Unrevealing arsenic and lead toxicity and antioxidant response in spinach: a human health perspective.

Arsenic (As) and lead (Pb) are highly toxic and carcinogenic metal(loid)s. The present study evaluated the human exposure risk via estimating As and Pb uptake and physiological/biochemical modifications inside spinach plant grown under metal(loid)-contaminated growth medium. Plants were treated with three levels of each metal(loid) (0, 25 and 125 µM) for four weeks. The spinach plants accumulated high concentration of metal(loid)s in roots (0-18.9 ug g-1 Pb and 0.2-22.7 ug g-1 As) and less were translocated towards shoot (0-0.3 ug g-1 Pb and 0.2-8.8 ug g-1 As). Metal(loid) accumulation in plants decreased plant biomass and pigment contents and provoked oxidative stress by increased hydrogen peroxide (H2O2) production in roots up to 65% and 22%, respectively, for As and Pb. The production of H2O2 in leaves was decreased up to 59% and 45%, respectively, for As and Pb than control. Moreover, the antioxidant system (superoxide, catalase, guaiacol peroxidase, ascorbate peroxidase) gets activated under metal(loid) stress. The exposure assessment indices revealed high carcinogenic (CR > 10-4) and non-carcinogenic (HQ > 1) risks owing to the consumption of As- and Pb-contaminated spinach leaves. Results revealed As is being more toxic to plants and humans than Pb. These findings suggest possible alarming consequences of As and Pb to spinach and their assimilation within the edible tissues.

A multivariate analysis of comparative effects of heavy metals on cellular biomarkers of phytoremediation using Brassica oleracea.

The biochemical/physiological variations in plant responses to heavy metals stress govern plant's ability to phytoremediate/tolerate metals. So, the comparative effects of different types of heavy metals on various plant responses can better elucidate the mechanisms of metal toxicity and detoxification. This study compared the physiological modifications, photosynthetic performance and detoxification potential of Brassica oleracea under different levels of chromium (Cr), nickel (Ni) and selenium (Se). All the heavy metals induced a severe phytotoxicity to B. oleracea in terms of chlorophyll contents, Ni being the most toxic (76% decrease). Brassica oleracea showed high lipid oxidation: 87% and 273%, respectively in leaves and roots. Furthermore, all the metals increased the activities of catalase and peroxidase, while decreased superoxide dismutase and ascorbate peroxidase. Interestingly, heavy metals decreased hydrogen peroxide contents perhaps due to their possible transformation to another form of reactive oxygen species such as hydroxyl radical. Among the three metals, Ni was more phytotoxic than Cr and Se. Moreover, the phytoremediation/tolerance potential of B. oleracea to Ni, Cr and Se stress varied with the type of metal, their applied levels, response variables and plant organ type (root/shoot). The multivariate analysis separated different plant response variables and heavy metal treatments into different groups based on their correlations.

Celiac disease and celiac crisis in children.

OBJECTIVE: To determine the frequency of clinical features of Celiac disease (CD) and Celiac crisis in children. STUDY DESIGN: Case series. PLACE AND DURATION OF STUDY: Paediatrics Unit, Sheikh Zayed Medical College and Hospital, Rahim Yar Khan, from September 2009 to September 2010. METHODOLOGY: Forty children aged between 4 to 13 years of either gender, presenting with complaints of recurrent diarrhea, abdominal distention, severe emaciation and dehydration were included. The information about breast feeding, weaning diets, age of introduction of wheat diets, onset of diarrhea, characteristics and frequency of stools, growth, vaccination status, symptoms in 1st degree relatives, restriction of Gluten diet in the past and anthropometric measures were recorded. Serological tests against anti-Tissue Transglultaminase (anti-tTG) antibodies were obtained in all cases. Upper gastrointestinal endoscopies were performed and multiple biopsies were taken from distal parts of duodenum. RESULTS: Among the forty children, twenty four (60%) were females and 16 were males (40%). The mean age was 6.35 ± 2.83 years. Thirty five (87.5%) parents were cousins. Breast feeding was not exclusively given and the Gluten containing weaning diets were given as early as 3.5 months of age. Thirty (75%) children presented with typical sign and symptoms of CD. Celiac crisis presented with profuse diarrhea, severe dehydration; abdominal distention; pedal edema, carpopedal spasm due to tetany; wasted muscles; head drop and inability to stand. The serum TtG antibodies in thirty-eight cases (95%) were above the cut off level of 7 u/ml ranging from 35-99 u/ml. The histopathology of specimens from distal duodenum revealed lesions of M3 type in thirteen (32.5%) and M2 type in eighteen cases (45%). All cases recovered and improved on follow-up after strict adherence to gluten-free diet (GFD). CONCLUSION: Majority of children with Celiac disease presented with typical symptom, while Celiac crisis was characterized by severe dehydration, weakness and calcium deficiency signs. Most were the product of consanguineous marriages and were given Gluten-containing weaning foods as early as the 4th month of life.