Prediction of Stroke Onset Time with Combined Fast High-Resolution Magnetic Resonance Spectroscopic and Quantitative T2 Mapping

OBJECTIVE: The purpose of this work is to develop a multispectral imaging approach that combines fast high-resolution 3D magnetic resonance spectroscopic imaging (MRSI) and fast quantitative T2 mapping to capture the multifactorial biochemical changes within stroke lesions and evaluate its potentials for stroke onset time prediction. METHODS: Special imaging sequences combining fast trajectories and sparse sampling were used to obtain whole-brain maps of both neurometabolites (2.0×3.0×3.0 mm3) and quantitative T2 values (1.9×1.9×3.0 mm3) within a 9-minute scan. Participants with ischemic stroke at hyperacute (0-24h, n = 23) or acute (24h-7d, n = 33) phase were recruited in this study. Lesion N-acetylaspartate (NAA), lactate, choline, creatine, and T2 signals were compared between groups and correlated with patient symptomatic duration. Bayesian regression analyses were employed to compare the predictive models of symptomatic duration using multispectral signals. RESULTS: In both groups, increased T2 and lactate levels, as well as decreased NAA and choline levels were detected within the lesion (all p<0.001). Changes in T2, NAA, choline, and creatine signals were correlated with symptomatic duration for all patients (all p<0.005). Predictive models of stroke onset time combining signals from MRSI and T2 mapping achieved the best performance (hyperacute: R2 = 0.438; all: R2 = 0.548). CONCLUSION: The proposed multispectral imaging approach provides a combination of biomarkers that index early pathological changes after stroke in a clinical-feasible time and improves the assessment of the duration of cerebral infarction. SIGNIFICANCE: Developing accurate and efficient neuroimaging techniques to provide sensitive biomarkers for prediction of stroke onset time is of great importance for maximizing the proportion of patients eligible for therapeutic intervention. The proposed method provides a clinically feasible tool for the assessment of symptom onset time post ischemic stroke, which will help guide time-sensitive clinical management

Diagnosis of pulmonary tuberculosis among asymptomatic HIV+ patients in Guangxi, China

BACKGROUND: Pulmonary tuberculosis (PTB) among asymptomatic Chinese patients with HIV infection has not been investigated despite high tuberculosis burden in China. This study was aimed to evaluate the prevalence, risk factors and clinical outcomes of PTB among asymptomatic patients with HIV/AIDS in Guangxi to facilitate the development of diagnostic and treatment strategies. METHODS: All asymptomatic adult HIV-infected patients with CD4 < 350 cells/µl who attended four HIV clinics in Guangxi between August 2006 and March 2008 were evaluated for active PTB with physical examination, chest X-ray (CXR), sputum smear and/or sputum liquid culture. Data were described using median (interquartile range, IQR) and frequencies. Univariate and multivariate Logistic regression analyses were performed to identify risk factors associated with PTB. RESULTS: Among 340 asymptomatic subjects, 15 (4%) were diagnosed with PTB, with 4 (27%) sputum smear positive and 8 (53%) sputum culture positive. CXR has higher diagnostic sensitivity (87%) than sputum smear (25%) and sputum culture (67%), but lower specificity (56%) compared with sputum smear (99%) and culture (100%). In univariate analysis, injection drug user, body mass index (BMI) < 18 kg/m(2), CD4 < 50 cells/µl and presence of peripheral lymphadenopathy were associated with an increased risk of asymptomatic PTB, while in multivariate analysis only peripheral lymphadenopathy maintained statistical significance (OR = 7.6, 95%CI 1.4 - 40). Patients with negative smear and minor or no abnormalities on CXR had longer interval between screening and TB treatment. CONCLUSIONS: PTB was relatively common in this group of HIV(+) asymptomatic Chinese patients. Diagnosis is challenging especially where sputum culture is unavailable. These findings suggest that an enhanced evaluation for PTB needs to be integrated with HIV care in China and transmission prevention in China to control at both households and health care facilities, especially for patients with factors associated with a higher risk of PTB

The XRE Family Transcriptional Regulator SrtR in Streptococcus suis Is Involved in Oxidant Tolerance and Virulence

Streptococcus suis is a zoonotic pathogen that harbors anti-oxidative stress genes, which have been reported to be associated with virulence. Serial passage has been widely used to obtain phenotypic variant strains to investigate the functions of important genes. In the present study, S. suis serotype 9 strain DN13 was serially passaged in mice 30 times. The virulence of a single colony from passage 10 (SS9-P10) was found to increase by at least 140-fold as indicated by LD50 values, and the increased virulence was stable for single colonies from passage 20 (SS0-P20) and 30 (SS0-P30). Compared to the parental strain, the mouse-adapted strains were more tolerant to oxidative and high temperature stress. Genome-wide analysis of nucleotide variations found that reverse mutations occurred in seven genes, as indicated by BLAST analysis. Three of the reverse mutation genes or their homologs in other bacteria were reported to be virulence-associated, including ideSsuis in S. suis, a homolog of malR of Streptococcus pneumoniae, and a homolog of the prepilin peptidase-encoding gene in Legionella pneumophila. However, these genes were not involved in the stress response. Another gene, srtR (stress response transcriptional regulator), encoding an XRE family transcriptional regulator, which had an internal stop in the parental strain, was functionally restored in the adapted strains. Further analysis of DN13 and SS9-P10-background srtR-knock-out and complementing strains supported the contribution of this gene to stress tolerance in vitro and virulence in mice. srtR and its homologs are widely distributed in Gram-positive bacteria including several important human pathogens such as Enterococcus faecium and Clostridioides difficile, indicating similar functions in these bacteria. Taken together, our study identified the first member of the XRE family of transcriptional regulators that is involved in stress tolerance and virulence. It also provides insight into the mechanism of enhanced virulence after serial passage in experimental animals

PP2A Inhibitors Arrest G2/M Transition Through JNK/Sp1-Dependent Down-Regulation of CDK1 and Autophagy-Dependent Up-Regulation of p21

Protein phosphatase 2A (PP2A) plays an important role in the control of the cell cycle. We previously reported that the PP2A inhibitors, cantharidin and okadaic acid (OA), efficiently repressed the growth of cancer cells. In the present study, we found that PP2A inhibitors arrested the cell cycle at the G2 phase through a mechanism that was dependent on the JNK pathway. Microarrays further showed that PP2A inhibitors induced expression changes in multiple genes that participate in cell cycle transition. To verify whether these expression changes were executed in a PP2A-dependent manner, we targeted the PP2A catalytic subunit (PP2Ac) using siRNA and evaluated gene expression with a microarray. After the cross comparison of these microarray data, we identified that CDK1 was potentially the same target when treated with either PP2A inhibitors or PP2Ac siRNA. In addition, we found that the down-regulation of CDK1 occurred in a JNK-dependent manner. Luciferase reporter gene assays demonstrated that repression of the transcription of CDK1 was executed through the JNK-dependent activation of the Sp1 transcription factor. By constructing deletion mutants of the CDK1 promoter and by using ChIP assays, we identified an element in the CDK1 promoter that responded to the JNK/Sp1 pathway after stimulation with PP2A inhibitors. Cantharidin and OA also up-regulated the expression of p21, an inhibitor of CDK1, via autophagy rather than PP2A/JNK pathway. Thus, this present study found that the PP2A/JNK/Sp1/CDK1 pathway and the autophagy/p21 pathway participated in G2/M cell cycle arrest triggered by PP2A inhibitors

Targeting uPAR by CRISPR/Cas9 System Attenuates Cancer Malignancy and Multidrug Resistance

Urokinase plasminogen activator receptor (uPAR), a member of the lymphocyte antigen 6 protein superfamily, is overexpressed in different types of cancers and plays an important role in tumorigenesis and development. In this study, we successfully targeted uPAR by CRISPR/Cas9 system in two human cancer cell lines with two individual sgRNAs. Knockout of uPAR inhibited cell proliferation, migration and invasion. Furthermore, knockout of uPAR decreases resistance to 5-FU, cisplatin, docetaxel, and doxorubicin in these cells. Although there are several limitations in the application of CRISPR/Cas9 system for cancer patients, our study offers valuable evidences for the role of uPAR in cancer malignancy and drug resistance

Differences in regional homogeneity between patients with Crohn's disease with and without abdominal pain revealed by resting-state functional magnetic resonance imaging

Abnormal pain processing in the central nervous system may be related to abdominal pain in patients with Crohn's disease (CD). The purpose of this study was to investigate changes in resting-state brain activity in patients with CD in remission and its relationship with the presence of abdominal pain. Twenty-five patients with CD and with abdominal pain, 25 patients with CD and without abdominal pain, and 32 healthy subjects were scanned using a 3.0-T functional magnetic resonance imaging scanner. Regional homogeneity (ReHo) was used to assess resting-state brain activity. Daily pain scores were collected 1 week before functional magnetic resonance imaging. We found that patients with abdominal pain exhibited lower ReHo values in the insula, middle cingulate cortex (MCC), and supplementary motor area and higher ReHo values in the temporal pole. In contrast, patients without abdominal pain exhibited lower ReHo values in the hippocampal/parahippocampal cortex and higher ReHo values in the dorsomedial prefrontal cortex (all P < 0.05, corrected). The ReHo values of the insula and MCC were significantly negatively correlated with daily pain scores for patients with abdominal pain (r = -0.53, P = 0.008 and r = -0.61, P = 0.002, respectively). These findings suggest that resting-state brain activities are different between remissive patients with CD with and without abdominal pain and that abnormal activities in insula and MCC are closely related to the severity of abdominal pain

Oxymatrine and Cisplatin Synergistically Enhance Anti-tumor Immunity of CD8+ T Cells in Non-small Cell Lung Cancer

Oxymatrine (OMT) has shown broad antitumor activities for the treatment of several types of cancers. However, little is known about its effect on anti-tumor immunity. Combination therapy is a potentially promising strategy of cancer to enhance anticancer activity, overcome drug resistance, and lower treatment failure rate. In the present study, we demonstrated that the combination of OMT with cisplatin (DDP) synergistically inhibited non-small cell lung cancer (NSCLC) cells growth when co-cultured with peripheral blood mononuclear cells in vitro. Furthermore, the combination of OMT with DDP significantly inhibited the growth of Lewis lung cancer (LLC) mouse xenograft tumors. Flow cytometry analysis revealed that OMT and DDP synergistically increase the CD8+/ regulatory T cells ratio and enhanced more CD8+ T cells secreted cytokines of IFN-γ, TNF-α, and IL-2 in vivo. Mechanistically, upregulation of miR-155 and downregulation of suppressor of cytokine signaling-1 (SOCS1) were confirmed as a target signaling pathway to positively regulate the anti-tumor response of CD8+ T cells. Overall, OMT in combination with DDP showed outstanding synergistic anti-tumor immunity, suggesting that this beneficial combination may offer a potential immunotherapy for NSCLC patients

Effects of Acrylamide on the Activity and Structure of Human Brain Creatine Kinase

Acrylamide is widely used worldwide in industry and it can also be produced by the cooking and processing of foods. It is harmful to human beings, and human brain CK (HBCK) has been proposed to be one of the important targets of acrylamide. In this research, we studied the effects of acrylamide on HBCK activity, structure and the potential binding sites. Compared to CKs from rabbit, HBCK was fully inactivated at several-fold lower concentrations of acrylamide, and exhibited distinct properties upon acrylamide-induced inactivation and structural changes. The binding sites of acrylamide were located at the cleft between the N- and C-terminal domains of CK, and Glu232 was one of the key binding residues. The effects of acrylamide on CK were proposed to be isoenzyme- and species-specific, and the underlying molecular mechanisms were discussed

Early lipofuscin accumulation in Frontal Lobe Epilepsy

OBJECTIVE: This study reports on a novel brain pathology in young patients with frontal lobe epilepsy (FLE) that is distinct from focal cortical dysplasia (FCD). METHODS: Surgical specimens from 20 young adults with FLE (mean age, 30 years) were investigated with histological/immunohistochemical markers for cortical laminar architecture, mammalian target of (mTOR) pathway activation and inhibition, cellular autophagy, and synaptic vesicle-mediated trafficking as well as proteomics analysis. Findings were correlated with pre-/postoperative clinical, imaging, and electrophysiological data. RESULTS: Excessive lipofuscin accumulation was observed in abnormal dysmorphic neurones in 6 cases, but not in seven FCD type IIB and 7 pathology-negative cases, despite similar age and seizure histories. Abnormal dysmorphic neurones on proteomics analysis were comparable to aged human brains. The mTOR pathway was activated, as in cases with dysplasia, but the immunoreactivities of nucleoporin p62, DEP-domain containing protein 5, clathrin, and dynamin-1 were different between groups, suggesting that enhanced autophagy flux and abnormal synaptic vesicle trafficking contribute to early lipofuscin aggregation in these cases, compared to suppression of autophagy in cases with typical dysplasia. Cases with abnormal neuronal lipofuscin showed subtle magnetic resonance imaging cortical abnormalities that localized with seizure onset zone and were more likely to have a family history. INTERPRETATION: We propose that excess neuronal lipofuscin accumulation in young patients with FLE represents a novel pathology underlying this epilepsy; the early accumulation of lipofuscin may be disease driven, secondary to as-yet unidentified drivers accelerating autophagic pathways, which may underpin the neuronal dysfunction in this condition