Primary spinal primitive neuroectodermal tumour - a case report.

Primitive neuroectodermal tumours (PNET) are aggressive childhood malignancies and offer a significant challenge to treatment. A two years old female child presented with weakness both lower limbs. Preoperative MRI of the spine and paravertebral regionIso - hyper intense posterior placed extradural lesion, non contrast enhancing from D11-L2 levels with cord compression D9 to L3 laminectomy done. Granulation tissue found from D11 to L2. with cord compression. The granulation tissue removed in toto. The pathological findings were consistent with PNET. Post operative neurological improvement was minimal. Cranial screening ruled out any intracranialtumour. Hence a diagnosis of primary spinal PNET was made. A review of the literature shows that only 19 cases of primary intraspinal PNETs have been reported to date and the present case extradural in location. Primary intraspinal PNETs are rare tumors and carry a poor prognosis.

Miniaturized redox potential probe for in situ environmental monitoring.

The need for accurate, robust in situ microscale monitoring of oxidation-reduction potentials (ORP) is required for continuous soil pore water quality monitoring. We are developing a suite of self-contained microelectrodes that can be used in the environment, such as at Superfund sites, to monitor ORP in contaminated soils and sediments. This paper presents details on our development of microelectrode sensor arrays for ORP measurements. The electrochemical performance of these ORP electrodes was fully characterized by measuring redox potentials in standard solutions. It found that the newly developed integrated ORP microelectrodes produced a very stable voltage response (the corresponding rate of the integrated microelectrode potential change was in the range of 0.6-1.1 mV/min), even when the measurement was carried out outside of a Faraday cage where signals from most conventional microelectrodes are usually inhibited by external electrical nose. These new microelectrodes were easier to fabricate and were more robust than conventional microelectrodes. The tip size of the integrated ORP microelectrode was approximately 200 nm square, with a taper angle of approximately 20 degrees and a length of 57 microm. The integrated ORP microelectrode exhibited better signal stability and substantially shorter response times (from less than a few milliseconds to 30 s, depending on the standard solution used) than the commercial millielectrode (a few minutes). Compared with the slope of the commercial millelectrode, the slope of the integrated microelectrode (61.5 mV/pH) was closerto the ideal slope against quinhydrone calibration solutions. Therefore, it is to be expected that the newly developed ORP microelectrode may have wider applications in contaminated soils, biofilms, and sediments.

Genetic analysis of certain in vitro and in vivo parameters in pigeonpea (Cajanus cajan L.).

Studies on callus growth and shoots/cotyledon, using seven different genotypes of pigeonpea and their hybrid progenies, revealed continuous variation for these traits. Hence, the type of gene action influencing in vitro cell proliferation and differentiation has been investigated in a diallel analysis of seven pigeonpea genotypes. Highly significant average heterosis was recorded for callus growth and seed yield/plant. In general, the F1 hybrids which showed heterosis for callus growth also exceeded their better parent for yield/ plant. Combining ability analysis revealed both additive and non-additive gene effects for callus growth, while number of shoots/cotyledon was mostly governed by non-additive gene effects. The genotype, 'ICP 7035', was the best general combiner for callus growth and shoot forming capacity of cotyledons. Two cross combinations, '7186'×'6974' and '7035'×'T-21', showed maximum SCA effects for callus growth and shoots/cotyledon. Callus dry weight was positively correlated with seed yield/plant and seedling weight. The strong positive association of callus growth with seed yield indicates the possibility of using this system for mass screening and selection of superior hybrids.