A field study was conducted in the fly ash lagoons of Santandih Thermal Power Plant located in West Bengal (India) to find out total, EDTA and DTPA extractable metals in fly ash and their bioaccumulation in root and shoot portion of the naturally growing vegetation. Fly ash sample has alkaline pH and low conductivity. The concentration of total Cu, Zn, Pb and Ni were found higher than weathered fly ash and natural soil, where as Co, Cd and Cr were found traces. Five dominant vegetation namely, Typha latifolia, Fimbristylis dichotoma, Amaranthus defluxes, Saccharum spontaenum and Cynodon dactylon were collected in the winter months (November-December). Bioaccumulation of metals in root and shoot portions were found varied significantly among the species, but all concentration were found within toxic limits. Correlation between total, DTPA and EDTA extractable metals viz. root and shoot metals concentration were studied. Translocation factor (TF) for Cu, Zn and Ni were found less than unity, indicates that these metals are immobilized in the root part of the plants. Metals like Mn have TF greater than unity. The study infers that natural vegetation removed Mn by phytoextraction mechanisms (TF > 1), while other metals like Zn, Cu, Pb and Ni were removed by rhizofiltration mechanisms (TF < 1). The field study revealed that T. latifolia and S. spontaenum plants could be used for bioremediation of fly ash lagoon.
An aggressive malignant peripheral nerve sheath tumor of an atypical site such as the scalp, in which complete surgery may not always be possible, could benefit from postoperative radiotherapy. A dose of approximately 60 Gy could be effectively delivered with a satisfactory outcome.
Aim: To study the outcome and recurrence in supratentorial anaplastic ependymoma. Methods: Sixteen cases of supratentorial anaplastic ependymoma were reviewed. The average age of presentation was 8.2 years ranging from 1 to 16 years of age. The mean duration between the onset of first symptoms to time of presentation was 4.2 months. Follow-up ranged from 5 to 58 months with a mean of 16.8 months. Results: Gross total excision of tumor was achieved in 14 cases, as judged on the basis of intraoperative impression and confirmed with postoperative contrast MR or CT scan. There were 2 unfortunate deaths in the series, one as result of disseminated intravascular coagulation in view of massive blood loss and the other child had evidence of central transtentorial herniation preoperatively which failed to recover. Postoperative cranial radiotherapy was offered to all the 14 remaining cases. Twelve of 14 cases showed evidence of recurrence at follow-up. Recurrence occurred as early at 6 months and as late as 58 months. Only 2 children were recurrence free at follow-up of 6 months and 14 months, respectively. Two operated and irradiated cases of differentiated ependymomas (grade II) developed anaplastic recurrence at follow-up of 5 years and 9 years, respectively, suggesting a malignant transformation of tumor at follow-up. Four out of 12 cases were reoperated for their recurrence in view of localized nature of recurrence and good Karnofsky’s performance status. Conclusion: It is obvious that anaplastic ependymomas of the supratentorial compartment are aggressive tumors with high rates of recurrence even after gross total excision and irradiation. Gross total excision and postoperative irradiation are not effective in preventing early recurrence in anaplastic ependymomas, and other factors affecting the outcome need to be analyzed.
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