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Prions are unprecedented infectious pathogens that are devoid of nucleic acid and cause a group of rare and invariably fatal neurodegenerative disorders, affecting approximately 1 person per 1 million inhabitants annually worldwide. These disorders include Creutzfeld-Jacob disease (CJD), Gerstmann-Sträussler-Scheinker syndrome (GSS), kuru, fatal insomnia (FI), and variable protease- sensitive prionopathy (VPSPr), all of which involve a conformational change of the normal cellular prion protein (PrPC) into the abnormal scrapie prion protein (PrPSc) through a posttranslational process during which PrPc acquires high β-sheet content. This structural change is accompanied by profound changes in the physicochemical properties of PrPC, rendering the molecule resistant to proteolysis. The conformational change of PrPC can occur due to either spontaneous conversion, dominant mutations in the prion protein (PRNP) gene encoding PrPC, or infection with pathogenic isoform PrPsc from exogenous sources. There is general agreement that PrPC serves as a substrate for conversion to abnormal PrPSc. This latter multiplies exponentially and aggregates in the brain, forming deposits that are associated with the neurodegenerative changes. Although the understanding of the primary causes of prion-induced neurodegeneration is still limited, propagation of PrPSc and neurotoxic signaling seem to interplay in pathogenic process of prions. Here, we review recent findings that have provided fresh insights into this process, and present an overview of incidence, causes and spectrum of related disorders. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To discuss the expression features of serum cystatin C, and ho-mocysteine in patients of Parkinson's disease (PD) with mild cognitive impairment. PATIENTS AND METHODS: Patients with PD from the neurology department of the Central Hospital of Xuzhou from august 2012 to august 2014 were enrolled in this study. The Hoehn-Yahr (H&Y) grading rating scale was used to rate the degree of severity of PD, and the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) rating scale was used to rate and group their cognitive impairment, test the level of the serum cystatin C (CysC) and homocysteine (HCY) and their variations after treatment with vitamin B and folic acid. RESULTS: (1) The CysC and HCY in the PD group was higher than that in the normal control (p<0.05); (2) As the H&Y rating upgraded, the CysC and HCY in the PD group gradually increased with the progression of the disease (p<0.05); (3) The level of CysC and HCY in the PD-mild cognitive impairment (MCI) group increased significantly compared with those in the PD group (p<0.05) The correlation analysis showed that there was significant positive correlation between CysC and HCY. (4) After treatment with vitamin B and folic acid, the CysC, and HCY levels were lower than before, but the grades of the repetition measurement scale, MMSE and MoCA had no significant improvement (p>0.05). CONCLUSIONS: A high level of CysC and HCY might be involved in the development of Parkinson disease. Their expression levels were higher in the PD patients with mild cognitive dysfunction and both showed a remarkably positive correlation. [ABSTRACT FROM AUTHOR]

Event-related potentials (ERPs) are very small voltages recorded from the scalp which originate in the brain structures in response to specific events or stimuli. They appear as a series of peaks and troughs interspersed in the Electroencephalogram (EEG) waves. The exact neural origins and neuropsychological meaning of the P300 are imprecisely known, even though appreciable progress has been made in the last 25 years. In this review, we will focus on the possible neural generators of this potential. Given the attention and memory operations associated with P300 generation, the first human studies on the neural origins of this ERP focused on the hippocampal formation using depth electrodes implanted to assess sources of epileptic foci in patients. Other lesion studies have found that the integrity of the temporal-parietal lobe junction is involved with either generation or transmission processes subsequent to hippocampal activity and contributes to ERP measures. These findings imply that hippocampal absence does not eliminate the P300, but that the temporal-parietal junction does affect its production. As mentioned till now, the neuroelectric events that underlie P300 generation stem from the interaction between frontal lobe and hippocampal/temporal-parietal function. ERP and fMRI studies using oddball tasks have obtained pat terns consistent wi th this frontal - to-temporal and parietal lobe activation pattern. Further support comes from magnetic resonance imaging (MRI) of gray matter volumes that suggest individual variation in P3a amplitude from distracter stimuli is correlated with frontal lobe area size, whereas P3b amplitude from target stimuli is correlated with parietal area size. Given distinct neuropsychological correlates for P3a and P3b, different neurotransmitters may be engaged for each constituent subcomponent under specific stimulus/task processing requirements. Available data suggest that dopaminergic/frontal processes for P3a and locus-coeruleus-norepinephrine/ parietal activity for P3b are reasonable to propose. This dual-transmitter P300 hypothesis is speculative but appears to account for a variety of findings and provides a useful framework for evaluating drug effects. [ABSTRACT FROM AUTHOR]

Gaucher disease is a multisystemic disorder that affects men and woman in equal numbers and occurs in all ethnic groups at any age with racial variations and an estimated worldwide incidence of 1/75 000. It is caused by a genetic deficient activity of the lysosomal enzyme glucocerebrosidase due to mutations in the β-glucocerebrosidase gene, and resulting in lack of glucocerebroside degradation. The subsequent accumulation of glucocerebroside in lysosomes of tissue macrophages primarily in the liver, bone marrow and spleen, causes damage in haematological, skeletal and nervous systems. The clinical manifestations show a high degree of variability with symptoms that varies according to organs involved. In many cases, these disorders do not correlate with mutations in the β-glucocerebrosidase gene. Although several mutations have been identified as responsible for the deficient activity of glucocerebrosidase, mechanisms by which this enzymatic defect leads to Gaucher disease remain poorly understood. Recent reports indicate the implication of complex mechanisms, including enzyme deficiency, substrate accumulation, unfolded protein response, and macrophage activation. Further elucidating these mechanisms will advance understanding of Gaucher disease and related disorders. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To investigate the characteristic changes in serum estradiol and leptin levels in patients with cerebral-cardiac syndrome (CCS) induced by subarachnoid hemorrhage (SAH). PATIENTS AND METHODS: Ninety-six female patients with early stage of SAH (within 48 h of onset), who were admitted in our department between February 2008 and February 2014, were included in this study. Clinical conditions of patients were rated using Hunt-Hess scale. Serum levels of estradiol, leptin and echocardiography were determined in patients with various neurological injuries as well as in post-SAH patients and patients with SAH-induced CCS. RESULTS: No significant differences (p > 0.05) were observed in the levels of estradiol or leptin between patients with different HuntHess grades. While serum levels of estradiol and leptin were significantly elevated in SAH and CCS patients compared to normal controls (p < 0.05) but the elevated levels were more profound in CCS patients. Meanwhile there were also variable extents of left ventricular expansion and decrease of ejection fraction in CCS patients, with the same trends of estradiol and leptin. CONCLUSIONS: Thus the results show that a significant increase in estradiol and leptin levels occurred in post-SAH CCS patients. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To investigate the difference between myocardial injuries caused by nonaneurysmal subarachnoid hemorrhage (SAH) or aneurysmal SAH. PATIENTS AND METHODS: A total of 92 in-patients with SAH at early stage (within 48h), who were treated in our hospital from 2008 to 2014 were enrolled in this study. Differences in cerebral-cardiac syndrome seen in perimesencephalic subarachnoid hemorrhage (PMSAH), non-perimesencephalic subarachnoid hemorrhage (n-PMSAH), and aneurysmal subarachnoid hemorrhage (aSAH) were recorded based Hunt-Hess scores, electrocardiogram/echocardiography findings, and serum myocardial enzymes. RESULTS: The Hunt-Hess grade was relatively lower in the PMSAH group (mainly at grades I and II) than in aSAH group and n-PMSAH group. The ECG score was significantly lower in the PMSAH Group than in the aSAH or n-PMSAH Group. In the PMSAH group, the left ventricular function was normal; in contrast, the left ventricular end-systolic diameter, left ventricular end-diastolic diameter, left ventricular wall thickness, and left ventricular ejection fraction showed certain abnormal ities in the aSAH group and n-PMSAH group. The myocardial enzymes remarkably increased only in the aSAH group. CONCLUSIONS: In PMSAH patients, the lower Hunt-Hess grade, milder ECG abnormalities, less changes in cardiac enzymes and echocardiography are associated with better prognosis. The clinical course and myocardial injuries are poorer in n-PMSAH patients when compared with the PMSAH patients but better than aSAH patients. [ABSTRACT FROM AUTHOR]

To predict the evolutions of turning forces, temperatures and tool wears, finite element method (FEM) models for micro-turning by using cubic and spherical single-grain ceramic tools have been established. Single-grain ceramic tools with different grain sizes and shapes have been investigated. Initial and boundary conditions of numerical simulations have been adopted and the coefficients of archard models for different grain sizes have been obtained by reciprocating friction tests. The results are summarized as follows. Wear depths of spherical ceramic tools with size 1 µm are bigger than those caused by cube ceramic tools with the same conditions. The predicted maximum turning forces for globular single-grain tools are bigger than those of cube single-grain tool. Also, turning forces of three directions for cube single-grain ceramic tools with size 10 µm are significantly higher than those of single-grain ceramic tools with 1 µm. Wear depths increase sharply with the increase of single-grain ceramic tool sizes, and wear depths of cube single-grain ceramic tools with size 10 µm are bigger than those of 1 µm cube single-grain tool with the same turning condition. The obtained results would provide the fundamental and practical guidelines of single-grain ceramic tools choice for the hard micro-turning. [ABSTRACT FROM AUTHOR]

Abstract: Turning speed, depth of cut, and feed rate are only considered for the traditional turning tool life model of nano ceramic tool. But installation and geometry parameters of the tool and the material characteristics for manufactured materials have not been taken into account for ordinary tool life model. Three-dimensional numerical simulations of turning process using nano ceramic tool have been researched by finite element method (FEM) and archard wear model in the research. The influences of tool shapes, tool rake angle and manufactured metal properties on the contact stresses, sliding speeds, and the temperature have been discussed. A new type of tool life model for nano ceramic tool has been established which include turning speed, depth of cut, the feed amount and other factors. The influences of tool shape, tool rake angle and manufactured metal properties, as well as other turning parameters on tool wear life have been studied deeply. Turning experiments have been done. The preliminary tool life prediction model and evaluation system based on the finite element simulation for nano ceramic tool turning hard steel have been constructed. The model can provide fundamental and practical guidelines of the hard turning. [Copyright &y& Elsevier]

Background. Dyspepsia is a popular complication in many disease, including diarrhea or constipation. This finding of antir- ghrelin serum can be used to improve the discomfort of patients. Objective. To study the effects of anti-r-ghrelin serum on plasma acylated-ghrelin, growth hormone (GH) and insulinlike growth factor-1 (IGF-1) concentration, and mechanism of gastrointestinal (GI) motility (e.g. gastric emptying and intestinal transit) in female rats. Subjects and Methods. Female rats (estrus cycle confirmed) were fasted overnight and treated with i.p (intraperitoneal) injection anti-r-ghrelin serum, cholecystokinin 1 (CCK1) receptor antagonist, and ghrelin receptor antagonist (cortistatin-8, CST-8) to examine the GI motility. The concentration of plasma acylated ghrelin, GH, and IGF-1 was analyzed by ELISA assay. Results. Our data showed that (1) treatment with anti-r-ghrelin serum (diluted 1:100) inhibited the gastric emptying (12.12±2.191 %) but increased the concentration of acylated ghrelin (34.54±3.506 pg/ mL), GH (259.2±24.60 ng/mL) and IGF-1 (1033.9±33.66 ng/mL); (2) the CCK1 receptor antagonist, lorglumide (5 and 10 mg/mL/ kg) reversed the inhibition of gastric emptying (31.95±2.425 % and 30.50±3.624 %) and increased the concentration of plasma acylated ghrelin (101.8±9.422 pg/mL) and GH (508.5±44.11 ng/mL); (3) the ghrelin receptor antagonist, CST-8 under the doses of 1, 20, 40, 100 μg/mL/kg, promoted the gastric emptying (25.85±3.197 % to 33.43±2.513 %) in female rats. Conclusion. Anti-r-ghrelin serum both induced the concentration of plasma acylated-ghrelin, GH and IGF-1 as well as inhibited the GI motility by CCK1 receptor in female rats. [ABSTRACT FROM AUTHOR]