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PubMed2002

The effect of chronic alcohol abuse on gastric and duodenal mucosa.

Alcohol consumed in small quantities is not dangerous for health but if it is drunk in big amounts it has a negative effect on somatic and psychical health. A number of studies have been published on the harmful effect of ethanol on the nervous system, circulation, endocrine and immune systems. Ethyl alcohol can directly damage the mucosa of the alimentary tract. The studies conducted and published so far have estimated acute ethanol damage of gastric mucosa in experimental animals. The views found in literature on the effect of continuous consumption of ethanol on the stomach are differentiated. The purpose of the paper was to provide a morphological and functional analysis of stomach and duodendum in patients who continuously abuse alcohol. Besides, at attempt was made to find the answer to the question whether the changes observed in gastric mucosa point to any connection with the period of alcohol abuse. The study referred to 79 persons: 61 male aged 17-65 who had been chronically drinking alcohol for the period of 5-37 years and 18 persons aged 17-59 (9 male and 9 female) who had never drunk alcohol or who had drunk it only rarely and in small were divided into three groups differing with the period of addiction (I--5-10 years; II--10-20 years; III--over 20 years). Hydrochloric acid secretion in gastric juice was marked and gastroscopy was performed in all the examined patients. Gastroscopy estimated the appearance of the gastric and duodenal mucosa, while biopsy specimens were taken for histological examination from the pyloric area, the body of the stomach and the duodendal bulb. Hydrochloric acid secretion was determined using the Kay's aspiration method. Pentagastrin was used to stimulate gastric secretion. Within the group of 79 patients, gastric mucosa inflammation was observed in all patients chronically drinking alcohol and in 72% patients who were the control. Both groups differed considerably with the degree of progression of the inflammatory process, which was estimated with histological examination. Atrophic gastritis was observed only in patients addicted to alcohol. The appearance of atrophic changes pointed to a close relation with the period of addiction. 13 out of 14 people with this type of inflammation had been drinking alcohol for at least 10 years. The studies did not show any relation existing between the percentage of cases with atrophic inflammation and the kind of drinks or the content of ethanol in them. Examinations concerning the secretory function of the stomach showed lower values of hydrochloric acid secretion, both in basic conditions and after pentagastrin stimulation, in patients addicted to alcohol as compared to the control. The results prove that continuous abuse of alcohol predisposes to atrophic inflammation of the gastric mucosa, and the appearance of this type of inflammatory changes is related to the duration of addiction. The longer the addiction, the lower the secretion of hydrochloric acid is.

Adolescent↗
PubMedDate not supplied

Shear bond strength of resin to acid/pumice-microabraded enamel.

The effect of enamel microabrasion techniques consisting of either 18% hydrochloric acid in pumice or a commercially available abrasive/10% hydrochloric acid mixture, PREMA, on composite/enamel shear bond strengths was investigated. Sixty extracted third molars had the bonding surface flattened and were divided into six treatment groups (n=10) with the enamel treated prior to bonding as follows: Group 1-- untreated; Group 2--37% phosphoric acid etched for 30 seconds; Group 3--18% hydrochloric acid/pumice mixture applied for five 20-second treatments; Group 4--similar to Group 3 with additional 37% phosphoric acid etch; Group 5--treated with PREMA compound applied for five 20-second treatments; Group 6--similar to Group 5 treatment with additional 37% phosphoric acid. Herculite XR composite resin was then bonded to all samples using a VLC unit. Samples were tested in shear, and fractured enamel surfaces were evaluated using light microscopy to determine the enamel-to-resin failures. Resin bond strengths to microabraded and H3PO4-etched enamel were similar to bond strengths of untreated H3PO4-etched enamel and were significantly better than bond strengths to PREMA-treated or unetched enamel.

Acid Etching, Dental↗
PubMed1991

Alternative mobile phases for enhanced chromatographic selectivity and increased sensitivity in peptide separations.

The standard method for separating peptide mixtures is reversed-phase high-performance liquid chromatography with gradients of increasing concentrations of acetonitrile in the presence of trifluoroacetic acid. With modern instruments and columns, complex peptide mixtures can be separated, and low picomole amounts can be collected in tens of microliters. Difficult separations are addressed by modifying the gradient slope or organic eluant composition. Further improvements in resolution are often needed, requiring fundamental changes in mobile phase composition or selection of complementary chromatographic separation mechanisms. For the present study, tryptic digests of cytochrome c from various species were separated in the presence of dilute hydrochloric acid by reversed phase on a Waters Delta-PakTM C18 high-performance insert column and by strong cation exchange on a Waters Protein-PakTM SP 8HR. Different and enhanced reversed-phase selectivity was obtained by replacing trifluoroacetic acid with dilute hydrochloric acid at the same pH. The increased optical clarity of hydrochloric acid-based mobile phases in the low ultraviolet wavelengths yielded increased sensitivity. Very different selectivity was observed with the cation-exchange chromatography. These data expand the options for peptide mapping by providing additional selectivity combined with increased mass sensitivity and spectral information in the low ultraviolet.

Amino Acid Sequence↗
PubMed1991

Removal of intrinsic enamel stains with vital bleaching and modified microabrasion.

This study utilized a vital bleaching agent as well as an enamel microabrasion compound with low hydrochloric acid concentration to remove intrinsic stains on the facial surfaces of anterior teeth. In addition, scanning electron microscopic analyses of enamel from extracted teeth compared the etching pattern of the commercial compound used in this study to 18% hydrochloric acid. Type 1 and Type 2 etch patterns were observed with 18% hydrochloric acid after 5 and 20 seconds, respectively. Milder and more diffuse etch patterns were observed with the enamel microabrasion compound. A conservative form of treatment to remove intrinsic stains would employ the use of a vital bleaching agent, followed by an enamel microabrasion compound.

Acid Etching, Dental↗
PubMed1991

In vitro stress selection of nematophagous fungi for biocontrol of parasitic nematodes in ruminants.

Laboratory experiments were designed to select nematophagous fungi that were able to survive in vitro conditions simulating passage through the gastro-intestinal tract of cattle. All of the tests were conducted at 39 degrees C. In a primary stress selection step in diluted rumen fluid, 21 isolates were obtained. Each of the primary stress selected isolates was tested in synthetic saliva, rumen fluid simulating the activity in the rumen, rumen fluid followed by pepsin-hydrochloric acid treatment simulating the additional effect of ruminal and abomasal activity, pepsin-hydrochloric acid solution simulating conditions in the abomasum and finally in a trypsin solution as an example of enzyme activity in the gut. The effect of the rumen fluid alone, or rumen fluid followed by pepsin-hydrochloric acid treatment, were responsible for the reduction in surviving fungal isolates. Only six of thirteen isolates belonging to the genus Arthrobotrys survived while seven of eight isolates of the genus Duddingtonia survived. Fourteen isolates were tested for their predatory capacity in a dung pat bioassay. Fungi of the genera Arthrobotrys and Duddingtonia reduced the development of Ostertagia ostertagi third stage larvae by approximately 75% and 96% respectively compared to the number of larvae that developed from fungus-free control pats.

Animals↗
PubMed1990

From Prout to the proton pump--a history of the science of gastric acid secretion and the surgery of peptic ulcer.

Prior to the 17th century, there was considerable confusion regarding the process of digestion. Although some physicians were certain that it was initiated by acid in the stomach, both the source and the nature of the acid were unclear. In the early 19th century, Prout confirmed the active secretion of hydrochloric acid by the stomach and related it to the symptoms of dyspepsia. Jacob Helm and, subsequently, Beaumont studied digestion in humans with gastric fistulas and each commented extensively on the physiologic manifestation of digestion. The role of the vagus nerves in the control of gastric acid secretion was identified in the early and mid-19th century by Brodie, and subsequently elaborated upon by Pavlov. By the early 20th century, Latarjet and Jaboulay in France, performing operations for abdominal pain and tabes, reported the effects of vagotomy on acid secretion and gastric motility. In 1943, Dragstedt, in the United States, reported the cure of duodenal peptic ulcer disease by supradiaphragmatic vagotomy. He later observed the substantial delays in emptying of the stomach, which necessitated the introduction of concomitant gastric drainage procedures, such as gastrojejunostomy and pyloroplasty. In 1902, Bayliss and Starling had described the existence of a chemical regulator of function--secretin--which they termed a hormone. Shortly thereafter, Edkins reported results of studies that supported the presence of an acid regulatory hormone, gastrin, in the antrum of the stomach. Unfortunately, controversy marred this observation, and the action of gastrin was for more than 30 years ascribed to histamine. Komarov, in 1938, confirmed the existence of gastrin and its stimulatory effects on acid secretion. Physiologic recognition of the roles of vagal stimulation and antral gastrin in the secretion of acid from the stomach resulted in the development of the operation of vagotomy and antrectomy for peptic ulcer disease. Studies of the pylorus and the motility of the stomach resulted in an appreciation of the genesis of the postgastrectomy syndromes. By the middle of the 20th century, a clear appreciation of the morphologic characteristics of the parietal cell and its ability to secrete hydrochloric acid was under way. The complex metabolic process of the cell was correlated with the major morphologic transformation necessary to generate secretion of hydrochloric acid. The development of sophisticated research technology allowed the appreciation of the complex intracellular processes necessary to allow the generation of a 2.5 million-fold gradient of hydrogen ion secretion.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenosine Triphosphatases↗
PubMedDate not supplied

Treating severe metabolic alkalosis.

The pathophysiology, symptomatology, and treatment of metabolic alkalosis are reviewed, with emphasis on treatment with intravenous hydrochloric acid. Three buffering systems are used by the body to correct an arterial pH above 7.45--tissue, respiratory, and renal systems. The kidneys have the primary responsibility for correcting a severe metabolic alkalosis, but several conditions (e.g., severe volume contraction) can interfere with the renal mechanisms. No unique symptoms are associated with metabolic alkalosis. Conventional conservative treatment of metabolic alkalosis involves meeting the patient's fluid and electrolyte needs and allowing the body to correct the alkalosis through its own mechanisms. However, when more rapid resolution of the alkalosis is needed or the patient cannot tolerate fluid and electrolyte therapy, mineral acids may be administered. Ammonium chloride and arginine monohydrochloride infusions may both be used; since both require hepatic conversion for full activity, patients with hepatic dysfunction may require alternative therapy. Dilute hydrochloric acid (0.1-0.2 N) may be given intravenously to these patients through a central-venous catheter. Dosage guidelines and formulation procedures are described in the paper, as are other possible therapeutic alternatives (dialysis, acetazolamide, cimetidine). Most cases of metabolic alkalosis can be managed with fluid and electrolyte therapy. When metabolic alkalosis needs to be resolved quickly or when conventional therapy cannot be tolerated, mineral acid administration should be instituted. The primary drug of choice for these patients is intravenous ammonium chloride; patients with hepatic or severe renal dysfunction should receive dilute hydrochloric acid via a central-venous catheter.

Acetazolamide↗
PubMed2002

Slow fluid infusion alters esophageal tone before onset of esophageal contraction in humans.

We investigated whether esophageal tone was altered by fluid infusion before the onset of esophageal contraction. In nine healthy volunteers, intraluminal esophageal pressure and esophageal pH were measured with a three-channel solid-state transducer and microglass electrodes, respectively. Saline or 0.1 N hydrochloric acid was infused at 0.25 ml/sec 5 cm above the lower esophageal sphincter. The effect of atropine (80 microg/kg, intravenously) was also studied. Infusion of either saline or hydrochloric acid suddenly increased the midesophageal intraluminal pressure (8.2-8.4 mm Hg) and decreased the pressure more distally (8.0-8.5 mm Hg) with a latency of 23 sec. There were no significant differences between the effects of saline and hydrochloric acid. Atropine significantly (P < 0.05) lessened the midesophageal increase in pressure, but only slightly inhibited the distal decrease. Atropine did not alter the latency. Esophageal tone was altered by slow fluid infusion. This previously unknown physiological response may be a mechanism for storing liquid in the esophageal body until the start of contractions for clearance.

Adult↗
PubMed1992

A separation method for the assay of adenylylcyclase, intracellular cyclic AMP, and cyclic-AMP phosphodiesterase using tritium-labeled substrates.

A method for the separation of cyclic AMP from adenosine and polyvalent adenine nucleotides is described. The method consists of the sequential elution of adenosine and cyclic AMP from a single column of acidic aluminum oxide (alumina) with dilute hydrochloric acid and ammonium acetate. Adenosine, adenine, xanthine, and hypoxanthine are rapidly eluted with the application of 0.005 N hydrochloric acid while cyclic AMP remains adsorbed to the alumina. A subsequent application of 0.1 M ammonium acetate elutes more than 90% of the cyclic AMP. Under these conditions, polyvalent nucleotides (AMP, ADP, and ATP) remain adsorbed to the alumina. The method permits the measurement of adenylylcyclase activity using [3H]ATP as the labeled substrate. The same technique can be used to measure the accumulation of cyclic AMP in intact cells after labeling the ATP pool with [3H]adenine. With slight modification, the technique can be used to measure the activity of cyclic-AMP phosphodiesterase using [3H]cyclic AMP as the substrate. The proposed technique provides rapid, highly reproducible assays using inexpensive, disposable columns.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed2001

Titanium-porcelain system. Part III: effects of surface modification on bond strengths.

During its development, titanium was found to be incompatible with conventional dental porcelains due to weak bond strength brought about by titanium's high yet oxidative nature. In spite of the development of new low-fusing porcelains designed for titanium application, previous studies have shown that sandblasting pre-treatment prior to porcelain application led to weakening of the metal-ceramic bonding. The aim of this study is to search for an effective alternative to sandblasting for the surface treatment of the titanium substrate in the titanium-porcelain system. The research evaluated the bond strength of 165 samples of titanium-porcelain systems divided into 11 groups. A three-point flexural bend test was conducted to measure the force required to fracture the porcelain on the titanium substrate. A correlation between the type of surface treatment and the bond strengths of each group was evaluated if it resulted to significant differences. The study found significantly differences in the energy-to-break of titanium-porcelain systems treated with hydrochloric acid and sandblasting compared with the control group. The bonds strength achieved by the titanium-porcelain system when treated with hydrochloric acid is comparable to that of conventional metal-ceramic alloy system. Hydrochloric acid treatment of the titanium substrate is a promising alternative to sandblasting for the surface treatment of the titanium substrate in the titanium-porcelain system.

Aluminum Oxide↗
PubMed2005

Observations on dental structures when placed in contact with acids: experimental studies to aid identification processes.

In a "mafia" crime case, a magistrate asked us whether it is possible to destroy a cadaver by immersing it in acids, and would it be possible to identify any residues. The aim of this study was to observe the behavior of teeth exposed to four kinds of acid solutions. The teeth were placed in plastic containers with 25 mL of acid and observed. The experiences showed that teeth are completely dissolved after 14 h of immersion in 37% solution of hydrochloric acid, while at 90h in 96% sulfuric acid, the destruction of the samples is still incomplete. In nitric acid the teeth undergo a complete dissolution in 12 h, and in 17 h in aqua regia (chloroazotic acid-hydrochloric/nitric acid 1:3). It was possible to recognize the characteristic morphological features of dental tissues and structures up until the advanced stages of degradation.

Acids↗
PubMed2001

Transient inflammation and dysfunction of the eustachian tube secondary to multiple exposures of simulated gastroesophageal refluxant.

Gastroesophageal reflux is a common problem in the newborn and preschool periods. Recent research suggests that it may be related to eustachian tube dysfunction and otitis media with effusion. The purpose of this experiment was to investigate the relationship between simulated gastroesophageal reflux and eustachian tube dysfunction. Rat middle ears were repeatedly exposed (transtympanically) to pepsin in hydrochloric acid or to phosphate-buffered saline solution. Their eustachian tube function was evaluated by assessing passive opening and passive closing pressures, and active clearance of positive and negative pressure. The passive pressure function tests showed variable results. The rats exposed to pepsin in hydrochloric acid had an impaired ability to clear positive and negative pressure from the middle ear as compared to the rats exposed only to phosphate-buffered saline solution. The results demonstrate that multiple middle ear exposures to pepsin in hydrochloric acid leads to eustachian tube dysfunction in rats.

Animals↗
PubMed2005

Pepsinogen and H,K-ATPase mediate acid secretion in gastric glands of Triturus carnifex (Amphibia, Caudata).

The gastric glands of Triturus carnifex (Amphibia, Caudata) have been examined by histochemical and immunohistochemical methods with particular regard to hydrochloric acid and pepsinogen secretion. Fundic glands consist of mucous neck cells, endocrine cells and oxynticopeptic cells producing both pepsinogen and hydrochloric acid. The neck cells showed an unexpected distribution pattern which was only observed in the oral fundus, and produced neutral mucins with glycosidic residues of GalNAc and Gal beta1,3GalNAc, and in this respect they differ from the neck cells of anuran amphibians. The secretion of pepsinogen and hydrochloric acid as demonstrated by immunolabelling with anti-H,K-ATPase and with anti-pepsinogen, respectively, seems not to vary significantly along the longitudinal axis of the stomach. The mechanism of gastric acid secretion seems to be mediated by an ATPase, having similar features to the mammalian gastric H,K-ATPase, and is localised in the luminal membrane and in the subapical cytoplasm of the oxynticopeptic cells. Unusually, the same cytoplasmic areas revealed binding specificity for the winged pea lectin (WPA) from Lotus tetragonolobus, even after beta elimination, indicating the presence of fucosyl residues in N-linked oligosaccharidic chains in glycoproteins of beta-H,K-ATPase subunits.

Animals↗