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Acid Control (acid + control)
Selected Abstracts, -Amino Butyric Acid Control of Arginine Vasopressin Release from the Ewe Hypothalamus In Vitro: Sensitivity to OestradiolREPRODUCTION IN DOMESTIC ANIMALS, Issue 5 2007SPS Ghuman Contents The present study aims to ascertain the influence of , -amino butyric acid (GABA)A or B receptors on arginine vasopressin (AVP) release in vitro and determine whether E2 modulates GABA,AVP interaction. Within 10 min of ewe killing, saggital midline hypothalamic slices (from the anterior preoptic area to the mediobasal hypothalamus along with the median eminence, 2-mm thick, two per ewe) were dissected, placed in oxygenated minimum essential media (MEM)- , at 4°C and within 2 h were singly perifused at 37°C with oxygenated MEM- , (pH 7.4; flow rate 0.15 ml/min), either with or without E2 (24 pg/ml). After 4-h equilibration, 10-min fractions were collected for 4 h interposed with a 10-min exposure at 60 min to a specific GABAA or B receptor agonist or antagonist at various doses (0.1,10 mm). GABAA (muscimol; no E2, n = 7 perifusion chambers, with E2, n = 11) or GABAB (baclofen; no E2, n = 8, with E2, n = 15) agonists (10 mm) did not influence AVP concentrations. However, AVP release increased (p < 0.05) 20,30 min after exposure to 10 mm GABAA or B antagonists (bicuculline, no E2, n = 7: from 4.6 ± 0.7 to 33.0 ± 0.4, with E2, n = 17: from 11.9 ± 1.4 to 32.8 ± 6.0; CGP52432, with E2, n = 14: from 14.0 ± 2.6 to 28.8 ± 3.9 pg/ml). At the end of the collection period, hypothalamic slices responded to KCl (100 mm) with AVP efflux (p < 0.05). GABAB but not GABAA antagonist-stimulated AVP release was enhanced in the presence of E2. In summary, AVP release is under the inhibitory influence of GABA input with further potentiation by E2 through GABAB receptors in vitro. [source] Autophagy and amino acid homeostasis are required for chronological longevity in Saccharomyces cerevisiaeAGING CELL, Issue 4 2009Ashley L. Alvers Summary Following cessation of growth, yeast cells remain viable in a nondividing state for a period of time known as the chronological lifespan (CLS). Autophagy is a degradative process responsible for amino acid recycling in response to nitrogen starvation and amino acid limitation. We have investigated the role of autophagy during chronological aging of yeast grown in glucose minimal media containing different supplemental essential and nonessential amino acids. Deletion of ATG1 or ATG7, both of which are required for autophagy, reduced CLS, whereas deletion of ATG11, which is required for selective targeting of cellular components to the vacuole for degradation, did not reduce CLS. The nonessential amino acids isoleucine and valine, and the essential amino acid leucine, extended CLS in autophagy-deficient as well as autophagy-competent yeast. This extension was suppressed by constitutive expression of GCN4, which encodes a transcriptional regulator of general amino acid control (GAAC). Consistent with this, GCN4 expression was reduced by isoleucine and valine. Furthermore, elimination of the leucine requirement extended CLS and prevented the effects of constitutive expression of GCN4. Interestingly, deletion of LEU3, a GAAC target gene encoding a transcriptional regulator of branched side chain amino acid synthesis, dramatically increased CLS in the absence of amino acid supplements. In general, this indicates that activation of GAAC reduces CLS whereas suppression of GAAC extends CLS in minimal medium. These findings demonstrate important roles for autophagy and amino acid homeostasis in determining CLS in yeast. [source] Clinical trial: intragastric acid control in patients who have Barrett's oesophagus,comparison of once- and twice-daily regimens of esomeprazole and lansoprazoleALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 2 2009S. J. SPECHLER Summary Background, Gastric acid control is important for treatment of gastro-oesophageal reflux disease associated with Barrett's oesophagus. Substantial indirect evidence suggests that gastric acid control may have a chemopreventive role in Barrett's oesophagus. Aim, To compare the pharmacodynamic efficacy of esomeprazole and lansoprazole at two dosages for intragastric pH control with Barrett's oesophagus. Methods, Patients with Barrett's oesophagus received open-label consecutive treatment (a 15-day period of once-daily dosing followed by a 10-day period of twice-daily dosing) with esomeprazole (40-mg capsules) and lansoprazole (30-mg capsules) in random order with no washouts. Twenty-four-hour intragastric pH was recorded on the last day of each dosing period. The primary end point was the percentage of time with intragastric pH > 4.0. Results, In the per-protocol once- (n = 46) and twice-daily (n = 41) analyses, the percentage of time with intragastric pH > 4.0 was significantly (P < 0.0001) longer after once- (67.1%) or twice-daily (81.2%) esomeprazole than after once- (50.8%) or twice-daily (64.3%) lansoprazole. The proportion of patients with intragastric pH > 4.0 for >12 h was significantly higher for esomeprazole than lansoprazole with once- (P = 0.004) and twice-daily (P = 0.016) dosing. Conclusion, Esomeprazole 40 mg is significantly more effective than lansoprazole 30 mg in controlling intragastric pH with Barrett's oesophagus. [source] Relationship between intragastric acid control and healing status in the treatment of moderate to severe erosive oesophagitisALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 5 2007P. O. KATZ Summary Aim, To assess the relationship between the percentage of time intragastric pH >4.0 and healing of erosive oesophagitis. Methods, In this proof-of-concept study, adults with endoscopically verified Los Angeles grade C or grade D erosive oesophagitis were randomly assigned to oral esomeprazole 10 or 40 mg once daily for 4 weeks. On day 5, patients underwent 24-h pH monitoring. At 4 weeks, erosive oesophagitis healing status was endoscopically assessed. Investigators scored gastro-oesophageal reflux disease symptoms on a 4-point scale [none to severe (0,3)] before and 4 weeks after treatment. The percentage of time intragastric pH was >4.0 and healing status were correlated and tested for significance using a Spearman rank correlation (r). Results, 103 patients had evaluable data (mean age, 48.7 years; 65% men). Mean percentages of time with intragastric pH >4.0 on day 5 in patients with healed and unhealed erosive oesophagitis were 61% and 42%, respectively (P = 0.0002), indicating that erosive oesophagitis healing rates were positively related to the percentage of time intragastric pH was >4.0. Greater intragastric acid control correlated with lower final daytime and night-time heartburn and acid regurgitation symptom scores (r = ,0.029, ,0.029 and ,0.021; P = 0.003, 0.003 and 0.032, respectively). Conclusion, A positive relationship between intragastric acid control and erosive oesophagitis healing was demonstrated. [source] Plasma vitamin values and antiepileptic therapy: Case reports of pregnancy outcomes affected by a neural tube defectBIRTH DEFECTS RESEARCH, Issue 1 2007Mirande Candito Abstract BACKGROUND: Folic acid supplementation reduces the occurrence of neural tube defects (NTDs); however, it is not clear whether it protects against teratogenic effects of antiepileptic drugs. METHODS: We report the cases of four pregnant women receiving valproic acid therapy, who all had NTD-affected offspring, despite periconceptional 5 mg/day of folic acid supplementation (cases), and investigated homocysteine metabolism, linked with folate metabolism. Their plasma homocysteine, folates, and vitamin B6 and B12 results were compared with values of two other women, who were also receiving valproic acid and folic acid complement, but who had normal pregnancies (valproic acid controls), and values of 40 pregnant women who had normal pregnancies and were not receiving any therapy (controls without therapy). Because of the possible existence of a genetic susceptibility, polymorphisms in homocysteine metabolism were sought. RESULTS: Two cases showed a decreased phosphopyridoxal level, compared with levels in the controls not receiving therapy. The genotype TT (C677T) is an NTD genetic susceptibility, but it was observed in only one valproic acid control. Various polymorphisms were observed in the cases, but were also common in the controls. Several studies have reported that valproic acid therapy lowers vitamin B6 levels. Our case with the greatest decrease in plasma phosphopyridoxal, who was taking periconceptional folic acid plus pyridoxine therapy, had a normal second pregnancy outcome. CONCLUSIONS: In addition to folates, other vitamins, such as vitamin B6, may have played a role in NTDs in our patients taking an antiepileptic drug. Birth Defects Research (Part A) 2007. © 2006 Wiley-Liss, Inc. [source] Drug metabolic activity of cultured hepatocytes can synchronize with bile acid concentration in the mediumCELL BIOCHEMISTRY AND FUNCTION, Issue 1 2002Nobuhiro Sugihara Abstract The regulation of drug metabolic activity of cultured hepatocytes can be applied to the evaluation of pharmacokinetics, analysis of drug delivery and the bioartificial liver system. It is very difficult to maintain the drug metabolic activity mediated by cytochrome P-450 (CYP) 3A. Recently we found that the CYP3A aminopyrine N-demethylase (AMND) activity of hepatocytes cultured on collagen surface oscillated with culture time. This phenomenon was related to the concentration of bile acid in the culture medium. CYP3A, multidrug resistant gene 2 (MDR2) and heat shock protein 84 (HSP84) mRNA appeared in a manner corresponding to this oscillation. When a large quantity of bile acid was taken up into hepatocytes from the medium, low AMND activity was observed, and these proteins did not appear. When bile acid was secreted and the bile acid concentration inside the hepatocytes was low, high AMND activity was obtained, and these proteins appeared. In order to clarify the mechanism of oscillation between AMND activity and bile acid, 8,,M glycocholic acid was added to the culture medium 15,h before the measurement. No oscillation in AMND activity was observed in the presence of 8,,M glycocholic acid. Bile acid controls the AMND activity in the transcription of hepatocytes. Copyright © 2001 John Wiley & Sons, Ltd. [source] | |||||||||||||