Abstract  It is known that calcium induces the formation of potent vasodilators in endothelial cells and vasocontriction in smooth muscle cells, whereas in the renal parenchyma, it modulates sodium excretion through vascular and tubular mechanisms. Consequently, an increased concentration of calcium in renal circulation may induce a sequence of contrasting hemodynamics and excretory effects depending on the threshold of a particular mechanism that is first being stimulated. In order to identify this sequence of responses and their respective thresholds, we infused into the renal artery of anesthetized dogs progressively increasing doses of calcium gluconate that ranged from 1 to 400-mu-g/kg/min.

The administration of 1, 10, and 100-mu-g/kg/min of calcium gluconate was followed by a significant increase in urinary excretion of PGE2 and 6-keto-PGF1-alpha and by a marked diuresis and natriuresis without altering renal blood flow (RBF) or glomerular filtration rate (GFR). Renin release was increased by 80% only during the infusion of the 10-mu-g/kg/min dose. The intrarenal infusion of a 400-mu-g/kg/min dose of calcium produced marked decreases in RBF and GFR, while urine sodium excretion (U(Na)V), U(PGE2)V, and U6-keto-PGF1-alpha-V continued and were markedly elevated. During all these maneuvers, mean arterial pressure remained unchanged. After the administration of indomethacin, the intrarenal infusion of 10 and 100-mu-g/kg/min of calcium produced marked reductions in urine prostaglandins and caused a decrease in RBF and GFR comparable to those obtained with the 400-mu-g/kg/min dose, abolished completely the increments in urine volume and urine sodium, and prevented the increase in renin produced by the 10-mu-g/kg/min dose. These studies show that all the intrarenal effects of low doses of calcium are dependent on the production of prostaglandins. The use of systemic infusion of calcium gluconate as a specific probe to test the renal ability to produce prostaglandins is further emphasized by the finding that in humans the threshold of renal responses to calcium is much greater than that of the systemic circulation.

Abstract  Gluconic acid is a multifunctional organic acid used as a bulk chemical in the food, feed, pharmaceutical, textile, metallurgy, detergent, paper, and construction industries. It is derived from glucose through a simple oxidation reaction catalyzed by glucose oxidase (EC 1.1.3.4.). Oxidation of the aldehyde group on C-1 of β-d-glucose to a carboxyl group results in the production of glucono-δ-lactone (C6H10O6) and hydrogen peroxide using molecular oxygen as the electron acceptor. Glucono-δ-lactone is further hydrolyzed to gluconic acid either spontaneously or by lactone-hydrolyzing enzyme. There are various approaches such as chemical, biochemical, and electrochemical available for its production, but microbial fermentation by Aspergillus niger using glucose oxidase is the most widely studied method. Microbial production of gluconic acid by bacteria, Gluconobacter, has also been demonstrated well. The enzyme involved in this process is glucose dehydrogenase. This chapter gives a review of microbial gluconic acid production; its recovery, properties, and applications; and the enzyme glucose oxidase.

Abstract  Objective: To explore the effects of calcium gluconate and thrombin on the formation of platelet-rich gel (PRG) and the release of bioactive substances in human platelet-rich plasma (PRP) and the clinical significance. Methods: Six healthy blood donors who met the inclusion criteria were recruited in our unit from May to August in 2016. Platelet samples of each donor were collected for preparation of PRP. (1) PRP in the volume of 10 mL was collected from each donor and divided into thrombin activation group (TA, added with 0.5 mL thrombin solution in dose of 100 U/mL) and calcium gluconate activation group (CGA, added with 0.5 mL calcium gluconate solution in dose of 100 g/L) according to the random number table, with 5 mL PRP in each group. Then the PRP of the two groups was activated in water bath at 37 ℃ for 1 h. The formation time of PRG was recorded, and the formation situation of PRG was observed within 1 hour of activation. After being activated for 1 h, one part of PRG was collected to observe the distribution of fibrous protein with HE staining, and another part of PRG was collected to observe platelet ultrastructure under transmission electron microscope (TEM). After being activated for 1 h, the supernatant was collected to determine the content of transforming growth factor β(1, )platelet-derived growth factor BB (PDGF-BB), vascular endothelial growth factor, basic fibroblast growth factor (bFGF), epidermal growth factor, and insulin-like growth factorⅠby enzyme-linked immunosorbent assay. (2) Another 10 mL PRP from each donor was collected and grouped as above, and the platelet suspension was obtained after two times of centrifugation and resuspension with phosphate buffered saline, respectively. And then they were treated with corresponding activator for 1 h as that in experiment (1). Nanoparticle tracking analyzer was used to detect the concentrations of microvesicles with different diameters and total microvesicles derived from platelet. Data were processed with t test. Results: (1) The formation time of PRG in group TA was (228±40) s, and the PRG volume reached the maximum at this moment. The PRG volume shrunk to the minimum after 30 minutes of activation. The formation time of PRG in group CGA was (690±71) s, and the PRG volume reached the maximum at this moment. After 55 minutes of activation, the PRG volume shrunk to the minimum. The formation time of PRG in group TA was obviously shorter than that in group CGA (t=15.17, P<0.01). (2) HE staining showed that after 1 hour of activation, the red-stained area of fibrous protein in PRG of group TA was large and densely distributed, while that of group CGA was small and loosely distributed. TEM revealed that after 1 hour of activation, the platelets in PRG of group TA were fragmented, while lysing platelet structure, lysing α granule structure, intact α granule structure, and intact dense body structure were observed in PRG of group CGA. (3) The content of PDGF-BB released by PRP in group TA was (7.4±0.8) ng/mL, which was obviously higher than that in group CGA [(4.9±0.5) ng/mL, t=5.41, P<0.01]. The content of bFGF released by PRP in group CGA was (960±151) pg/mL, which was significantly higher than that in group TA [(384±56) pg/mL, t=8.75, P<0.01]. The content of the other 4 growth factors released by PRP in the two groups was close (with t values from 0.11 to 1.97, P values above 0.05). (4) The concentrations of total microvesicles, microvesicles with diameter more than 100 nm, and exosomes with diameter less than or equal to 100 nm derived from platelet in group CGA were (165.8±15.1)×10(8)/mL, (142.4±12.3)×10(8)/mL, and (23.4±2.9)×10(8)/mL respectively, which were significantly higher than those in group TA [(24.7±4.6)×10(8)/mL, (22.6±4.0)×10(8)/mL, and (2.1±0.7)×10(8)/mL, with t values from 17.36 to 22.66, P values below 0.01]. Conclusions: Calcium gluconate can slowly activate PRP, resulting in slowly shrunk PRG with high content of bFGF and high concentration of microvesicles, which is suitable for repairing articular cavity and sinus tract wound. Thrombin can rapidly activate PRP, resulting in quickly shrunk PRG with high content of PDGF-BB and a certain concentration of microvesicles, which is suitable for repairing acute trauma.

Abstract  INTRODUCTION: Calcium gluconate extravasation is a process, which, while not common, occurs more frequently in neonatal intensive care units. The aim of this study is to present a number of cases of calcium gluconate extravasation, which have occurred in our hospital, and to carry out a review of those clinical cases published in the literature to obtain relevant epidemiological data.

METHODS: Data were gathered on the medical histories of 5 patients who presented lesions secondary to calcium gluconate extravasation in our center. A review of the literature was also performed to include clinical cases of calcium gluconate extravasation already published.

RESULTS: Data were collected on 60 cases published in 37 articles. Most patients (55%) were neonates. The average age of these neonates was 8 days. The commonest location of injuries was the back of the hand and wrist (42%). The 2 most frequent symptoms were the appearance of erythema (65%) and swelling/edema (48%) followed by the appearance of skin necrosis (47%), indurated skin (33%), and yellow-white plaques or papules (33%). Most cases are cured within a period of 3 to 6 months. Fifty percent of patients required surgery, and in 13% of cases, skin grafts were performed. The most frequent histological finding was the presence of calcium deposits. Other histological findings described were the presence of necrosis, lymphohistiocytic infíltrate, and granulomas. Most histological findings were located in the dermis. Most x-rays showing calcium deposits had been performed at 3 to 4 weeks.

CONCLUSIONS: Calcium gluconate extravasation is a process, which, although infrequent, is associated with serious skin and soft-tissue lesions, mainly affecting infants. Further studies are needed to determine possible specific procedures to be carried out in these cases.

Abstract  Metaldehyde, a cyclic polymer of acetaldehyde, is the active ingredient in many of the slug and snail baits used in the coastal and low lying areas of the United States (US) and Europe. Over 4.5 million kg of metaldehyde were used in households across the US from 1976 to 1977. Metaldehyde has also been used as a portable solid fuel. It is more efficient than silver iodide as a cloud-seeding chemical and has been listed as an anesthetic.

Abstract  Mutagenic test results are reported in microbial and mammalian cell systems.

Abstract  Over a 2‐year period in Dundee City hospitals, 16.5% of babies in the specical care baby unit (SCBU) received drugs, being given a mean number of 2.2 drugs each, compared with 2.3% of maternity ward babies who received a mean of 1.2 drugs each. In the SCBU, 26.5% of ‘low birth weight’ (< 2,500 g) babies and 32.1% of pre‐term (< 37 weeks) babies received drugs, as compared with 11.9% of ‘normal weight’ ( 2,500 g) babies, and 11.0% of term ( 37 weeks) babies. There was no apparent relationship between the mean number of drugs received by babies and their birth weight or gestational age. Antimicrobials were the most frequently prescribed drugs, and of the others, calcium gluconate was used most commonly.

Abstract  Estimate of acceptable daily intake for man. ADI "not specified". The fact that high doses of GDL exert a laxative effect in man should be taken into account when considering its level of use.

Abstract  There are five U.S. manufacturers of propylene glycol ether derivatives shown in Table 1. This table also lists the trade names for these materials. The ethers of mono‐, di‐, tri‐, and polypropylene glycol are prepared commercially by reacting propylene oxide with the alcohol of choice in the presence of a catalyst. They may also be prepared by direct alkylation of the selected glycol with an appropriate alkylating agent such as a dialkyl sulfate in the presence of an alkali. The monoalkyl ethers of propylene glycol occur in two isomeric forms, the alpha or beta isomer. The alpha isomer is a secondary alcohol (on the middle carbon of the propane backbone) that forms the ether linkage at the terminal alcohol of propylyene glycol. This alpha isomer is predominant during synthesis. The beta isomer is a primary alcohol with the ether linkage formed at the secondary alcohol. The toxicological significance of the alpha and beta isomers of propylene glycol is discussed later in this narrative. The monoalkyl ethers of dipropylene glycol occur in four isomeric forms. The commercial product Dowanol® DPM Glycol Ether is believed to be a mixture of these but to consist to a very large extent of the isomer in which the alkyl group has replaced the hydrogen of the primary hydroxyl group of the dipropylene glycol, which is a secondary alcohol. The internal ether linkage is between the 2 position of the alkyl‐etherized propylene unit and the primary carbon of the other propylene unit, thus leaving the remaining secondary hydroxyl group unsubstituted. In the case of dipropylene glycol monomethyl ether, the primary isomer is 1‐(2‐methoxy‐1‐methylethoxy)‐2‐propanol. The monoalkyl ethers of tripropylene glycol can appear in eight isomeric forms. The commercial product Dowanol® TPM Glycol Ether, however, is believed to be a mixture of isomers consisting largely of the one in which the alkyl group displaces the hydrogen of the primary hydroxyl group of the tripropylene glycol and the internal ether linkages are between secondary and primary carbons. The known physical properties of the most common ethers are given in Tables 5 and 8. The methyl and ethyl ethers of these propylene glycols are miscible with both water and a great variety of organic solvents. The butyl ethers have limited water solubility but are miscible with most organic solvents. This mutual solvency makes them valuable as coupling, coalescing, and dispersing agents. These glycol ethers have found applications as solvents for surface coatings, inks, lacquers, paints, resins, dyes, agricultural chemicals, and other oils and greases. The di‐ and tripropylene series also are used as ingredients in hydraulic brake fluids. Occupational exposure would normally be limited to dermal and/or inhalation exposure. The toxicological activity of the propylene glycol‐based ethers generally indicates a low order of toxicity. Under typical conditions of exposure and use, propylene glycol ethers pose little hazard. As with many other solvents, appropriate precautions should be employed to minimize dermal and eye contact and to avoid prolonged or repeated exposures to high vapor concentrations. The propylene glycol ethers (PGEs), even at much higher exposure levels, do not cause the types of toxicity produced by certain of the lower molecular weight ethylene glycol ethers (EGEs). Specifically, they do not cause damage to the thymus, testes, kidneys, blood, and blood‐forming tissues as seen with ethylene glycol methyl and ethyl ethers. In addition, the propylene glycol ethers induce neither the development effects of certain of the methyl‐ and ethyl‐substituted ethylene glycol‐based ethers nor the hemolysis and associated secondary effects seen in laboratory animals with EGEs. Other propylene glycol ethers also exhibit a similar lack of toxicity. For example, propylene glycol ethyl ether (PGEE) and its acetate do not cause the critical toxicities of testicular, thymic, or blood injury and do not produce birth defects. Propylene glycol tertiary‐butyl ether (PGTBE) also has been tested and fails to elicit these toxicities or birth defects in rats exposed by inhalation to substantial concentrations. The methyl, ethyl, and n‐butyl ethers of butylene glycol considered herein are prepared by reacting the appropriate alcohol with the so‐called straight‐chain butylene oxide, consisting of about 80% 1,2 isomer and about 20% 2,3 isomer in the presence of a catalyst. They are colorless liquids with slight, pleasant odors. The methyl and ethyl ethers are miscible with water, but the butyl ether has limited solubility. All are miscible with many organic solvents and oils; thus, they are useful as mutual solvents, dispersing agents, and solvents for inks, resins, lacquers, oils, and greases. Industrial exposure may occur by any of the common routes. The common esters and diesters of the polyols are prepared commercially by esterifying the particular polyol with the acid, acid anhydride, or acid chloride of choice in the presence of a catalyst. Mono‐ or diesters result, depending on the proportions of each reactant employed. The ether esters are prepared by esterifying the glycol ether in a similar manner. Other methods can also be used. The acetic acid esters have remarkable solvent properties for oils, greases, inks, adhesives, and resins. They are widely used in lacquers, enamels, dopes, adhesives, and in fluids to dissolve plastics or resins as applied by lacquer, paint, and varnish removers. Generally speaking, the fatty acid esters of the glycols and glycol ethers, in either the liquid or vapor state, are more irritating to the mucous membranes than those of the parent glycol or glycol ethers. However, once absorbed into the body, the esters are hydrolyzed and the systemic effect is quite typical of the parent glycol or glycol ethers. It should be noted that the nitric acid esters of glycols are highly toxic and exert a physiological action quite different from that of the parent polyols. The nitric acid esters of glycols are not typical of the esters or ether esters of organic acids and are considered separately in this chapter. They are used as explosives, usually in combination with nitroglycerin, to reduce the freezing point. Industrial exposures of consequence are most likely to occur through the inhalation of vapors, but may also occur through contact with the eyes and skin. With the dinitrate, a serious hazard exists from absorption through the skin.

Abstract  Intense diffuse uptake of Tc-99m HMDP was seen in the gastrointestinal tract of a patient given liquid calcium gluconate. Bone scintigraphy was performed as a routine follow up 8 years after surgery for breast cancer. The gastrointestinal uptake disappeared when the administration of the liquid calcium gluconate was discontinued.

Abstract  Six-week-old male rats were placed on two high calcium regimens: one with calcium carbonate and monobasic calcium phosphate, with calcium content increased via calcium carbonate; and another with calcium phosphate and calcium gluconate, with calcium gluconate the source of increased calcium. Animals fed the gluconate-containing diets absorbed 29% of the ingested calcium over the entire calcium intake range, whereas those fed the calcium carbonate diets absorbed 25% over an intake range of 225 to 450 mg Ca/d, but at calcium intakes above 450 mg Ca/d their absorption reached a plateau at approximately 109 mg/d. Active calcium transport decreased with increased calcium intake in both the calcium carbonate- and calcium gluconate-fed groups. Nonsaturable transport was unchanged as a result of increasing calcium intake and did not differ among the diet groups. Because the absorptive processes were unaffected by the calcium source, events in the lumen must have been responsible for the observed differences. Because phosphate is nearly 18 times more soluble than carbonate, very little calcium of calcium carbonate origin can have been solubilized in the presence of phosphate and this, we conclude, accounts for the limit on calcium absorption observed in diets high in calcium carbonate. Moreover, when intake is expressed as soluble calcium, absorption approaches 50%, the value expected when intestinal transit time (approximately 3 h) is multiplied by 16%/h, the experimental value of nonsaturable absorption.

Abstract  Calcium carbonate, calcium gluconate and calcium citrate can be used as alternative phosphate binders to supplement aluminum hydroxide. The use of these substances reduces the amount of aluminum hydroxide needed to stabilize phosphate homeostasis in patients with renal failure and therefore the risk of aluminum intoxication. Patients treated with calcium citrate should be monitored very carefully, especially since citrate facilitates the absorption of aluminum by the gut. The phosphate level can be lowered best by calcium carbonate; calcium gluconate tends to produce an increase in serum calcium. Calcium gluconate also has to be carefully dosed, since gastrointestinal side effects can occur.