Addition Of Magnesium Sulfate Research Articles

Nebulized magnesium sulfate and salbutamol combination compared to salbutamol alone in the treatment of acute bronchial asthma: A randomized study

Study objectives: This study tests the hypothesis that the combined administration of multiple doses of nebulized salbutamol and magnesium sulfate provides additional benefit compared with salbutamol alone in adult patients with acute asthma. Methods: This was a randomized, double-blind, prospective study. One hundred patients who presented to an emergency department with an acute attack of bronchial asthma were randomized into 2 groups. Group A were nebulized with a combination of salbutamol and magnesium sulfate every 20 minutes 3 times, whereas group B patients were assigned to receive salbutamol nebulization alone 3 times at 20-minute intervals. Salbutamol and magnesium sulfate were administered in doses of 0.5 mg and 500 mg, respectively, and the solutions were made isotonic to plasma osmolality. Drugs were coded by one of the investigators. Pulse rate, blood pressure, and peak expiratory flow rate (PEFR) were measured at baseline and then at 15, 60, 75, and 120 minutes. Serum magnesium levels and blood gases were measured at 0 and 120 minutes in both the groups. Results: The baseline parameters were comparable in the 2 groups. Both the groups showed significant increase in PEFR at all intervals. However, there was no significant difference in rise in PEFR between both groups at any time of the study. Serum magnesium levels remained within limits in both groups, although the difference between the 2 groups was significant. There was no difference in requirement of additional medications during the study or hospital admission rates in the 2 groups. No significant side effects were noted. Conclusion: The study suggests that there is no therapeutic benefit from addition of magnesium sulfate to salbutamol nebulization in the treatment of acute bronchial asthma.

Intrathecal Magnesium Prolongs Fentanyl Analgesia: A Prospective, Randomized, Controlled Trial

UNLABELLED Magnesium is a noncompetitive, N-methyl-D-aspartate receptor antagonist that does not effectively cross the blood-brain barrier when given IV. Intrathecal magnesium potentiates opioid antinociception in rats, and the safety of intrathecal magnesium has been demonstrated in animals. This is the first prospective human study evaluating whether intrathecal magnesium could prolong spinal opioid analgesia. Fifty-two patients requesting analgesia for labor were randomized to receive either intrathecal fentanyl 25 micro g plus saline or fentanyl 25 micro g plus magnesium sulfate 50 mg as part of a combined spinal-epidural technique. The duration of analgesia of the intrathecal drug combination was defined by the time of patient request for additional analgesia. There was significant prolongation in the median duration of analgesia (75 min) in the magnesium plus fentanyl group compared with the fentanyl alone group (60 min). There was no associated increase in adverse events in the group that received intrathecal magnesium. Larger doses of intrathecal magnesium were not studied in this group of patients because of the limitations on cephalad spread when hyperbaric solutions are injected in the sitting position. Our data indicate that intrathecal magnesium prolongs spinal opioid analgesia in humans and suggest that the availability of an intrathecal N-methyl-D-aspartate antagonist could be of clinical importance for pain management. IMPLICATIONS Magnesium occurs naturally in the spinal cord and blocks the NMDA glutamate channel. In animal studies, intrathecal magnesium sulfate improves spinal morphine analgesia. For patients receiving spinal analgesia for labor, the addition of magnesium sulfate to the opioid fentanyl prolonged analgesia with no increase of side effects.

Magnesium ions alleviate the negative effect of manganese on Glomus claroideum BEG23.

The phytotoxicity of excessive levels of manganese (Mn), an essential micronutrient, can be alleviated significantly by a high supply of magnesium (Mg) ions to plants. A similar interaction of these two elements in the development of arbuscular mycorrhizal (AM) fungi has been verified in two experimental systems. In in vitro experiments, an outgrowth of hyphae from excised, surface-disinfected root segments colonised with Glomus claroideum BEG23 was measured after 5 days incubation in liquid media. When only Mn ions were present in the media at higher concentrations (>0.05 mM), the growth of hyphae from root segments was reduced significantly. Addition of magnesium sulphate to the incubation solution reduced the inhibitory effects of Mn on hyphal growth. Alleviation of Mn toxicity by Mg ions observed in in vitro experiments was verified also for the symbiotic association between G. claroideum and maize as a host plant in a hydroponics sand culture experiment.

Development of a Simple Recovery-Enrichment System for Enhanced Detection of Heat-Injured Listeria monocytogenes in Pasteurized Milk

A simple anaerobic recovery-enrichment system, semisolid Penn State University (ssPSU) broth, that enhances recovery of heat-injured Listeria monocytogenes, was rapidly achieved in 10-ml screw-capped tubes by adding Bacto-agar (2.5 g/liter) and L-cysteine (0.5 g/liter) to Penn State University broth. Glucose was removed from the formulation for ssPSU broth to prevent the growth of thermoduric lactobacilli. Ferric ammonium citrate was added to ssPSU broth to detect esculin hydrolysis and to indicate the presumptive presence of L. monocytogenes. Replacement of phosphate buffer with 3-[N-morpholino]propanesulfonic acid (MOPS) buffer and addition of magnesium sulfate (15 mM) enhanced recovery and detection of L. monocytogenes heat treated at 62.8°C for 20 min. D-Serine, at a concentration of 150 mM, was found to inhibit germination of Bacillus spp. spores but did not inhibit severely heat-injured L. monocytogenes. Finally, ssPSU broth was modified (to mPSU broth) to contain the following: (i) Bacto-agar, 2.5 g/liter; (ii) ferric ammonium citrate, 0.5 g/liter; (iii) MOPS buffer, pH 7.0; (iv) D-serine, 13.7 g/liter; (v) D-alanine, 11.6 g/liter; and (iv) magnesium sulfate, 1.81 g/liter. Incubation temperature significantly affected the recovery and detection of severely heat-injured L. monocytogenes. L. monocytogenes that were heat challenged in filter-sterilized whole milk at 62.8°C for 20, 25, and 30 min could not be detected at incubation temperatures ≥30°C but were consistently detected after incubation at 25°C for 174, 199, and 330 h, respectively. Heat-injured cells of L. monocytogenes that were added to various commercial brands of pasteurized whole milk were also detected using mPSU broth. When clostridial spores (104 spores per ml) were added to filter-sterilized milk containing either heat-injured or non–heat-injured L. monocytogenes, only the latter could be detected in mPSU broth. The mPSU broth system requires no purging with nitrogen gas to create anaerobic conditions and permits recovery, growth, and detection of L. monocytogenes in one vessel in the presence of thermoduric background microflora commonly found in pasteurized milk.

The comparison of two forms of sodium and potassium and chloride versus sulfur in the Dietary Cation-Anion Difference equation: Effects on acid-base status and mineral balance in sedentary horses

Summary Six mature geldings were randomly assigned treatments within a 6×6 latin square design experiment to study the effects of the Dietary Cation-Anion Difference equation (DCAD) on acid-base status and mineral balance in sedentary horses. Dietary Cation-Anion Difference was calculated as: meq ((Na+K)-(Cl+S))/kg diet DM. High (H) diets were formulated with the addition of sodium citrate (H:NaC), sodium bicarbonate (H:NaB), potassium citrate (H:KC), and potassium bicarbonate (H:KB). Low (L) diets were formulated with the addition of magnesium sulfate (L:S) and ammonium chloride (L:Cl). Experimental diets consisted of a pelleted base concentrate fed in a 60:40 ratio with native prairie grass hay, and were fed for a 12-day adjustment period followed by a 72-h sample collection period. Post-feeding venous blood samples were analyzed for the determination of pH and HCO 3 . Post-feeding urine samples were analyzed for the determination of urine pH. Representative samples of feed, feces, and urine were analyzed for mineral content and apparent mineral balances were calculated by difference. Horses consuming L:Cl and L:S had lower (P 3 values as compared to those consuming L:S at 6 of 12 intervals measured, and had lower (P 3 values as compared to those consuming all H diets at all intervals measured. Horses consuming H:NaB and H:NaC excreted more Na in the urine (P

Antinociceptive Potentiation and Attenuation of Tolerance by Intrathecal Co-Infusion of Magnesium Sulfate and Morphine in Rats

N-methyl-D-aspartate (NMDA) antagonists, such as MK801, delay the development of morphine tolerance. Magnesium, a noncompetitive NMDA antagonist, reduces postoperative morphine requirements. The present study was designed to evaluate the effects of intrathecal co-administration of magnesium sulfate with morphine on antinociceptive potentiation, tolerance, and naloxone-induced withdrawal signs. Magnesium sulfate (40-60 [micro sign]g/h) co-administration for 7 days, similar to MK801 (10 nmol/h), prevented the decline in antinociceptive response compared with morphine (20 nmol/h). Magnesium sulfate (60 [micro sign]g/h) produced no antinociception, but co-infused with morphine (1 nmol/h), it resulted in potentiated antinociception compared with morphine throughout the 7-day period. Probe morphine doses after 7-day infusions demonstrated a significantly greater 50% effective dose value for morphine 1 nmol/h (109.7 nmol) compared with saline (10.9 nmol), magnesium sulfate 60 [micro sign]g/h (10.9 nmol), and magnesium sulfate 60 [micro sign]g/h plus morphine 1 nmol/h (11.2 nmol), which indicates that magnesium had delayed morphine tolerance. Morphine withdrawal signs after naloxone administration were not altered by the co-infusion of magnesium sulfate. Cerebrospinal fluid magnesium levels after intrathecal magnesium sulfate (60 [micro sign]g/h) for 2 days increased from 17.0 +/- 1.0 [micro sign]g/mL to 41.4 +/- 23.6 [micro sign]g/mL, although serum levels were unchanged. This study demonstrates antinociceptive potentiation and delay in the development of morphine tolerance by the intrathecal co-infusion of magnesium sulfate and morphine in the rat. Implications: The addition of magnesium sulfate, an N-methyl-D-aspartate antagonist, to morphine in an intrathecal infusion provided better analgesia than morphine alone in normal rats. These results suggest that intrathecal administration of magnesium sulfate may be a useful adjunct to spinal morphine analgesia. (Anesth Analg 1998;86:830-6)

Partition of horseradish peroxidase in aqueous two-phase systems containing polyvinylpyrrolidone

Growing peroxidase utilisation in different industries encourages the search for high benefit/cost ratio purification methods such as aqueous two-phase partition. In this way, the partitioning behaviour of peroxidase from Armoracia rusticanaroots in polyvinylpirrolidone/Reppal and polyvinylpirrolidone/salt aqueous two-phase systems was investigated. Based on these results, a two-step purification process was developed. In the first system (polyvinylpyrrolidone K30/Reppal PES 200, pH 7.0), cell debris and some contaminating proteins were shifted to the bottom phase while peroxidase concentrated in the top phase. After discarding the bottom phase, the second step involved addition of magnesium sulphate thus forming a second aqueous two-phase system. At this step, the enzyme was extracted into the salt-rich bottom phase. The overall yield was 75% and the purification factor 7.3.

The effects of dihydralazine, labetalol and magnesium sulphate on the isolated, perfused human placental cotyledon.

To assess the effects of dihydralazine, labetalol and magnesium sulphate on the vascular tone in the isolated, perfused human placental cotyledon. In vitro perfusion of the fetal compartment of isolated, human placental cotyledons. None of the drugs affected basal vascular tone. The thromboxane A2-mimic U46619 and endothelin-1 induced a concentration-dependent increment in perfusion pressure, while 5-hydroxytryptamine induced a variable increase, and norepinephrine induced a small, transient increase in perfusion pressure. After preconstriction with U46619, magnesium sulphate (1.5 x 10(-3) to 6 x 10(-3) mol/l) induced a decrease in perfusion pressure, while dihydralazine (10(-6) to 10(-4) mol/l) or labetalol (10(-7) to 10(-4) mol/l) enhanced the perfusion pressure. These effects of dihydralazine and labetalol were unaffected by treatment with indomethacin 10(-6) mol/l, but could be reversed by addition of magnesium sulphate 6 x 10(-3) mol/l. Labetalol 10(-6) to 10(-4) mol/l also caused an increase in the perfusion pressure induced by endothelin-1, but showed no effects after preconstriction with 5-hydroxytryptamine. Pretreatment with labetalol 10(-4) mol/l inhibited the transient increase in perfusion pressure induced by norepinephrine 3 x 10(-5) mol/l. The present data demonstrated that the commonly used vasodilating agents labetalol and dihydralazine do not produce vasodilatation in the human perfused cotyledon after vasoconstriction induced by agents of suggested importance for maintenance of fetal placental vascular tone, and that high concentrations of these drugs may even enhance vasoconstriction induced by thromboxane and endothelin-1 in this area. Magnesium sulphate may show the potential to reverse such unwanted effects of dihydralazine and labetalol.

The effect of water quality on nutrient availability for grower/finisher pigs

Two 6 × 6 Latin square experiments were conducted with male grower/finisher pigs (initial weight approximately 45 kg) to determine the effects of increasing levels of total dissolved solids (TDS) in water on the partitioning of nutrients from the diet. The first experiment consisted of six water treatments, 0 (distilled water), 370 (tap water), 1000, 4000, 6350, and 8000 ppm TDS. The increased TDS levels were obtained by the addition of sodium bicarbonate, sodium chloride, and sodium sulphate (in the ratio 3:3:1) to the tap water. At these levels there was no significant treatment effect (P > 0.05) on growth rate (GR), digestibility of energy (DE) or crude protein, or metabolizable crude protein. As water TDS increased, metabolizable energy (ME) decreased (P < 0.05) from 3150 kcal kg−1 to 2932 kcal kg−1. In the second experiment, six water treatments were prepared by the addition of magnesium sulphate, sodium sulphate, and sodium chloride (in the ratio of 3:3:1) to tap water (450 ppm TDS) to obtain water containing 1100, 4000, 7000, or 11 700 ppm TDS. Distilled water (0 ppm TDS) was used as a control. No significant treatment effect (P > 0.05) was observed for water intake, urinary output, GR, DE, ME, or metabolizable crude protein. However, sulphates at 11 700 ppm TDS significantly decreased (P < 0.05) the digestibility of dry matter and crude protein. Mineral excretion, in feces and urine, and retention were also examined in both experiments. Key words: Water quality, pigs, salinity, digestibility, minerals

高温におけるＦｅ２（ＳＯ４）３溶液の加水分解に関する湿式冶金学的研究（第３報） 高温におけるＦｅ２（ＳＯ４）３溶液の加水分解に及ぼすＭｇＳＯ４の影響

Solubilities of magnesium sulphate in sulphuric acid solutions and hydrolysis of acidic ferric sulphate solutions of various concentrations with the addition of magnesium sulphate have been investigated in an autoclave at temperatures of 185°C and 200°C.The results obtained were as follows:1. Solubilities of magnesium sulphate increased with an increase in sulphuric acid concentrations in solutions, while at the same sulphuric acid concentration, solubilities of magnesium sulphate at 185°C were slightly higher than that at 200°C.2. Solubilities of magnesium sulphate in sulphuric acid solutions at temperatures of 185°C and 200°C were represented by the following emnirical formulas:Mg2+ (g/l)=4.981+3.044×10-1 [H2SO4 (g/l)]-4.651×0-1 [H2SO4 (g/l)] 2at a tenlperature of 185°CMgSUP>2+ (g/l)=2.962+2.947×10--1 [H2SO4 (g/l)]-3.889×10-4 [HH2SO4 (g/l)] 2 at a temperature of 200°C3. When the hydrolysis of ferric sulphate soulutions was at equilibrium, the concentration of ferric ion increased with an increase in that of sulphuric acid in solutions, while at the same sulphuric acid concentration, the concentration of ferric ion decreased considerably with an increase in the addition of magnesium sulphate.4. In the hydrolysis of acidic ferric sulphate solutions, ferric oxide, Fe203, was precipitated at lower sulphuric acid concentrations, and ferric basic sulphate, Fe (OH) SO4, was precipitated at higher concentrations of sulphuric acid, while hydrolysis and precipitation of ferric oxide increased withthe addition of magnesium sulphate in the ferric sulphate solutions.5. At a temperature of 185°C in the absence of magnesium sulphate, hydrolysis and precipitation of ferric oxide occurred up to the sulphuric acid concentration of 55.8g/l or below, and at 55.8g/l or above, ferric basic sulphate was precipitated. When respectively about 15g/l Mg2+ion and 30g/l Mg2+ion as magnesium sulphate were added in the ferric sulphate solutions, hydrolysis and precipitation of ferric oxide occurred up to the sulphuric acid concentration of 76.5g/l and 100.5g/l.6. At a temperature of 200°C in the absence of magnesium sulphate, hydrolysis and precipitation of ferric oxide occurred up to the sulphuric acid concentration of 69.3g/l or below, and at 69.3g/l or above, ferric basic sulphate was precipitated. When respectively about 15g/l Mg2+ion and 30g/lMg2+ion as magnesium sulphate were added, hydrolysis and precipitation of ferric oxide occurred up to the sulphuric acid concentration of 82.1g/l and 105.1g/l.7. When magnesium sulphate was added in solutions, empirical formulas of the ferric ion concentration and the sulphuric acid concentration over the stable region of ferric oxide were as follows. at a temperature of 185°Clog [Fe3+ (g/l)] =5.30 log [H2SO4 (g/l)]-9.61 about 15g/l Mg2+ion as magnesium sulphate log [Fe3+ (g/l)] =5.46 log [H2SO4 (g/l)] -10.24 about 30g/l Mg2+ion as magnesium sulphate at a temperature of 200°Clog [Fe3+ (g/l)] =5.09 log [H2SO4 (g/l)] -9.46 about 15g/l Mg2+ion as rnagnesium sulphate log [Fe3+ (g/l)] =5.74 log [H2SO4 (g/l)] -11.02 about 30g/l Mg2+ion as magnesium sulphate

In vivo and in vitro effects of magnesium sulfate in cerebrovascular bed of the goat

The effects of magnesium sulfate in the cerebrovascular bed were studied both in vivo, by measuring cerebral blood flow in conscious nonpregnant goats, and in vitro, by recording isometric tension in isolated goat middle cerebral arteries. Injections of increasing doses (10 to 300 mg) of magnesium sulfate directly into the cerebral circulation elicited transient and dose-dependent increases in cerebral blood flow and decreases in cerebral vascular resistance. Similar results were obtained when increasing doses (0.3 to 3 gm/15 min) of magnesium sulfate were infused intravenously, although the vasodilatations reached a stable plateau that remained when the infusions finished. Cumulative addition of magnesium sulfate (10(-5) to 3 x 10(-2) mol/L) did not change the isometric tension of isolated arterial segments at resting tone, but relaxed in a concentration-dependent manner the arterial segments preconstricted with 10(-5) mol/L prostaglandin F2 alpha. These results demonstrate that magnesium sulfate acts as a dilator in the cerebral circulation by acting directly on the cerebral arteries. This could explain, at least in part, its beneficial effects on preeclampsia-eclampsia.

In vivo and in vitro effects of magnesium sulfate in the cerebrovascular bed of the goat

The effects of magnesium sulfate in the cerebrovascular bed were studied both in vivo, by measuring cerebral blood flow in conscious nonpregnant goats, and in vitro, by recording isometric tension in isolated goat middle cerebral arteries. Injections of increasing doses (10 to 300 mg) of magnesium sulfate directly into the cerebral circulation elicited transient and dose-dependent increases in cerebral blood flow and decreases in cerebral vascular resistance. Similar results were obtained when increasing doses (0.3 to 3 gm/15 min) of magnesium sulfate were infused intravenously, although the vasodilatations reached a stable plateau that remained when the infusions finished. Cumulative addition of magnesium sulfate (10−5 to 3 × 10−2 mol/L) did not change the isometric tension of isolated arterial segments at resting tone, but relaxed in a concentration-dependent manner the arterial segments preconstricted with 10−5 mol/L prostaglandin F2α. These results demonstrate that magnesium sulfate acts as a dilator in the cerebral circulation by acting directly on the cerebral arteries. This could explain, at least in part, its beneficial effects on preeclampsia-eclampsia. The effects of magnesium sulfate in the cerebrovascular bed were studied both in vivo, by measuring cerebral blood flow in conscious nonpregnant goats, and in vitro, by recording isometric tension in isolated goat middle cerebral arteries. Injections of increasing doses (10 to 300 mg) of magnesium sulfate directly into the cerebral circulation elicited transient and dose-dependent increases in cerebral blood flow and decreases in cerebral vascular resistance. Similar results were obtained when increasing doses (0.3 to 3 gm/15 min) of magnesium sulfate were infused intravenously, although the vasodilatations reached a stable plateau that remained when the infusions finished. Cumulative addition of magnesium sulfate (10−5 to 3 × 10−2 mol/L) did not change the isometric tension of isolated arterial segments at resting tone, but relaxed in a concentration-dependent manner the arterial segments preconstricted with 10−5 mol/L prostaglandin F2α. These results demonstrate that magnesium sulfate acts as a dilator in the cerebral circulation by acting directly on the cerebral arteries. This could explain, at least in part, its beneficial effects on preeclampsia-eclampsia.

Batch fermentation kinetics of sugar beet molasses by Zymomonas mobilis

A new osmotolerant mutant strain of Zymomonas mobilis was successfully used for ethanol production from beet molasses. Addition of magnesium sulfate to hydrolyzed molasses allowed repeated growth without the need of yeast extract addition. The kinetics and yields parameters of fermentation on media with different molasses concentrations were calculated. The anabolic parameters (specific growth rate, mu, and biomass yield, Y(X/S)) were inhibited at elevated molasses concentrations while the catabolic parameters (specific ethanol productivity, q(p), and ethanol yield, Y(p/s)) were not significantly affected. In addition to ethanol and substrate inhibition, osmotic pressure effects can explain the observed results.

Magnesium sulfate-induced relaxation of uterine arteries from pregnant and nonpregnant patients

The effects of magnesium sulfate at different concentrations were investigated in isolated rings of uterine arteries from pregnant and nonpregnant patients. Addition of magnesium sulfate (0.5 to 9.6 mmol/L) to the suffusion medium containing the normal concentration of 1.2 mmol/L magnesium sulfate produced concentration-dependent relaxation of norepinephrine (1 mumol/L)-induced or potassium chloride (35 mmol/L)-induced contractions. Magnesium sulfate was about three times more potent in causing inhibition of potassium chloride-induced contractions in uterine arteries from pregnant patients than in those from nonpregnant patients. The concentrations that inhibited 50% of the contraction induced by potassium chloride were 0.6 +/- 0.2 mmol/L (n = 4) in the arteries from pregnant patients and 1.6 +/- 0.2 mmol/L (n = 4) in the arteries from nonpregnant patients. At high concentrations (4.8 and 9.6 mmol/L), magnesium sulfate also was more potent in inhibiting norepinephrine-induced contractions in arteries from pregnant women than in arteries from nonpregnant women. The magnesium sulfate-induced relaxation was almost completely inhibited by calcium chloride (2 mmol/L) added to the suffusion medium containing the normal concentration of 2.5 mmol/L calcium chloride but was not affected by indomethacin (5 mumol/L), methylene blue (10 mumol/L), or removal of the endothelium. The results show that magnesium sulfate, at therapeutic blood concentrations, acts as a potent dilator of human uterine arteries, especially those from pregnant patients. The results are consistent with the view that magnesium sulfate may facilitate uteroplacental perfusion.

Preservation of 32 Human Kidneys by Simple Cold Storage for more than 48 Hours

Transplant centers are reluctant to use kidneys stored cold for more than 48 hours. During a 6-year interval we transplanted 32 kidneys preserved by Intracellular electrolyte flushing that were stored cold for 48.2 to 61.4 hours. Of the recipients 91 per cent required dialysis within 1 week after transplantation. The mean serum creatinine nadir within 1 month was 3.0mg. per dl. and graft survival at 1 month was 81 per cent. Short-term kidney graft function was not Influenced significantly by the addition of magnesium sulfate to the flush solutions or by cyclosporin immunosuppression. The 1 and 2-year actuarial kidney graft survival rates were 72 and 58 per cent, respectively. The 1 and 2-year mean serum creatinine levels were 1.9 and 1.6mg. per dl., respectively. Kidneys can be transplanted successfully after 48 hours of simple cold storage following flushing with an ice-cold intracellular electrolyte solution.

Addition of magnesium sulfate improves effectiveness of ritodrine in preventing premature delivery

From October, 1981, to July, 1983, 225 patients were evaluated for premature labor at Forsyth Memorial Hospital. Sixty-five of these patients were considered to be candidates for intravenous ritodrine treatment. Of this group, 24 patients were successfully treated and had pregnancy prolongation ranging from 1 to 17 weeks. Forty-one patients did not respond to maximal intravenous ritodrine therapy (300 to 350 micrograms/min). Eleven patients subsequently delivered within 24 to 48 hours of treatment initiation. The remaining 30 patients received intravenous magnesium sulfate (1 to 3 gm/hr) in addition to intravenous ritodrine. Eighteen patients responded favorably to this combination treatment and had pregnancy prolongation ranging from 1 to 11 weeks. Twelve patients delivered within 1 week from treatment initiation. In all cases where pregnancy prolongation was achieved, birth weight and neonatal outcome were significantly improved compared to patients who did not respond to either intravenous ritodrine alone or intravenous ritodrine and magnesium sulfate combination. Treatment related maternal/fetal complications were not significantly different in the various groups examined. From the foregoing we conclude that, in a select group of patients in premature labor not responding to conventional ritodrine therapy, magnesium supplementation in pharmacologic doses could have a beneficial effect with respect to pregnancy outcome.

Production of rennin-like enzyme by Absidia cylindrospora

The composition of the culture medium influenced the production of extracellular and intracellular milk-clotting and proteolytic enzymes by Absidia cylindrospora. An appreciable increase of both enzyme activities, particularly proteolytic, was found when using molasses instead of sucrose. The use of milk whey as nitrogen source favoured production of the extracellular caseinase and intracellular milk-clotting enzymes. Corn-steep favoured production of extracellular milk-clotting more than proteolytic enzymes. A maximum milk-clotting/proteolytic activity ratio was reached at a corn-steep N concentration of 1·0 g/litre and C/N ratio of 21:1. Potassium dihydrogen phosphate concentrations below or above 1·0 g/litre had an adverse effect on the milk-clotting/proteolytic activity ratio, while addition of magnesium sulphate to the culture medium did not significantly affect production of the milk-clotting enzyme. An initial pH value of the culture medium of 5·0 gave the highest milk-clotting/proteolytic activity ratio and hence good rennin properties of the enzyme.

Insoluble Starch Xanthate: Preparation, Stabilization, Scaleup and Use

AbstractThe addition of magnesium sulfate to xanthation mixtures of crosslinked starch aided isolation, scaleup and room‐temperature product stability on storage. Pilot‐plant scaleup of laboratory‐developed procedures also yielded water‐insoluble products effective in removing heavy metals from water. Several different processing methods are presented to show the ease of preparation and use of the products.

Improving mass transfer characteristics of limestone slurries by use of magnesium sulfate

Poor mass transfer coefficients for limestone scrubbing slurries limit the effectiveness of spray-type scrubbers in removing SO/sub 2/ from power plant stack gases. Large resistances in the liquid phase, due to the need for limestone or calcium sulfite to dissolve during the absorption process, are the cause of this inefficiency. Experimental work is presented to show that these resistances can be largely eliminated by addition of magnesium sulfate to the slurry, enabling an efficiency to be achieved that approaches that of strong sodium carbonate solution. A detailed description of the chemical processes involved is given, accompanied by experimental data showing the effect of sulfate addition on the dissolved scrubbing capacity of the slurries. The magnesium sulfite ion pair, MgSO/sub 3//sup 0/, is shown to be responsible for the increased scrubbing efficiency. As a bonus, it was found that slurries containing magnesium sulfate could be treated with air to convert sulfite sludge into filterable gypsum.

Interaction of Calcium and Magnesium on Gastric Acid Secretion and Serum Gastrin Concentration in Man

The effect of magnesium on calcium- and pentagastrin-induced gastric acid secretion and on calcium-induced gastrin secretion were studied in healthy volunteers. Intravenous infusion of calcium gluconate increased serum gastrin concentration as well as gastric volume secretion, acidity, and acid output. Addition of magnesium sulfate to the infusion caused a slight but insignificant increase in serum gastrin concentration, whereas volume secretion, acidity, and acid output were significantly depressed. Intravenous infusion of magnesium sulfate had no effect on gastric acid secretion induced by a submaximal pentagastrin infusion. The results indicate that magnesium antagonizes the activation of gastric acid secretion by calcium without suppressing gastrin release and may suggest that magnesium does not change the sensitivity of the parietal cell to gastrin.