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Exploiting algal mineralization for nanotechnology: bringing coccoliths to the fore.
Skeffington, AW, Scheffel, A
Current opinion in biotechnology. 2018;:57-63
Abstract
Complex mineral structures are produced by many microalgal species. Pioneering work on diatom silica has demonstrated the potential of such structures in nanotechnology. The calcified scales of coccolithophores (coccoliths) have received less attention, but the large diversity of architectures make coccoliths attractive as parts for nano-devices. Currently coccolith calcite can be modified by the incorporation of metal ions or adsorption of enzymes to the surface, but genetic modification of coccolithophores may permit the production of coccoliths with customized architectures and surface properties. Further work on the laboratory cultivation of diverse species, the physiochemical properties of coccoliths and on genetic tools for coccolithophores will be necessary to realize the full potential of coccoliths in nanotechnology.
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Microbially-induced Carbonate Precipitation for Immobilization of Toxic Metals.
Kumari, D, Qian, XY, Pan, X, Achal, V, Li, Q, Gadd, GM
Advances in applied microbiology. 2016;:79-108
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Abstract
Rapid urbanization and industrialization resulting from growing populations contribute to environmental pollution by toxic metals and radionuclides which pose a threat to the environment and to human health. To combat this threat, it is important to develop remediation technologies based on natural processes that are sustainable. In recent years, a biomineralization process involving ureolytic microorganisms that leads to calcium carbonate precipitation has been found to be effective in immobilizing toxic metal pollutants. The advantage of using ureolytic organisms for bioremediating metal pollution in soil is their ability to immobilize toxic metals efficiently by precipitation or coprecipitation, independent of metal valence state and toxicity and the redox potential. This review summarizes current understanding of the ability of ureolytic microorganisms for carbonate biomineralization and applications of this process for toxic metal bioremediation. Microbial metal carbonate precipitation may also be relevant to detoxification of contaminated process streams and effluents as well as the production of novel carbonate biominerals and biorecovery of metals and radionuclides that form insoluble carbonates.
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Hypocalcaemia following thyroidectomy unresponsive to oral therapy.
Etheridge, ZC, Schofield, C, Prinsloo, PJ, Sturrock, ND
Hormones (Athens, Greece). 2014;(2):286-9
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Abstract
Hypocalcaemia due to hypoparathyroidism following thyroidectomy is a relatively common occurrence. Standard treatment is with oral calcium and vitamin D replacement therapy; lack of response to oral therapy is rare. Herein we describe a case of hypoparathyroidism following thyroidectomy unresponsive to oral therapy in a patient with a complex medical history. We consider the potential causes in the context of calcium metabolism including: poor adherence, hungry bone syndrome, malabsorption, vitamin D resistance, bisphosphonate use and functional hypoparathyroidism secondary to magnesium deficiency. Malabsorption due to intestinal hurry was likely to be a contributory factor in this case and very large doses of oral therapy were required to avoid symptomatic hypocalcaemia.
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The development and validation of a new technology, based upon 1.5% arginine, an insoluble calcium compound and fluoride, for everyday use in the prevention and treatment of dental caries.
Cummins, D
Journal of dentistry. 2013;:S1-11
Abstract
OBJECTIVE This paper briefly discusses caries prevalence, the multi-factorial nature of caries etiology, caries risk and the role and efficacy of fluoride. The paper also highlights research on bacterial metabolism which provided understanding of the mouth's natural defenses against caries and the basis for the development of a new technology for the everyday prevention and treatment of caries. Finally, evidence that the technology complements and enhances the anti-caries efficacy of fluoride toothpaste is summarized. CONCLUSIONS Global data show that dental caries is a prevalent disease, despite the successful introduction of fluoride. Caries experience depends on the balance between consumption of sugars and oral hygiene and the use of fluoride. Three scientific concepts are fundamental to new measures to detect, treat and monitor caries: (1) dental caries is a dynamic process, (2) dental caries is a continuum of stages from reversible, pre-clinical to irreversible, clinically detectable lesions, and (3) the caries process is a balance of pathological and protective factors that can be modulated to manage caries. Fluoride functions as a protective factor by arresting and reversing the caries process, but fluoride does not prevent pathological factors that initiate the process. A novel technology, based upon arginine and an insoluble calcium compound, has been identified which targets dental plaque to prevent initiation of the caries process by reducing pathological factors. As the mechanisms of action of arginine and fluoride are highly complementary, a new dentifrice, which combines arginine with fluoride, has been developed and clinically proven to provide superior caries prevention.
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Hypercalcemia in pregnancy: a case of milk-alkali syndrome.
Kolnick, L, Harris, BD, Choma, DP, Choma, NN
Journal of general internal medicine. 2011;(8):939-42
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Abstract
Milk-alkali syndrome is a rare cause of hypercalcemia characterized by the triad of hypercalcemia, renal insufficiency, and metabolic alkalosis that results from the overconsumption of calcium containing products. In the setting of pregnancy where there is a physiologic increase in calcium absorption, milk-alkali syndrome can be potentially life threatening. We report a case of a 26-year-old woman in her second trimester of pregnancy who presented with 2 weeks of flank pain, nausea, vomiting, anorexia, headache, and lightheadedness. The history revealed consumption of a large quantity of milk, calcium carbonate antacid, and calcium-containing prenatal vitamins. Her symptoms and hypercalcemia resolved with intravenous fluids and a loop diuretic. With the increased use of calcium carbonate for peptic ulcer disease, gastroesophageal reflux disease, and osteoporosis, milk-alkali syndrome has experienced a resurgence and must be considered in the differential diagnosis of hypercalcemia. In this clinical vignette we review the literature on milk-alkali syndrome in pregnancy and discuss important diagnostic and therapeutic considerations when managing the pregnant patient with hypercalcemia.