Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0847097 (acidity)
 15,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Salicylhydroxamic acid (SHAM) and glycerol, when administered together, cause destruction of bloodstream forms of Trypanosoma brucei brucei, both in vitro and in vivo, but the dose required is exceedingly high. In an attempt to improve the efficacy of this drug combination, we examined the ability of various polyols and hydroxamic acids to substitute for glycerol and SHAM, respectively. No satisfactory substitute for glycerol was found. The inhibition of the trypanosomal alpha-glycerophosphate oxidase system (GPO) by SHAM (Ki 21 microM) was uncompetitive. Only primary and secondary aromatic hydroxamates were inhibitory. Among a series of 19 benzhydroxamates, no correlation existed between their acidity or their affinity for iron and their inhibition of the GPO in a cell free preparation. The Ki's of most of the primary hydroxamates ranged from 10 to 24 microM, with the more lipophilic derivatives being slightly more active. The Ki's of secondary hydroxamates were more variable, the best having Ki's of about 10 microM. Several other classes of iron chelators were also evaluated. Tropolones were active with 3-bromo-4,5-benzotropolone being as active as SHAM. 3,4-Dihydroxybenzaldehyde (Ki 15 microM) also inhibited the GPO. On the other hand, diphenylamine and 8-hydroxyquinoline, known inhibitors of the GPO, were 30 to 50 times less active. The results suggest that a lipophilic aromatic iron-chelating agent may be useful as a substitute for SHAM in combination therapy.
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PMID:Trypanosoma brucei brucei: a systematic screening for alternatives to the salicylhydroxamic acid-glycerol combination. 679 1

Four low cost supplements containing whole wheat, pearl millet, bengal gram, green gram grain and amaranth leaves employing roasting and malting methods were developed. Nutritional evaluation showed that chemical composition of developed supplements was within the range prescribed for processed supplements and could meet satisfactorily one third requirements of protein, energy, iron and calcium for young children. Developed supplements were stored in three packings, polythene bags, tins with lids, glass bottle with lids (each 1 kg capacity, under ambient temperature (24-32 degrees C) and RH (70-80%) for a period of 30 days and analysed for moisture, peroxide value, fat acidity and alcoholic acidity. Stored samples were also evaluated organoleptically. The values of moisture, peroxide value, fat acidity and alcoholic acidity of stored samples were within the range of prescribed specifications for processed supplements. Storage of supplements for 30 days resulted in non-significant changes in organoleptic traits except for taste and aroma of bajra based supplements on 20th and 30th day of storage. In spite of these variations, all the supplements were found to be acceptable till 30th day of storage.
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PMID:Development, nutritive content and shelf life of home processed supplementary foods. 797 74

A colloidal iron probe was fed to the amoeba Dictyostelium discoideum and chased for different intervals. Successive segments of the endocytic pathway were then isolated magnetically at high yield and purity. There were approx. 500 endocytic vacuoles per cell; their diameters increased from approx. 0.1-0.2 microns after 3 min of feeding to approx. 2 microns after 15 min of feeding and 60 min of chase. The wave-like progression of ingested probes along the endocytic pathway suggested that the transfer of cargo involved a maturation mechanism rather than the shuttling of cargo between stable compartments. The lifetime of primary pinosomes was calculated to be approx. 1 s. Multivesicular bodies were common in the 3 min fraction and abundant in 15 min lysosomes. alpha- and beta-adaptins of molecular masses of approx. 89 and 83 kDa were richer in the 3 min vesicles than in plasma membranes and later endocytic vacuoles. Acid phosphatase, intrinsic vacuole acidity, the vacuolar proton pump protein and pump activity were present at all endocytic stages but rose between the 3 min and 15 min vacuoles and declined thereafter. Bis(monoacyglycero)phosphate or BMP, a lipid characteristic of lysosomes, followed a similar time course; it contributed up to half of the total lipid in lysosomal vacuoles. We conclude that there is both continuity and differentiation along this endocytic pathway.
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PMID:Analysis of successive endocytic compartments isolated from Dictyostelium discoideum by magnetic fractionation. 798 Dec 38

Orange juice concentrate has been fortified with calcium in order to fulfil part of the recommended daily allowance of calcium and to overcome the problem of the shortage of milk and dairy products in Egypt. The loss of quality of calcium-fortified and unfortified orange juice concentrate was evaluated in three different packaging materials and when stored for ten weeks at room temperature. The results showed that vitamin C content decreased during storage for both the fortified and the unfortified samples. The trend of ascorbic acid breakdown was similar in all packaging treatments. The total titratable acidity declined during storage period; however, the decline was higher in the unfortified sample than in the fortified one. Also, the pH values increased along with the storage period. The results illustrated that the color values of both the fortified and unfortified diluted orange juice concentrate changed little at the end of the storage period. However, the samples packaged in low density polyethylene bags had the higher orange in the color values R and Y. The changes in the iron content for both samples was negligible during the storage period. However, a very slight change in the calcium content (4.5% and 4%) was observed after ten weeks of storage for both the unfortified and the fortified samples respectively. The acceptability of fortified orange juice rated higher than the unfortified one. The panelists' evaluation values were affected by the packaging treatment and storage time. The samples packaged in low density polyethylene bags had a higher level of decline of the panelists' evaluations than the ones packaged in laminated pouches or cans, while the latter had a lower level of decline.
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PMID:The storage effects of calcium-fortified orange juice concentrate in different packaging materials. 805 82

Lactic acid 4 mM acted as a lipoperoxidant by increasing production of thiobarbituric acid-reactive substances (TBARS) in rat kidney slices and homogenates. This effect occurred mainly when slices and homogenates were incubated in a pH 5.4 medium conductive to full expression of compound acidity. TBARS increase was only slight when incubation was performed in Krebs buffer, pH 7.4. Moreover, sodium lactate 4 mM increased TBARS production only when homogenates were incubated in the pH 5.4 medium. Deferoxamine (1 mM) inhibited the prooxidant effect of lactic acid 4 mM, and TBARS increase was correlated with iron release. The iron mobilized may come from reserves where it is weakly bound or from ferritin; and ascorbic acid, present in low quantities in kidney, might trigger the release of this product.
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PMID:Iron- and lactic acid-induced lipid peroxidation in rat kidney homogenates and slices. 811 16

We have investigated the effect of pH on LDL oxidation by macrophages (in the presence of iron ions), using a modification of Hanks' balanced salt solution. Increasing the acidity of the medium greatly increased the oxidation of the LDL by the macrophages as measured by thiobarbituric acid-reactive substances or increased uptake and degradation by a second set of macrophages. The rate of oxidation of LDL by iron ions alone, measured in terms of conjugated dienes, was also increased greatly even at mildly acidic pH. It is quite possible that atherosclerotic lesions have an acidic extracellular pH, particularly in the vicinity of macrophages, and the observation that LDL oxidation by macrophages is increased at acidic pH may therefore help to explain why atherosclerotic lesions are apparently one of the very few sites in the body where LDL oxidation occurs.
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PMID:Acidic pH increases the oxidation of LDL by macrophages. 822 92

This study was designed to determine whether gastric acidity, added phytate or iron status significantly influenced the effects that dietary proteins have on iron absorption. Rats were fed test meals of wheat cereal, with and without an added dietary protein (beef, pork, chicken, fish or egg white), by gavage. The influences of phytate and gastric acid were investigated by adding sodium phytate to the test meals and by treating the rats with cimetidine to inhibit gastric acid production. Iron status was altered by dietary regimens. Significant (P < 0.05) effects of the proteins were determined by comparison of the various protein-containing meals to control meals of cereal or cereal + phytate, as appropriate. Gastric acidity, phytate and iron status were all confirmed as factors significantly affecting iron absorption. Beef, pork and chicken enhanced iron absorption, but only when phytate had been added to the meals and only in iron-deficient rats. Enhancement by meat was sufficient to overcome the inhibition by phytate. Fish was an inhibitor or enhancer in cimetidine-treated, iron-deficient rats, depending on the absence or presence of phytate, respectively. Egg white inhibited absorption from cereal meals in cimetidine-treated, iron-deficient rats.
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PMID:Gastric acid production, iron status and dietary phytate alter enhancement by meat of iron absorption in rats. 848 5

Salmonella typhimurium periodically confronts acid environments during its life. These situations arise in chemically compromised ponds, soil, degradative cellular organelles, host digestive systems, and may even result from byproducts of their own metabolism. The levels of acid that are encountered range from mild to extreme. As a neutralophile, S. typhimurium prefers to grown in pH environments above pH 5.5. They can survive down to pH 4 for extended periods of time. However, the limits of endurance can be stretched if the organisms are first adapted to a moderate acid pH before exposing them to acidity below pH 4.0. This adaptation, called the acid-tolerance response (ATR), includes several log phase and stationary phase systems. Some of these systems are dependent on an alternate sigma factor for RNA polymerase called sigma s, whereas other systems are sigma s-independent. A key to the ATR is the synthesis of a series of acid shock inducible proteins (ASPs), 51 for log phase ATR and 15 for stationary phase ATR. Some of these ASPs require sigma s for their synthesis; others require the participation of the ferric uptake regulator protein Fur. Effective acid tolerance involves RecA-independent DNA repair systems, iron, and facets of fatty acid metabolism. Aspects of medium composition and carbon metabolism are also known to influence the nature of acid tolerance in this organism. In addition to aiding survival in the natural non-host environment, aspects of acid tolerance are also tied to virulence, as evidenced by the involvement of the mouse virulence locus mviA and the fact that acid-sensitive strains of S. typhimurium exhibit reduced virulence. This review summarizes these aspects of acid adaptation and includes a discussion of acid-regulated gene expression.
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PMID:Low pH adaptation and the acid tolerance response of Salmonella typhimurium. 868 53

This study demonstrates a pH-dependent inhibition of Mg(2+)- and Ca(2+)-ATPase activities of Nostoc linckia and Chlorella vulgaris exposed to AlCl3, AlF3, NaF and AlCl3+NaF together. AlF3 and the combination of AlCl3+NaF were more inhibitory to both the enzymes as compared with AlCl3 and NaF. Toxicity of the test compounds increased with increasing acidity. Interaction of AlCl3+NaF was additive on N. linckia and C. vulgaris, respectively, at pH 7.5 and 6.8, and synergistic at pH 6.0 and 4.5. In the presence of 60 and 100 microM PO4(3-) an increased NaF concentration (in the AlCl3+NaF combination) was required to produce the same degree of inhibition in ATP synthesis and ATPase activity. Toxicity of fluoroaluminate was reduced in the presence of EDTA and citrate. Except for beryllium to some extent, combinations of cadmium, cobalt, iron, manganese, tin and zinc with fluoride were not as effective as aluminium in inhibiting the ATPase activity. The presence of a 100 kDa protein band in SDS-PAGE of both control as well as AlCl3+NaF-treated samples suggested that AlF4- inhibits the ATPase activity by acting as a functional barrier without affecting the structure of the enzyme.
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PMID:Impact of aluminium, fluoride and fluoroaluminate complex on ATPase activity of Nostoc linckia and Chlorella vulgaris. 869 79

We carried out a balance study to examine the effects of isomaltulose, lactose, isomalt, and isomaltulose-based oligomers (IBOs) on mineral (calcium, magnesium, phosphorus, and iron) absorption and retention. Four-week-old male Wistar rats were divided into five groups of six rats each and fed a basal diet or diet the containing either 5% isomaltulose, 5% lactose, 5% isomalts or isomaltulose-based oligomers (IBOs) ad libitum for 16 d. After 1 wk, the animals were subjected to a 5-d mineral (calcium, magnesium, phosphorus, and iron) balance study. The isomalt feeding, as well as the IBOs feeding, led to significantly elevated mineral absorption and retention. On the other hand, lactose feeding, widely known to enhance calcium absorption, increased only calcium absorption and isomaltulose feeding did not affect mineral absorption or retention. The organic acids in cecum contents were increased by IBOs or isomalt feeding. Succinic and acetic acids in cecum contents were significantly increased by IBOs feeding. Similarly, succinic, acetic, and i-valeric acids and total amount of organic acid in cecum content were significantly increased by isomalt feeding. Although the organic acids in cecum contents were increased by IBOs or isomalt feeding, the pH values and acidity in cecum contents were not changed by IBOs or isomalt feeding. The effect of addition of various organic acids to the mucosal fluid was examined with in vitro study using a hindgut segment. By the addition of acetic acid, and butyric acid, the mineral (calcium, magnesium, and phosphorus) uptake was increased.
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PMID:The effects of isomaltulose, isomalt, and isomaltulose-based oligomers on mineral absorption and retention. 890 97


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