Exogenous hydrogen sulphide alleviates copper stress impacts in Artemisia annua L.: Growth, antioxidant metabolism, glandular trichome development and artemisinin biosynthesis.

A supply of plant micronutrients (some of which are metals) is necessary to regulate many plant processes; their excess, however, can have detrimental consequences and can hamper plant growth, physiology and metabolism. Artemisia annua is an important crop plant used in the treatment of malaria. In this investigation, the physio-biochemical mechanisms involved in exogenous hydrogen sulphide-mediated (H2 S) alleviation of copper (Cu) stress in A. annua were assessed.. Two different levels of Cu (20, 40 mg·kg-1 ), one H2 S treatment (200 µm) and their combinations were introduced while one set of plants was retained as control. Results showed that the presence of excess Cu in the soil reduced growth and biomass, photosynthetic parameters, chlorophyll content and fluorescence, gas exchange parameters and induced antioxidant enzyme activity. Copper stress enhanced the production of thiobarbituric acid reactive substances (TBARS) and increased Cu content in both roots and shoots of affected plants. Exogenous application of H2 S restored the physio-biochemical characteristics of Cu-treated A. annua plants by reducing lipid peroxidation and enhancing the activity of antioxidant enzymes in Cu-stressed plants as compared with the controls. Hydrogen sulphide also reduced the Cu content in different plant parts, increased photosynthetic efficiency, trichome density, average area of trichomes and artemisinin content. Therefore, our results provide a comprehensive assessment of the defensive role of H2 S in Cu-stressed A. annua.

Papillary glioneuronal tumors: Distinctive cytological characteristics and cyto-histologic correlation.

Intraoperative cytological examination and cyto-histologic correlation of papillary glioneuronal tumors have rarely been described in detail in the literature. A 23-year-old female presented at our institution with seizure-like activity, and a 3.0 cm left temporal lobe hypoattenuating lesion. She was accurately diagnosed with papillary glioneuronal tumor on Intraoperative cytology. The patient subsequently proceeded to stealth-guided awake left temporal craniotomy, confirming the diagnosis. In this article, we present a detailed report of papillary glioneuronal tumor (extremely rare central nervous system neoplasm) describing the cytologic and histologic morphologic features, its differential diagnosis with review of the literature.