[Myoclonus and it's associated factors in Creutzfeldt-Jakob disease].

Objective: To analyze features and the related factors of myoclonus of 47 patients with probable or possible Creutzfeldt-Jakob disease (CJD). Methods: All patients diagnosed with"suspected CJD" and hospitalized in Xuanwu Hospital from January 2013 to November 2015 were included, and their clinical information and myoclonus features were analyzed. Age, clinical, course and manifestation, EEG, MRI, CSF14-3-3 features between myoclonus positive group and negative group were compared, and the correlation between myoclonus features and these factors was analyzed using Spearman correlation analyses. Results: (1) Occurrence rate of extrapyramidal symptoms (P=0.028), visual impairment (P=0.025) and dyssomnia (P=0.004) were higher in myoclonus positive group, the differences were significant. Spearman correlation analysis showed that myoclonus was related to extrapyramidal symptoms (P=0.024), visual impairment (P=0.030) and dyssomnia (P=0.001). (2) EEG features showed no significant difference between myoclonus positive and negative group. The 17 myoclonus positive patients were divided into three subgroups, typical EEG change group 52.94%(9/17), atypical EEG change group 23.53%(4/17) and no EEG change group 23.53%(4/17). Difference of myoclonus and other clinical manifestations were not significant among the three subgroups(P>0.05); correlation analysis also found no statistically significant correlation between myoclonus and EEG (P=0.201). Conclusions: Myoclonus often occurs after the damage of locomotor system (including pyramidal tract, extracorticospinal tract and cerebellum) among CJD patients, and it is related to extrapyramidal symptoms , visual impairment and dyssomnia . There is undefined correlation between myoclonus and periodic sharp wave complexes (PSWC) in EEG.

[Clinical features and scalp video electroencephalogram analysis of patients with insular epilepsy].

Objective: To explore the clinical and scalp video electroencephalographic(EEG) characteristics of insula lobe epilepsy identified by intracranial electrode, and to provide some references for early diagnosis and clinical evaluation in patients with insula lobe epilepsy. Methods: A total of 12 patients diagnosed with insula lobe epilepsy identified by intracranial electrode were included from Xuanwu Hospital of Capital Medical University from January 2013 to December 2015.Their clinical and EEG data were analyzed. Results: 91.7% of patients had sensory aura before seizure, and had clear consciousness at onset initial time.Visceral motor and visceral sensation were the most common symptoms, and the epilepsy was always ended with somatic movement.There was no prominent characteristic changes in scalp EEG. Conclusions: Clinical features are important for insula lobe epilepsy diagnosis.When patients present symtoms aforementioned, insula lobe epilepsy should be considered.

Characterization, stabilization and activity of uricase loaded in lipid vesicles.

Uricase-containing lipid vesicles (UOXLVs) were prepared by reverse-phase evaporation method with high efficiency and the characteristics of UOXLVs were described. The average size and zeta potential of UOXLVs obtained by the optimized formulation were 205.47 nm and -37.33 mV, respectively. Uricase was encapsulated in the alkaline aqueous phase of the lipid vesicle and the stability of its tetrameric structure was thus improved and its activity preserved. The storage stability of uricase in lipid vesicles was significantly increased compared to that of free uricase at 4 degrees C in borate buffer of pH 8.5. At 55 degrees C, free uricase was deactivated much more quickly especially at lower concentration predominantly due to enhanced dissociation of uricase into subunits. An intrinsic tryptophan of uricase recovered from the lipid vesicle thermally treated at 55 degrees C revealed that a partially denatured uricase molecule was stabilized through its hydrophobic interaction with lipid vesicle membrane. This interaction was depressed mainly by dissociation of uricase into subunits. At the physiological pH, significant increase of enzyme activity was found for the uricase entrapped in the lipid vesicles (1.8 times that of free uricase) at their respective optimum pH. The shift of optimum pH and increased uricolytic activity suggested the conformation change of the uricase during the entrapment process. The stability to proteolytic digestion was increased obviously by entrapping the uricase in the lipid vesicles. UOXLVs also showed relatively slower loss in activity compared with free uricase when treated with some chemical reagents. Lastly, in vitro study explicitly indicated that the uricase entrapped by UOXLVs possessed higher uricolytic activity than that of native uricase solution.

Functional effects of protein kinase C activation on the human cardiac Na+ channel.

The cardiac Na+ current plays an important role in determining normal and abnormal impulse propagation in the heart. We have investigated the effects of protein kinase C (PKC) activation on the recombinant human cardiac Na+ channel (hH1) following heterologous expression in Xenopus laevis oocytes. Phorbol 12-myristate 13-acetate (PMA), which directly activates PKC, reduced current amplitude at all test potentials (43 +/- 12% at -10 mV). In contrast to the rat brain IIA (rBIIA) channel, there was no apparent change in either macroscopic Na+ current decay or the voltage dependence of channel gating. Further experiments indicate that the effects of PMA were mediated by PKC activation: (1) an inactive stereoisomer, 4 alpha-PMA, had no effect; (2) preincubation with the protein kinase inhibitor chelerythrine prevented the PMA effects; and (3) a hydrolyzable diacylglycerol analogue, 1-oleoyl-2-acetyl-glycerol, also reduced current (22 +/- 5%). In addition, when the alpha 1B-adrenergic receptor was coexpressed with hH1, the alpha-receptor agonist methoxamine reduced hH1 current (45 +/- 10%), an effect that could be eliminated by chelerythrine preincubation. When a conserved consensus PKC site (serine 1503) in the III-IV interdomain linker thought to be responsible for the PKC effects on rBIIA was mutated, PMA still reduced Na+ current, but the magnitude of the effect was smaller compared with that for the wild-type channel. Similar findings were obtained with alpha 1-receptor stimulation following receptor coexpression with the mutant channel. We conclude that activation of PKC modulates the human cardiac Na+ channel by at least two mechanisms, one similar to that seen with rat brain channels, involving a conserved putative PKC site, and a second more specific to the cardiac isoform.

Modulation of an inactivating human cardiac K+ channel by protein kinase C.

The transient outward current (ITO) is an important repolarizing component of the cardiac action potential. In native cardiac myocytes, ITO is modulated after activation of protein kinase C, although the molecular nature of this effect is not well understood. A channel recently cloned from human ventricular myocardium (Kv1.4, HK1) produces a rapidly inactivating K+ current, which has phenotypic similarities to the 4-aminopyridine-sensitive component of ITO. Therefore, we examined whether this recombinant channel was also modulated by protein kinase C activation by investigating the effects of the diacylglycerol analogue phorbol 12-myristate 13-acetate (PMA) on Kv1.4 K+ current expressed in Xenopus oocytes. At a concentration of 10 nmol/L, PMA caused a biphasic response with an initial increase (14 +/- 4%, mean +/- SEM) in current, which peaked in 14 minutes. This was followed by a significant reduction (40 +/- 11%) in the current within 30 minutes. There was no significant change in cell membrane electrical capacitance with 10 nmol/L PMA (1 +/- 1% decline in 30 minutes), demonstrating that loss of cell membrane surface area did not explain the reduction in K+ current, although cell capacitance did decrease when using a higher concentration of PMA (81 nmol/L). The inactive stereoisomer, 4 alpha-PMA, had no effect on Kv1.4 current, whereas preincubation with the protein kinase inhibitor staurosporine or protein kinase C-selective chelerythrine prevented the effects of PMA. When purified from a stably transfected mammalian cell line by using immunoprecipitation, the channel protein was readily phosphorylated in vitro by purified protein kinase C.(ABSTRACT TRUNCATED AT 250 WORDS)