Polymorphisms of the lipoprotein lipase gene are associated with atherosclerotic cerebral infarction in the Chinese

BACKGROUND

Lipoprotein lipase (LPL), which plays an essential role in plasma lipoprotein metabolism and transportation, appears to be a risk factor for ischemic vascular diseases. Several studies have recently reported the presence of relationship between HindIII, PvuII, Ser447Ter (C-->G) polymorphisms of LPL and ischemic vascular diseases.

PURPOSE

We first studied the relationship between LPL polymorphisms and the risk of atherosclerotic cerebral infarction (CI) by detecting the frequencies of LPL HindIII, PvuII and Ser447Ter genotypes and combined genotypes in the Chinese.

METHODS

We recruited 185 CI patients, confirmed by cranial computed tomography or magnetic resonance imaging/angiography, or both, and 186 control subjects. Polymerase chain reaction-restriction fragment length polymorphisms technique was used to detect HindIII, PvuII and Ser447Ter polymorphisms of the LPL gene.

RESULTS

The frequencies of the H+H+ genotype and H+ allele did not differ between CI and control groups. The frequencies of the P+P+ genotype and P+ allele gene were significantly higher in the CI group (P=0.040, P=0.015). The frequencies of CG+GG genotype and G allele were lower in the CI group (P<0.001, P<0.001). In the CI group, the individuals with P+P+ genotype had a significantly higher level of plasma triglyceride (TG) and a lower level of plasma high density lipoprotein cholesterol (HDL-c). CG+GG genotypes were correlated with significantly higher levels of plasma total cholesterol (TC), HDL-c and low density lipoprotein cholesterol (LDL-c) in the CI group. The frequencies of H+/C and P+/C combined genotypes were higher in the CI group than in controls (P<0.001, P<0.001). The frequency of H+/P+/C combined genotype was significantly higher in the CI group than in controls (P<0.001).

CONCLUSIONS

Our study suggests that PvuII and Ser447Ter polymorphisms are associated with lipid profile and CI.

Hamilton-Jacobi skeleton on cortical surfaces

In this paper, we propose a new method to construct graphical representations of cortical folding patterns by computing skeletons on triangulated cortical surfaces. In our approach, a cortical surface is first partitioned into sulcal and gyral regions via the solution of a variational problem using graph cuts, which can guarantee global optimality. After that, we extend the method of Hamilton-Jacobi skeleton [1] to subsets of triangulated surfaces, together with a geometrically intuitive pruning process that can trade off between skeleton complexity and the completeness of representing folding patterns. Compared with previous work that uses skeletons of 3-D volumes to represent sulcal patterns, the skeletons on cortical surfaces can be easily decomposed into branches and provide a simpler way to construct graphical representations of cortical morphometry. In our experiments, we demonstrate our method on two different cortical surface models, its ability of capturing major sulcal patterns and its application to compute skeletons of gyral regions.

[Hypoxia induced HIF-1 accumulation and VEGF expression in gastric epithelial mucosa cell: involvement of ERK1/2 and PI3K/Akt]

Hypoxia is a common environmental stress that influences signaling pathways and cells function, which through initiating intracellular signaling pathways and hence leading to the activation of the transcription factor hypoxia-inducible factor-1 (HIF-1). In this study, we initially confirm that hypoxia activates HIF-1alpha protein expression in a time-dependent manner with a maximum reached at 60 min in vitro and 4h in vivo in gastric mucosa epithelial cells. The expression of HIF-1alpha is correlated with the activation of HIF-1 DNA binding and transcriptional activity. Hypoxia dose not affect HIF-1alpha mRNA transcription but regulates HIF-1alpha protein expression through a translation-dependent pathway to regulate protein synthesis. Hypoxia could induce phosphorylation of Akt, MAPK (ERK), and target of p70S6K1. PI3K and MAPK inhibitor, LY294002 and U0126 could inhibit hypoxia-induced HIF-1 and VEGF expression. We also investigated the role of reactive oxygen species (ROS) involved in HIF-1 and VEGF expression Exogenous addition of H2O2 was sufficient to activate Akt and ERK, scavengers of H2O2 significantly inhibited hypoxia-induced Akt and ERK, and subsequent HIF-lax expression and transcriptional activity. In conclusion, our data suggested that hypoxia- PI3K signaling through Akt and ERK kinases regulated ROS-dependent, hypoxia- induced HIF-1 activation and VEGF expression in gastric mucosa epithelial cells.

Recombinant early secreted antigen target 6 protein as a skin test antigen for the specific detection of Mycobacterium tuberculosis infection

Although the delayed-type hypersensitivity skin test reaction to tuberculin purified protein derivative (PPD) is used worldwide for tuberculosis (TB) detection, it is incapable of distinguishing Mycobacterium tuberculosis (MTB) infection from bacille Calmette-Guérin (BCG) vaccination or infection with non-tuberculous Mycobacteria. As a result, there is an urgent need for a more specific diagnostic tool for TB. This study reports the skin reactions of guinea pigs and human volunteers to recombinant early secreted antigen target 6 (rESAT6), a secretory protein found only in MTB, M. bovis and few other mycobacterial species. These volunteers had varying histories of BCG vaccination and exposure to MTB, allowing us to determine the specificity of their response to TB exposure. Our results show that 1.0 microg of the purified MTB rESAT6 antigen elicited a positive skin response in both animals and humans exposed to MTB, as well as in animals exposed to M. bovis and M. marinum, all species of Mycobacteria that contain the gene for early secreted antigen target 6 (ESAT6). ESAT6 appears to be more specific to MTB infection than PPD, as demonstrated by the fact that we saw no skin responses in the BCG-vaccinated volunteers, nor in the guinea pigs sensitized with BCG vaccine, or with Mycobacteria that do not contain the gene encoding ESAT6. We believe that this is the first report of the use of a rESAT6 protein in a skin test in human volunteers, and that these data support its use in the specific detection of MTB infection.

Segmenting lung fields in serial chest radiographs using both population-based and patient-specific shape statistics

This paper presents a new deformable model using both population-based and patient-specific shape statistics to segment lung fields from serial chest radiographs. There are two novelties in the proposed deformable model. First, a modified scale invariant feature transform (SIFT) local descriptor, which is more distinctive than the general intensity and gradient features, is used to characterize the image features in the vicinity of each pixel. Second, the deformable contour is constrained by both population-based and patient-specific shape statistics, and it yields more robust and accurate segmentation of lung fields for serial chest radiographs. In particular, for segmenting the initial time-point images, the population-based shape statistics is used to constrain the deformable contour; as more subsequent images of the same patient are acquired, the patient-specific shape statistics online collected from the previous segmentation results gradually takes more roles. Thus, this patient-specific shape statistics is updated each time when a new segmentation result is obtained, and it is further used to refine the segmentation results of all the available time-point images. Experimental results show that the proposed method is more robust and accurate than other active shape models in segmenting the lung fields from serial chest radiographs.

The mitotic checkpoint kinase NEK2A regulates kinetochore microtubule attachment stability

Loss or gain of whole chromosome, the form of chromosome instability commonly associated with cancers is thought to arise from aberrant chromosome segregation during cell division. Chromosome segregation in mitosis is orchestrated by the interaction of kinetochores with spindle microtubules. Our studies show that NEK2A is a kinetochore-associated protein kinase essential for faithful chromosome segregation. However, it was unclear how NEK2A ensures accurate chromosome segregation in mitosis. Here we show that NEK2A-mediated Hec1 (highly expressed in cancer) phosphorylation is essential for faithful kinetochore microtubule attachments in mitosis. Using phospho-specific antibody, our studies show that NEK2A phosphorylates Hec1 at Ser165 during mitosis. Although such phosphorylation is not required for assembly of Hec1 to the kinetochore, expression of non-phosphorylatable mutant Hec1(S165) perturbed chromosome congression and resulted in a dramatic increase in microtubule attachment errors, including syntelic and monotelic attachments. Our in vitro reconstitution experiment demonstrated that Hec1 binds to microtubule in low affinity and phosphorylation by NEK2A, which prevents aberrant kinetochore-microtubule connections in vivo, increases the affinity of the Ndc80 complex for microtubules in vitro. Thus, our studies illustrate a novel regulatory mechanism in which NEK2A kinase operates a faithful chromosome attachment to spindle microtubule, which prevents chromosome instability during cell division.

Grain sorghum is a viable feedstock for ethanol production

Sorghum is a major cereal crop in the USA. However, sorghum has been underutilized as a renewable feedstock for bioenergy. The goal of this research was to improve the bioconversion efficiency for biofuels and biobased products from processed sorghum. The main focus was to understand the relationship among "genetics-structure-function-conversion" and the key factors impacting ethanol production, as well as to develop an energy life cycle analysis model (ELCAM) to quantify and prioritize the saving potential from factors identified in this research. Genetic lines with extremely high and low ethanol fermentation efficiency and some specific attributes that may be manipulated to improve the bioconversion rate of sorghum were identified. In general, ethanol yield increased as starch content increased. However, no linear relationship between starch content and fermentation efficiency was found. Key factors affecting the ethanol fermentation efficiency of sorghum include protein digestibility, level of extractable proteins, protein and starch interaction, mash viscosity, amount of phenolic compounds, ratio of amylose to amylopectin, and formation of amylose-lipid complexes in the mash. A platform ELCAM with a base case showed a positive net energy value (NEV) = 25,500 Btu/gal EtOH. ELCAM cases were used to identify factors that most impact sorghum use. For example, a yield increase of 40 bu/ac resulted in NEV increasing from 7 million to 12 million Btu/ac. An 8% increase in starch provided an incremental 1.2 million Btu/ac.

Cannabinoid 2 receptor induction by IL-12 and its potential as a therapeutic target for the treatment of anaplastic thyroid carcinoma

Anaplastic thyroid carcinoma is the most aggressive type of thyroid malignancies. Previously, we demonstrated that tumorigenicity of anaplastic thyroid carcinoma cell line ARO was significantly reduced following interleukin (IL)-12 gene transfer. We suspected that tumor target structure in ARO/IL-12 cells might be changed and such a change may make them more susceptible to be killed through mechanisms apart from natural killer-dependent pathway. To identify genes involved, we examined gene expression profile of ARO and ARO/IL-12 by microarray analysis of 3757 genes. The most highly expressed gene was cannabinoid receptor 2 (CB2), which was expressed eightfold higher in ARO/IL-12 cells than ARO cells. CB2 agonist JWH133 and mixed CB1/CB2 agonist WIN-55,212-2 could induce significantly higher rate of apoptosis in ARO/IL-12 than ARO cells. Similar results were obtained when ARO cells were transfected with CB2 transgene (ARO/CB2). A considerable regression of thyroid tumors generated by inoculation of ARO/CB2 cells was observed in nude mice following local administration of JWH133. We also demonstrated significant increase in the induction of apoptosis in ARO/IL12 and ARO/CB2 cells following incubation with 15 nM paclitaxel, indicating that tumor cells were sensitized to chemotherapy. These data suggest that CB2 overexpression may contribute to the regression of human anaplastic thyroid tumor in nude mice following IL-12 gene transfer. Given that cannabinoids have shown antitumor effects in many types of cancer models, CB2 may be a viable therapeutic target for the treatment of anaplastic thyroid carcinoma.

Oxygen-derived free radicals mediate endothelium-dependent contractions in femoral arteries of rats with streptozotocin-induced diabetes

BACKGROUND AND PURPOSE

The present experiments were designed to study the contribution of oxygen-derived free radicals to endothelium-dependent contractions in femoral arteries of rats with streptozotocin-induced diabetes.

EXPERIMENTAL APPROACH

Rings with and without endothelium were suspended in organ chambers for isometric tension recording. The production of oxygen-derived free radicals in the endothelium was measured with 2',7'-dichlorodihydrofluorescein diacetate using confocal microscopy. The presence of protein was measured by western blotting.

KEY RESULTS

In the presence of L-NAME, the calcium ionophore A23187 induced larger endothelium-dependent contractions in femoral arteries from diabetic rats. Tiron, catalase, deferoxamine and MnTMPyP, but not superoxide dismutase reduced the response, suggesting that oxygen-derived free radicals are involved in the endothelium-dependent contraction. In the presence of L-NAME, A23187 increased the fluorescence signal in femoral arteries from streptozotocin-treated, but not in those from control rats, confirming that the production of oxygen-derived free radicals contributes to the enhanced endothelium-dependent contractions in diabetes. Exogenous H2O2 caused contractions in femoral arterial rings without endothelium which were reduced by deferoxamine, indicating that hydroxyl radicals contract vascular smooth muscle and thus could be an endothelium-derived contracting factor in diabetes. The reduced presence of Mn-SOD and the decreased activity of catalase in femoral arteries from streptozotocin-treated rats demonstrated the presence of a redox abnormality in arteries from rats with diabetes.

CONCLUSIONS AND IMPLICATIONS

These findings suggest that the redox abnormality resulting from diabetes increases oxidative stress which facilitates and/or causes endothelium-dependent contractions.

Inhibition of malignant activities of nasopharyngeal carcinoma cells with high expression of CD44 by siRNA

Since CD44 was found to be significantly inhibited in the human nasopharyngeal carcinoma cell line CNE-2L2 with profound reduction of malignant activities caused by inhibition of alpha-mannosidase Man2c1 gene expression and CD44 has been observed to be involved in many tumor-supporting functions, we studied the association of CD44 expression with the malignant activities of CNE-2L2 cells. Suppression of CD44 gene expression by RNA silencing technique resulted in profound reduction of malignant potential of the cells, including growth in vitro, colony formation, tumorigenesis and metastasis of tumors in nude mice. Direct injection of the adenoviruses harboring and producing siRNA to CD44 into the tumor inoculated with CNE-2L2 cells in nude mice caused inhibition of tumor growth. The data indicate a positive association of CD44 expression with the malignant activities of CNE-2L2 cells and suggest a possible therapeutic effect of direct introduction of siRNA to CD44 into tumors in some human solid tumors with high expression of CD44 gene.

Chinese medicinal herbs for sore throat

BACKGROUND

Chinese herbal medicines are commonly used to treat sore throat in China and among Chinese people worldwide. Their efficacy in treating sore throat has not previously been systematically reviewed.

OBJECTIVES

To assess the efficacy and safety of Chinese herbal medicines for patients with sore throat.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 3, 2006) which contains the Acute Respiratory Infections Group's specialised register; MEDLINE (1966 to August 2006); EMBASE (1980 to August 2006); AMED (1985 to August 2006); the Chinese Biomedical Database (CBM) (1975 to August 2006), and China National Knowledge Infrastructure (CNKI) (1994 to August 2006).

SELECTION CRITERIA

We only included randomised controlled trials (RCTs) assessing Chinese herbal medicines for the treatment of sore throat with the outcomes of recovery, inefficacy, and adverse events.

DATA COLLECTION AND ANALYSIS

One review author contacted the trial authors of claimed RCTs. Three review authors extracted and analysed the data.

MAIN RESULTS

Seven trials involving 1253 participants were included. All trials were identified as being of methodologically poor quality (C category). All of the Chinese herbal preparations in this review were inadequately characterised and were assessed in one trial only. It is highly likely that there was selection bias or detection bias, or both, in all of the included trials. Conflict of interest may have been another factor in producing a positive result in three studies as the prepared drugs were made in the trial author's hospital. We did not perform a meta-analysis and the results of the studies are reported separately. Three formulations were shown to be superior to the control in improving recovery: Ertong Qingyan Jiere Koufuye was more effective than Fufang Shuanghua Koufuye for acute pharyngitis (OR 1.54, 95% Cl 1.11 to 5.74); Yanhouling mixture was more effective than the gentamicin atomised inhalation for acute pharyngitis (OR 5.39, 95% CI 2.69 to 10.81) for acute pharyngitis; and Qinganlan Liyan Hanpian was more effective than Fufang Caoshanhu Hanpian for chronic pharyngitis (OR 2.25, 95% CI 1.08 to 4.67). Four four formulations were shown to be equal in efficacy to the control.

AUTHORS' CONCLUSIONS

Based on the existing evidence included in this review, the efficacy of Chinese herbal medicine for treating sore throat is controversial and questionable. We cannot recommend any kind of Chinese medical herbal formulation as an effective remedy for sore throat, due to the lack of high quality clinical trials.

A Mg2+-responding RNA that controls the expression of a Mg2+ transporter

Mg2+ is the most abundant divalent cation in biological systems. It is required for ATP-mediated enzymatic reactions and as a stabilizer of ribosomes and membranes. The enteric bacterium Salmonella enterica serovar Typhimurium harbors three Mg2+ transporters and a regulatory system-termed PhoP/PhoQ-whose activity is regulated by the extracytoplasmic levels of Mg2+. We have determined that expression of the PhoP-activated Mg2+ transporter MgtA is also controlled by its 5'-untranslated region (5'UTR). The 5'UTR of the mgtA gene can adopt different stem-loop structures depending on the Mg2+ levels, which determine whether transcription reads through into the mgtA-coding region or stops within the 5'UTR. This makes the mgtA 5'UTR the first example of a cation-responding riboswitch. The initiation of mgtA transcription responds to extracytoplasmic Mg2+, and its elongation into the coding region to cytoplasmic Mg2+, which provides a singular example where the same ligand is sensed in different cellular compartments to regulate disparate steps in gene transcription. The PhoP-activated Mg2+ transporter mgtB is also regulated by Mg2+ in a strain lacking the Mg2+ sensor PhoQ, suggesting the presence of additional Mg2+-responding devices.