Liquid crystal-assisted optical biosensor for early-stage diagnosis of mammary glands using HER-2.

Breast cancer (BC) is one of the most commonly diagnosed cancers and the second leading cause of cancer mortality among women around the world. The purpose of this study is to present a non-labeled liquid crystal (LC) biosensor, based on the inherent feature of nematic LCs, for the evaluation of BC using the human epidermal growth factor receptor-2 (HER-2) biomarker. The mechanism of this sensing is supported by surface modification with dimethyloctadecyl [3-(trimethoxysilyl) propyl] ammonium chloride (DMOAP) encouraging the long alkyl chains that induce a homeotropic orientation of the LC molecules at the interface. To enhance the binding efficacy of more HER-2 antibody (Ab) on LC aligning agents, a simple ultraviolet radiation-assisted method was also used to increase functional groups on the DMOAP coated slides, thereby improving binding affinity and efficiency onto HER-2 Abs. The designed biosensor makes use of the specific binding of HER-2 protein to HER-2 Ab and disruption of the orientation of LCs. This orientation change leads to a transition of the optical appearance from dark to birefringent, enabling the detection of HER-2. This novel biosensor exhibits a linear optical response to HER-2 concentration in the wide dynamic range of 10-6-102 ng/mL, with an ultra-low detection limit of 1 fg/mL. As a proof of concept, the designed LC biosensor was successfully investigated for the quantification of HER-2 protein in patients suffering from BC. Owing to the sensitivity, selectivity, and label-free detection, this biosensor may amplify the application of LC-based biosensors for the detection of most types of cancers.

First Report of Orobanche aegyptiaca Parasitism on Sesame in Iran.

A field survey revealed infestations of broomrape, Orobanche aegyptiaca (syn. Phelipanche aegyptiaca), on sesame (Sesamum indicum L.) plants in the province of Khorasan (36°12'N, 57°39'E, 972 m above sea level) in northeastern Iran in November 2011. About 5% of total sesame fields in this area were infested, and the estimated average yield losses were approximately 30 to 40%. The annual mean air temperature and the average maximum and minimum air temperatures were 17.5, 24.2, and 10.6°C, respectively. In a pot experiment that was also conducted at the Isfahan University of Technology to study the effect of sesame as a trap crop for managing broomrape, a total of 20 genotypes of sesame were infested with broomrape. The infestation of sesame was confirmed by verifying the attachment of the broomrape to the sesame roots. Broomrape plant heights were between 20 and 35 cm, with flowering stems 15 to 20 cm. The stems were erect, usually branched, slender, glandular-pubescent, pale yellowish, and inflorescent rather than lax. Flowers had one bract and two bracteoles. The bracts measured 6 to 8 mm, had ovate lanceolates shorter than the calyces, and filiform, lanceolate bracteoles measuring 8 mm. The calyces measured 10 to 11 mm, and were gamosepalous, entire, whitish, hairy, and glandular. Corollas measured 32 to 35 mm, and were blue violet or sky blue with darker veins and cream proximally, straight or slightly curved, conspicuously infundibuliform in distal parts, and glandular-pubescent with two lips. Stamens were epipetalous, inserted 4 to 5 mm above the corolla base, with filaments hairy below, sparsely so above; anthers were villous or spidery hairy along sutures. Stigma lobes were white. The Botanists Group of the College of Agriculture of IUT confirmed the plants' identity. Sesame has been mentioned before as a trap crop for broomrape (1); however, to our knowledge, this is the first report of broomrape parasitism on sesame in Iran. Reference: (1) B. M. Chittapur et al. Allelopathy J. 8:147, 2001.

[Plant from New-Caledonia. Alkaloids of Melodinus reticulatus]. / Plante de Nouvelle-Caledonie. Alcaloïdes de Melodinus reticulatus.

(-)Tabersonine and (-)-11-methoxytabersonine were isolated from fruits of Melodinus reticulatus. Stems and leaves contain uvaol and eight alkaloids, five of which were previously described: (-)tabersonine, venalstonidine, kopsinine, venalstonine and its 3-oxoderivative. Three are new: 19-hydroxyvenalstonine, 19-hydroxyvenalstonidine and 3-oxovenalstonidine.