Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0848332 (Spots)
 453 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Natural systems excel in directing the synthesis of inorganic materials for various functional purposes. One of the best-studied systems is silica synthesis, as occurs in diatoms and marine sponges. Various biological and synthetic polymers have been shown to template and catalyze silica formation from silicic acid precursors. Here, we describe the use of poly-L-lysine to promote the synthesis of silica in neutral, aqueous solution and when immobilized onto a silicon support structure under similar conditions. Either reagent jetting or conventional photolithography techniques can be used to pattern the templating polymer. Spots created by reagent jetting led to the creation of silica structures in the shape of a ring that may be a result of the spotting process. Photolithographically defined poly-L-lysine spots led to thin laminate structures after exposure to a dilute aqueous silicic acid solution. The laminate structures were nanostructured and highly interconnected. Photolithographic patterning of (3-aminopropyl)trimethoxysilane, a reagent that mimics the lysine functional group, led to similar silica coatings even though low-molecular-weight materials do not rapidly promote silica synthesis in solution. This result highlights the importance of functional-group arrangement for templating and promoting the synthesis of inorganic materials. The described surface-patterning techniques offer a route to integrate conventional silicon-patterning technologies with biologically based material synthesis. Such combined fabrication techniques enable controlled assembly over multiple length scales and an approach to understanding interfacial silica synthesis, as occurs in natural systems.
 ...
PMID:Surface patterning of silica nanostructures using bio-inspired templates and directed synthesis. 1537 57

For pathologists, pneumologists, and occupational and environmental physicians it is relevant to know silica levels in lung tissue to better define limits of exposure. Environmental Scanning Electron Microscopy (ESEM) has been employed to detect silica particles and to compare silica levels in subjects with and without Lung Cancer (LC). We investigated 25 paraffin-embedded tissue samples of patients with LC adenocarcinoma, and 20 fresh samples of subjects without LC deceased for extra-pulmonary diseases. Silica levels were quantified considering the Number of Spots of silica particles (NS), and the Number of Positive Zones (NPZ) in which there was at least one spot. Levels of NS and NPZ were assessed with Poisson-type regression models, and in two samples of silica-exposed workers with LC the performance of models were evaluated. LC patients displayed higher silica levels, as compared to controls; smoking, age and gender had no significant effects on this relationship. Values of NS and NPZ for the exposed workers were in agreement with model estimates. The fitted model between NS and NPZ might be useful in evaluating new observations and in the development of threshold limit values of silica in biological tissues. ESEM is a rapid, simple and valid tool for the determination of silica levels in lung tissues.
 ...
PMID:Detection of silica particles in lung tissue by environmental scanning electron microscopy. 1901 58

During a routine nursery inspection in Hernando County, Florida in July 2011, leaf spot symptoms were observed on the popular sugar substitute stevia (Stevia rebaudiana). Spots were roughly circular to irregular in shape, variable in size, and dark brown with a yellow halo. White to cream-colored, circular, convex, gram-negative bacterial colonies were isolated on nutrient agar and identified as Pseudomonas cichorii based on the LOPAT scheme (2). DNA from four individual colonies inoculated in nutrient broth was extracted using DNeasy columns (Qiagen Inc., Valencia, CA). The PCR-amplified product from four different genes, 16S rRNA (1.5 Kbp), gyrB (0.9 Kbp), rpoB (1.2 Kbp), and rpoD (0.7 Kbp), was sequenced (GenBank Accession Nos. JQ994483, JQ994484, JQ994485, and JQ994486). Nucleotide and translated amino acid sequences for each gene were compared to the nucleotide and protein databases, respectively. The best matches were always with P. cichorii with nucleotide identities ranging from 98 to 99% and amino acid identities from 99 to 100%. Four healthy stevia plants were spray inoculated with 20 ml of a 108 CFU ml-1 suspension prepared from a 24-hour-old culture, of which two were sprayed with carborundum (silicon carbide) immediately prior to inoculation. Two additional plants were sprayed with carborundum only or sterile tap water only and served as healthy controls. Symptoms began to develop 4 days after inoculation. Spots originated at the tips or edges of the leaves and enlarged over time. Enlarging lesions progressed to encompass the entire leaf, accompanied by water soaking, curling, and necrosis. Blighting typically spread down to the stem and caused dieback. The pathogen was successfully reisolated from the lesions and produced identical LOPAT scheme results. Based on the information collected, it is believed that this is the first confirmed report of bacterial leaf spot caused P. cichorii on stevia worldwide. This find is significant due to the rising popularity of stevia cultivation for its sweetness and medicinal properties (1). To our knowledge, stevia is not currently being grown commercially in Florida; however, there is commercial acreage being developed elsewhere in the United States. References: (1) D. Patil et al. Asian J. Pharm. Clin. Res. 5:1, 2011. (2) N. W. Schaad et al. Laboratory Guide for Identification of Plant Pathogenic Bacteria. 3rd Edition. The American Phytopathological Society. St. Paul, MN, 2001.
 ...
PMID:First Report of Pseudomonas cichorii Causing Leaf Spot of Stevia Detected in Florida. 3072 90