108 research outputs found

    Synthesis, Characterization, and Flocculation Properties of Branched Cationic Polyacrylamide

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    A water soluble branched cationic polyacrylamide (BCPAM) was synthesized using solution polymerization. The polymerization was initiated using potassium diperiodatocuprate, K5[Cu(HIO6)2](Cu(III)), initiating the self-condensing vinyl copolymerization of acrylamide and acryloxyethyltrimethyl ammonium chloride (DAC) monomer. The resulting copolymer was characterized by the use of Fourier-transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. Its flocculation properties were evaluated with standard jar tests of sewage. The effects of initiator concentration, monomer concentration, reaction temperature, and the mass ratio of monomers on intrinsic viscosity and flocculation properties of the product were determined using single-factor experiments and orthogonal experiment

    Biostratigraphy of the Small Shelly Fossils From the Upper Maidiping Formation (Terreneuvian) at the Fandian Section, Sichuan Province, South China

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    Small shelly fossils (SSFs) are a useful and critical tool for subdivision and correlation of the Cambrian Terreneuvian stratigraphy. The Maidiping Formation in southern Sichuan is a well-known Terreneuvian lithologic unit with rich SSFs. Here, the upper Maidiping Formation at the Fandian section, an important supplementary section of the classic Maidiping section, is studied for understanding its SSF assemblages and stratigraphic implication. There are 26 genera, 24 species, and 3 undetermined species recovered from the Fandian section, and Watsonella crosbyi was discovered from this section for the first time. Two SSF biozones of the Yangtze Platform, i.e., the possible Paragloborilus subglobosus–Purella squamulosa Assemblage Zone (? Zone II) and the W. crosbyi Assemblage Zone (Zone III), can be recognized. Comparing with the Maidiping section, the Fandian section has a relatively successive SSF biostratigraphy and carbon isotope stratigraphy in the upper Maidiping Formation. The SSF Zone II (?) and Zone III from the Fandian section can be, respectively, correlated to the same zones from the upper Maidiping Formation of the nearby Maidiping section (only Zone III), the upper Zhongyicun and Dahai members of the Zhujiaqing Formation in eastern Yunnan, the top Kuanchuanpu Formation in southern Shaanxi and northern Sichuan, and the beds 4 and 5 (or units 3 and 4) of the Yanjiahe Formation in western Hubei. The almost cosmopolitan distribution and nearly synchronous earliest appearance of W. crosbyi strengthen the applicability of its first appearance data (FAD) to define the base of Cambrian Stage 2 in South China (Xiaotanian) as well as in other continents. The FAD of W. crosbyi just around the onset of the ZHUCE carbon isotope excursion at the Fandian section also further reinforces the utility of the onset of ZHUCE as an auxiliary maker for defining the base of the Xiaotanian in South China

    Dose-related liver injury of Geniposide associated with the alteration in bile acid synthesis and transportation.

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    Fructus Gardenia (FG), containing the major active constituent Geniposide, is widely used in China for medicinal purposes. Currently, clinical reports of FG toxicity have not been published, however, animal studies have shown FG or Geniposide can cause hepatotoxicity in rats. We investigated Geniposide-induced hepatic injury in male Sprague-Dawley rats after 3-day intragastric administration of 100 mg/kg or 300 mg/kg Geniposide. Changes in hepatic histomorphology, serum liver enzyme, serum and hepatic bile acid profiles, and hepatic bile acid synthesis and transportation gene expression were measured. The 300 mg/kg Geniposide caused liver injury evidenced by pathological changes and increases in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and γ-glutamytransferase (γ-GT). While liver, but not sera, total bile acids (TBAs) were increased 75% by this dose, dominated by increases in taurine-conjugated bile acids (t-CBAs). The 300 mg/kg Geniposide also down-regulated expression of Farnesoid X receptor (FXR), small heterodimer partner (SHP) and bile salt export pump (BSEP). In conclusion, 300 mg/kg Geniposide can induce liver injury with associated changes in bile acid regulating genes, leading to an accumulation of taurine conjugates in the rat liver. Taurocholic acid (TCA), taurochenodeoxycholic acid (TCDCA) as well as tauro-α-muricholic acid (T-α-MCA) are potential markers for Geniposide-induced hepatic damage

    Regional and Cellular Mapping of Sortilin Immunoreactivity in Adult Human Brain

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    Sortilin is a member of the vacuolar protein sorting 10 protein (VPS10P) domain receptor family, which carries out signal transduction and protein transport in cells. Sortilin serves as the third, G-protein uncoupled, receptor of neurotensin that can modulate various brain functions. More recent data indicate an involvement of sortilin in mood disorders, dementia and Alzheimer-type neuropathology. However, data regarding the normal pattern of regional and cellular expression of sortilin in the human brain are not available to date. Using postmortem adult human brains free of neuropathology, the current study determined sortilin immunoreactivity (IR) across the entire brain. Sortilin IR was broadly present in the cerebrum and subcortical structures, localizing to neurons in the somatodendritic compartment, but not to glial cells. In the cerebrum, sortilin IR exhibited differential regional and laminar patterns, with pyramidal, multipolar and polymorphic neurons in cortical layers II–VI, hippocampal formation and amygdaloid complex more distinctly labeled relative to GABAergic interneurons. In the striatum and thalamus, numerous small-to-medium sized neurons showed light IR, with a small group of large sized neurons heavily labeled. In the midbrain and brainstem, sortilin IR was distinct in neurons at the relay centers of descending and ascending neuroanatomical pathways. Dopaminergic neurons in the substantia nigra, cholinergic neurons in the basal nuclei of Meynert and noradrenergic neurons in the locus coeruleus co-expressed strong sortilin IR in double immunofluorescence. In comparison, sortilin IR was weak in the olfactory bulb and cerebellar cortex, with the mitral and Purkinje cells barely visualized. A quantitative analysis was carried out in the lateral, basolateral, and basomedial nuclei of the amygdaloid complex, as well as cortical layers II–VI, which established a positive correlation between the somal size and the intensity of sortilin IR among labeled neurons. Together, the present study demonstrates a predominantly neuronal expression of sortilin in the human brain with substantial regional and cell-type variability. The enriched expression of sortilin in pyramidal, dopaminergic, noradrenergic and cholinergic neurons suggests that this protein may be particularly required for signal transduction, protein trafficking and metabolic homeostasis in populations of relatively large-sized projective neurons

    Immunogenicity of a Virus-Like-Particle Vaccine Containing Multiple Antigenic Epitopes of Toxoplasma gondii Against Acute and Chronic Toxoplasmosis in Mice

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    There is no effective protective vaccine against human toxoplasmosis, which is a potential threat to nearly a third of the world population. Vaccines based on virus-like particles (VLPs) have been highly successful in humans for many years, but have rarely been applied against Toxoplasma gondii infection. In this study, we inserted a B cell epitope (SAG182−102 or SAG1301−320), a CD8+ cell epitope (HF10 or ROP7), and a CD4+ cell epitope (AS15) of T. gondii into a truncated HBcΔ(amino acids1–149) particle to construct four chimeric VLP vaccine formulations, i.e., HBcΔH82, HBcΔH301, HBcΔ R82, and HBcΔ R301. When these chimeric HBc particles were expressed in Escherichia coli, they showed icosahedral morphology similar to that of the original VLPs and were evaluated as vaccine formulations against acute and chronic toxoplasmosis in a mouse model (BALB/c mice (H-2d). All these chimeric HBc VLPs induced strong humoral and cellular immune responses with high IgG antibody titers and interferon(IFN)-γ production. Only the mice immunized with HBcΔH82 showed prolonged survival time (15.6 ± 3.8 vs. 5.6 ± 0.8 days) against acute infection with RH tachyzoites and decrease in brain parasite load (1,454 ± 239 vs. 2,091 ± 263) against chronic infection with Prugniuad cysts, as compared to the findings for the control group. These findings suggest that HBc VLPs would act as an effective carrier for delivering effective multiple antigenic epitopes and would be beneficial for developing a safe and long-acting vaccine against toxoplasmosis

    Preliminary findings on the reliability and validity of the Cantonese Birmingham Cognitive Screen in patients with acute ischemic stroke

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    BACKGROUND: There are no currently effective cognitive assessment tools for patients who have suffered stroke in the People’s Republic of China. The Birmingham Cognitive Screen (BCoS) has been shown to be a promising tool for revealing patients’ poststroke cognitive deficits in specific domains, which facilitates more individually designed rehabilitation in the long run. Hence we examined the reliability and validity of a Cantonese version BCoS in patients with acute ischemic stroke, in Guangzhou. METHOD: A total of 98 patients with acute ischemic stroke were assessed with the Cantonese version of the BCoS, and an additional 133 healthy individuals were recruited as controls. Apart from the BCoS, the patients also completed a number of external cognitive tests, including the Montreal Cognitive Assessment Test (MoCA), Mini Mental State Examination (MMSE), Albert’s cancellation test, the Rey–Osterrieth Complex Figure Test, and six gesture matching tasks. Cutoff scores for failing each subtest, ie, deficits, were computed based on the performance of the controls. The validity and reliability of the Cantonese BCoS were examined, as well as interrater and test–retest reliability. We also compared the proportions of cases being classified as deficits in controlled attention, memory, character writing, and praxis, between patients with and without spoken language impairment. RESULTS: Analyses showed high test–retest reliability and agreement across independent raters on the qualitative aspects of measurement. Significant correlations were observed between the subtests of the Cantonese BCoS and the other external cognitive tests, providing evidence for convergent validity of the Cantonese BCoS. The screen was also able to generate measures of cognitive functions that were relatively uncontaminated by the presence of aphasia. CONCLUSION: This study suggests good reliability and validity of the Cantonese version of the BCoS. The Cantonese BCoS is a very promising tool for the detection of cognitive problems in Cantonese speakers

    Sortilin fragments deposit at senile plaques in human cerebrum

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    Genetic variations in the vacuolar protein sorting 10 protein (Vps10p) family have been linked to Alzheimer's disease (AD). Here we demonstrate deposition of fragments from the Vps10p member sortilin at senile plaques (SPs) in aged and AD human cerebrum. Sortilin changes were characterized in postmortem brains with antibodies against the extracellular and intracellular C-terminal domains. The two antibodies exhibited identical labeling in normal human cerebrum, occurring in the somata and dendrites of cortical and hippocampal neurons. The C-terminal antibody also marked extracellular lesions in some aged and all AD cases, appearing as isolated fibrils, mini-plaques, dense-packing or circular mature-looking plaques. Sortilin and β-amyloid (Aβ) deposition were correlated overtly in a region/lamina- and case-dependent manner as analyzed in the temporal lobe structures, with co-localized immunofluorescence seen at individual SPs. However, sortilin deposition rarely occurred around the pia, at vascular wall or in areas with typical diffuse Aβ deposition, with the labeling not enhanced by section pretreatment with heating or formic acid. Levels of a major sortilin fragment ~15 kDa, predicted to derive from the C-terminal region, were dramatically elevated in AD relative to control cortical lysates. Thus, sortilin fragments are a prominent constituent of the extracellularly deposited protein products at SPs in human cerebrum.Xia Hu, Zhao-Lan Hu, Zheng Li, Chun-Sheng Ruan, Wen-Ying Qiu, Aihua Pan, Chang-Qi Li, Yan Cai, Lu Shen, Yaping Chu, Bei-Sha Tang, Huaibin Cai, Xin-Fu Zhou, Chao Ma and Xiao-Xin Ya

    Increased Circulating Endothelial Microparticles Associated with PAK4 Play a Key Role in Ventilation-Induced Lung Injury Process

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    Inappropriate mechanical ventilation (MV) can result in ventilator-induced lung injury (VILI). Probing mechanisms of VILI and searching for effective methods are current areas of research focus on VILI. The present study aimed to probe into mechanisms of endothelial microparticles (EMPs) in VILI and the protective effects of Tetramethylpyrazine (TMP) against VILI. In this study, C57BL/6 and TLR4KO mouse MV models were used to explore the function of EMPs associated with p21 activated kinases-4 (PAK-4) in VILI. Both the C57BL/6 and TLR4 KO groups were subdivided into a mechanical ventilation (MV) group, a TMP + MV group, and a control group. After four hours of high tidal volume (20 ml/kg) MV, the degree of lung injury and the protective effects of TMP were assessed. VILI inhibited the cytoskeleton-regulating protein of PAK4 and was accompanied by an increased circulating EMP level. The intercellular junction protein of β-catenin was also decreased accompanied by a thickening alveolar wall, increased lung W/D values, and neutrophil infiltration. TMP alleviated VILI via decreasing circulating EMPs, stabilizing intercellular junctions, and alleviating neutrophil infiltration
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