Liver extracellular volume fraction values obtained with magnetic resonance imaging can quantitatively stage liver fibrosis: a validation study in monkeys with nonalcoholic steatohepatitis.

OBJECTIVES: This study was to evaluate the diagnostic value of liver extracellular volume (LECV) for the staging of liver fibrosis in a cynomolgus monkey model of nonalcoholic steatohepatitis (NASH). METHODS: Forty-eight cynomolgus monkeys were enrolled in this prospective study. There are 17 healthy monkeys and 31 monkeys with NASH. Ten of these monkeys were used for repeatability assessment. The remaining 38 monkeys were used to compare LECV with other indicators including pathology fibrosis score, native T1, and serum chemical indexes by Spearman, Pearson correlation test, and ROC curves. The inter-reader variability was assessed by interclass correlation. The repeatability measurement of LECV was analyzed using Bland-Altman plots and the coefficient of variation. Partial correlation analysis was performed to assess the effects of fat content and inflammation scores on the correlation between LECV/T1 and liver fibrosis score. RESULTS: This study demonstrated a good intra-reader agreement (intraclass correlation = 0.79) of LECV in all monkeys and an excellent repeatability in 10 monkeys (coefficient of variation = 2.01%). The LECV has a strong correlation with the fibrosis score (r = 0.949; p < 0.0001), low-density lipoprotein (r = 0.72; p < 0.0001), and cholesterol (r = 0.70; p < 0.0001). LECV showed high diagnostic efficacy in the diagnosis of liver fibrosis (area under the curve of ROC, 0.945~1; p < 0.001). CONCLUSIONS: LECV may serve as a noninvasive valuable biomarker for the quantification and differentiating of the non-severe liver fibrosis (stage ≤ F3). However, circulating serum markers low-density lipoprotein and cholesterol (CHO) may not serve for this purpose. KEY POINTS: • This paper demonstrated the excellent repeatability (intraclass correlation coefficient = 0.79) of LECV in monkey animal model. • LECV-MRI has a strong correlation with histopathological fibrosis score stage (r = 0.949; p < 0.0001) and shows high diagnostic efficacy in the staging of non-severe liver fibrosis (the area under ROC curve ≥ 0.945). • The new fibrosis score maps appeared to provide a better imaging tool for the spatial assessment of liver fibrosis. It may eventually facilitate the diagnosis of liver fibrosis distribution.

[Movement Control of Striatum Neural Pathway].

Striatum is the central structure controlling movement. It plays a pivotal role in the regulation of voluntary movement, unconscious movement, muscle tone, posture adjustment and fine movement. Dysfunction of striatum causes a variety of movement disorders ranging from the hypokinetic disorders with increased muscle tone, such as Parkinson's disease, to the hyperkinetic disorders with decreased muscle tone, such as Huntington's disease. It is generally recognized that striatum receives the neural movement signals from the motor cortex, and then processes and modifies these signals and subsequently transfers the signals back to the motor cortex via thalamus for execution of the movement through pyramidal system. The movement control function of striatum depends on a complex neural circuit system. In this review, the studies on the movement control function of striatum as well as the striatal neural circuit system are summarized with an emphasis on the progress made during recent years for better understanding the mechanism underlying the movement control function as well as the disease association of striatum.

[Protein Kinase A and Lipid Metabolism].

Protein kinase A(PKA),as a pivotal factor in the cellular signal transduction,plays an es-sential role in the regulation of lipid metabolism.PKA activates the key lipases including hormone sensi-tive lipase (HSL)and adipose triglyceride lipase (ATGL)to promote the fat mobilization.PKA signaling up-regulates the mitochondrial thermogenesis by enhancing the expression of uncoupling protein-1 (UCP-1),which critically contributes to the body heat production.PKA is closely involved in the regulation of lipogenesis in the liver.Notably,the dysregulation of PKA signaling is associated with the pathogenic mechanisms underlying the obesity,cardiovascular diseases and diabetes mellitus.The pharmacological studies show that PKA is linked to the pharmacological effects of the major lipid regulating agents.In this review,the studies on roles of PKA in the regulation of lipid metabolism are summarized with an emphasis on progress made during the last five years for providing insights into the mechanism by which PKA regu-lates the lipid metabolism as well as the novel therapeutic strategy for lipid-metabolic diseases.

[Leptin Signalings and Leptin Resistance].

Leptin plays a critical role in the regulation of energy balance and metabolic homeostasis. Impairment of leptin function is closely involved in the pathogenesis of obesity, diabetes mellitus and some other metabolic diseases. Leptin initiates intracellular signal transductions in the leptin-receptor-expressing neurons in the central nervous system to exert its physiological functions. The fact that high circulating levels of leptin partially or completely fail to promote weight loss in obesity has given rise to the notion of "leptin resistance". Recently, the impairment of leptin signalings in the hypothalamus has been regarded as a critical contributor to leptin resistance. In this review, the studies on leptin signaling and leptin resistance are summarized with an emphasis on the progress made during the last five years.

Imaging characterization of myocardial function, fibrosis, and perfusion in a nonhuman primate model with heart failure-like features.

Introduction: The availability of a human-like chronic heart failure (HF) animal model was critical for affiliating development of novel therapeutic drug treatments. With the close physiology relatedness to humans, the non-human primate (NHP) HF model would be valuable to better understand the pathophysiology and pharmacology of HF. The purpose of this work was to present preliminary cardiac image findings using echocardiography and cardiovascular magnetic resonance (CMR) in a HF-like cynomolgus macaque model. Methods: The NHP diet-induced model developed cardiac phenotypes that exhibited diastolic dysfunction with reduced left ventricular ejection fraction (LVEF) or preserved LVEF. Twenty cynomolgus monkeys with cardiac dysfunction were selected by echocardiography and subsequently separated into two groups, LVEF < 65% (termed as HFrEF, n = 10) and LVEF ≥ 65% with diastolic dysfunction (termed as HFpEF, n = 10). Another group of ten healthy monkeys was used as the healthy control. All monkeys underwent a CMR study to measure global longitudinal strain (GLS), myocardial extracellular volume (ECV), and late gadolinium enhancement (LGE). In healthy controls and HFpEF group, quantitative perfusion imaging scans at rest and under dobutamine stress were performed and myocardial perfusion reserve (MPR) was subsequently obtained. Results: No LGE was observed in any monkey. Monkeys with HF-like features were significantly older, compared to the healthy control group. There were significant differences among the three groups in ECV (20.79 ± 3.65% in healthy controls; 27.06 ± 3.37% in HFpEF group, and 31.11 ± 4.50% in HFrEFgroup, p < 0.001), as well as for stress perfusion (2.40 ± 0.34 ml/min/g in healthy controls vs. 1.28 ± 0.24 ml/min/g in HFpEF group, p < 0.01) and corresponding MPR (1.83 ± 0.3 vs. 1.35 ± 0.29, p < 0.01). After adjusting for age, ECV (p = 0.01) and MPR (p = 0.048) still showed significant differences among the three groups. Conclusion: Our preliminary imaging findings demonstrated cardiac dysfunction, elevated ECV, and/or reduced MPR in this HF-like NHP model. This pilot study laid the foundation for further mechanistic research and the development of a drug testing platform for distinct HF pathophysiology.

Computed tomography-guided biopsy of small lung nodules: diagnostic accuracy and analysis for true negatives.

OBJECTIVE: We evaluated the diagnostic accuracy of computed tomography (CT)-guided transthoracic core needle biopsy (TCNB) for small (≤20-mm) lung nodules and identified predictive factors for true negatives among benign biopsy results. METHODS: From March 2010 to June 2015, 222 patients with small lung nodules underwent CT-guided TCNB. We retrospectively analysed data regarding technical success, diagnostic accuracy, and predictors of true negatives. RESULTS: The technical success rate was 100%. The TCNB results of the 222 lung nodules included malignancy (n = 136), suspected malignancy (n = 8), specific benign lesion (n = 17), and nonspecific benign lesion (n = 61). The final diagnosis of 222 lung nodules included malignant (n = 160), benign (n = 60), and nondiagnostic lesions (n = 2). The sensitivity, specificity, and overall diagnostic accuracy of CT-guided TCNB for small lung nodules were 90.0%, 100%, and 92.7%, respectively. Pneumothorax and haemoptysis occurred in 23 and 41 patients, respectively. Based on the Cox regression analysis, the significant independent predictive factor for true negatives was a biopsy result of chronic inflammation with fibroplasia. CONCLUSIONS: CT-guided TCNB offers high diagnostic accuracy for small lung nodules, and a biopsy result of chronic inflammation with fibroplasia can predict a true-negative result.

Species and epitope specificity of two 65 kDa glutamate decarboxylase time-resolved fluorometric immunoassays.

The 65 kDa isoform of human glutamate decarboxylase (GAD65) is a major autoantigen in type 1 diabetes (T1D). In the present study, we have developed a sensitive sandwich time-resolved fluorescence immunoassay (TRFIA) for the quantification of GAD65 in cell extracts, cell media and serum. The monoclonal antibody GAD-6 is used to selectively capture GAD65 but not the slightly larger isoform GAD67, and the utilization of different detecting antibodies with distinct GAD65 epitope specificity allows modulating the specificity of the assay. To this effect we have biotinylated a recombinant antigen-binding fragment (rFab) with epitope specificity for the N-terminal region of rat and human GAD65 (rFab N-GAD65) and another rFab that selectively binds to the middle part of human GAD65 (rFab b96.11). In the assay the biotinylated rFabs are recognized by Europium labeled streptavidin. The obtained time-resolved fluorescence (TRF) is directly proportional to the concentration of GAD65 over a large measuring range (0.1 to >100 ng/mL). Based on total error estimation including both bias and imprecision, the lower limit of quantitation (LLOQ) of GAD65 in cell extracts is 0.33 ng/mL with the N-GAD65 TRFIA, and 0.10 ng/mL with the b96.11 TRFIA, but the latter is suitable for human GAD65 only, whereas the N-GAD65 TRFIA has equal sensitivity with rat and human GAD65. Specificity was further checked with GAD65/67 fusion proteins, confirming that the presence of intact capture as well as detection epitope on the analyte is a prerequisite for recognition in both assays. We show that the beta cell-specific marker GAD65 can be quantified in pancreatic cell extracts and in serum, allowing studies on discharge during cell death in vitro as well as in vivo.

[Investigations on Sulfur and Carbon Isotopic Compositions of Potential Polluted Sources in Atmospheric PM2.5 in Nanjing Region].

Potential pollution sources of atmospheric PM2.5 in Nanjing region were collected, and sulfur and carbon isotopic compositions were determined by EA-IRMS synchronously. The results showed that δ³4S and δ¹³C values ranged from 1.8‰-3.7‰ and -25.50‰- -23.57‰ in coal soot particles; 4.6‰-9.7‰ and -26.32‰- -23.57‰ in vehicle exhaust; 5.2‰-9.9‰ and -19.30‰- -30.42‰ in straw soot particles, respectively. Besides, the δ¹³C value of dust was -13.45‰. It can be observed that sulfur isotopic compositions in coal soot were lower, while the carbon isotopic composition in dust was higher. Comparing with δ³4S and δ¹³C values in domestic and foreign polluted sources, we found that sulfur and carbon isotopes in atmospheric PM2.5 in Nanjing region presented an obvious regional characteristics. Therefore, the source spectrum of sulfur and carbon isotopic compositions in Nanjing region might provide an insight into source apportionment of atmospheric PM2.5.

Role of the central interleukin-1 in stress responses.

The molecules of interleukin-1 (IL-1) system are widely distributed in central nervous system. As a classical pro-inflammatory factor, central IL-1 has diverse biological functions and plays a pivotal role in a number of important physiological and pathophysiological processes. During the past few years, particular attentions have been directed to the stress mediator actions of central IL-1. This paper reviews some recent findings in the studies of central IL-1 functions in stress responses, including the effects of stress on central IL-1, the roles of IL-1 in the initiation of stress responses, the neural circuitries and intracellular signal transduction pathways involved in the central IL-1 mediated stress responses, as well as the actions of central IL-1 on brain high function and behavior under stressful conditions.

[Characteristics and sources apportionment of OC and EC in PM1.1 from Nanjing].

The concentrations of OC and EC in PM1.1 collected from Nanshi (NS) and Nanhua (NH) in 2011 were analyzed using DRI Model 2001A Thermal Optical Carbon Analyzer. In addition, source apportionment was simultaneously evaluated. The results showed that the annual average concentrations of OC and EC in PM1.1 were 10. 10 µg x m(-3) and 2.52 µg x m(-3) in NS area, and 11.22 µg x m(-3) and 3.12 µg x m(-3) in NH area, respectively. This result indicated that OC and EC pollution in NH was more serious than that in NS area. Meanwhile, the concentrations of OC and EC in winter and spring were obviously higher compared to those in summer in these two sampling sites, which was mainly ascribed to the increased coal combustion and the unfavorable emission condition of air pollutants in summer and spring. We noted that the SOC/TOC value was the highest in summer and the lowest in winter. In addition, the SOC concentration was observed to show a positive correlation with ozone concentrations, which indicated that the photochemical reaction was a main way of SOC formation in autumn.

Relation between disease phenotype and HLA-DQ genotype in diabetic patients diagnosed in early adulthood.

We investigated inaugural disease phenotype in relation to the presence or absence of diabetes-associated autoantibodies and human leukocyte antigen (HLA) DQ risk genotypes in adult-onset diabetic patients. Blood samples and questionnaires were obtained from 1584 recent-onset Belgian Caucasian patients (age 15-39 yr at diagnosis of primary diabetes) who were recruited by the Belgian Diabetes Registry over an 11-yr period. At clinical diagnosis, antibody-positive patients (n = 1198) were on average younger and had more symptoms, a more acute disease onset, lower body mass index, and random C-peptide levels, but higher insulin needs, glycemia, and prevalence of ketonuria, HLA-DQ, and 5' insulin gene susceptibility genotypes (P < 0.001 vs. antibody-negative patients; n = 386). In antibody-positive patients, these characteristics did not differ according to HLA-DQ genotype. However, in antibody-negative subjects, we found that patients were younger (P = 0.001); had a lower body mass index (P < 0.001), higher insulin needs (P = 0.014), and amylasemia (P = 0.001); and tended to have a higher glycemia and lower C-peptide in the presence of susceptible HLA-DQ genotypes. Differences according to HLA-DQ genotype subsisted after careful age-matching. In conclusion, we found no relation between initial disease phenotype and HLA-DQ genotype in antibody-positive diabetic young adults. In contrast, antibody-negative patients displayed more type 1-like features when carrying susceptible HLA-DQ genotypes known to promote the development of antibody-positive diabetes. The overrepresentation of these susceptibility genotypes in antibody-negative patients suggests the existence of an immune-mediated disease process with as yet unidentified immune markers in a subgroup of seronegative patients.

[Central interleukin-1beta involved in modulation of motor behavior in novelty stress rats].

OBJECTIVE: To investigate the effect of central interleukin-1beta (IL-1beta) on motor behavioral responses in novelty stress rats. METHODS: The novelty stress was elicited by novel environmental stimuli with novelty stress box. The intracerebrolventricular (ICV) cannula and microinjection were performed with rat brain stereotaxic system. Movement behaviors of rats were monitored by behavioral radio-telemetry system. As behavior index, mean percent immobility (MPI) was used to assess immobility of rats. RESULTS: The decrease of MPI was remarkably elicited by novel environmental stimuli. In non-stressful condition, ICV anti-IL-1beta antibody did not influence the MPI. The decrease of MPI induced by novel environmental stimuli was significantly blocked by ICV pretreatment with anti-IL-1beta antibody. In novel stress, MPI of rats was not affected by ICV injection of non specific IgG. CONCLUSION: Central interleukin-1beta plays an important role in modulation of motor behavioral response to novelty stress.

[Progress in central interleukin-1 system and its signaling pathway].

Central interleukin-1 (IL-1 ) system is a relatively independent system which is composed of IL-1 and other molecules associated with IL-1 in functions or structures. The knowledge of central IL-1 system in the constitution and function have been extended with the discovery of new members and its function, the extensive and intensive research on intracellular signaling pathways, as well as the relationship among those molecules. This paper reviews the recent findings in the study of central IL-1 system, which comprises the new members, new signaling molecules, new biological functions, and the effects in the processes of physiology and pathophysiology.

p38 MAPK mediates cardiovascular and behavioral responses induced by central IL-1 beta and footshock in conscious rats.

AIM: To investigate the roles of p38 mitogen-activated protein kinase (p38 MAPK) in the cardiovascular and behavioral responses induced by intracerebral ventricular injection (i.c.v.) of interleukin-1 beta (IL-1 beta) or footshock. METHODS: We examined the effects of p38 MAPK on mean artery blood pressure (mABP), heart rate (HR), and motor activity (MA) during central administration of IL-1 beta, or footshock after i.c.v. SB203580 (a specific inhibitor of the p38 MAPK) with Cardiovascular and Behavior Telemetry System in conscious SD rats. RESULTS: (1) IL-1 beta (i.c.v.) or footshock remarkably rise the mABP, and the maximal changes are (7.8+/-1.8) and (12.3+/-3.5) mmHg, respectively, which was abrogated by the pretreatment with p38 inhibitor SB203580 intracerebroventricularly. (2) Compared with icv saline group, the motor activity was significantly decreased in SB203580 group with maximal changes (-7.6+/-1.1) counts/min after footshock. CONCLUSION: p38 MAPK plays an important role in the pressor response induced by central administration of IL-1 beta or footshock and change of motor activity after footshock in conscious rats.