PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “CITRIC ACID”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources
PubMed1993

Comparative SEM study on the effect of acid etching with tetracycline HCl or citric acid on instrumented periodontally-involved human root surfaces.

This study compared the surface characteristics of periodontally diseased single-rooted human teeth extracted after treatment with either tetracycline HCl or citric acid solutions. The study group was comprised of 30 teeth from 22 patients with advanced periodontal disease extracted before the start of periodontal therapy. Diseased surfaces were identified, outlined, and root planed by hand curet or finishing bur. The teeth were sectioned and solutions of tetracycline HCl or citric acid (pH 1) were applied to the surfaces with cotton pellets for 5 minutes. Extracted teeth were processed and root surface samples then examined by scanning electron microscope. The surfaces of both acid-treated sets of specimens differed considerably from specimens treated with root planing alone, regardless of root planing method. Acid-treated specimens exhibited dentinal tubules exposed by the removal of the smear layer, surfaces devoid of the debris normally present in root planed-only specimens, and the dense network of collagen fibers that make up the dentin structure. Although differences were seen in surface depressions and fiber-like structures among some specimens, the tetracycline HCl and citric acid solutions produced comparable morphologic characteristics.

Acid Etching, Dental↗
PubMed2005

Enhanced phytoextraction: II. Effect of EDTA and citric acid on heavy metal uptake by Helianthus annuus from a calcareous soil.

High biomass producing plant species, such as Helianthus annuus, have potential for removing large amounts of trace metals by harvesting the aboveground biomass if sufficient metal concentrations in their biomass can be achieved However, the low bioavailability of heavy metals in soils and the limited translocation of heavy metals to the shoots by most high biomass producing plant species limit the efficiency of the phytoextraction process. Amendment of a contaminated soil with ethylene diamine tetraacetic acid (EDTA) or citric acid increases soluble heavy metal concentrations, potentially rendering them more available for plant uptake. This article discusses the effects of EDTA and citric acid on the uptake of heavy metals and translocation to aboveground harvestable plant parts in Helianthus annuus. EDTA was included in the research for comparison purposes in our quest for less persistent alternatives, suitable for enhanced phytoextraction. Plants were grown in a calcareous soil moderately contaminated with Cu, Pb, Zn, and Cd and treated with increasing concentrations of EDTA (0.1, 1, 3, 5, 7, and 10 mmol kg(-1) soil) or citric acid (0.01, 0.05, 0.25, 0.442, and 0.5 mol kg(-1) soil). Heavy metal concentrations in harvested shoots increased with EDTA concentration but the actual amount of phytoextracted heavy metals decreased at high EDTA concentrations, due to severe growth depression. Helianthus annuus suffered heavy metal stress due to the significantly increased bioavailable metal fraction in the soil. The rapid mineralization of citric acid and the high buffering capacity of the soil made citric acid inefficient in increasing the phytoextracted amounts of heavy metals. Treatments that did not exceed the buffering capacity of the soil (< 0.442 mol kg(-1) soil) did not result in any significant increase in shoot heavy metal concentrations. Treatments with high concentrations resulted in a dissolution of the carbonates and compaction of the soil. These physicochemical changes caused growth depression of Helianthus annuus. EDTA and citric acid added before sowing of Helianthus annuus did not appear to be efficient amendments when phytoextraction of heavy metals from calcareous soils is considered.

Biodegradation, Environmental↗
PubMed2002

Acidification of formula with citric acid is equally effective and better tolerated than acidification with hydrochloric acid.

OBJECTIVE: To determine whether acidification of formula with citric acid is equally protective against bacterial translocation and gut colonization but better tolerated than acidification with hydrochloric acid in neonatal rabbits. DESIGN: Paired animal model with control. SETTING: Animal laboratory. SUBJECTS: Premature neonatal New Zealand rabbit pups. INTERVENTIONS: A standard neonatal rabbit model in two versions, a bacterial challenge and a no bacterial challenge model, was used to assess bacterial translocation and gut colonization. Two hundred forty-six rabbit pups were delivered by cesarean section 1 day premature and randomly placed into two groups sorted by type of formula acidification (hydrochloric acid or citric acid). Pups were gavage fed pH 3 kitten formula every 12 hrs. Ranitidine hydrochloride at 20 mg x kg(-1) x day(-1) was added to all formula. Bacterial challenge animals were given 1 x 10(6) colony-forming units/mL of Enterobacter cloacae with the third feeding. Animals in the no bacterial challenge group received no bacterial challenge. Animals were killed on day of life 3, and the liver, spleen, mesenteric lymph nodes, and cecum were sequentially harvested and cultured. Organs were qualitatively judged for growth, whereas cecal cultures were quantified as colony-forming units/gram. Stomach biopsies were performed to look for mucosal damage. Long-term tolerance was assessed in 48 pups fed formula acidified to pH 3 with either hydrochloric acid or citric acid and 20 animals fed pH 7 formula without ranitidine. Weight gain and mortality rate were followed for 14 days. MEASUREMENTS AND MAIN RESULTS: Gut colonization and bacterial translocation to liver, spleen, and mesenteric lymph nodes were equivalent between citric acid and hydrochloric acid in both bacterial challenge and no bacterial challenge models. Long term, citric acid animals exceeded hydrochloric acid animals in daily weight gain and survival (p <.05 for both) and equaled pH 7 animals in these measurements. CONCLUSION: Acidification of formula with citric acid is equally protective against bacteria but better tolerated than acidification with hydrochloric acid.

Animals↗