy of 8 or 12weeks of generic ledipasvir-sofosbuvir with or without ribavirin for Chinese genotype 1b HCV-infected patients. METHODS: In this open-labelled observational study, 63 cirrhotic (group 1) and 65 non-cirrhotic (group 2) patients were administered generic ledipasvir-sofosbuvir plus 1000-1200mg of ribavirin daily for 12 and 8weeks, respectively; and 64 non-cirrhotic patients (group 3) received ledipasvir-sofosbuvir for 8weeks. The primary efficacy endpoint was undetectable HCV RNA at week 12 (SVR12) after cessation of therapy. Safety and pharmacokinetic data were collected. RESULTS: One hundred and eighty-seven patients completed treatment, and the latest undetectable HCV RNA was observed in three patients with cirrhosis at week 5 during treatment. Intention-to-treat analysis revealed 96.8% (61/63), 96.9% (63/65), and 96.9% (62/64) of SVR12 rates in groups 1, 2, and 3, respectively. One patient in group 3 relapsed at post-treatment week 4. The regimens were generally well-tolerated. The most common adverse events were fatigue (17.8%), diarrhea (10.9%), and headache (9.9%). Four patients discontinued therapy due to diarrhea and vomiting. One patient from group 2 discontinued treatment on day 29 because of drug-unaffordability; fortunately, she achieved SVR12. CONCLUSION: This study demonstrated that 8 or 12weeks of generic ledipasvir-sofosbuvir with or without ribavirin are safe and effective for patients with genotype 1b HCV infection. LAY SUMMARY: The price of Harvoni® has led to restrictions and access limitations in many developing and even developed countries with limited healthcare budgets. Gilead approved generic ledipasvir-sofosbuvir costs far less than Harvoni® and presents a similar cure rate for patients with chronic hepatitis C.

Comparative RNA-seq based transcriptomic analysis of bud dormancy in grape.

BACKGROUND: Bud dormancy is an important biological phenomenon of perennial plants that enables them to survive under harsh environmental circumstances. Grape (Vitis vinifera) is one of the most grown fruit crop worldwide; however, underlying mechanisms involved in grape bud dormancy are not yet clear. This work was aimed to explore the underlying molecular mechanism regulating bud dormancy in grape. RESULTS: We have performed transcriptome and differential transcript expression analyses of "Shine Muscat" grape buds using the Illumina RNA-seq system. Comparisons of transcript expression levels among three stages of dormancy, paradormancy (PD) vs endodormancy (ED), summer buds (SB) vs ED and SB vs PD, resulted in the detection of 8949, 9780 and 3938 differentially expressed transcripts, respectively. Out of approximately 78 million high-quality generated reads, 6096 transcripts were differentially expressed (log2 ratio ≥ 1, FDR ≤ 0.001). Grape reference genome was used for alignment of sequence reads and to measure the expression level of transcripts. Furthermore, findings obtained were then compared using two different databases; Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), to annotate the transcript descriptions and to assign a pathway to each transcript. KEGG analysis revealed that secondary metabolites biosynthesis and plant hormone signaling was found most enriched out of the 127 total pathways. In the comparisons of the PD vs ED and SB vs ED stages of grape buds, the gibberellin (GA) and abscisic acid (ABA) pathways were found to be the most enriched. The ABA and GA pathways were further analyzed to observe the expression pattern of differentially expressed transcripts. Transcripts related to the PP2C family (ABA pathway) were found to be up-regulated in the PD vs ED comparison and down-regulated in the SB vs ED and SB vs PD comparisons. GID1 family transcripts (GA pathway) were up-regulated while DELLA family transcripts were down-regulated during the three dormancy stages. Differentially expressed transcripts (DEGs) related to redox activity were abundant in the GO biological process category. RT-qPCR assay results for 12 selected transcripts validated the data obtained by RNA-seq. CONCLUSION: At this stage, taking into account the results obtained so far, it is possible to put forward a hypothesis for the molecular mechanism underlying grape bud dormancy, which may pave the way for ultimate improvements in the grape industry.

[Effect of Chinese drugs for strengthening Pi, harmonizing Wei, and dispersing blood stasis on the expression of gastric mucosal heat shock protein 70 in chronic atrophic gastritis patients].

OBJECTIVE: To observe the effect of Chinese drugs for strengthening Pi, harmonizing Wei, and dispersing blood stasis (CDSPHWDBS) on the expression of gastric mucosal heat shock protein 70 (HSP70) in chronic atrophic gastritis (CAG) patients. METHODS: A total of 100 CAG patients were assigned to the control group and the treatment group by random digit table, 50 in each group. Patients in the control group took Folic Acid Tablet 10 mg each time, 3 times per day. Those in the treatment group took CDSPHWDBS, 100 mL each time, once per day. The treatment course was 6 months for all. Clinical symptoms and signs, endoscopic and histopathological changes were observed before and after treatment in the two groups. The expression of gastric mucosal HSP70 in CAG patients was determined using SP immunohistochemistry. Data were collected by HPIAS-1 000 pathological graphic analysis system, and its expression semi-quantitatively analyzed. RESULTS: The total effective rate of clinical Chinese medical symptoms and signs was 88. 0% (44/50 cases) in the treatment group and 56. 0% (28/50 cases) in the control group, with significant difference between the two groups (P <0. 01). The improvement rate of endoscopic manifestations such as congestion and edema, erosion, bile regurgitation, pale gastric mucosa, exposed blood vessels, particles proliferation in the treatment group were superior to those in the control group (P <0. 05). The total effective rate of atrophy was 80. 0% (40/50 cases) in the treatment group and 54. 0% (27/50 cases) in the control group, with significant difference between the two groups (P<0. 01). The effective rate of intestinal metaplasia was 75. 0% (12/16 cases) in the treatment group and 33.3% (5/15 cases) in the control group, with significant difference between the two groups (P < 0. 05). The optical density value of gastric mucosal HSP70 was significantly elevated in the two groups after treatment (both P <0. 05). It was higher in the treatment group than in the control group after treatment with significant difference (P <0. 01). CONCLUSION: CDSPHWDBS had obvious effect in treatment of CAG and could improve pathological changes of precancerous lesions possibly by promoting the expression of gastric mucosal HSP70 in CAG patients.

Longitudinal cerebral metabolic changes in pig-tailed macaques infected with the neurovirulent virus SIVsmmFGb.

Longitudinal cerebral metabolite changes in pig-tailed macaques inoculated with the simian immunodeficiency virus SIVsmmFGb were evaluated with in vivo proton MRS at 3 T. Blood sample collection, and MRS were carried out before and 2, 4, 8, 12, 16, 20, and 24 weeks after SIV inoculation. Significant reduction of N-acetylaspartate (NAA)/creatine (Cr) and choline (Cho)/Cr ratios in prefrontal gray matter (PGM) and glutamate/glutamine(Glx)/Cr ratio in striatum, and increase of myo-inositol (mI)/Cr in striatum were observed during acute SIV infection. The metabolite alterations during the SIVsmmFGb infection are largely in agreement with previous findings in other non-human primate models and HIV patients. Also, NAA/Cr in PGM and striatum and Glx/Cr in striatum are negatively correlated with the percentage of CD8+ T cells after the SIV infection, suggesting the interaction between brain metabolite and immune dysfunction. The present study complements previous studies by describing the time course of alterations of brain metabolites during SIVsmmFGb infection. The findings further demonstrate the efficacy of the SIVsmmFGb-infected macaque as a model to characterize central nervous system infection using novel neuroimaging approaches and also as a tool for exploration of novel and advanced neuroimaging techniques in HIV/AIDS studies.

An HPLC method for microanalysis and pharmacokinetics of marine sulfated polysaccharide PSS-loaded poly lactic-co-glycolic acid (PLGA) nanoparticles in rat plasma.

This study was aimed at developing a sensitive and selective HPLC method with postcolumn fluorescence derivatization for the detection of propylene glycol alginate sodium sulfate (PSS) in rat plasma. Plasma samples were prepared by a simple and fast ultrafiltration method. PSS was extracted from rat plasma with D-glucuronic acid as internal standard. Isocratic chromatographic separation was performed on a TSKgel G2500 PWxL column with the mobile phase of 0.1 M sodium sulfate at a flow rate of 0.5 mL/min. Analyte detection was achieved by fluorescence detection (FLD) at 250 nm (excitation) and 435 nm (emission) using guanidine hydrochloride as postcolumn derivatizing reagent in an alkaline medium at 120 °C. The calibration curve was linear over a concentration range of 1-500 µg/mL, and the lower limit of detection (LLOD) was found to be 250 ng/mL. This validated method was applied successfully to the pharmacokinetic study of PSS and PSS-loaded poly lactic-co-glycolic acid (PLGA) nanoparticles (PSS-NP) in rat plasma after a single intravenous (PSS only) and oral administration (PSS and PSS-NP). Significant differences in the main pharmacokinetic parameters of PSS and PSS-NP were observed. The relative bioavailability of PSS-NP was 190.10% compared with PSS which shows that PSS-NP can improve oral bioavailability.

Quantitative Evaluation of Oxygen Extraction Fraction Changes in the Monkey Brain during Acute Stroke by Using Quantitative Susceptibility Mapping.

BACKGROUND: The oxygen extraction fraction (OEF) indicates the brain's oxygen consumption and can be estimated by using the quantitative susceptibility mapping (QSM) MRI technique. Recent studies have suggested that OEF alteration following stroke is associated with the viability of at-risk tissue. In the present study, the temporal evolution of OEF in the monkey brain during acute stroke was investigated using QSM. METHODS: Ischemic stroke was induced in adult rhesus monkeys (n = 8) with permanent middle cerebral artery occlusion (pMCAO) by using an interventional approach. Diffusion-, T2-, and T2*-weighted images were conducted on day 0, day 2, and day 4 post-stroke using a clinical 3T scanner. Progressive changes in magnetic susceptibility and OEF, along with their correlations with the transverse relaxation rates and diffusion indices, were examined. RESULTS: The magnetic susceptibility and OEF in injured gray matter of the brain significantly increased during the hyperacute phase, and then decreased significantly on day 2 and day 4. Moreover, the temporal changes of OEF in gray matter were moderately correlated with mean diffusivity (MD) (r = 0.52; p = 0.046) from day 0 to day 4. Magnetic susceptibility in white matter progressively increased (from negative values to near zero) during acute stroke, and significant increases were seen on day 2 (p = 0.08) and day 4 (p = 0.003) when white matter was significantly degenerated. However, significant reduction of OEF in white matter was not seen until day 4 post-stroke. CONCLUSION: The preliminary results demonstrate that QSM-derived OEF is a robust approach to examine the progressive changes of gray matter in the ischemic brain from the hyperacute phase to the subacute phase of stroke. The changes of OEF in gray matter were more prominent than those in white matter following stroke insult. The findings suggest that QSM-derived OEF may provide complementary information for understanding the neuropathology of the brain tissue following stroke and predicting stroke outcomes.

Longitudinal evaluation of the functional connectivity changes in the secondary somatosensory cortex (S2) of the monkey brain during acute stroke.

Background: Somatosensory deficits are frequently seen in acute stroke patients and may recover over time and affect functional outcome. However, the underlying mechanism of function recovery remains poorly understood. In the present study, progressive function alteration of the secondary somatosensory cortex (S2) and its relationship with regional perfusion and neurological outcome were examined using a monkey model of stroke. Methods and materials: Rhesus monkeys (n = 4) were induced with permanent middle cerebral artery occlusion (pMCAo). Resting-state functional MRI, dynamic susceptibility contrast perfusion MRI, diffusion-weighted, T1 and T2 weighted images were collected before surgery and at 4-6, 48, and 96 h post stroke on a 3T scanner. Progressive changes of relative functional connectivity (FC), cerebral blood flow (CBF), and CBF/Tmax (Time to Maximum) of affected S2 regions were evaluated. Neurological deficits were assessed using the Spetzler approach. Results: Ischemic lesion was evidently seen in the MCA territory including S2 in each monkey. Relative FC of injured S2 regions decreased substantially following stroke. Spetzler scores dropped substantially at 24 h post stroke but slightly recovered from Day 2 to Day 4. Relative FC progressively increased from 6 to 48 and 96 h post stroke and correlated significantly with relative CBFand CBF/Tmax changes. Conclusion: The present study revealed the progressive alteration of function connectivity in S2 during acute stroke. The preliminary results suggested the function recovery might start couple days post occlusion and collateral circulation might play a key role in the recovery of somatosensory function after stroke insult. The relative function connectivity in S2 may provide additional information for prediction of functional outcome in stroke patients.

The reason and mechanism of propylene glycol alginate sodium sulfate (PSS) mediated allergic side effect.

Propylene glycol alginate sodium sulfate (PSS) is a heparinoid polysaccharide drug used in clinic for >30 years in China. But its allergy events happened from time to time and should not be ignored. Here, ammonium salt in PSS (PSS-NH4+), PSS fractions with high Mw (PSS-H-Mw) and low mannuronic acid (M) to guluronic acid (G) ratio (PSS-L-M/G) were found to induce allergic response by the structure-activity and impurity-activity relationships in vitro. Furthermore, we confirmed the reason and elucidated the mechanism accounted for allergic side effect of PSS in vivo. It was found that high IgE levels in PSS-NH4+ and PSS-H-Mw groups upregulate the cascade expression of Lyn-Syk-Akt or Erk and second messenger Ca2+, which accelerated mast cells (MCs) degranulation to release histamine, LTB4, TPS, and finally induced lung tissue injury. PSS-L-M/G caused a mild allergic symptom because it only enhanced the expression of p-Lyn and histamine release. In brief, PSS-NH4+ and PSS-H-Mw were main reasons to result in allergic response. Our results suggested that it is very necessary to control the range of Mw and the content of impurities (< 1 % ammonium salt) of PSS to guarantee its safety and effectiveness in clinical treatment.

Poly(acrylic acid)-modified Fe3O4 microspheres for magnetic-targeted and pH-triggered anticancer drug delivery.

Monodisperse poly(acrylic acid)-modified Fe(3)O(4) (PAA@Fe(3)O(4)) hybrid microspheres with dual responses (magnetic field and pH) were successfully fabricated. The PAA polymer was encapsulated into the inner cavity of Fe(3)O(4) hollow spheres by a vacuum-casting route and photo-initiated polymerization. TEM images show that the samples consist of monodisperse porous spheres with a diameter around 200 nm. The Fe(3)O(4) spheres, after modification with the PAA polymer, still possess enough space to hold guest molecules. We selected doxorubicin (DOX) as a model drug to investigate the drug loading and release behavior of as-prepared composites. The release of DOX molecules was strongly dependent on the pH value due to the unique property of PAA. The HeLa cell-uptake process of DOX-loaded PAA@Fe(3)O(4) was observed by confocal laser scanning microscopy (CLSM). After being incubated with HeLa cells under magnet magnetically guided conditions, the cytotoxtic effects of DOX-loaded PAA@Fe(3)O(4) increased. These results indicate that pH-responsive magnetic PAA@Fe(3)O(4) spheres have the potential to be used as anticancer drug carriers.

Improving delineation of the corticospinal tract in the monkey brain scanned with conventional DTI by using a compressed sensing based algorithm.

Background: The corticospinal tract (CST) is a major tract for motor function. It can be impaired by stroke. Its degeneration is associated with stroke outcome. Diffusion tensor imaging (DTI) tractography plays an important role in assessing fiber bundle integrity. However, it is limited in detecting crossing fibers in the brain. The crossing fiber angular resolution of intra-voxel structure (CFARI) algorithm shows potential to resolve complex fibers in the brain. The objective of the present study was to improve delineation of CST pathways in monkey brains scanned by conventional DTI. Methods: Healthy rhesus monkeys were scanned by diffusion MRI with 128 diffusion encoding directions to evaluate the CFARI algorithm. Four monkeys with ischemic occlusion were also scanned with DTI (b = 1000 s/mm2, 30 diffusion directions) at 6, 48, and 96 hours post stroke. CST fibers were reconstructed with DTI and CFARI-based tractography and evaluated. A two-way repeated MANOVA was used to determine significances of changes in DTI indices, tract number, and volumes of the CST between hemispheres or post-stroke time points. Results: CFARI algorithm revealed substantially more fibers originated from the ventral premotor cortex in healthy and stroke monkey brains than DTI tractography. In addition, CFARI showed better sensitivity in detecting CST abnormality than DTI tractography following stroke. Conclusion: CFARI significantly improved delineation of the CST in the brain scanned by DTI with 30 gradient directions. It showed better sensitivity in detecting abnormity of the CST following stroke. Preliminary results suggest that CFARI could facilitate prediction of function outcomes after stroke.