Positioning of a polymorphic quantitative trait nucleotide in the Ncf1 gene controlling oxidative burst response and arthritis severity in rats

The Ncf1 gene, encoding the P47(PHOX) protein that regulates production of reactive oxygen species (ROS) by the phagocyte NADPH oxidase (NOX2) complex, is associated with autoimmunity and arthritis severity in rats. We have now identified that the single-nucleotide polymorphism (SNP) resulting in an M153T amino acid substitution mediates arthritis resistance and thus explains the molecular polymorphism underlying the earlier identified Ncf1 gene effect. We identified the SNP in position 153 to regulate ROS production using COS(PHOX) cells transfected with mutated Ncf1. To determine the role of this SNP for control of arthritis, we used the Wistar strain, identified to carry only the postulated arthritis resistant SNP in position 153. When this Ncf1 allele was backcrossed to the arthritis susceptible DA strain, both granulocyte ROS production and arthritis resistance were restored. Position 153 is located in the hinge region between the PX and SH3 domains of P47(PHOX). Mutational analysis of this position revealed a need for an -OH group in the side chain but we found no evidence for phosphorylation. The polymorphism did not affect assembly of the P47(PHOX)/P67(PHOX) complex in the cytosol or membrane localization, but is likely to operate downstream of assembly, affecting activity of the membrane NOX2 complex.     

MAPKs ERK and p38, but not JNK phosphorylation, modulate IL-6 and TNF-α secretion following OK-432 in vitro stimulation of purified human monocytes

Interaction between the immune system and cancer allows for the use of biological response modifiers, e.g. OK-432, in cancer therapy. OK-432, penicillin-killed Streptococcus pyogenes, is used in treating carcinomas, but also lymphangiomas. We have studied the role of monocytes (MOs) in the immune response to OK-432 by examining IL-6 and tumour necrosis factor (TNF)-α secretion after in vitro MO stimulation with OK-432, to some extent in comparison with lipoteichoic acid (LTA) and lipopolysaccharide (LPS). LTA stimulation of whole blood gave IL-6 but not TNF-α secretion, as previously shown with OK-432 stimulation, whereas both cytokines were secreted following LPS stimulation. Addition of the MAPK kinase (MAPKK) MEK inhibitor U0126 inhibited IL-6/TNF-α secretion in a dose-dependent manner. Flow cytometry and to some extent Western blot (Wb) analyses showed that MAPK ERK, located downstream of MEK1/2, is predominantly phosphorylated at isolation from peripheral blood. Addition of the p38 MAP kinase inhibitor SB202190 decreased MO IL-6/TNF-α production upon OK-432 stimulation in a dose-dependent manner. Addition of the MAPK JNK inhibitor SP600125 did not systematically change the MO IL-6/TNF-α OK-432 response. Flow cytometry showed that when stimulating the MOs before isolation from blood, LPS yielded ERK phosphorylation and LPS/LTA p38 phosphorylation, whereas OK-432 had no effects on phosphorylation levels. In conclusion, we have shown that OK-432 resembles TLR2 more than TLR4 stimulation of MOs and depends on MAPKK MEK and MAPK p38, but not on JNK phosphorylation. The MEK and p38 MO OK-432 stimulation dependence is possibly related to the differentiation of cells of the MO lineage.     

Short echo time MR spectroscopy of brain tumors: Grading of cerebral gliomas by correlation analysis of normalized spectral amplitudes

Purpose:

To process single voxel spectra of low‐ and high‐grade gliomas. To propose correlation analysis of the scatter plots of normalized spectral amplitudes as a pattern recognition tool for the classification (grading) of brain tumors. To propose a spectrum processing approach that improves the differentiation of proton spectra with dominating macromolecule and lipid peaks.

Materials and Methods:

LCModel was used to process spectra. Mean metabolite concentrations and mean normalized spectra were obtained for normal white matter and for gliomas. The mean spectra of macromolecules and lipids (ML) in the range 1.4–0.9 ppm, and mean difference spectra (DS) without ML and lactate were computed. Correlation analysis of the scatter plot of the patient and mean normalized spectral amplitudes and dispersion of the scatter plot points were used for classification and grading of tumors.

Results:

It was found advantageous to perform the classifications using DS spectra. The shape of ML spectrum and concentration of tCr seem to be a good markers for glioma grade.

Conclusion:

Combining a qualitative comparison of the patient and mean DS spectra of the tumors using correlation analysis of normalized spectra amplitudes with a quantitative comparison of metabolite concentrations is a powerful tool in studying brain lesions. J. Magn. Reson. Imaging 2010;31:39–45. © 2009 Wiley‐Liss, Inc.     

4支肝动脉伴胆囊动脉起始及走行变异1例

正笔者在解剖1具老年男性尸体时发现4支肝动脉,分别为肝左、中、右动脉和副肝右动脉。肝中动脉和肝右动脉共干起自肝总动脉,副肝右动脉由肠系膜上动脉发出,胆囊动脉从副肝右动脉发出(图1),现报道如下:肝总动脉外径4.05 mm,走行1.91 cm、2.62 cm后分别发出肝左动脉、以及肝中动脉和肝右动脉的共干支,外径分别为3.25 mm、2.95 mm。肝左动脉走行3.24 cm后经肝圆韧带裂入肝,在距离肝左动脉起点2.97 cm处发出一支副胃左动脉,外径1.80 mm;共干支走行1.27 cm后发出肝中动脉和肝右动脉,都经门静脉前方至第一肝门处入肝。     

生物医学工程专业《数字信号处理》课程教学实验的设计

目的根据生物医学工程专业本科教学特点,设计了《数字信号处理》课程的实验教学方法和内容。方法采用Dreamweaver将实验讲义开发成网页形式;利用JAVA设计了4个教学辅助插件,方便地嵌入网页结构中;利用辅助插件对教学中的算法原理进行验证和演示,并使实验内容在Matlab平台下编程实现。结果实验结果证实该实验教学课件有效地提高了生物医学工程专业《数字信号处理》课程教学的效果。     

Detection of orientation-specific anti-gp120 antibodies by a new N-glycanase protection assay

Several functions have been assigned to the extensive glycosylation of HIV-1 envelope glycoprotein gp120, especially immune escape mechanisms, but the intramolecular interactions between gp120 and its carbohydrate complement are not well understood. To analyse this phenomenon we established a new microwell deglycosylation assay for determining N-linked glycan accessibility after binding of gp120-specific agents. Orientation-specific exposition of gp120 in ELISA microplates was achieved by catching with either anti-C5 antibody D7324 or anti-V3 antibody NEA-9205. We found that soluble CD4 inhibited the deglycosylation of gp120 only when gp120 was caught by D7324 and not by NEA9205. In contrast, antibodies from HIV-infected individuals inhibited the deglycosylation best when gp120 was caught by NEA9205. These results demonstrated that both the CD4-binding site and the epitopes recognised by antibodies from HIV-infected individuals have N-glycans in the close vicinity. However, the difference in gp120 orientation indicates that antibodies in HIV-infected individuals, at least partly, bind to epitopes different from the CD4-binding site. Finally, we determined the structural class of the glycan of one V1 glycosylation site of prototype HIV-1 LAI gp120, which remained unsolved from previous studies, and found that it belonged to the complex type of glycans.     

Synergistic effect of aqueous extract of Telfaria occidentalis on the biological activities of artesunate in Plasmodium berghei infected mice

Background

Resistance to most antimalarial drugs has encouraged the use of herbal preparations along with prescribed orthodox drugs.

Objective

To investigate effect of co-administration of aqueous extract of T. occidentalis leaves; commonly used as antimalarial and haematinic agent in Nigeria and artesunate using P. berghei animal model.

Methods

In vivo curative antiplasmodial effect of T. occidentalis (200mg/kg) alone and combination with artesunate (2mg/kg) were evaluated using albino mice infected with 10⁶ parasitized erythrocytes of P. berghei intraperitoneally. The haematological parameters: haemoglobin level, red blood cells and white blood cells and packed cell volume were monitored using standard methods.

Results

Aqueous extract of T. occidentalis, artesunate and the combination gave 72.17±4.07%, 70.43± 4.27% and 85.43±3.65% reduction in parasitaemia after 48hours respectively. A significant enhancement of the PCV was obtained with the coadministration of artesunate and aqueous extract (p< 0.01). Similar trends were also observed with heamatological parameters at 72hours of administration.

Conclusion

This study revealed a synergistic effect of the co-administration on parasite clearance rate of P. berghei infection in mice, with a significant enhancement of haematological parameters within 48 hours of administration. This indicates a rapid rate of recovery from plasmodial infections with the co-administration.