Biotechnology for Metal Extraction, Mineral Beneficiation and Environmental Control

With the rapid depletion of high grade ores and concerns about environmental degradation, the necessity for utilisation of lean grade mineral resources have become all the more urgent. With the advent of bioleaching since the early 1960's possibilities of metal extraction in an environment-friendly fashion have emerged. As of now three metals namely copper, uranium and gold are commercially produced around the world using biooxidation in the presence of Acidithiobacillus ferrooxidans

Activity Concentrations of Natural Radionuclides in Soils of Rainforest Sites in Western Ghats

Assessments of naturally occurring radionuclides in soil collected from a tropical rainforest forest of western Ghats, India were conducted. These radionuclides were distributed unevenly in the forest soil. For all soil samples, the terrestrial gamma dose rate and the corresponding outdoor annual effective dose equivalents were evaluated. The activity concentration of 232Th and average outdoor gamma dose rates were found to be higher than the global average which appears to affects Western Ghats environment in general, the radiological hazard indices were found to be within the International Commission on Radiological Protection recommended limits. Hence, obtained results for natural radionuclides in the forest soils were within the range specified by UNSCEAR (2000) report for virgin soils except 232Th

Mycrobially Induced Processing of Mineral Fines

Microorganisms such as Bacillus polymyxa which occur indigenously associated with several ore deposits, bring about significant surface chemical changes on interacted minerals such as hematite, corundum,calcite, quartz and kaolinite. Bacterial interaction rendered quartz and kaolinite surfaces hydrophobic, while hematite, corundum and calcite surfaces became more hydrophilic. Biotrearment of mineral mixtures containing the above minerals was found to result in selective _flocculation and selective flotation. It is shown that selective removal of silica and alumina from iron ores and bauxite can be brought about by biological processes.Mechanisms behind such microbially induced beneficiation processes are illustrated with res-pect to processing of fine particles

Improving Scheelite Recovery from Gold Tailings

Tungsten occupies a very important place amongst the strategic metals. However, resources available in India are scarce and lean in grade. Various physical methods of beneficiation have been tried to beneficiate such, low grade ores, but these have not been generally efficient in terms of high recoveries and concentrate grades. Tungsten minerals, wolframite and scheelite being friable, tend to slime during size reduction stages. Because of this, high loss in slimes occurs during conventional gravity opera-tions. Flotation techniques too have not been very succe-ssful though some excellent results have been reported by Mercade (1) on direct flotation of scheelite from low grade ores. Recently special gravity concentration equi-pment such as Bartles Mozley Separator (MIS)and Cross Belt Concentrator (CBC) have been used in separation of a wide variety of fine heavy minerals including scheelite (2, 3, 4, 5). To obtain a high grade concentrate, a combination of gravity and flotation and/or magnetic separation method is generally employed

Diagnostic value of in situ polymerase chain reaction in childhood leprosy

Objective: Our aim was to assess the diagnostic value of in situ polymerase chain reaction (PCR) in leprosy, particularly for enhancing histopathological diagnosis. Methods: We prospectively studied 20 children (aged <16 years) with leprosy. Clinical examination of each case was performed, and skin smear for acid-fast bacillus was prepared. A biopsy of the lesion site was performed for histopathological examination and in situ PCR testing. Results: Histopathological examination confirmed the clinical diagnosis in only 45% of the cases; nonspecific histopathology was reported for the remaining 55% of the cases. In situ PCR showed a positivity of 57.1% in the early/localized form of leprosy (indeterminate/borderline tuberculoid) and 61.5% in the borderline borderline/borderline lepromatous group. When compared with the histopathological examination, a significant enhancement of 15% in diagnosis was seen. With in situ PCR, the diagnosis could be confirmed in 4 (36.3%) of 11 cases with nonspecific histopathological features (which is common in early disease) in addition to confirmation of 8 (88.8%) of 9 histopathologically confirmed tissue sections. Histopathology and in situ PCR combined together confirmed the diagnosis in 13 (65%) of the 20 cases. Conclusions: In situ PCR is an important diagnostic tool, especially in early and doubtful cases of leprosy

Integrative analyses identify modulators of response to neoadjuvant aromatase inhibitors in patients with early breast cancer

Introduction Aromatase inhibitors (AIs) are a vital component of estrogen receptor positive (ER+) breast cancer treatment. De novo and acquired resistance, however, is common. The aims of this study were to relate patterns of copy number aberrations to molecular and proliferative response to AIs, to study differences in the patterns of copy number aberrations between breast cancer samples pre- and post-AI neoadjuvant therapy, and to identify putative biomarkers for resistance to neoadjuvant AI therapy using an integrative analysis approach. Methods Samples from 84 patients derived from two neoadjuvant AI therapy trials were subjected to copy number profiling by microarray-based comparative genomic hybridisation (aCGH, n = 84), gene expression profiling (n = 47), matched pre- and post-AI aCGH (n = 19 pairs) and Ki67-based AI-response analysis (n = 39). Results Integrative analysis of these datasets identified a set of nine genes that, when amplified, were associated with a poor response to AIs, and were significantly overexpressed when amplified, including CHKA, LRP5 and SAPS3. Functional validation in vitro, using cell lines with and without amplification of these genes (SUM44, MDA-MB134-VI, T47D and MCF7) and a model of acquired AI-resistance (MCF7-LTED) identified CHKA as a gene that when amplified modulates estrogen receptor (ER)-driven proliferation, ER/estrogen response element (ERE) transactivation, expression of ER-regulated genes and phosphorylation of V-AKT murine thymoma viral oncogene homolog 1 (AKT1). Conclusions These data provide a rationale for investigation of the role of CHKA in further models of de novo and acquired resistance to AIs, and provide proof of concept that integrative genomic analyses can identify biologically relevant modulators of AI response

Characterisation of the Stromal Microenvironment in Lobular Breast Cancer

SIMPLE SUMMARY: Invasive lobular breast cancer (ILC) accounts for approximately 5–15% of breast cancers, and although response rates to treatments are initially good, an ILC diagnosis is associated with adverse long-term outcomes; better treatments, specifically targeted to this sub-type of breast cancer, are required to improve patient survival. The tumor microenvironment (TME) plays an important role in determining how cancers respond to treatment, and in this study, we carried out an in-depth analysis of the TME in ILC following laser-capture microdissection of the tumor stroma, and analysis of primary cancer-associated fibroblasts (CAFs), which comprise the majority of non-malignant cells within tumors. This identified changes in genes involved in regulation of the extracellular matrix and also growth factor signaling pathways that were differentially regulated in ILC. Further analysis of breast cancer datasets showed that two of these genes which encode a secreted metalloproteinase (PAPPA) and a metalloproteinase inhibitor (TIMP2) were associated with survival outcomes in ILC. ABSTRACT: Invasive lobular carcinoma (ILC) is the second most common histological subtype of breast cancer, and it exhibits a number of clinico-pathological characteristics distinct from the more common invasive ductal carcinoma (IDC). We set out to identify alterations in the tumor microenvironment (TME) of ILC. We used laser-capture microdissection to separate tumor epithelium from stroma in 23 ER+ ILC primary tumors. Gene expression analysis identified 45 genes involved in regulation of the extracellular matrix (ECM) that were enriched in the non-immune stroma of ILC, but not in non-immune stroma from ER+ IDC or normal breast. Of these, 10 were expressed in cancer-associated fibroblasts (CAFs) and were increased in ILC compared to IDC in bulk gene expression datasets, with PAPPA and TIMP2 being associated with better survival in ILC but not IDC. PAPPA, a gene involved in IGF-1 signaling, was the most enriched in the stroma compared to the tumor epithelial compartment in ILC. Analysis of PAPPA- and IGF1-associated genes identified a paracrine signaling pathway, and active PAPP-A was shown to be secreted from primary CAFs. This is the first study to demonstrate molecular differences in the TME between ILC and IDC identifying differences in matrix organization and growth factor signaling pathways

Dual Targeting of PDGFRα and FGFR1 Displays Synergistic Efficacy in Malignant Rhabdoid Tumors

© 2016 The Author(s) Subunits of the SWI/SNF chromatin remodeling complex are mutated in a significant proportion of human cancers. Malignant rhabdoid tumors (MRTs) are lethal pediatric cancers characterized by a deficiency in the SWI/SNF subunit SMARCB1. Here, we employ an integrated molecular profiling and chemical biology approach to demonstrate that the receptor tyrosine kinases (RTKs) PDGFRα and FGFR1 are coactivated in MRT cells and that dual blockade of these receptors has synergistic efficacy. Inhibitor combinations targeting both receptors and the dual inhibitor ponatinib suppress the AKT and ERK1/2 pathways leading to apoptosis. MRT cells that have acquired resistance to the PDGFRα inhibitor pazopanib are susceptible to FGFR inhibitors. We show that PDGFRα levels are regulated by SMARCB1 expression, and assessment of clinical specimens documents the expression of both PDGFRα and FGFR1 in rhabdoid tumor patients. Our findings support a therapeutic approach in cancers with SWI/SNF deficiencies by exploiting RTK coactivation dependencies