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The lower extremity may be exposed to prolonged periods of ischemia, resulting in depletion of intracellular energy stores in the affected skeletal muscle. The role of adenine nucleotide reduction and failure of resynthesis on reperfusion in determining the extent of muscle necrosis was investigated in this study, in addition to the possible beneficial effects of the addition of exogenous adenosine triphosphate-magnesium chloride during early reperfusion. The isolated paired canine gracilis muscle model was used. After 4 hours of normothermic ischemia in group I, a perfusate Krebs-Henseleit solution plus the gradual reintroduction of oxygenated blood flow was compared to standard reperfusion. In group II, a similar infusion protocol was used, with the addition of 2 mmol/L adenosine triphosphate-magnesium chloride and compared to normal reperfusion. Adenosine triphosphate-magnesium chloride resulted in the salvage of skeletal muscle, 57% +/- 12% versus 44% +/- 14% (p less than 0.05, n = 6 pairs). Reperfusion with the solution alone increased the resulting necrosis (42% +/- 13% vs 60% +/- 20%, n = 6 pairs). Adenine nucleotide stores were not increased, but oxygen consumption was increased by magnesium chloride-adenosine triphosphate (p less than 0.05, analysis of variance [ANOVA]). A clear relationship was demonstrated between the fall in energy stores, as measured by a change in energy charge potential from preischemia to end ischemia levels, and the extent of resulting necrosis (p less than 0.01). In summary, the addition of 2 mmol/L to an infusion of Krebs-Henseleit solution during reperfusion results in significant salvage of skeletal muscle.(ABSTRACT TRUNCATED AT 250 WORDS)
The effects on the calcium oxalate urolithiasis urinary risk factors of "Rosa Canina", in herb infusion form, and magnesium chloride have been studied using female Wistar rats under balanced dietary conditions. No significant effects on the volume of liquids drunk or on creatinine, phosphate, and oxalate urinary concentrations and excretions were observed. The herb infusion did not cause any diuretic effect. Calciuria decreased and citraturia increased when taking the herb infusion, and vice versa when taking magnesium chloride. Magnesium chloride decreased the urinary pH value, but this effect was not observed when magnesium chloride was administered with herb infusion. In conclusion, the same beneficial effects of the studied infusion herb on calcium oxalate urolithiasis urinary risk factors can be clearly detected. An interesting fact is that it seems that some possible effects depend on dietary components, thus, i.e., an increase in the urinary pH was only detected when the intake of the herb infusion was studied in a magnesium chloride-supplemented diet.
Recent findings on changes in the mineral content of tissues in bovine hypocalcaemia and hypomagnesaemia show the necessity of using different mineral solutions for the treatment and prevention of these conditions. Infusion of 2% CaCl2-6H2O with 10% MgCl2-6H2O and 5% glucose one after the other or in combination produced severe functional changes in cardiac activity and respiration. Recommended concentrations for treatment or prophylaxis of hypomagnesaemia were 10 g magnesium chloride and 2 g calcium chloride, or alternatively 12 g magnesium adipate and 5 g calcium gluconate, in 100 ml of distilled water (total dose 500 ml). This was well tolerated and it overcame the mineral deficiency in tissues.
Reactive uptake coefficients for nitric acid onto size-selected (d(ve) = 102 and 233 nm) sodium chloride aerosols are determined for relative humidities (RH) between 85% and 10%. Both pure sodium chloride and sodium chloride mixed with magnesium chloride (X(Mg/Na) = 0.114, typical of sea salt) are studied. The aerosol is equilibrated with a carrier gas stream at the desired RH and then mixed with nitric acid vapor at a concentration of 60 ppb in a laminar flow tube reactor. At the end of the reactor, the particle composition is determined in real time with a laser ablation single particle mass spectrometer. For relative humidities above the efflorescence relative humidity (ERH), the particles exist as liquid droplets and the uptake coefficient ranges from 0.05 at 85% RH to >0.1 near the ERH. The droplet sizes, relative humidity and composition dependencies, are readily predicted by thermodynamics. For relative humidities below the ERH, the particles are nominally "solid" and uptake depends on the amount of surface adsorbed water (SAW). The addition of magnesium chloride to the particle phase (0.114 mole ratio of magnesium to sodium) facilitates uptake by increasing the amount of SAW. In the presence of magnesium chloride, the uptake coefficient remains high (>0.1) down to 10% RH, suggesting that the displacement of chloride by nitrate in fine sea salt particles is efficient over the entire range of conditions in the ambient marine environment. In the marine boundary layer, displacement of chloride by nitrate in fine sea salt particles should be nearly complete within a few hours (faster in polluted areas)-a time scale much shorter than the particle residence time in the atmosphere.
A study was conducted to compare the pharmacokinetic profile of three oral magnesium supplements--magnesium chloride solution, slow-release magnesium chloride tablets, and magnesium gluconate tablets--at 16 mmol/dose. Twelve healthy normomagnesemic subjects were evaluated during an initial baseline study, followed by three magnesium supplementation studies. Supplements were administered in a randomized, crossover fashion at weekly intervals. During each of the four trials, subjects followed the same routines and consumed identical diets. Magnesium concentrations were measured in urine samples collected from 0 to 4, 4 to 8, 8 to 12, and 12 to 24 hours. Intraleukocyte, total serum, and ultrafiltrable magnesium were measured in blood samples drawn at 0, 1, 2, 3, 4, 8, 12, and 24 hours. Compared with baseline, 24-hour urinary magnesium excretion significantly increased (P < 0.05) after the administration of the magnesium chloride solution and also increased after the administration of the other supplements, but the difference was not significant. The 24-hour areas under the curve (AUCs) for total serum, ultrafiltrable, and leukocyte magnesium were greater after the administration of each of the supplements when compared with baseline, although the differences were not statistically significant. Differences in delta AUCs (supplement AUC minus baseline AUC) for total magnesium, ultrafiltrable magnesium, and 24-hour urinary magnesium excretion were statistically different from zero or between supplements. Statistically significant differences (P < 0.05) in total serum, ultrafiltrable, and leukocyte magnesium concentrations were observed at various time points. These results suggest that there were no major differences in the overall effect of these supplements on total serum, ultrafiltrable, and leukocyte magnesium concentrations but do reveal differences in the time-concentration profiles in magnesium levels in blood and urine among the three supplement forms.
Patients with diabetes mellitus were surveyed to determine magnesium utilization and supplementation patterns and the extent to which these patterns correlate with American Diabetes Association (ADA) consensus panel recommendations. Participating ADA member physicians were asked to enroll five or more patients with insulin-dependent diabetes mellitus (IDDM, or type I diabetes) or non-insulin-dependent diabetes mellitus (NIDDM, or type II diabetes) who were not currently receiving magnesium supplementation and who they believed required or could benefit from oral magnesium chloride administration. Data were then collected regarding specific patient characteristics (ie, current diabetes therapy and glucose control); concomitant diseases and cardiovascular medications; baseline serum magnesium level, if measured before initiating magnesium chloride supplementation; and magnesium chloride dosage and duration. A total of 199 patients with diabetes began treatment with magnesium chloride supplementation after enrollment by a specialist. The mean baseline serum magnesium level for patients with IDDM was 1.48 mg/dL and for patients with NIDDM was 1.44 mg/dL (normal range, 1.80 to 2.40 mg/dL). No differences in mean serum magnesium levels were observed between men and women and between those with IDDM and those with NIDDM. Glucose control, as measured by glycosylated hemoglobin Alc, did not correlate with magnesium serum levels. A concomitant cardiovascular disease was present in 70% of patients. In 78.3% of patients, supplementation was initiated because of low serum magnesium levels; in 21.7%, magnesium chloride therapy was initiated empirically. No correlation was found between serum magnesium levels and the prescribed dosage or the recommended duration of magnesium therapy. Patterns of magnesium utilization among survey respondents generally followed ADA consensus panel recommendations. A majority of diabetic patients who were given magnesium chloride supplementation had concomitant cardiovascular disease. Primary care physicians and cardiologists who treat large numbers of patients with diabetes and cardiovascular disease should be knowledgeable of the ADA consensus report because of the high prevalence of hypomagnesemia and because of the consequences of magnesium deficiency in these high-risk groups. To achieve successful long-term maintenance in these patients, additional physician education appears to be necessary regarding initial dosing strategies and recommended duration of supplementation.
1. Glutamate in the extracellular compartment of the striatum of freely moving rats was monitored at 5 min intervals using microdialysis and an enzyme-based assay. 2. Basal levels of dialysate glutamate were 3.6 +/- 0.5 microM. Local infusion through the dialysis probe of tetrodotoxin (TTX), cadmium chloride or magnesium chloride produced no reduction in basal levels of glutamate; with the latter two there was, instead, an increase. 3. Neuronal activation stimulated by induced grooming was accompanied by an increase in total glutamate efflux of 47.5 +/- 25.0% above basal level; this increase was not reduced by local infusion of TTX. 4. We propose that the TTX-insensitive release of glutamate in response to physiological stimulation is derived from glial cells and is a Ca(2+)-dependent mechanism triggered by a receptor-mediated release of Ca2+ from internal stores that spreads through the network of astrocytes.
The antifungal effects of zinc chloride (znCl), Calcium chloride (CaCl), magnesium chloride (MgCl) as well as soot collected from a local kitchens were tested on five isolated species of the dermatophytes from cases of human dermatophytoses. Of these three metallic salts, ZnCl showed the highest inhibitory effect on the dermatophytes. At a concentration of 0.01 M it showed 100% inhibition on these fungi. Although the other two metallic salts showed some inhibitory effect CaCl at concentration between 0.01 M and 1 M showed only 50% inhibitory effect while MgCl at concentration between 0.1 M and 1 M showed less than 50% inhibitory effect on the fungi. Also soot inhibited the growth of all the dermatophytes tested at concentration between 0.1 and 2%. Trichophyton rubrum and Microspum audouinii appeared to be most sensitive to these compounds compared to the other three species which include T. mentagrophytes, T. tonsurans and M. gypseum.
Dependence of stability of glucose upon electrolyte composition of solutions used for peritoneal dialysis was studied. Stability of glucose was estimated by determinations of formed 5-HMF. It has been stated that stability of glucose depends on the kind of electrolytes present in the solution, glucose concentration and conditions of thermal sterilization. The highest levels of 5-HMF were found in glucose solutions containing sodium acetate and sodium chloride, while glucose proved more stabile in solutions containing calcium chloride and magnesium chloride.
In the rescue treatment of acute asthma, injected and inhalant magnesium are relatively weak having demonstrated value only in severe illness, although theoretical and laboratory considerations suggest that magnesium should be strongly effective as an asthma rescue agent. It was hypothesized that a mouth-lung biologically closed electric circuit (BCEC) exists capable of nearly instantly transporting positively charged magnesium ions from the mouth and throat into the lungs. One hundred milligram magnesium (magnesium chloride) 4-g throat lozenges producing 100+ mM magnesium ion concentration in saliva were tested to determine if they had beneficial effects in asthma rescue and prevention. Subjects were selected based solely on need for asthma rescue, and lozenges were used as needed. Case histories are presented showing the nearly immediate effect of magnesium chloride throat lozenges in terminating and preventing asthma attacks. Throat lozenges containing magnesium chloride produced much more rapid and stronger benefits than has been reported for inhaled and injected magnesium. An added benefit from magnesium chloride lozenge treatment of asthma was relaxation. In this first report of its kind, magnesium chloride throat lozenges appeared to provide rescue benefits in the treatment of asthma equivalent to pharmaceutical asthma drugs. Countering these benefits, strong ionic magnesium solutions greatly increase rhinovirus, herpesvirus and Candida albicans in vitro, and appear to worsen these infections in humans. Magnesium lozenges releasing concentrated magnesium ions appear contraindicated during common colds, oral herpes infections, chronic rhinosinusitis, oral and respiratory infections in general, and their use must immediately be terminated if respiratory or oral symptoms worsen. Double-blind, placebo-controlled, clinical trials in people without respiratory or oral infections are needed to determine magnesium lozenge safety, and the extent by which drug treatment of asthma can be reduced.
The amount of coagulant added to soy milk is a critical factor for tofu-making; particularly it affects the textural properties of tofu. Earlier research indicated that the critical point of coagulant concentration (CPCC) is a characteristic parameter of soy milk and could be used as an effective indicator of optimal coagulant concentration (OCC) for making filled tofu. The objective of this study was to investigate the possible correlations between CPCC and the characteristics of soy milk made from various soybean samples and the effect of soy milk cooking and dilution conditions on CPCC. CPCC was determined by a titration method. Calcium chloride and magnesium chloride were used as coagulants. Soy milk characteristics including solid, protein, phytate, pH, titratable acidity, mineral content, and 11S/7S protein and these characteristics as affected by heating rate, heating time, and sequence of dilution and heating were studied. The results showed that the CPCC was significantly (p < 0.05) positively correlated with phytate content (grams per gram of protein), pH, and 7S protein content but negatively correlated with protein content, 11S protein content, 11S/7S ratio, titratable acidity, and original calcium content. Within the same soybean material, more proteins required more coagulant, but higher protein concentration during cooking resulted in less coagulant required by each gram of protein during coagulation. The CPCC decreased with increasing soy milk heating time or decreasing heating rate. The sequence of heating and diluting for preparing soy milk also had an effect on CPCC.
Matrix or impurities remaining in a DNA sample solution after various sample treatment procedures may influence a subsequent DNA analysis. In this work, several matrices were investigated concerning their effects on the analysis of oligonucleotide by using an ion-trap mass spectrometer equipped with a sonic spray ionization source. Inorganic salts of sodium chloride and magnesium chloride depressed the signal intensity by about 50% when the content of the salts was about 10 microM. dNTPs and Taq showed more severe depression on the oligonucleotide. However, Tris, or (hydroxymethyl)aminomethane, intensified the signal intensity, if its content was within an appropriate range. When the content of Tris was about 500 microM, the signal intensity was enhanced by factors of 3 and 5 for the 6-mer and the 20-mer oligonucleotides, respectively. With the existence of Tris, matrix effects from the inorganic salts, dNTPs and Taq were reduced.
The infectivity of murine hepatitis virus (MHV-A59) was optimally stable at pH 6.0 and was unaffected by ionic strength or at least 15 cycles of freezing and thawing. It was completely inactivated within 25 minutes at 56 degrees C, but was protected by 1 M magnesium chloride or magnesium sulphate. It was completely inactivated within 14 days at 37 and 22 degrees C, but was relatively stable for as long as 72 days at 4 degrees C and optimal pH.
The circular dichroism of bovine serum albumin in divalent salt solutions was investigated. The salts selected were magnesium chloride and calcium chloride. Their effects on the secondary and tertiary structures of the protein were compared with that of lithium chloride. It is well known that the elements Ca, Mg, and Li have many properties in common. The results show the similarity of their ions in the capacity of deforming protein, in spite of their characteristic pharmacological functions.
The contribution of intracellular calcium stores to Mannheimia haemolytica leukotoxin (LKT)-induced increase in cytosolic calcium concentration was studied by pharmacologically inhibiting transport of calcium across the plasma and endoplasmic reticulum membranes of bovine neutrophils exposed to LKT. Active intracellular storage of calcium by sarcoplasmic/endoplasmic reticulum calcium ATPase, influx of extracellular calcium across the plasma membrane, and release of stored calcium via inositol triphosphate receptors and ryanodine-sensitive calcium channels were inhibited using thapsigargin, lanthanum chloride, xestospongin C, and magnesium chloride, respectively. Pre-incubation with thapsigargin attenuated the increase in cytosolic calcium concentration produced by LKT, thus confirming the involvement of intracellular calcium stores. Inhibitory effects of lanthanum chloride, xestospongin C, and magnesium chloride indicated that the increase in cytosolic calcium concentration induced by LKT resulted from both influx of calcium across the plasma membrane and release of calcium from intracellular stores.
BACKGROUND: The purpose of this study was to determine if mixing of fluoroquinolones with a common enteral feeding formulation, Ensure (Ross Products Division, Abbott Laboratories, Columbus, OH), would alter the measured in vitro quinolone concentrations over a 24-hour period. METHODS: Tablets of ciprofloxacin (500 mg), levofloxacin (500 mg), and ofloxacin (300 mg) were crushed and mixed with 240 mL of Ensure, water and calcium chloride (500 mg/L), water and magnesium chloride (200 mg/L), water and calcium chloride and magnesium chloride, and water alone. Fluoroquinolone concentrations of the mixtures were measured, via high-performance liquid chromatography, at baseline and serially over 24 hours. Experiments were performed in duplicate, at three temperatures (5 degrees C, 25 degrees C, and 37 degrees C). RESULTS: Average decreases of 82.5% +/- 1.5% for ciprofloxacin, 61.3% +/- 5.2% for levofloxacin, and 45.7% +/- 10.1% for ofloxacin (mean +/- 95% CI) were observed in vitro for Ensure over the two experimental sets at baseline. Serial analysis revealed no further significant change in any of the quinolone concentrations over the remaining 24-hour period. No significant decrease was noted with the quinolones when mixed in water and calcium, water and magnesium, water and calcium and magnesium, or water alone. This phenomenon appears to be unaffected by time and temperature. CONCLUSIONS: These data suggest there is an immediate and significant loss of fluoroquinolone when mixed with Ensure. An explanation for the loss of fluoroquinolone remains unclear.
Heparinase was released from the periplasmic space of Flavobacterium heparinum by three-step osmotic shock procedure. The procedure involves resuspending exponentially growing cells consecutively into (1) 40% sucrose, (2) 10 mM sodium phosphate, 2 mM magnesium chloride, pH 7, and (3) 10 mM sodium phosphate, 300 mM sodium chloride, 2 mM magnesium chloride, pH 7. Typically, 50-75% of the total heparinase activity is recovered by this procedure with an observed 7-15-fold increase in purity. The majority of heparinase activity is released in the final step of the procedure allowing for resolution from cytoplasmic and nonspecific periplasmic material. F. heparinum cells can be stored in 40% sucrose at 4 degrees C for up to one week without significant losses in recovery yields.