Thermodynamic parameters of complexation of naphto-15-crown-5 with four alkaline earth ions in aqueous media was determined using titration microcalorimetry at 298.15 K. The stability of the complexes, thermal effect and entropy effect of the complexation is discussed on the basis of the guest ions structure and the solvent effect. The stability constants tendency to vary with ion radius was interpreted. Complex of naphtha-15-crown-5 with calcium ion is very stable due to the synergism of static electric interaction and size selectivity between the host and the guest.
Calorimetry ; methods ; Crown Ethers ; chemistry ; Ions ; chemistry ; Macromolecular Substances ; analysis ; chemistry ; Metals, Alkaline Earth ; chemistry ; Microchemistry ; methods

OBJECTIVETo develop a new nonisotopic detection method of enzyme-amplified time-resolved fluorescence (EATRF) or enzyme-amplified lanthanide luminescence (EALL) for nucleic acid hybridization assays, which can be applied extensively in clinical diagnosis.

METHODSThe method combines the high affinity of biotin-streptavidin system, amplification of enzyme, and inherent advantage of lanthanide chelate with the background elimination of time-resolved fluorescence detection. The conversion of 5-fluorosalicyl phosphate to 5-fluorosalicylic acid (5-FSA) by alkaline phosphatase. The salicylic acid product forms a luminescent ternary chelate with Tb3+ and EDTA.

RESULTSThe dynamic range of the standard curve of EATRFA for nucleic acid hybridization assay was very wide, the range was more than third order of magnitude. The detection sensitivity was about 10 pg of target sequence. When the known target sequence was 20, 10 and 2 ng, the ratio of measured amount to known amount was 110%, 90% and 115% respectively. The main experimental conditions, for example, the irradiating time of ultraviolet rays, the concentrations of biotinylated probe, AP-SA, 5-FSAP and Tb-EDTA and the methods of washing in the related steps, have been optimized. A new stable technology of fluorescence has been developted.

CONCLUSIONSEATRF detection for nucleic acid hybridization assays is a new sensitive simple method, which has a great prospect.

Alkaline Phosphatase ; analysis ; Blotting, Southern ; DNA ; genetics ; Fluoroimmunoassay ; methods ; Luminescent Measurements ; Metals, Rare Earth ; Nucleic Acid Hybridization ; methods ; Spectrometry, Fluorescence ; Substrate Specificity

BACKGROUND: Several ions, such as calcium or magnesium ions, are reported to have regulatory effects on epidermal permeability barrier homeostasis. Recently, it has been suggested that strontium ion can play a substitutive role for calcium ion in various cellular reactions. OBJECTIVE: This study was conducted to investigate the effects of strontium ion, either alone or in combination with calcium or magnesium ions, on epidermal permeability barrier homeostasis. METHODS: Female hairless mice were used to study the effects of various ions on epidermal permeability barrier recovery. Calcium chloride solution, magnesium chloride solution or strontium chloride solution were topically applied to barrier-disrupted skin, either alone or simultaneously. Change of transepidermal water loss, which represents permeability barrier function, was measured by TEWameter and morphological change was also observed by light and electron microscopy. RESULTS: Topical application of strontium chloride solution accelerated permeability barrier recovery rate, compared with vehicle-applied skin. Magnesium chloride solution also accelerated barrier recovery rate, as reported in previous studies. Interestingly, simultaneous application of strontium and calcium ions significantly accelerated barrier recovery rate, compared to application of strontium or calcium ion alone. Nile red staining confirmed the increased neutral lipid deposition in strontium ion applied skin. Electron microscopic observation also revealed an increased lamellar body secretion in strontium ion applied skin. CONCLUSION: Strontium ion can play a regulatory role in epidermal permeability barrier homeostasis due to, at least in part, its competitive action on calcium ion for the same ion channel.
Animals ; Calcium ; Calcium Chloride ; Female ; Homeostasis ; Humans ; Ion Channels ; Ions* ; Magnesium ; Magnesium Chloride ; Mice ; Mice, Hairless ; Microscopy, Electron ; Permeability* ; Skin ; Strontium*

OBJECTIVETo investigate the distribution of rubidium (Rb), cesium (Cs), beryllium (Be), strontium (Sr), and barium (Ba) in blood and urine in general Chinese population.

METHODSA total of 18 120 subjects aged 6~60 years were enrolled from 24 regions in 8 provinces in Eastern, Central, and Western China from 2009 to 2010 based on the method of cluster random sampling. Questionnaire survey was conducted to collect the data on living environment and health status. Blood and urine samples were collected from these subjects, and the levels of Rb, Cs, Be, Sr, and Ba in these samples were determined by inductively coupled plasma mass spectrometry. The distribution of these elements in blood and urine in male or female subjects living in different regions was analyzed statistically.

RESULTSIn the general Chinese population, the concentration of Be in the whole blood was below the detection limit (0.06 μg/L); the geometric mean (GM) of Ba in the whole blood was below the detection limit (0.45 μg/L), with the 95th percentile (P95)of 1.37 μg/L; the GMs (95% CI)of Rb, Cs, and Sr in the whole blood were 2 374(2 357~2 392) μg/L, 2.01 (1.98~2.05) μg/L, and 23.5 (23.3~23.7) μg/L, respectively; in males and females, the GMs (95%CI)of blood Rb, Cs, and Sr were 2 506 (2 478~2 533) μg/L and 2 248 (2 227~2 270) μg/L, 1.88 (1.83~1.94) μg/L and 2.16 (2.11~2.20) μg/L, and 23.4 (23.1~23.7) μg/L and 23.6 (23.3~23.9) μg/L, respectively(P<0.01, P>0.05, and P>0.05). In the general Chinese population, the GM of urine Be was below the detection limit (0.06 μg/L), while the GMs (95%CI)of urine Rb, Cs, Sr, and Ba were 854 (836~873) μg/L, 3.65 (3.56~3.74) μg/L, 39.5 (38.4~40.6) μg/L, and 1.10 (1.07~1.12) μg/L, respectively; in males and females, the GMs (95%CI)of urine Rb, Cs, Sr, and Ba were 876 (849~904) μg/L and 832 (807~858) μg/L, 3.83 (3.70~3.96) μg/L and 3.47 (3.35~3.60) μg/L, 42.5 (40.9~44.2) μg/L and 36.6 (35.1~38.0) μg/L, and 1.15 (1.12~1.19) μg/L and 1.04 (1.01~1.07) μg/L, respectively (all P< 0.01). Correlation analyses showed that there were weak correlations between blood Rb and urine Rb (r=0.197)and between blood Sr and urine Sr (r=0.180), but a good correlation between blood Cs and urine Cs (r=0.487).

CONCLUSIONThe levels of Rb, Cs, Be, Sr, and Ba in the general Chinese population are similar to those reported in other countries, and there is a significant difference in the concentration of each element among the populations living in different regions, as well as significant differences in blood Rb, urine Rb, urine Cs, urine Sr, and urine Ba between males and females.

Adolescent ; Adult ; Barium ; blood ; urine ; Beryllium ; blood ; urine ; Cesium ; blood ; urine ; Child ; China ; Female ; Humans ; Limit of Detection ; Male ; Middle Aged ; Rubidium ; blood ; urine ; Strontium ; blood ; urine ; Young Adult

OBJECTIVE: This study aimed to estimate the association between total and ionized magnesium, and the changes in serum magnesium and calcium levels in patients with preterm labor during magnesium sulfate (MgSO4) administration. METHODS: The study population included 64 women who were candidates for intravenous MgSO4 treatment for preterm labor. Serial blood samples were taken and measured total magnesium (T-Mg), ionized magnesium (I-Mg), total calcium (T-Ca), and ionized calcium (I-Ca) levels every one-week interval (1st, 2nd, 3rd). RESULTS: There was no significant difference in T-Mg and I-Mg levels during MgSO4 administration (P>0.05). There was no significant difference in T-Ca and I-Ca levels during MgSO4 administration (P>0.05). Compared before and after administration of MgSO4, T-Mg and I-Mg levels and T-Ca levels were changed allow statistically significant (P < 0.05). But, there was no significant difference in the I-Ca serum levels before and after MgSO4 administration (P=0.495). The I-Mg levels for patients with adverse effect were higher than other group but did not reach statistical significance (P>0.05). There was significant correlation between levels of I-Mg and T-Mg (I-Mg=0.395×T-Mg+0.144, P < 0.01). CONCLUSION: There were no significant differences in serum Mg and Ca levels during MgSO4 administration for preterm labor. Compared to the before and after administration of MgSO4, only I-Ca levels were not substantially changed. There are significant correlations between I-Mg and T-Mg levels during administration of MgSO4 and I-Mg level seemed to have more correlation with adverse effect than T-Mg.
Calcium ; Female ; Humans ; Magnesium Sulfate ; Magnesium ; Obstetric Labor, Premature ; Pregnancy

The use of magnesium sulphate has recently increased in anesthesiology and pain medicine. The roles of magnesium sulphate are as an analgesic adjuvant, a vasodilator, a calcium channel blocker and reducing the anesthetic requirement. These effect are primarily based on the regulation of calcium influx into the cell and antagonism of the N-methyl-D-aspartate receptor. We discuss here the clinical effects of magnesium sulphate on anesthesiology and pain medicine.
Anesthesiology ; Calcium ; Calcium Channels ; Magnesium ; N-Methylaspartate

No abstract available.
Breast* ; Calcium* ; Magnesium* ; Milk, Human* ; Phosphorus*

To providean evidence tosupport thecalcium hypothesis ofcerebral ischemia, we examinedthe effectsoftheextracellular calciumandcalciumchelating agent(Bapta-AM), and magnesiumon in vitro ischemia usingrat hippocampal slices. Loss of the populationspike on thehippocampal CA1 region afterelectrical stimulation was usedas indexof damageon thesynaptictransmission andspike amplitudeof the population spikeas index ofrecovery level.Recovery from theloss of orthodromic responses aftertransient hypoxia in lowcalcium treated sliceswas more rapid than nontreated normal calciumslices, and remained robust for4 hours in slices exposed in lowcalcium, whileresponses inslices madehypoxic in normalcalcium remained depressed or more slowlyrecovered. There were statistical significant differences of amplitude between the two group at 5, 10 15, 30, 60, 90 and 120 minute after 10 minute hypoxia (p<0.05).To thelesserextent, similarresults wasobservedin calcium chelating agent, BAPTA-AM, treatedslices, with statistical significant difference at 10minute afterhypoxia(p<0.05). Butin additionto reducingcalcium, elevating magnesium levelwhich is knownas voltagedependent NMDA receptorblocker, did not improve recoverycompared to reducingcalcium alone. We concludethat recovery from the lossof function afterhypoxia was improved bydecreasing extracellular calcium concentration of neuronsand activation of NMDA receptorsprobably played no part in early neuronal damage.
Anoxia* ; Calcium* ; Ischemia ; Magnesium* ; N-Methylaspartate ; Neurons

No abstract available.
Animals ; Calcium ; Glucose ; Insulin ; Magnesium ; Pancreas ; Rats

142 cases of nasopharyme cancer were treated by radiotherapy using the method of sample external radotherapy and method of external radio therapy and method of external radio therapy in combining with the source of radium applied in situ supported by a foam rubber hoder. Results showed that by combining method reduced the risk of recurrence occurred later and in a location other than the primary cancer. The technique was carried with low cost and easy looking for materials.
Therapeutics ; Carcinoma ; Nasopharyngeal Neoplasms ; Monensin ; Radium