Search Results
Results 501 - 550 of 1166
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Shibata K - - 2001
The effects of pyrazinamide on the metabolism of tryptophan to niacin and of tryptophan to serotonin were investigated to elucidate the mechanism for pyrazinamide action against tuberculosis. Weanling rats were fed with a diet with or without 0.25% pyrazinamide for 61 days. Urine samples were periodically collected for measuring the ...
Sifrim D - - 2001
BACKGROUND & AIMS: Gastroesophageal reflux can be acid, nonacid, pure liquid, or a mixture of gas and liquid. We investigated the prevalence of acid and nonacid reflux and the air-liquid composition of the refluxate in ambulant healthy subjects and patients with reflux disease (GERD). METHODS: Twenty-four-hour ambulatory recordings were performed ...
Vela M F - - 2001
BACKGROUND & AIMS: Nonacid reflux may explain symptoms in acid-suppressed patients. Simultaneous intraesophageal impedance and pH measurement was used to evaluate the frequencies of postprandial acid and nonacid reflux before and after omeprazole administration. METHODS: Twelve heartburn patients underwent two 2-hour studies of intraesophageal impedance and pH in the right ...
Ibarra G - - 2001
Gastroesophageal reflux disease (GERD) is a condition where acid contents of the stomach are regurgitated into the oral cavity, which results in continual exposure of the teeth to these acids. Knowledge of the relationship between GERD and dental erosion enables the appropriate diagnosis and treatment of the underlying medical condition ...
Gardner J D - - 2001
OBJECTIVES: The aim of this study was to demonstrate that integrated esophageal and gastric acidity values, calculated from 24-h pH recordings, can provide more precise quantitative temporal data than the conventional pH parameters historically associated with gastroesophageal reflux disease (GERD) investigations. METHODS: Esophagogastroduodenoscopy results and pH tracings from 20 GERD ...
Gerde P - - 2001
Exposure to diesel exhaust is a suspected risk factor for human lung cancer. The carbonaceous core of the soot particles found in diesel exhaust and the condensed organic compounds adsorbed (or bound) onto the surface of the particles are both possible contributors to this suspected risk. The extent and rate ...
Lien H C - - 2001
BACKGROUND: Postprandial gastric distention is frequently associated with transient lower esophageal sphincter relaxation and gastroesophageal reflux (GER). Since the role of nutrient perfusion into the jejunum in inducing GER is not well understood, we studied the effect of jejunal feeding on GER through a percutaneous gastrojejunal tube in patients with ...
Beckett W S - - 2001
Boron is widely used in industrial materials, most frequently as the salt borax. Systemic exposure (eg, ingestion) to boron in boric acid been associated with reversible toxic alopecia among other manifestations. There is scant clinical literature on alopecia caused by topical exposure to boron. We observed a series of 3 ...
Weng Larsen S - - 2001
The rate constants for transfer of a homologous series of nicotinic acid esters from oil vehicles to aqueous buffer phases were determined using a rotating dialysis cell. The chemical stability of butyl nicotinate has been investigated at 60 degrees C over pH range 0.5--10. Maximum stability occurs at pH 4--5 ...
Ogura Y - - 2001
The effects of jasmonic acid (JA) and abscisic aid (ABA) on secondary metabolism in barley (Hordeum vulgare L.) were investigated. Treatment with JA at 100 microM for 48 h induced accumulation of four compounds in barley primary leaves. The accumulation of these compounds was also observed after treatment with ABA ...
Garrido R - - 2001
Hydrolysis of membrane phospholipids of spinal cord neurons is one of the first events initiated in spinal cord trauma. In this process, free fatty acids, and in particular arachidonic acid, are released. Exposure of spinal cord neurons to free arachidonic acid can compromise cell survival and initiate apoptotic cell death. ...
Schowengerdt C G - - 2001
Patients who present with uncontrolled esophageal acid reflux symptoms require endoscopy to determine the presence or absence of ulcers and stenoses, acid reflux testing to determine if acid reflux is present, and manometry to evaluate esophageal peristalsis and spastic states. These studies are usually done in stages, at separate times. ...
White R J - - 2001
Acute intraluminal acid perfusion induces esophageal shortening in humans and opossums. Lower esophageal sphincter (LES) hypotension and peristaltic dysfunction occur in patients and animal models of reflux esophagitis. This study examined whether similar shortening and motor dysfunction occur in anesthetized opossums after repeated esophageal acid exposure and whether this is ...
Fitzgerald R C - - 2001
Barrett's oesophagus, a significant complication of gastro-oesophageal reflux disease (GERD), is the single most important risk factor for oesophageal adenocarcinoma. The strong association between Barrett's oesophagus and chronic GERD suggests that abnormal oesophageal acid exposure plays an important role in this condition. The progression of Barrett's oesophagus from specialized intestinal ...
Fass R - - 2001
BACKGROUND: Gastro-oesophageal reflux disease (GORD) plays a major role in the development of Barrett's oesophagus. However, it has yet to be elucidated what factors determine the length of Barrett's mucosa in each individual patient. AIMS: To determine if there is a correlation between oesophageal acid exposure and the length of ...
Lorenzen A - - 2001
Nicotinic acid is a lipid-lowering agent widely used to treat hypertriglyceridemia and to elevate low high density lipoprotein levels. However, the underlying mechanisms are poorly understood. In this study, G protein activation by nicotinic acid and derivatives was assessed as stimulation of guanosine 5'-(gamma-[(35)S]-thio)triphosphate ([(35)S]GTPgammaS) binding, and [(3)H]nicotinic acid was ...
Todd J A - - 2001
BACKGROUND: There has been a dramatic rise in incidences of Barrett's oesophagus and oesophageal adenocarcinoma. It has been suggested that the introduction and use of acid suppression therapy may be a factor in the rising incidences of Barrett's oesophagus and oesophageal adenocarcinoma. METHODS: This was a record linkage study, using ...
Castell D O - - 2001
Barrett's esophagus (BE) is a change in the cellular structure of the lower esophagus believed by many to be caused by frequent acid exposure. The condition is troublesome because of a tendency toward cell proliferation, dysplastic transformation, and cancerous changes within the lesions. It is speculated that the pronounced increase ...
Chambers K L - - 2001
A simple, quick and inexpensive test for smoking status would be useful in a variety of settings. The non-polar barbituric acid derivative 1,3-dibutyl-2-thiobarbituric acid (DBTB) is described as a novel derivatisation reagent for nicotine and its metabolites in the König reaction to assess smoking status. The relative performance of qualitative ...
Penagini R - - 2001
Duodenal contents, and especially bile acids and trypsin, are noxious to the oesophageal mucosa, their damaging potential depending on pH. Various methodologies have been used to measure duodenogastric or duodenogastro-oesophageal reflux, all of them having technical limitations. Controversy exists as to the extent of duodenogastric reflux in GORD. Reflux of ...
Begley T P - - 2001
The nicotinamide adenine dinucleotides (NAD, NADH, NADP, and NADPH) are essential cofactors in all living systems and function as hydride acceptors (NAD, NADP) and hydride donors (NADH, NADPH) in biochemical redox reactions. The six-step bacterial biosynthetic pathway begins with the oxidation of aspartate to iminosuccinic acid, which is then condensed ...
Nakazawa K - - 2001
OBJECTIVE: The purpose of this study was to investigate the effects of aerosolized prostacyclin (A-PGI2) and intratracheally instilled prostacyclin (I-PGI2) during partial liquid ventilation (PLV) on gas exchange and pulmonary circulation in rabbits with acute respiratory distress. DESIGN: Prospective control study. SETTING: A research laboratory at a university medical centre. ...
Ciolino L A - - 2001
Commercial moist snuff products are used by placing a portion of tobacco inside the mouth between the inner cheek or lip and gum. Nicotine is absorbed into the blood stream via transfer across various oral membranes including the buccal mucosa (cheek lining). The resulting salivary pH when a given moist ...
Cleaves H J - - 2001
Many of the biosynthetic pathways, especially those leading to the coenzymes, must have originated very early, perhaps before enzymes were available to catalyze their synthesis. While a number of enzymatic reactions in metabolism are known to proceed nonenzymatically, there are no examples of entire metabolic sequences that can be achieved ...
Laitinen S - - 2001
The aim of this study was to assess workers' exposure to endotoxins and peptidoglycans, as well as associations between workers' reported symptoms and the detected bacterial exposures. From the filter samples, biologically-active endotoxins were analysed with the Limulus amebocyte lysate (LAL) assay. The total amount of endotoxins was analysed as ...
Cuomo R - - 2000
Some methodological in vitro observations concerning bile reflux monitoring (Bilitec) suggested that Bilitec monitoring is underestimating reflux in an acid environment. Moreover, other studies showed that the area above the cutoff level of bilirubin absorbance would provide an adequate quantitative marker for reflux of duodenal contents. Our aim was to ...
Katz P O - - 2000
The role of acid in the pathogenesis of gastro-oesophageal reflux disease (GERD) has been extensively studied and is well accepted. The role, if any, of non-acid reflux, in particular duodenogastro-oesophageal reflux, is much debated. The availability of new technology to detect non-acid reflux has heightened interest in this question. This ...
Hecht S S SS University of Minnesota Cancer Center, Minneapolis, MN 55455, USA. - - 2000
Smokers or people undergoing nicotine replacement therapy excrete approximately 10% of the nicotine dose as 4-oxo-4-(3-pyridyl)butanoic acid (keto acid) and 4-hydroxy-4-(3-pyridyl)butanoic acid (hydroxy acid). Previously, these acids were thought to arise by secondary metabolism of the major nicotine metabolite cotinine, but our data did not support this mechanism. Therefore, we ...
Stacher G - - 2000
AIMS: To evaluate the impact of total and proximal stomach emptying on 24 hour and postprandial reflux as well as the number of reflux episodes per hour in relation to the impact of lower oesophageal sphincter (LOS) pressure, and oesophageal contractile and clearance function. METHODS: Seventy one outpatients (37 female, ...
Dunne D P DP GI Diseases Research Unit, Queen's University, Kingston, - - 2000
Hiatus hernia and gastroesophageal reflux disease commonly coexist, and there is pathophysiological evidence that the presence of a hiatus hernia contributes to abnormal acid reflux. However, the cause of hiatus hernia remains unclear. In an animal model, it has been shown that acute acid injury to the esophagus results in ...
de Vries H - - 2000
To obtain an idea of the photostability of Lomefloxacin (Lom) under in vivo conditions the compound was exposed to UV-A (310-360 nm) in PBS buffer pH 7.4. Exposure of 10 microg/ml of Lom in PBS pH 7.4 led to more than 50% decomposition within 10 min. Loss of the fluorine ...
Fennerty M B - - 2000
Most treatment of Barrett's esophagus (BE) has focused on normalization of the acidic esophageal environment in which the change from squamous to columnar epithelium takes place. In conjunction with creating a normal acid environment, several other therapies are under investigation. Although the data do not yet support the use of ...
Shaw G Y - - 2000
The recognition of extraesophageal manifestations of gastroesophageal reflux (GER) has gained acceptance in recent years. Objective measurements of acid reflux have been aided greatly by the advent of multiprobe pH monitoring. The development of the multiprobe pH monitor has enabled researchers and clinicians to objectively measure acid exposure in the ...
Vaezi M F - - 2000
The role of duodenogastro-oesophageal reflux (DGOR), once erroneously termed 'bile reflux', in causing oesophageal mucosal damage has been an area of interest in both animal and human studies. However, due to the lack of appropriate techniques for accurately measuring DGOR, extrapolation of findings from animal studies to humans was difficult ...
Castell D O - - 2000
Barrett's esophagus is a complication of gastroesophageal reflux disease (GERD) and may result from prolonged acid exposure in the esophagus. As a result, clinicians are investigating a possible relationship between acid suppression and a decrease in the risk of Barrett's esophagus progression. Some studies suggest that the length of Barrett's ...
van Herwaarden M A - - 2000
OBJECTIVE: Gastroesophageal reflux (GER) is increased in the right compared to the left recumbent position. Esophageal acid exposure is related to the acidity at the cardia, but the effect of body position on the acidity at the cardia has not yet been investigated. We aimed to investigate the mechanisms underlying ...
Wu J H - - 2000
BACKGROUND/AIMS: Calcium channel blocking agents have been reported to increase the risk of gastroesophageal reflux. However, whether felodipine, a newer calcium channel blocker, increases reflux episodes and decreases esophageal acid clearance in patients with gastroesophageal reflux disease has never been studied. Therefore, the aim of this study was to evaluate ...
Barbezat G O - - 2000
Barrett's esophagus is characterised by the presence of specialised intestinal metaplasia in the lower esophagus. Its importance is related primarily to its link with adenocarcinoma of the lower esophagus, often preceded by dysplastic changes. The incidence of this carcinoma has increased dramatically over the last few decades. Although modern treatments, ...
Valls F - - 2000
A simple and sensitive method for determining simultaneously nicotinic acid and nicotinamide content in cooked sausages by ion-pair reversed-phase liquid chromatography is described. Samples are extracted with ultrapure water, centrifuged, deproteinized with zinc hydroxide, filtered, and chromatographed with UV detection at 261 nm on a 25 cm x 4 mm ...
Casal S - - 2000
Arabica and robusta roasted coffees from several geographical origins, in a total of 29 samples, were characterized for their contents in caffeine, trigonelline, and nicotinic acid by a recently developed HPLC/diode-array detector method. All samples were subjected to the same roasting procedure in order to eliminate the variations due to ...
Pandolfino J E - - 2000
The role of smoking in the pathogenesis of gastrooesophageal reflux disease has been controversial since the early 1970s when Stanciu reported the two to be 92% epidemiologically associated (a study subsequently challenged by inconsistencies in the observational data). Mechanistically, reflux disease is caused by excessive oesophageal acid exposure, which is ...
Pastrakuljic A - - 2000
The inhibitory effects of cocaine and nicotine on placental amino acid transport, as a mechanism contributing to intrauterine growth restriction, were investigated in the in vitro placental perfusion model. Amino acids that represent substrates for known placental transporters were selected: alanine (system A), glutamine (system N), phenylalanine and valine (system ...
Barr H - - 2000
Barrett's esophagus has been identified as the premalignant precursor of esophageal adenocarcinoma. The eradication of metaplastic or dysplastic columnar-lined (Barrett's) esophagus may prevent progression to esophageal adenocarcinoma. 5-Aminolevulinic acid photodynamic therapy is a simple method for the mucosal ablation of the abnormal segment. Areas of metaplastic epithelium may remain buried ...
Llorente B - - 2000
We have studied the transcript levels of YGR260w and YLR004c, two genes encoding members of the yeast Dal5p subfamily of the major facilitator family, and we show that they increase when extracellular nicotinic acid and thiamine, respectively, are absent. The deletion of YGR260w in a bna1 auxotrophic mutant for nicotinic ...
Singh V - - 2000
OBJECTIVE: To study the change in airway reactivity due to presence of acid in lower esophagus and its reversibility by antacid. METHOD: In this double blind study 12 subjects with asthma and gastroesophageal reflux received acid (N/10 hydrochloric acid) and antacid (mixture of magnesium trisilicate and aluminum hydroxide) perfusion in ...
Eubanks T R - - 2000
BACKGROUND: Laparoscopy has increased the number of patients undergoing operative correction of gastroesophageal reflux disease (GERD). Symptom improvement has been most commonly reported as the means to assess operative outcome. We compared symptomatic outcome to postoperative pH testing at short-term follow-up to determine the accuracy of clinical assessment at predicting ...
Garrido R - - 2000
Arachidonic acid release from cellular membranes due to spinal cord trauma may be one of the principal destructive events that can lead to progressive injury to spinal cord tissue. Exposure to arachidonic acid can compromise neuronal survival and viability. Because nicotine is known to be a neuroprotective agent, we propose ...
Sontag S J - - 2000
The relationship between gastroesophageal reflux (GER) and asthma has troubled physicians for centuries and has been a source of debate among pulmonologists, allergists, and gastroenterologists for decades. Attempting to tie together the pieces of the puzzle, numerous investigators have struggled to show that in patients with asthma, GER symptoms occur ...
Fass R - - 2000
INTRODUCTION: elderly patients appear to have a more aggressive form of gastro-oesophageal reflux disease than younger patients. Reduced pain perception with age is a possible underlying mechanism. AIMS: to compare the extent of oesophageal mucosal injury, acid exposure, symptom severity and perception thresholds for acid infusion in older (aged 60 ...
Hogan W J - - 2000
Supraesophageal complications of GERD have become more commonly recognized or suspected by physicians. However, the direct association between these complications and GERD has often been difficult, if not impossible, to establish. Furthermore, the majority of patients with suspected supraesophageal complications of GERD do not have either the characteristic symptoms of ...
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