The -238 tumor necrosis factor-alpha promoter polymorphism is associated with decreased susceptibility to cancers

We investigated the potential association of tumor necrosis factor-alpha (TNF-alpha) promoter polymorphisms with cancers. The study included 169 patients with gastric cancer, uterine cervical cancer, colorectal cancer, or renal cell carcinoma and 92 healthy controls. The -308 and -238 polymorphisms in the TNF-alpha promoter were analyzed by PCR-restriction fragment length polymorphism (RFLP). The proportion of individuals carrying the TNF-238A allele was significantly lower in the cancer group than in the control group. The odds ratio for cancer in subjects with the TNF-238A allele was 0.25 (95% CI, 0.10-0.64). No association was found between the -308 polymorphism and cancers. These results suggest that the -238A allele has a protective function against cancers.

Association between TNF-alpha promoter polymorphism and Helicobacter pylori cagA subtype infection

AIMS

To assess the importance of tumour necrosis factor alpha (TNF-alpha) promoter polymorphism in relation to infection with the cytotoxin associated gene A (cagA) subtype of Helicobacter pylori within a dyspeptic Korean population.

METHODS

Eighty three patients with gastric disease and 113 healthy controls were studied. The DNA from gastric biopsy specimens was analysed by H pylori specific and cagA specific polymerase chain reaction (PCR). To characterise TNF-alpha polymorphism at positions -308 and -238, PCR based restriction fragment length polymorphism analysis was performed.

RESULTS

Helicobacter pylori infection was closely correlated with G to A transition at position -308 of the TNF-alpha promoter when compared with healthy controls (odds ratio (OR), 2.912; 95% confidence interval (CI), 1.082 to 7.836; p = 0.034). Although TNF-alpha -308 polymorphism in patients with H pylori was not significantly different from that in patients without H pylori, the -308A polymorphism was strongly associated with H pylori cagA subtype infection when compared with the polymorphism in cagA negative H pylori infection (OR, 8.757; 95% CI, 1.413 to 54.262; p = 0.019) and healthy controls (OR, 3.683; 95% CI, 1.343 to 10.101; p = 0.011). G to A genetic change at position -238 of the TNF-alpha gene was not significantly associated with H pylori cagA subtype infection. In addition, genetic polymorphisms at both sites of the TNF-alpha promoter in patients with H pylori infection did not correlate with the severity of disease.

CONCLUSION

TNF-alpha -308A polymorphism was significantly related to infection with the H pylori cagA subtype in Korean patients with gastric disease.

Control of DNA capture by nanofluidic transistors

We report the use of an array of electrically gated ~200 nm solid-state pores as nanofluidic transistors to manipulate the capture and passage of DNA. The devices are capable of reversibly altering the rate of DNA capture by over 3 orders of magnitude using sub-1 V biasing of a gate electrode. This efficient gating originates from the counter-balance of electrophoresis and electroosmosis, as revealed by quantitative numerical simulations. Such a reversible electronically tunable biomolecular switch may be used to manipulate nucleic acid delivery in a fluidic circuit, and its development is an important first step toward active control of DNA motion through solid-state nanopores for sensing applications.

Microcystin-induced down-regulation of lymphocyte functions through reduced IL-2 mRNA stability

Here we report that lymphocyte functions were down-regulated by cyanobacterial hepatotoxin microcystin. Treatment of three microcystin (MC) isotypes, MC-LR, MC-YR and nodularin, on B6C3F1 mouse splenocytes produced dose-dependent inhibition of in vitro polyclonal antibody response and lymphoproliferation to LPS. ConA-induced lymphoproliferative response was decreased by MC-YR and nodularin, but no significant effect was observed in the MC-LR treatment. Intraperitoneal administration of nodularin into B6C3F1 mice decreased humoral immune responses to sheep red blood cell (sRBC), and the inhibitory effect became severe when hepatic uptake of nodularin was blocked by rifampicin. Each MC 1 microM suppressed phorbol 12-myristate 13-acetate (PMA) plus ionomycin-induced IL-2 mRNA expression in splenocytes and thymocytes, but not in EL-4 mouse thymoma cells. To further characterize the mechanism for the reduced IL-2 mRNA level, IL-2 mRNA stability was measured using RT-PCR. Deprivation of PMA/ionomycin stimuli from activated splenocytes and blockade of new transcription resulted in destabilization of IL-2 mRNA, which was accelerated by MC treatment. These results demonstrated that MC down-regulated lymphocyte functions and the immunosuppression was mediated, at least in part, through decreased IL-2 mRNA stability.

Portable Cytometry Using Microscale Electronic Sensing

In this manuscript, we present three different micro-impedance sensing architectures for electronic counting of cells and beads. The first method of sensing is based on using an open circuit sensing electrode integrated in a micro-pore, which measures the shift in potential as a micron-sized particle passes through. Our micro-pore, based on a funnel shaped microchannel, was fabricated in PDMS and was bound covalently to a glass substrate patterned with a gold open circuit electrode. The amplification circuitry was integrated onto a battery-powered custom printed circuit board. The second method is based on a three electrode differential measurement, which opens up the potential of using signal processing techniques to increase signal to noise ratio post measurement. The third architecture uses a contactless sensing approach, which significantly minimizes the cost of the consumable component of the impedance cytometer. We demonstrated proof of concept for the three sensing architectures by measuring the detected signal due to the passage of micron sized beads through the pore.

A case of mitochondrial trifunctional protein deficiency diagnosed by acylcarnitine profile and DNA analysis in a dried blood spot of a 4-day-old boy

We report a Korean case, consistent with a biochemical diagnosis of trifunctional protein (TFP) deficiency, in which molecular diagnosis revealed a novel mutation in the alpha-subunit of TFP and the rare combination of two intergenic region (C/C and G/G) polymorphisms.

Transcriptome analysis of the response of cultured murine podocytes to puromycin aminonucleoside

AIMS

Idiopathic nephrotic syndrome is known as a disease of the renal glomerular epithelial cells (podocytes). Recent advances in podocyte biology showed that podocytopathy is the culprit of nephrotic syndrome. To obtain comprehensive information about the response of podocytes to injury, we investigated the gene expression profile of podocytes in response to puromycin aminonucleoside (PAN)-induced injury.

METHODS

Differentiated mouse podocyte cell line (MPC5) cells were treated with 25 microg/ml PAN for 24, 48, or 72 h. Gene expression profiles of these cells were analyzed. Real time PCR analysis was used to confirm the findings of microarray.

RESULTS

Expression levels of 23 genes (differentially expressed genes, DEGs), including laminin alpha(1) and MMP3, were significantly different between PAN-treated podocytes and untreated cells. Gene ontology of DEGs indicated that their functional categories were cell adhesion, extracellular matrix (ECM) formation, and ECM degradation. Real-time PCR and indirect immunohistochemistry of PAN-treated and untreated podocytes confirmed the differential expression of DEGs.

CONCLUSION

Using unbiased global gene expression profiling, we found that podocytes respond to PAN-induced injury by down-regulating the expression of genes involved in cell adhesion and extracellular matrix.

Label-free monitoring of embolotherapy via catheter electrochemical impedance spectroscopy

Catheter-based embolization has become a widely adopted minimally-invasive treatment for a broad range of applications. However, assessment of embolization endpoints requires x-ray fluoroscopic monitoring, exposing patients and physicians performing embolization procedures to harmful ionizing radiation. Moreover, x-ray fluoroscopy assessment of embolization endpoints is low sensitivity, subjective, and may not reflect the actual physiology of blood flow reduction, thus providing little oversight of the embolization procedure. Inspired by the observation that the dielectric properties of blood differ from those of fluids injected during the embolization procedure, a customized angiographic catheter was created with embedded electrodes for catheter-based electrochemical impedance spectroscopy as a way to monitor embolization. Real-time electrochemical impedance spectroscopy was performed in a phantom and compared to visual and videographic monitoring. Electrochemical impedance spectroscopy was able to sense endpoints of embolization, including stasis, reflux, and persistent flow. This new technique offers a label-free method of sensing embolization progress with potentially higher sensitivity and reproducibility compared to x-ray, as well as offer substantial reduction in x-ray exposure to patients and physicians.