Design of an integrated sensor for in vivo simultaneous electrocontractile cardiac mapping.

While there is extensive mapping of the spread of electrical activity in the heart, there have been no measurements of electrical and localized mechanical, or contractile, activity. Yet the development of effective treatments for diseases like chronic heart failure and cardiac hypertrophy depend on the ability to quantify improvements in electrocontractile function. In this paper, we present a sensor that is capable of making simultaneous, electrocontractile measurements. Its small size facilitates placement in multiple myocardial sites for multichannel studies. Semiconductor strain gages are used for force sensing, and Ag/AgCl-plated tungsten electrodes act as electrogram sensors. The sensor contains electronics on-board, including instrumentation amplifiers and a microprocessor for data sampling and analog-to-digital conversion. Each sensor can accurately detect 0-245+/-5 mV in two electrogram channels with a sensitivity of 0.96+/-0.2 mV/step and less than 2% error, and 0-144+/-29 g of contractile force with a sensitivity of 0.56+/-0.11 g/step in the analog-to-digital conversion and less than 6% error. The sensor has been tested in vivo in open-chest rabbit and pig mapping studies. These studies indicated that the average peak-to-peak contractile force at the apex is smaller in the rabbit than the pig (13.3 versus 40.3 g), that the average peak-to-peak contractile force in the pig is smaller near the base than near the apex (31.3 versus 40.3 g), and that contractile force is visibly decreased during ventricular fibrillation compared to normal sinus rhythm.

Hypermethylation of p16 gene in clinical specimens of patients with lung cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To evaluate aberrant methylation of the p16 promoter as a useful biomarker of lung cancer.</p><p><b>METHODS</b>A modified methylation-specific semi-nested PCR was performed to detect p16 hypermethylation in the matched samples of tumor tissue, blood plasma and sputum derived from 51 cases of lung cancer patients.</p><p><b>RESULTS</b>Hypermethylation of p16 promoter was demonstrated in 84.3% of the tumor tissues, 70.6% of the blood plasma and 76.5% of the sputum specimens, respectively. Only the patients whose tumor tissues had p16 hypermethylation exhibited aberrant methylation in their plasma and/or sputum specimens. Combining with cytological examination, 92.2% of the patients with lung cancer could be detected by p16 hypermethylation assay in both sputum and plasma samples.</p><p><b>CONCLUSION</b>The results indicate that p16 hypermethylation in plasma and sputum identified by semi-nested PCR is a biomarker of lung cancer which can be useful as an auxillary diagnostic parameter.</p>

Detection of hypermethylation of p16 gene in plasma DNA from lung cancer patients / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To detect hyper methylation of p16 gene in plasma DNA from patients with lung cancer, and to assess its potential as a malignant marker.</p><p><b>METHODS</b>Using a modified semi-nested methylation-specific PCR (MSP), the status of methylation of the p16 was investigated in plasma DNA from 137 lung cancer patients and 112 matched tumor tissues.</p><p><b>RESULTS</b>Hypermethylation of the p16 was present in 75.2% (103/137) of the plasma samples and 80.4% (90/112) of the tumor tissues. Hypermethylation of the p16 in the plasma was detected in 77.9% squamous-cell carcinoma, 65.1% adenocarcionma, 75.1% adeno-squamous-cell carcinoma, and 91.7% small-cell lung cancer. Only in those patients whose tumor tissues had hypermethylation of p16 gene, similar changes could be detected in their plasma samples. Hypermethylation of the p16 in plasma and the corresponding tumor tissues was not significantly correlated with the clinical stage and pathological type of the tumor.</p><p><b>CONCLUSION</b>The result indicates that hypermethylation of the p16 may be a useful marker in the auxiliary diagnosis of lung cancer.</p>