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)

A sanitary and technological diagnosis of the goat cheese rural process was carried out. The purpose was to obtain more information for the planning of a program aimed to the improvement of this small agroindustry. Samples of milk, curdle, dry abomasum, rennet, water and cheese of 10% of the small industries of two rural villages in two agricultural seasons, were taken. Moreover, dilutions of the utensils and goat udders were prepared. The samples were subjected to microbiological analysis of mesophilic aerobic bacteria count, most probable number of total and fecal coliforms, and detection of Staphylococcus aureus coagulase (+), Salmonella typhi and Brucella melitensis. Proximate chemical analysis and determinations of sodium chloride and titratible acidity in milk, cheese, dry abomasum and rennet, were carried out. Goat milk was also subjected to analysis of density. It was found that significant sanitary failures are present during th whole goat cheese process, although the highest bacteria contamination occurred at the milking, curdling and filling stages. These are characterized by excessive handling and absolute lack of hygiene. The pathogen B. melitensis was absent; therefore the causes of poisoning were attributed to the toxin produced by S. aureus and to the significant count of fecal coliforms found in the goat cheese. Even though the goats are fed under a poor feeding system, the milk presented a normal physical and chemical composition. Nevertheless, protein and fat matter losses occur during cheese preparation, as a result of handling practices and lack of process control.
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PMID:[Sanitary and technologic evaluation of the rural processing of fresh goat cheese in Chile]. 315 1

The composition and quality of edible tender stems or cladodes of 3 Prickly Pear Cactus species (Opuntia amyclaea, O. ficus-indica, and O. inermis) were studied at different stages of development. This traditional Mexican vegetable is called "nopalitos" in Spanish and "cactus leaves" in English. Cladodes harvested when 20 cm in length have the following average composition per 100 g: 91.7 g of water, 1.1 g of protein, 0.2 g of lipid, 1.3 g of ash, 1.1 g of crude fiber, 4.6 g of complex carbohydrates and 0.82 g of simple sugars, 12.7 mg of ascorbic acid and 28.9 micrograms of carotenes. The cladode's juice has an average pH of 4.6, 0.45% titratable acidity and 6.9% soluble solids. The components which varied most during development of the cladodes were: carotenes, acidity and total carbohydrates which increased, and protein and crude fiber (acid-detergent) which decreased. The nutritive value of the tender cladodes in the stages of growth at which they are commonly harvested and consumed (15 to 25 cm long weighing 50 to 80 g per stem), was similar for the 3 species.
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PMID:Developmental changes in composition and quality of prickly pear cactus cladodes (nopalitos). 323 97

Mixtures of alginic acid and antacid, when given orally, react with gastric acid to form a viscous barrier (raft) which floats on the surface of the gastric contents. 111In was used to label magnesium alginate in order to study the effect of gastric acidity on the extent of formation of the raft. In vitro, acid concentrations less than 0.05 N diminished raft formation. In vivo, raft formation was significantly better in normal subjects who ingested dilute acid with the labeled alginate/antacid than in subjects who ingested the labeled alginate/antacid with plain water. Gastric emptying of the labeled alginate was also slowed by the presence of acidified gastric contents. These results suggest that the formation of an effective alginic acid antireflux barrier requires acidic gastric contents.
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PMID:Use of 111In-labeled alginate to study the pH dependence of alginic acid anti-esophageal reflux barrier. 325 79

Semiempirical minimal neglect of differential overlap-self-consistent field calculations, corrected and modified for multiple hydrogen-bonding interactions, were applied to models of the active site of aspartic proteinases (AP). The propensities of the two active-site aspartates to ionize were compared under the influence of various neighboring residues and of water molecules. Asp-32 and Asp-215 in three aspartic proteinases (endothiapepsin, Rhizopus pepsin, and penicillopepsin) are found to be basically asymmetric, Asp-32 being preferentially (by 2-3 kcal) ionized with respect to Asp-215. In penicillopepsin, this asymmetry is compensated by effects of surrounding residues. In our largest model for the active site, which includes such other residues, near equality is found for the ionizing tendency of Asp-32 and Asp-215. The pK difference is rationalized in terms of first and second ionizations of the full active-site model. Its ionization enthalpies correlate well with those of other small organic diacids. This "gas-phase" approach to AP active-site interactions represents the main possible contributions to the acidity of the active site.
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PMID:Theoretical calculations on the acidity of the active site in aspartic proteinases. 328 87

Rational pharmacotherapy is dependent upon an understanding of the clinical pharmacokinetic and pharmacodynamic properties of the drugs employed. Although the available data on drug biodisposition and action in the neonate have increased considerably in the last few years, pharmacokinetic-pharmacodynamic interactions for many drugs remain poorly understood. The ontogeny of drug absorption, distribution, metabolism, and elimination are addressed in this review. Drug absorption from any site depends upon both the physicochemical properties of the drug and a variety of patient factors. Absorption of orally administered drugs may be affected by changes in gastric acidity and emptying time as well as by bile salt pool size, bacterial colonisation, and extraintestinal disease states such as congestive heart failure. Factors affecting drug absorption following intramuscular, percutaneous, and rectal administration are also discussed. Drug distribution in the neonate is influenced by a variety of important and predictable age-dependent factors. The developmental aspects of protein binding and body water compartments are described. Additionally, hepatic drug metabolism assumes an important role in understanding the pharmacokinetic and pharmacodynamic properties of many compounds. Certain biotransformation pathways, including hydroxylation by the P450 mono-oxygenase system and glucuronidation, demonstrate only limited activity at birth, while other pathways, such as sulphate or glycine conjugation, appear very efficient at birth. Elimination of drugs excreted unchanged in the urine is dramatically reduced in the newborn, compared with older infants and children, due to immaturity of both glomerular filtration and tubular secretory processes. The glomerular filtration rate remains markedly reduced prior to 34 weeks gestational age, increasing as a function of post-conceptual age until adult values are achieved by approximately 2.5 to 5 months of age. Tubular secretory capacity is also limited at birth, approaching adult values by approximately 7 months of age. Published reports describing the pharmacokinetics and pharmacodynamics of commonly used drugs in the neonatal period, as well as differences in drug biodisposition among premature infants, full term neonates, and older infants and children, are reviewed. Our recommendations for neonatal drug therapy are based upon a critical interpretation of these data, an understanding of fetal development and maturational processes, and an understanding of how disease states may affect drug biodisposition in the neonate.
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PMID:Principles of drug biodisposition in the neonate. A critical evaluation of the pharmacokinetic-pharmacodynamic interface (Part I). 329

Acid precipitation affects the solubility of several metals in aquatic systems and in soil. Cadmium levels in tap water samples from geological areas having low resistance to acidic pollution were significantly higher than those in samples from a neighbouring reference area where there was a different geological structure. The median cadmium levels and pH values were 0.14 microgram l-1 and 5.6 respectively, for the acidic areas compared with 0.07 microgram l-1 and 6.4 respectively for the reference area. Further, there was a significant inverse relationship between both cadmium and lead contents and the pH values of the samples. The mobility of the metals was thus dependent on the acidity. The blood lead levels in 195 subjects from the acidic areas were lower than those in 91 subjects from the reference area (medians 60 vs. 70 micrograms l-1); no significant differences were found in blood cadmium or blood mercury levels. Subjects in the acidic areas had lower plasma selenium levels than those from the reference area (medians 85 vs. 90 micrograms l-1); the difference was mainly attributed to subjects with private wells. The data may indicate a negative effect of the acidic pollution on selenium intake via water and/or foods. There was also a positive relationship between intake of fish on the one hand and blood mercury and plasma selenium on the other, which is in accordance with the role of fish as a source of these metals.
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PMID:Acidic deposition and human exposure to toxic metals. 343 37

We prepared obstructive jaundice models in rats in order to study the mechanism of acute ulceration in obstructive jaundice centering on impediments to gastric wall blood flow and changes in gastric mucosal NA and PGE2 when the rats were subjected to water immersion restraint stress. The results were: In the obstructive jaundice 2 weeks group, when subjected to water immersion restraint stress, gastric mucosal NA reached a dried up stage from the incipient stage, causing gastric mucosal impediments at the same time, showing a significant decrease of gastric mucosal PGE2. Intragastric pH was at a similar level of excessive acidity in all groups; gastric acid is believed to be a secondary factor promoting ulceration. Gastric mucosal PGE2 showed a significant decrease coinciding with the increase in ulceration index, being a possible factor of ulceration; it is also presumed to regulate gastric wall blood flow alternatively with gastric mucosal NA. Pre-treatment with PGE2 prior to loading stress resulted in a decrease in gastric wall blood flow being significantly controlled. The administration of PGE2 brought about an improvement in gastric wall blood flow and a consequent increase in gastric mucosal NA, being judged effective for acute ulceration in obstructive jaundice.
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PMID:[Experimental study on the pathogenesis of acute ulceration in obstructive jaundice--with reference to gastric mucosal blood flow]. 345 15

Hot water extract of pine cone (PCE) of Pinus parviflora Sieb. et Zucc. dose-dependently suppressed both solid and ascites tumor cells transplanted into various mice. Acidic polysaccharides of PCE significantly increased the survival time of mice bearing ascites tumor cells, and activity increased with acidity. One of the four polysaccharide fractions obtained by NaOH extraction showed the most potent antitumor activity. This fraction significantly suppressed the growth of solid tumor cells, with occasional tumor regression and necrosis, and with little or no cytocidal effect on cultured tumor cells. All acidic polysaccharides were able to activate mouse macrophage-like cell line J774.1. There did not appear to be any correlation between the antitumor activity of these polysaccharides and their content of arabinose (or fucose), mannose, galactose, glucose, or uronic acid.
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PMID:Antitumor activity of polysaccharide fractions from pine cone extract of Pinus parviflora Sieb. et Zucc. 348 81

The degradation kinetics, products, and mechanisms of RS-10085(1), 2-[2-(1-ethoxycarbonyl)-3-phenylpropyl]amino-1-oxopropyl]-6,7- dimethoxy-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid(S,S,S), in aqueous solution were investigated at 40, 60, and 80 degrees C from pH 1 to pH 13. Pseudo-first-order kinetics were observed throughout the pH range studied and the log(rate)-pH profiles reflected four kinetic processes (ko, k'o, k'o, and kOH) as well as the two pKa's of 1. Excellent (greater than 98%) mass balance was obtained through products 2-5. At pH 4 or below, intramolecular cyclization leading to diketopiperazine 5 accounted for greater than 93% of the observed neutral- or water-catalyzed processes (ko and k'o). At pH levels greater than 5, hydrolysis giving 2 predominated and was responsible for the observed neutral- or water-catalyzed (k''o) and specific base-catalyzed (kOH) kinetic processes. Some epimerization leading to the S,S,R drug isomer (4) was also observed at pH levels greater than 7. The relative acidity of the protons at the three chiral centers of 1 was qualitatively compared and was used to explain the observed specificity in epimerization.
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PMID:Diketopiperazine formation, hydrolysis, and epimerization of the new dipeptide angiotensin-converting enzyme inhibitor RS-10085. 350 48

Congenital chloride diarrhoea is an autosomal recessive disease characterized by life-long watery diarrhoea of prenatal onset with high faecal Cl- concentration. Seventy-nine patients have so far been reported. The basic defect involves the active Cl-/HCO3- exchange mechanism of the distal ileum and colon. The defect causes impaired absorption of Cl-, acidity of intestinal contents because of impaired excretion of HCO3-, and, secondarily, impaired Na+ absorption. Intra-uterine diarrhoea leads to hydramnios and often to premature birth. Unless adequately treated, most patients will die of hypo-electrolytaemic dehydration within the 1st few months of life. Some infants will survive in such a state, with severe alkalosis, hypochloraemia, hypokalaemia, and retarded growth and development. Their plasma renin and aldosterone concentrations will become grossly elevated, and pathological changes will develop in the kidneys. The diagnosis is established when faecal Cl- concentration exceeds 90 mmol/l after water and electrolyte deficits have been corrected. Congenital chloride diarrhoea should be treated with full oral replacement of the faecal losses of Cl-, Na+, K+, and water. This therapy will abolish all the secondary disorders, provide for normal growth and development, and prevent renal disease. Though this therapy does not abolish the diarrhoea, most children will become toilet trained at a normal age, their social adjustment will be unimpaired, and they will live a perfectly normal life.
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PMID:Congenital chloride diarrhoea. 352 96


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