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Biomedical subjects

P Bauerfeind

Publications and source records attributed to P Bauerfeind.

At least 73 records · Page 4Linked to original sources
PubMed1994

Assessment of gastric acid output by H2 breath test.

BACKGROUND: The standard method to measure gastric acid secretion is the aspiration of gastric juice. A noninvasive breath test after application of magnesium has been proposed. The aim of this study was to modify the method, to possibly improve the discriminatory value of the test in comparison with intubation tests. METHODS: We measured the time course of the reaction of magnesium and gastric acid in vitro and determined the gastric hydrogen kinetics in humans by insufflation of hydrogen into the stomach and measuring its reappearance in the exhaled air. Thereafter, a comparison of the breath test and the intubation test was done in 10 healthy volunteers in different secretory states. RESULTS: After hydrogen insufflation 31.4% reappeared in 90 min (16.3% exhaled, rest belched). Discriminant analysis showed that the intubation test had a good discriminatory power. On the other hand, the breath test failed to distinguish between different secretory states (stimulation, inhibition, and intermediate). CONCLUSION: Whereas the intubation test discriminated between high and low acid secretion, the breath test did not. This test therefore seems, at least as performed here, unsuitable as a diagnostic test of gastric acid secretion.

Adult↗
PubMed1994

Prevalence of hookworm infection, anaemia and faecal blood loss among the Yupno people of Papua New Guinea.

The present report describes a study of hookworm infection, anaemia and the presence of blood in stool among the inhabitants of the Yupno area in Madang Province, Papua New Guinea. The study group comprised 588 persons of all age groups. A second group of 45 patients attending the Madang General Hospital, in the provincial capital on the coast, was used for comparison. In the Yupno area, 59% of the subjects were infected with hookworm; in the coastal group the infection rate was 82%, which was significantly higher. There is therefore a moderate prevalence of hookworm infection in the Yupno area, which does not impair the health of the population to any great extent. In both places there was a clear increase in the infection rate between the group of children 1-5 years old and the older groups. The mean blood haemoglobin level was 15.1 g/dl among the Yupno, which was significantly higher than that of the second group (10.7 g/dl). There was a significant negative linear correlation between the intensity of hookworm infection and blood haemoglobin level. The Colo-Rectal-Test for blood in stool was used on samples from 145 persons in the Yupno and from 43 in the coastal group. The test gave positive results in 17% of the cases without worm infection. In infected persons, the Colo-Rectal-Test gave an increasing rate of positive results as the parasite burden increased: 24% for subjects with low levels of infection, and 57% and 67% for moderate and high levels, respectively. The Colo-Rectal-Test is therefore a simple method for the detection of faecal blood loss in populations with a high prevalence of hookworm infection. However, it is not useful as an instrument for general screening for hookworm infections.

Adolescent↗
PubMed1993

[Simultaneous occurrence of lymphocytic gastritis and lymphocytic colitis with transition to collagenous colitis].

Lymphocytic gastritis and lymphocytic colitis are two rare disorders of unknown etiology, only diagnosable by histology. Simultaneous occurrence of lymphocytic colitis and lymphocytic gastritis has not been described up to now. A 69-year-old female patient was examined because of crampy abdominal pain and watery diarrhea. Laboratory tests did not reveal an etiology and in colonoscopy the colon and terminal ileum were normal. Histology disclosed lymphocytic colitis. Esophagogastroduodenoscopy showed erosive bulbitis. Biopsies of the stomach revealed lymphocytic gastritis. A second colonoscopy one year later showed the development of collagenous colitis.

Aged↗
PubMed1993

Early evening nizatidine intake with a meal optimizes the antisecretory effect.

The importance of the temporal relationship between meal and nizatidine intake was studied in a six-armed, double-blind, placebo-controlled trial. Eleven healthy volunteers received early (18.00 hours) or late (21.00 hours) supper, with either placebo, early (18.00 hours) nizatidine, or late (21.00 hours) 300 mg nizatidine. Ambulatory 21-hour gastric pH-metry was performed and plasma nizatidine concentrations were determined by high pressure liquid chromatography. Early-nizatidine/early-supper (median pH 2.50), but not late-nizatidine/late supper (median pH 2.30), produced significantly higher median 21-hour pH values than did early-nizatidine/late-supper (median pH 1.90). Concomitant food delayed the absorption of nizatidine but did not change the drug's bioavailability. Oral nizatidine should be taken with food, preferably early in the evening, to optimize its anti-secretory effect.

Adult↗
PubMed1993

Nocturnal oesophageal motor activity is dependent on sleep stage.

Simultaneous overnight oesophageal pH and manometric and sleep electroencephalographic recordings were performed in eight healthy subjects, aged 20-38 years, to test the hypothesis that the frequency of primary, swallow related contractions decreases progressively with deeper sleep stages whereas the frequency of secondary contractions remains constant throughout the night. During the nocturnal period (2300 to 0700), periods of oesophageal motor quiescence were interspersed by clusters of contractions detected 5 and 15 cm above the lower oesophageal sphincter. Primary contractions decreased in frequency from 1.42/min (median) during arousal periods to 0.22/min during stage 1 sleep, 0.05/min during stages 2 to 4 combined, and 0.03/min during rapid eye movement (REM) sleep. Secondary contractions were also most frequent during arousal periods (0.51/min) and they, too, decreased in frequency during stage 1 (0.35/min) and stages 2 to 4 combined (0.08/min). During REM sleep, however, the frequency of secondary contractions increased (0.50/min) to levels noted during arousal and stage 1 sleep. Compared with primary contractions, secondary contractions had a lower amplitude (51.9 hPa v 76.0 hPa; p = 0.0078) and a shorter duration (3.08 v 4.06 s; p = 0.0078). The results of this study suggest that there is no intrinsic oesophageal motor activity in the absence of a stimulatory input from the central nervous system and that the increased number of secondary contractions during REM sleep may be a result of an REM related increase in autonomic nervous system activity although a temporary decrease of efferent inhibitory influences cannot be ruled out. Nocturnal contraction clusters comprise both primary contractions during arousals and stage 1 sleep and secondary contractions during REM sleep.

Adult↗
PubMed1993

Continuous measurement of rat gastric blood flow using Doppler flowmeter.

We describe the use of pulsed Doppler flowmetry to permit continuous measurement of gastric blood flow in the anesthetized rat. The aims of this study were: 1) to assess the stability of blood flow during Doppler flowmetry; 2) to assess the ability of Doppler flowmetry to record rapid, transient blood flow changes; and 3) to validate Doppler flowmetry against an established blood flow measurement technique using labeled microspheres. Measurements over 3-h periods with a Doppler probe placed on the left gastric artery showed that there was an initial 30-min stabilization period; after this the mean percentage coefficient of variation, indicating intraindividual variability for blood flow, was < 10% for the remaining 150 min. The infusion of norepinephrine produced rapid, transient blood flow changes, including the typical "autoregulatory escape" and "postinfusion hyperemia," both of which were detected by Doppler flowmetry. The accuracy of pulsed Doppler flowmetry in measuring gastric blood flow was established by the demonstration of a highly significant agreement between blood flow measured by the Doppler flowmetry and microsphere techniques. These data indicate that pulsed Doppler flowmetry is an accurate method for the continuous measurement of left gastric artery blood flow in the rat.

Animals↗
PubMed1992

[Percutaneous endoscopic gastrostomy (PEG) for long-term nutrition--comparison of 2 different caliber tubes].

Percutaneous endoscopic gastrostomy (PEG) is often used nowadays for long-term enteral nutrition in patients with swallowing disorders and severely altered esophageal-duodenal transit. The most common indications for gastrostomy tubes were neurological disturbances and malignancies of the oropharynx and esophagus. We compared in a prospective sequential trial PEG-tubes of two different sizes (2.9 mm [CH-9] vs. 4.8 mm [CH-15]) with respect to placement, complications, durability and handling. The tube was successfully placed in 51 of 52 patients (98%). In 1 patient placement was impossible due to missing diaphanoscopy. The mean observation period was 22 weeks for the CH-9-tubes (n = 28) and 14 weeks for the CH-15-tubes (n = 23). The only early complication was 1 case with a hemorrhage at the site of implantation (CH-15). In both groups 2 cases of local infection were noted. In the CH-9-group 2 PEG-tubes disappeared into the stomach and in 1 case a cicatricial granuloma developed. In the CH-15-group a leak occurred 10 days after implantation. All complications were treated conservatively. There was no causal relationship between the size of tube and the complications. The period of implantation was mostly limited by the death due to the underlying disease of the patient and was not related to the type of PEG-tube. We conclude the both PEG-tubes were easy to place, safe and effective means of providing enteral nutrition. We would, however, recommend CH-15-tubes for long-term nutrition, since in our experience they were less frequently obstructed and handling for the nurses was easier.

Adult↗
PubMed1992

A physiological role for cholecystokinin as a regulator of gastrin secretion.

To explore the role of cholecystokinin (CCK) in regulating gastrin secretion in humans, the effect of a CCK antagonist (loxiglumide) on meal-stimulated hormone responses was investigated. Subjects received 500 mL of a liquid test meal in the presence and absence of loxiglumide (22 mumol.kg-1.h-1). In the control experiments, both plasma gastrin and CCK levels increased postprandially. In loxiglumide-treated subjects there was a marked elevation in gastrin (area under the curve, 11,042 +/- 1493/120 min vs. 2156 +/- 281 pg/120 min) and CCK levels compared with the control experiment. These observations were confirmed in experiments with modified sham feeding and gastrin-releasing peptide stimulation in which loxiglumide pretreatment also caused a significant increase in gastrin release compared with saline (P less than 0.05). Further studies with intravenous infusion of gastrin, CCK-8, and CCK-33 with and without loxiglumide showed that the increases in CCK and gastrin during loxiglumide application cannot be explained by alterations in clearance rates. The findings of this study show that postprandial gastrin secretion is influenced by CCK and support the concept of a negative feedback control of gastrin secretion by CCK.

Adult↗
PubMed1992

Oesophageal pH-metry: should meals be standardized?

To assess the effect of a late-evening, high-fat meal on nocturnal supine gastro-oesophageal reflux, eight healthy volunteers (aged 20 to 38 years) underwent two ambulatory oesophageal pH-metry recordings, the first after a standardized light meal at 1930 h and the second after a high-fat meal including peppermint and chocolate, at 2130 h. Between 2300 and 0700 h, when subjects were supine, the median acid exposure time (percentage recording with pH less than 4) increased from 0.0% (range, 0.0-6.8%) after the standardized meal to 7.9% (0.0-17.8%) after the high-fat meal (p = 0.031). Similarly, the median number of reflux episodes increased from 0 (0 to 11) after the standardized meal to 7 (0 to 26) after the high-fat meal (p = 0.031). Reflux occurred after both meals, but, in general, persistent nocturnal reflux was observed only after the high-fat meal. Thus, the analysis of oesophageal pH recordings should consider the effects of meal composition and timing on oesophageal acid exposure.

Adult↗
PubMed1992

[Differential diagnostic value of occult blood in stool in hookworm infection in the Third World. Study from Papua New Guinea].

In 633 persons of the Madang province in Papua-New Guinea hookworm-infection, blood hemoglobin and the presence of blood in stools were studied. 60% of the subjects were infected with hookworm (Necator americanus). There was a significant linear correlation between the intensity of hookworm infection and blood haemoglobin level. The Colo-Rectal test gave positive results in 17% of the cases without worm-infection. In infected persons, the Colo-Rectal test gave an increasing rate of positive results as the parasite infection increased: 24% for subjects with low levels of infection, and 57% and 67% for moderate and high levels, respectively. The mean blood-haemoglobin level was lower in persons with positive Colo-Rectal-Test and hookworm infection (11.8 g%) than among those with negative Colo-Rectal-Test and hookworm infection (15.0 g%, p < 0.01). In young populations with a known high prevalence of hookworm infection, Colo-Rectal test is therefore suitable for the detection of moderate or severe hookworm infections. It may serve as a simple and useful method to work up anaemia is such populations.

Adolescent↗
PubMed1991

The ion sensitive field effect transistor (ISFET) pH electrode: a new sensor for long term ambulatory pH monitoring.

Intraluminal pH monitoring in man should be performed with disposable multichannel assemblies that allow recordings at multiple sites and prevent transmission of infection. Currently available glass electrodes are unsuitable for this purpose because of their size and price. We have thus constructed and tested a small, combined ion sensitive field effect transistor (ISFET) pH electrode incorporating an integral reference electrode. In vitro studies showed that both ISFET and glass electrodes (440-M4, Ingold, Switzerland) have a linear response over the pH range 1.3-8.0 and that they are comparable with regard to response time and 24 hour drift. Twenty one hour intragastric pH recordings were performed simultaneously in eight healthy volunteers using a glass electrode and an ISFET electrode, placed no more than 2 mm apart in a combined assembly. This was located in the gastric corpus under fluoroscopic control. The 21 hour pH curves recorded by each electrode type showed identical patterns: an early morning rise in pH with three meal-associated pH peaks lasting for about two to three hours. The means of the 21 hour pH medians were 2.09 and 2.07 as measured by the glass and the ISFET electrodes respectively. Thus, ISFETs are suitable for the construction of inexpensive and hence disposable multichannel pH monitoring assemblies of small diameter. Provided that they can be produced in large numbers with appropriate technical support, ISFETs have the potential to replace glass electrodes for long term monitoring of gastrointestinal luminal acidity.

Evaluation Studies as Topic↗
PubMed1991

[Collagen colitis--a clinical entity of relevance].

Collagenous colitis is a clinical and pathological entity characterized by chronic watery diarrhea and deposition of collagen beneath the surface epithelium of the large intestine. By colonoscopy and barium enema the colon appears normal. The laboratory tests give usually normal results. 75% of the patients are middle-aged women with a mean age around 50 years. The etiology of the disease is still unknown. An association with various autoimmune diseases has been suggested, but was never proven. Up to now, it is not clear whether the collagenous colitis is a distinct entity or only an epi-phenomenon of another disease which leads to thickening of the collagen layer. Collagenous colitis is diagnosed if all other diseases with chronic watery diarrhea are excluded. A specific treatment is not known. Symptomatic treatment with bulk and antidiarrheal drugs improves the symptoms of most of the patients.

Colitis↗
PubMed1990

Fate of antacid gel in the stomach. Site of action and interaction with food.

The site of action of a high-power Al-Mg antacid gel (buffering capacity 70 meq/10 ml) and its interaction with food was examined in 10 healthy volunteers. Combined pH-metries in antrum and corpus were performed in each volunteer on four occasions. In a randomized study design, antacid or placebo were given 1 hr after either a protein or a carbohydrate pancake, of which only the former had any acid-buffering capacity. Before the meal, pH was higher in the antrum than in the corpus (median antrum: 3.2, corpus 1.5). In the corpus, a protein pancake but not a carbohydrate pancake raised the pH (median pH after protein pancake: 3.5; after carbohydrate pancake: 1.4). In the antrum, the protein pancake had no effect, but the carbohydrate pancake decreased the pH (median pH after protein pancake: 3.1; after carbohydrate pancake: 2.0). The antacid had no effect in the corpus after either pancake. It raised intraluminal pH markedly in the antrum after a carbohydrate pancake (median antral pH before antacid: 2.0; after antacid: 3.3), whereas its effect in the antrum was weak after a protein pancake. In vitro experiments were conducted to explain the in vivo results: in contrast to a carbohydrate pancake, a protein pancake reduced the buffering capacity of the antacid by direct interaction. In conclusion, the effect of an antacid gel on intragastric pH is predominantly localized in the antrum and is attenuated in the presence of proteins.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Pathogenic heterogeneity of Barrett's ulcers. Apropos of 38 case reports].

Barrett's ulcer is thought to develop in the columnar epithelium of Barrett's esophagus. In our series there is evidence that at least some Barrett's ulcers develop in squamous epithelium which may correspond to islets within Barrett's esophagus; in other cases Barrett's mucosa may surround a preexisting reflux-induced ulcer and thus transform it into Barrett's ulcer. In some individual cases of Barrett's ulcer development of the ulcer primarily in the columnar epithelium could not be ruled out. These ulcers may be produced by local acid secretion, by acid or alkaline gastroesophageal reflux in patients with reduced resistance of the columnar epithelium. Exceptionally, Barrett's ulcer may result from local irritation by medication (pill-induced ulcer) or by nasogastric intubation.

Adult↗
PubMed1989

Combined esophageal and gastric pH-metry in healthy volunteers. Influence of cable through LES and effect of misoprostol.

In order to evaluate whether combined esophageal and gastric pH-metry is feasible without interference due to the transcardial cable, four 24-hr ambulatory esophageal pH-metries were carried out in seven healthy volunteers in a randomized order. In two studies only one glass electrode was used. It was placed 5 cm above the lower esophageal sphincter. In the two other studies an additional electrode was placed in the corpus region 10 cm below the lower esophageal sphincter. In order to obtain a wide range of pH values, misoprostol (400 micrograms) was given at 9 AM and 9:15 PM in two studies. In the two other studies placebo was given. Misoprostol exerted only a weak and short-lasting effect on gastric acidity. The four measuring conditions did not differ with respect to medians of esophageal reflux time and duration of single reflux episodes, Kendall's coefficient of concordance yielded a high reproducibility for both variables (P less than 0.0025). Thus, combined esophageal and gastric pH-metry is feasible and highly reproducible.

Adult↗
PubMed1989

Luminal acid reduces gastric mucosal blood flow in the ischemic stomach.

Luminal gastric acid is essential for the formation of acute gastric mucosal lesions during ischemia. The mechanism by which luminal acid promotes gastric injury is, however, unclear. We investigated the effect of exogenous luminal acid on gastric mucosal blood flow using the radiolabeled microsphere technique. In rats with intact gastric blood supply application of exogenous luminal acid increased blood flow to the mucosa of the corpus and antrum. However, after ligation of the left gastric artery, which compromised mucosal blood flow to the corpus, application of luminal exogenous acid further decreased blood flow to the corpus. This indicates that the ability of the normal stomach to respond to luminal acidification with an increase in blood flow, which is thought to support clearance of back diffusing H+, is reversed in the ischemic stomach. The exposure to high luminal H+ concentrations may therefore promote gross injury in the ischemic stomach by further compromising nutritional mucosal blood flow.

Animals↗
PubMed1989

Early dinner reduces nocturnal gastric acidity.

This study examines whether eating food at different times has differential effects on intragastric pH. Experiments were done in 23 healthy volunteers (12 men). Intragastric acidity was monitored by ambulatory 22 hour pH-metry. Composition of meals was standardised: breakfast and lunch at 7 am and 12 noon respectively, and dinner at 6 or 9 pm, in random order. The time of going to bed and getting up was also standardised. With early dinner nocturnal pH was higher, than with late dinner (pH median: 1.67 and 1.39, p less than 0.001). During the remaining time periods, pH values were similar. Thus early dinner may be helpful in conditions where low intragastric acidity is desirable.

Adult↗