A theoretical study for the chaos and complexity of the synchronous oscillations in electrically coupled abnormal neurons.

Many experiments demonstrate that the synchrony of neurons is a hallmark in epileptic seizure and the dynamical process of the epilepsy is complex with new oscillations born. In fact, epileptic seizure is very complicated relating to many factors so that it can't be understood thoroughly only in some special aspect. Based on the previous work on synchronous oscillations of electrically coupled abnormal neurons, a theoretical effort is carried out to further investigate the chaos by Lyapunov exponent and phase portrait and degree of complexity by approximate entropy in the dynamical activities.

The SEMG analysis for the lower limb prosthesis using wavelet transformation.

Wavelet transformation (WT) and wavelet packet transformation (WPT) are used in this paper to eliminate the noises of surface EMG sampled from the lower limb during the subjects of study walked normally on the flat. By comparing the denoise result, WPT wins an advantage of WP with the same threshold. And the result shows that if the suitable scale and the threshold are selected, the high-frequency noises can be eliminated effectively.

Study of the effects of 50 Hz homogeneous magnetic field on apoptosis and proliferation of SNU cells in vitro.

The biological effects of magnetic field on SNU (human low differentiated gastric adenocarcinoma cell line) cells are studied in this paper. SNU cells were randomly divided into control groups and four treatment groups, the treatment groups were respectively irradiated by 50 Hz ferromagnetic field (0.097 T) 5 min.

Common SNPs of APM1 gene are not associated with hypertension or obesity in Chinese population.

Objective: To investigate whether the common variants 45T/G and 276G/T in APM1 gene were associated with hypertension combined with obesity (HO) and related clinical features in Chinese Han population.

Methods: A case-control study design was applied. Common polymorphisms of 45T/G and 276G/T were genotyped by PCR product sequencing in 484 cases with HO and 502 controls with normal blood presure and BMI < 25.

Structural and functional characterization of human microsomal prostaglandin E synthase-1 by computational modeling and site-directed mutagenesis.

Microsomal prostaglandin (PG) E synthase-1 (mPGES-1) has recently been recognized as a novel, promising drug target for inflammation-related diseases. Functional and pathological studies on this enzyme further stimulate to understand its structure and the structure-function relationships. Using an approach of the combined structure prediction, molecular docking, site-directed mutagenesis, and enzymatic activity assay, we have developed the first three-dimensional (3D) model of the substrate-binding domain (SBD) of mPGES-1 and its binding with substrates prostaglandin H2 (PGH2) and glutathione (GSH).

Results of L-[1-13C]phenylalanine breath test with air isotope ratio mass spectrometry can reflect the activity of phenylalanine hydroxylase in cirrhotic rat liver.

The L-[1-13C]phenylalanine breath test (PheBT) could potentially advance the evaluation of hepatocyte function and liver functional reserve. However, because the factors influencing PheBT results have not been clarified, the clinical application of the test has been limited. This study investigated the relationship between the parameters of PheBT, performed with air isotope ratio mass spectrometry, and the activity of phenylalanine hydroxylase (PAH), the phenylalanine metabolism rate-limiting enzyme, in rat liver, and proposes valid parameters for the assessment of liver function.

14-3-3zeta interacts with human thromboxane receptors and is involved in the agonist-induced activation of the extracellular-signal-regulated kinase.

Thromboxane receptor (TP) signaling results in a broad range of cellular responses including kinase activation and subsequent nuclear signaling events involved in cell transformation, proliferation, and cell survival. Proteins that may participate in the early signaling following receptor activation remain to be identified. We found that 14-3-3zeta is a novel protein interacting with TP intracellular loop 3 (i3) by yeast two-hybrid system.

Glycogen synthase kinase-3 phosphorylation, T-cell factor signaling activation, and cell morphology change following stimulation of thromboxane receptor alpha.

Previous reports showed that activation of the thromboxane receptor (TP) induced some types of cells to proliferate. We report here that TPalpha activates beta-catenin/T-cell factor (Tcf)/lymphoid enhancer factor (Lef) pathway through phosphorylation of glycogen synthase kinase (GSK)-3. TP agonist [1S-alpha,2alpha(Z),3beta(1E,3S),4alpha]]-7-[3-[3-hydroxy-4-(4-iodophenoxy)-1-butenyl]-7-oxabicyclo[2.

High-density lipoprotein cholesterol levels increase with age, body mass index, blood pressure and fasting blood glucose in a rural Uygur population in China.

Objectives: To investigate the distribution of the serum high-density lipoprotein cholesterol (HDLC) levels and its relationship with obesity, hypertension and diabetes in a Uygur case-control study on hypertension.

Design: A case-control (339 hypertensive cases, 272 normotensive controls) study on hypertension was conducted, and obesity, hypertension, lipid profiles and fasting blood glucose were analyzed.

Methods: The demographic data, history of disease and lifestyles, including diet, smoking and salt intake, were recorded and three measurements of blood pressure were obtained by trained observers.

L-[1-13C] phenylalanine breath test results reflect the activity of phenylalanine hydroxylase in carbon tetrachloride acute injured rat liver.

L-[1-13C] phenylalanine breath tests (PheBTs) have been used to determine the hepatocyte functional capacity of patients. This study investigated the relationship between the PheBT parameter 13C excretion rate constant (PheBT-k) and activity of the phenylalanine metabolic rate-limiting enzyme phenylalanine hydroxylase (PAH) in rat liver. We noted that the time-course curves of 13C excretion presented as a single peak, which appeared 2 min after administration of L-[1-13C] phenylalanine (13C-Phe).

Peroxisome proliferator-activated receptor-gamma coactivator-1alpha polymorphism is not associated with essential hypertension and type 2 diabetes mellitus in Chinese population.

To investigate whether variations in the peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha) are associated with essential hypertension and type 2 diabetes in a Chinese population. A case-control study design was applied in a Chinese population. Two single nucleotide polymorphisms (SNPs), +1302G>A and G482S, in the PGC-1alpha gene were genotyped and compared between 494 unrelated Chinese subjects with essential hypertension and type 2 diabetes and 555 normal control subjects with the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

Spatial resolution improvement of 3D EIT images by the shrinking sLORETA-FOCUSS algorithm.

This paper describes the use of the shrinking sLORETA-FOCUSS algorithm to improve the spatial resolution of three-dimensional (3D) EIT images. Conventional EIT yields inaccurate, low spatial resolution images, due to noise, the low sensitivity of boundary voltages to inner conductivity perturbations and a limited number of boundary voltage measurements. The focal underdetermined system solver (FOCUSS) algorithm produces a localized energy solution based on the weighted minimum-norm least-squares (MNLS) solution.

Polymorphisms in PLIN and hypertension combined with obesity and lipid profiles in Han Chinese.

The current study investigated the association between PLIN polymorphisms and the combination of hypertension and obesity (HO) and the related clinical features. The polymorphisms 1237 (T/C), 1243 (C/T), and 1323 (C/G) were genotyped in 503 cases with HO and 511 unrelated controls. No associations between polymorphism 1237 (T/C) or 1243 (C/T) and HO were found.

[Issues on association studies on complex diseases].

Association study is widely used in elucidating genetic basis of complex diseases such as cardiovascular diseases, type 2 diabetes, essential hypertension and obesity. Some issues were discussed in the review, which include defining and controlling of confounding effects, selection of candidate genes and single nucleotide polymorphisms (SNPs), application of intermediate phenotype and haplotype analyses as well as judgement of the result in association studies. Population stratification is one of the major causes of confounding in association studies.

The spatial resolution improvement of EIT images by GVSPM-FOCUSS algorithm.

The focal underdetermined system solver (FOCUSS) algorithm is a recursive algorithm to find the localized energy solution. It is an initialization-dependent algorithm. The generalized vector sample pattern matching (GVSPM) method has been applied to solve the inverse problem of electrical impedance tomography (EIT) and obtain smooth reconstructed images.

The application of the generalized vector sample pattern matching method for EIT image reconstruction.

This paper presents a new application of a generalized vector sample pattern matching (GVSPM) method for image reconstruction of conductivity changes in electrical impedance tomography. GVSPM is an iterative method for linear inverse problems. The key concept of the GVSPM is that the objective function is defined in terms of an angular component between the inner product of the known vector and solution of a system of equations.

Biomimetic synthesis of gramicidin s and analogues by enzymatic cyclization of linear precursors on solid support.

[reaction: see text] Gramicidin S is a potent decapeptide antibiotic with high hemolytic activity but is unlikely to provoke microbial resistance. Here we demonstrate that gramicidin thioesterase (GrsB TE) correctly cyclizes immobilized linear decapeptide precursors into head-to-tail products, indicating its suitability for parallel solid-phase synthesis of gramicidin analogues from linear precursors on solid support. This chemoenzymatic method will enable the optimization of the therapeutic index of the natural product to fight microbial resistance.

Substrate spectrum of tyrocidine thioesterase probed with randomized peptide N-acetylcysteamine thioesters.

Apparent kinetic constants k(cat) and K(m) were determined for tyrocidine thioesterase (TycC TE) using randomized peptide N-acetylcysteamine thioesters as substrate analogues. The enzyme has been found to be adequately active for the synthesis of positional-scanning libraries for novel antibiotic screening with reduced k(cat)/K(m) in the range of 2 to 82 folds lower than that of the wild-type sequence