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Saudi Medical Journal Dec 2019[No Abstract Available].
[No Abstract Available].
Topics: Aged; Barium; Contrast Media; Humans; Lung; Male; Tomography, X-Ray Computed
PubMed: 31828285
DOI: 10.15537/smj.2019.12.24689 -
Chemistry (Weinheim An Der Bergstrasse,... Sep 2021Photochemical activation is proposed as a general method for controlling the crystallization of sparingly soluble carbonates in space and time. The photogeneration of...
Photochemical activation is proposed as a general method for controlling the crystallization of sparingly soluble carbonates in space and time. The photogeneration of carbonate in an alkaline environment is achieved upon photo-decarboxylation of an organic precursor by using a conventional 365 nm UV LED. Local irradiation was conducted focusing the LED light on a 300 μm radius spot on a closed glass crystallization cell. The precursor solution was optimized to avoid the precipitation of the photoreaction organic byproducts and prevent photo-induced pH changes to achieve the formation of calcium carbonate only in the corresponding irradiated area. The crystallization was monitored in real-time by time-lapse imaging. The method is also shown to work in gels. Similarly, it was also shown to photo-activate locally the formation of barium carbonate biomorphs. In the last case, the morphology of these biomimetic structures was tuned by changing the irradiation intensity.
Topics: Barium; Calcium Carbonate; Carbonates; Crystallization
PubMed: 34236738
DOI: 10.1002/chem.202102321 -
Environmental Health Perspectives Jun 2011
Topics: Barium; Biodegradation, Environmental; Closterium; Fresh Water; Strontium Radioisotopes
PubMed: 21628117
DOI: 10.1289/ehp.119-a244 -
Thorax Aug 1986Four men who mined barytes in Scotland and who developed pneumoconiosis are described. Three developed progressive massive fibrosis, from which two died; and one...
Four men who mined barytes in Scotland and who developed pneumoconiosis are described. Three developed progressive massive fibrosis, from which two died; and one developed a nodular simple pneumoconiosis after leaving the industry. The radiological and pathological features of the men's lungs were those of silicosis and high proportions of quartz were found in two of them post mortem. The quartz was inhaled from rocks associated with the barytes in the mines. The features of silicosis in barium miners are contrasted with the benign pneumoconiosis, baritosis, that occurs in workers exposed to crushed and ground insoluble barium salts. Diagnostic difficulties arise when silicosis develops in workers mining minerals known to cause a separate and benign pneumoconiosis. These difficulties are compounded when, as not infrequently happens, the silicotic lesions develop or progress after exposure to quartz has ceased.
Topics: Aged; Barium; Humans; Lung; Male; Mining; Radiography; Scotland; Silicosis
PubMed: 3787542
DOI: 10.1136/thx.41.8.591 -
American Journal of Speech-language... Mar 2021Purpose Despite the emphasis on using evidence-based practice for patient care, as clinicians, we sometimes find that there is insufficient evidence to support our...
Purpose Despite the emphasis on using evidence-based practice for patient care, as clinicians, we sometimes find that there is insufficient evidence to support our clinical practices. One example of this is the "contentious" inclusion of routine, standardized visualization of the esophagus during modified barium swallow studies (MBSSs). This review sought to investigate the evidence for inclusion of routine esophageal visualization during the MBSS, a practice that is supported by the long-established interrelationship between all aspects of the oral, pharyngeal, and esophageal swallowing continuum. Method Searches were conducted in PubMed, Scopus, and CINAHL databases. Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were followed to identify articles that met prespecified inclusion and exclusion terms. Results Five articles were included in this review, which identified that esophageal findings were present in 48.67% of those participants whose MBSS included esophageal visualization. Conclusion This review supports a standardized, validated, reliable visualization protocol of the esophagus during the MBSS as a critical component to the accurate diagnosis and formulation of treatment recommendations for patients with swallowing disorders.
Topics: Barium; Deglutition; Deglutition Disorders; Fluoroscopy; Humans
PubMed: 33734825
DOI: 10.1044/2020_AJSLP-20-00255 -
The Journal of Biological Chemistry May 1989Barium ions enter chromaffin cells via voltage-sensitive calcium channels, although the intracellular site of barium action is distinct from that of calcium. The entry... (Comparative Study)
Comparative Study
Barium ions enter chromaffin cells via voltage-sensitive calcium channels, although the intracellular site of barium action is distinct from that of calcium. The entry of barium primarily through voltage-sensitive channels was indicated by experiments showing inhibition of 133Ba2+ uptake by blockers of voltage-dependent calcium channels. In addition, 133Ba2+ uptake was stimulated by 50 mM KCl but not by nicotine. Furthermore, 133Ba2+ uptake was inhibited by hyperosmolarity, which specifically blocks the voltage-sensitive calcium channel but not the receptor-associated calcium channel. These conclusions from studies on barium uptake were also borne out by experiments measuring catecholamine secretion. Thus, blockers of voltage-dependent calcium channels which inhibited barium uptake also inhibited barium-induced catecholamine secretion. In other experiments, simultaneous stimulation with nicotine and barium in the presence of calcium evoked coincident and additive catecholamine secretion. By contrast, when 50 mM KCl was substituted for nicotine in the same experimental design, barium ions inhibited potassium-induced catecholamine secretion at low calcium concentrations. Only at high calcium concentrations were barium-induced and potassium-induced secretion additive. These data also indicate that barium and calcium compete at the voltage-sensitive pathway. Furthermore, these additivity data suggest that once inside the cell, barium and calcium have two distinct mechanisms of action. As predicted by this hypothesis, in digitonin-permeabilized chromaffin cells either calcium or barium stimulated catecholamine release, and in the presence of both cations catecholamine secretion was equivalent to the sum of secretion with either cation alone. Additional support of this concept comes from experiments showing that while calcium-mediated catecholamine secretion is sensitive to trifluoperazine and imipramine, barium-mediated secretion is not. Taken together, all these data indicate that there are two distinct intracellular sites of action for barium and calcium. In contrast to catecholamine secretion, non-exocytotic ascorbic acid secretion was induced by nicotine and potassium in the presence of calcium, but not by barium alone. These data provide additional evidence that barium acts by a different mechanism than calcium, in still another secretory system in chromaffin cells.
Topics: Animals; Barium; Binding, Competitive; Biological Transport; Calcium; Calcium Channels; Catecholamines; Cations, Divalent; Cattle; Cells, Cultured; Chromaffin System; Digitonin; Egtazic Acid; Imipramine; Kinetics; Nicotine; Osmolar Concentration; Potassium Chloride; Trifluoperazine
PubMed: 2542253
DOI: No ID Found -
PloS One 2013Differences in the chemical composition of calcified skeletal structures (e.g. shells, otoliths) have proven useful for reconstructing the environmental history of many...
Differences in the chemical composition of calcified skeletal structures (e.g. shells, otoliths) have proven useful for reconstructing the environmental history of many marine species. However, the extent to which ambient environmental conditions can be inferred from the elemental signatures within the vertebrae of elasmobranchs (sharks, skates, rays) has not been evaluated. To assess the relationship between water and vertebral elemental composition, we conducted two laboratory studies using round stingrays, Urobatis halleri, as a model species. First, we examined the effects of temperature (16°, 18°, 24°C) on vertebral elemental incorporation (Li/Ca, Mg/Ca, Mn/Ca, Zn/Ca, Sr/Ca, Ba/Ca). Second, we tested the relationship between water and subsequent vertebral elemental composition by manipulating dissolved barium concentrations (1x, 3x, 6x). We also evaluated the influence of natural variation in growth rate on elemental incorporation for both experiments. Finally, we examined the accuracy of classifying individuals to known environmental histories (temperature and barium treatments) using vertebral elemental composition. Temperature had strong, negative effects on the uptake of magnesium (DMg) and barium (DBa) and positively influenced manganese (DMn) incorporation. Temperature-dependent responses were not observed for lithium and strontium. Vertebral Ba/Ca was positively correlated with ambient Ba/Ca. Partition coefficients (DBa) revealed increased discrimination of barium in response to increased dissolved barium concentrations. There were no significant relationships between elemental incorporation and somatic growth or vertebral precipitation rates for any elements except Zn. Relationships between somatic growth rate and DZn were, however, inconsistent and inconclusive. Variation in the vertebral elemental signatures of U. halleri reliably distinguished individual rays from each treatment based on temperature (85%) and Ba exposure (96%) history. These results support the assumption that vertebral elemental composition reflects the environmental conditions during deposition and validates the use of vertebral elemental signatures as natural markers in an elasmobranch. Vertebral elemental analysis is a promising tool for the study of elasmobranch population structure, movement, and habitat use.
Topics: Animals; Barium; Biomarkers; Calcium; Elasmobranchii; Environment; Temperature; Water
PubMed: 24098320
DOI: 10.1371/journal.pone.0062423 -
Materials Science & Engineering. C,... May 2021Dual labeled contrast agents could provide better complementary information for bioimaging than available solely from a single modality. In this paper we investigate the...
Dual labeled contrast agents could provide better complementary information for bioimaging than available solely from a single modality. In this paper we investigate the suitability of Yb and Er-doped BaYF upconversion nanoparticles (UCNPs) as both optical and X-ray micro computed tomography (μCT) contrast agents. Stable, aqueous UCNP dispersions were synthesised using a hydrothermal method with the addition of polyethyleneimine (PEI). UCNPs were single crystal and had a truncated cuboidal and/or truncated octahedral morphology, with average particle size of 47 ±9 nm from transmission electron microscopy which was further used to characterize the structure and composition in detail. A zeta potential value of +51 mV was measured for the aqueous nanoparticle dispersions which is beneficial for cell permeability. The outer hydrated PEI layer is also advantageous for the attachment of proteins for targeted delivery in biological systems. The prepared UCNPs were proven to be non-toxic to endothelial cells up to a concentration of 3.5 mg/mL, when assessed using an MTT assay. The particles showed intense green upconversion photoluminescence when excited at a wavelength of 976 nm using a diode laser. Quantitative X-ray μCT contrast imaging confirmed the potential of these UCNPs as X-ray contrast agents and confirming their dual modality for bioimaging.
Topics: Barium; Contrast Media; Endothelial Cells; Fluorides; Nanoparticles; X-Ray Microtomography; Yttrium
PubMed: 33947528
DOI: 10.1016/j.msec.2021.111937 -
The Journal of Biological Chemistry Jan 1989Measurements of free cystolic Ca2+ ([Ca2+]i) and Ba2+ ([Ba2+]i) concentrations with Fura 2 were used to identify and characterize the properties of a...
Measurements of free cystolic Ca2+ ([Ca2+]i) and Ba2+ ([Ba2+]i) concentrations with Fura 2 were used to identify and characterize the properties of a depolarization-activated Ca2+ and Ba2+ entry in the plasma membrane of osteoblast-like cells. The presence of this pathway was demonstrated in two osteoblastic cell lines, UMR-106 and MC3T3-E1 and osteoblasts isolated from rat long bone and rat neonatal calvariae. Subsequent characterization of the pathway was performed in the osteosarcoma cell line UMR-106. Depolarization of the cells with high medium K+ was followed by an increase in [Ca2+]i which was dependent on medium Ca2+. Ba2+ ions depolarized the cells and were transported by this pathway. Mg2+ ions interfered with Ca2+ and Ba2+ entry. At 140 mM KCl and 1 mM MgCl2, the pathway could be saturated with Ca2+ or Ba2+. The apparent affinity for Ca2+ was 0.78 mM and for Ba2+ 1.82 mM. Ca2+ or Ba2+ entry into the cells was blocked by low concentrations of nicardipine, diltiazem, verapamil, and La3+. In the absence of an increase in [Ca2+]i or [Ba2+]i, the pathway inactivated within about 5 min after depolarization. When [Ca2+]i or [Ba2+]i was allowed to increase, the pathway inactivated within about 20 s. These properties suggest that Ca2+ and Ba2+ entry are mediated by an L-type, depolarization-activated Ca2+ channel in osteoblasts. The activity of these channels changes little with an increase or decrease in cell volume. Thus, it is concluded that these pathways do not provide the Ca2+ entry pathway required for initiation of volume decrease by osteoblasts.
Topics: Animals; Barium; Benzofurans; Calcium; Calcium Channel Blockers; Cell Line; Cell Membrane; Cells, Cultured; Egtazic Acid; Fura-2; Kinetics; Membrane Potentials; Osteoblasts; Rats
PubMed: 2491847
DOI: No ID Found -
The Journal of Thoracic and... Aug 2018The value of routine timed barium esophagram (TBE) in longitudinal follow-up of achalasia after Heller myotomy is unknown. We prospectively prescribed a yearly follow-up...
OBJECTIVES
The value of routine timed barium esophagram (TBE) in longitudinal follow-up of achalasia after Heller myotomy is unknown. We prospectively prescribed a yearly follow-up TBE. Purposes were to characterize esophageal emptying over time after myotomy, identify preoperative TBE measures associated with follow-up TBE, and characterize follow-up TBE over time in relationship to reintervention.
METHODS
From March 1995 to April 2013, 635 patients underwent Heller myotomy for achalasia; 559 had at least 1 follow-up TBE. Temporal trends of 1335 follow-up TBEs in all nonreintervention and reintervention patients were assessed. Multivariable longitudinal analysis identified preoperative TBE measures associated with follow-up TBE.
RESULTS
On average, TBE height and width at 1 and 5 minutes decreased approximately 50% and 60%, respectively, at first postoperative follow-up, and remained stable or slightly decreased for up to 5 years. Wider TBE width at 5 minutes was associated with greater follow-up TBE height and width at 1 minute. Of 118 patients undergoing reintervention, 64 (57%) had only 1 reintervention, with follow-up TBE returning to that of nonreintervention patients. Patients whose follow-up TBE remained abnormal underwent a further reintervention, some normalizing on subsequent TBE, and some not.
CONCLUSIONS
Follow-up TBE is valuable postmyotomy, particularly if there is substantial esophageal dilatation preoperatively. Follow-up TBE reassures patients with stable or decreasing TBE measures, permitting decreased follow-up intensity. Reintervention should not be considered a myotomy failure, because a successful, single, nonsurgical reintervention often results in long-term successful palliation. More than 1 reintervention requires intensification of TBE follow-up, facilitating treatment planning.
Topics: Adult; Aged; Aged, 80 and over; Barium; Contrast Media; Esophageal Achalasia; Female; Follow-Up Studies; Humans; Male; Middle Aged; Myotomy; Radiography; Young Adult
PubMed: 29627183
DOI: 10.1016/j.jtcvs.2018.03.001