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Biomedical subjects

B Stenquist

Publications and source records attributed to B Stenquist.

33 records · Page 2Linked to original sources
PubMed1983

Pitfalls in postoperative testing of the completeness of vagotomy.

The gastric acid response to insulin hypoglycemia represents an effect of several stimulatory and inhibitory mechanisms. In the intact stomach the direct vagal excitation of the acid secreting glands is the predominant mechanism. After vagotomy, however, the balance between the stimulatory and inhibitory mechanisms is unpredictable. Some stimulatory and inhibitory mechanisms are non-vagal, and may after vagotomy result in a false conception of remaining vagal fibers and complete vagotomy, respectively. Sham feeding may be a safer and more reliable test of completeness of vagotomy. A study of the spontaneous variation of basal acid secretion over several hours after vagotomy in 22 patients showed in 15-min samples a maximal range of 0.49 and 0.65 mmol with a P value of 0.05 and 0.01, respectively. A higher range may thus indicate a true acid response to a given stimulus. In 3 patients with an acid response to sham feeding but no acid response to insulin in a dose of 0.2 IU/kg after vagotomy, a repeated test with a lower dose of insulin resulted in an unequivocal acid response. In 4 patients with no acid response to sham feeding and a substantial acid response to insulin after vagotomy, the acid response to insulin was abolished after pretreatment with an adrenergic blocker. The insulin test may thus give false negative and positive information about the completeness of vagotomy.

Animals↗
PubMed1982

Gastric mycosis following gastric resection and vagotomy.

In a prospective five-year follow-up study of 289 consecutive patients subjected to antrectomy and gastroduodenostomy with or without vagotomy, 130 patients underwent gastroscopy. Gastric mycosis was present almost exclusively in patients subjected to combined antrectomy and vagotomy (36%). Gastric acidity seemed to be of only minor or no importance in the development of the mycosis. The residual volume in the gastric remnant was significantly higher in patients with gastric mycosis. The impaired emptying of the gastric remnant is most likely a vagotomy effect and may be the main reason for the development of gastric mycosis. A simple but effective method was developed to evacuate gastric yeast cell aggregates. Gastric mycosis seems to give rise to only slight symptoms, mainly nausea and foul-smelling belching, whereas the reflux of duodenal contents that often occurred in combination with gastric mycosis was more likely to cause gastritis and substantial discomfort.

Bile Reflux↗
PubMed1982

The effect of different anticholinergics on the gastric acid response to sham feeding in man.

Modified sham feeding by the chew and spit technique stimulates gastric acid secretion at a level about 50% of peak acid output. This response is vagal and can be totally blocked by vagotomy. The effect on the acid response to modified sham feeding produced by a quaternary amine, benzilonium bromide, and a presumably more selectively acting antimuscarinic drug, pirenzepine, was compared. The drugs were given 45 min and 10 min before the start of the sham feeding, respectively. Benzilonium bromide, 1 + 1 mg, blocked 73% of the acid response to sham feeding and pirenzepine, 10 + 10 mg, blocked 48% of the response. The difference was not statistically significant. The data confirm that a part, about one third, of the acid response to sham feeding is non-cholinergic, although it is vagal.

Adult↗
PubMed1980

Torsion of the testis--a misinterpreted diagnosis in the young adult.

Torsion of the spermatic cord is fairly common even in young adults but is too often misdiagnosed. The anatomical anomaly and clinical features of 31 cases are reviewed. If a patient is operated upon within 10 hours of the onset of symptoms the testis will usually survive. In most patients a basic deformity that permits torsion is present on both sides of the scrotum. A plea is made for early diagnosis and bilateral fixation of the testes in all patients with a suspicion of torsion.

Adolescent↗
PubMed1979

Effect of proximal gastric vagotomy and anticholinergics on the acid and gastrin responses to sham feeding in duodenal ulcer patients.

Plasma gastrin concentrations and gastric acid output after modified sham feeding were determined in 20 duodenal ulcer patients. Sham feeding produced an acid response corresponding to 40-68% of the maximal acid output after pentagastrin stimulation, with no significant increase of plasma gastrin concentrations. In eight patients proximal gastric vagotomy almost abolished the acid responses to both insulin hypoglycaemia and sham feeding. Sham feeding in the vagotomised patients did not change the gastrin concentrations in plasma. After pretreatment with benzilonium, an anticholinergic with minimal central nervous effects, plasma gastrin concentrations increased after sham feeding. The study confirms that sham feeding is a poor stimulus for gastrin release in duodenal ulcer patients and supports a cholinergic inhibition of gastrin release. Intravenous injection of benzilonium bromide in a dose close to 70 micrograms/kg, and atropine in the low dose of 30 micrograms/kg inhibited the acid response to sham feeding by about 65%. Atropine in a dose of 50 micrograms/kg virtually abolished the acid sham feeding response, possibly owing to ganglionic or central nervous blockade. Vagal activation of the acid secretory glands does not seem to involve a purely cholinergic neurotransmission.

Adult↗
PubMed1979

Plasma gastrin concentrations following sham feeding in duodenal ulcer patients.

Sham feeding experiments were performed in 20 duodenal ulcer (DU) patients by using adequate sham feeding and modified sham feeding (the 'chew-and-spit' technique). A 15-min sham feeding induced a marked secretion of gastric acid but only an insignificant increase in total gastrin or in gastrin17 concentrations in plasma. Nor did prolonged sham feeding (30 min) with intragastric neutralization significantly increase the gastrin concentrations. We conclude that sham feeding in DU patients induces a release of recognized gastrin components in amounts that are barely detectable radioimmunologically. Therefore, the acid secretory effects of vagally released gastrins in DU patients remains to be established.

Adult↗
PubMed1979

Cephalic phase of pancreatic-polypeptide secretion studied by sham feeding in man.

The effect of sham feeding on pancreatic-polypeptide (PP) secretion was studied in 26 duodenal ulcer (DU) patients and in 8 healthy subjects. Modified sham feeding (MSF) by the 'chew and spit' technique induced a rapid increase in plasma concentrations of PP both in DU patients, 56 (2-138) pmol/l, and in the healthy subjects, 24 (2-45) pmol/l, median peak-increment and range. Four out of 26 DU patients and 2 out of 8 healthy subjects did not show any PP response to MSF. The PP response to MSF was abolished by pretreatment with atropine, or benzilonium, a quarternary anti-muscarinic agent with minimal cerebral actions. The PP response to MSF was not dependent on the gastric acid response, since a PP response to sham feeding was found in 13 out of 17 patients with selectively denervated parietal cell area, and thus, without acid response. During adequate sham feeding, in which the food is also swallowed but does not reach the stomach, the PP increment, 100 (81-129) pmol/l, was larger than during MSF in the same patients, 51 (8-78) pmol/l, median and total range, P less than 0.05, N = 7. No correlation was found between the PP and acid responses to sham feeding. It is concluded that cephalic stimulation provoked by tasting, chewing and swallowing is a major stimulus in the initial, rapid PP response during a meal; and that the PP cells are probably stimulated directly by a cholinergic mechanism.

Adult↗
PubMed1979

Studies on vagal activation of gastric acid secretion in man.

Vagal activation produces a gastric acid secretory response by direct nervous stimulation of the parietal cell area and, at least in dogs, by gastrin released mainly from the antrum. In duodenal ulcer (DU) patients antrectomy reduces the acid response to sham feeding slightly more than the maximal acid output in response to pentagastrin, indicating that an antral factor contributes to the acid secretion induced by sham feeding. The marked acid response to sham feeding in antrectomized patients suggests that the direct nervous stimulation of the acid-secreting glands is the predominating stimulus in the vagal activation of acid secretion in man. In the present study vagal activation has been induced by adequate and modified sham feeding and insulin hypoglycemia in DU patients and healthy subjects. The acid response to adequate and modified sham feeding amounted to about 50% of the peak acid output in response to pentagastrin and corresponded to the acid response to an insulin dose of 0.1 U/kg b.w. Modified sham feeding seems to be a simple method of inducing physiological vagal activation of acid secretion. Sham feeding for 15 min increased only insignificantly the plasma concentrations of total gastrin immunoreactivity or heptadecapeptide gastrin. Prolonged sham feeding during intragastric neutralization or sham feeding after proximal gastric vagotomy did not significantly increase the plasma gastrin concentrations. Sham feeding is obviously a poor stimulus for release of gastrin in man. Either release effect of very small amounts of gastrin-17 or release of non-established gastrins may explain the biological effect of an antral factor. Pretreatment with benzilonium, an anticholinergic drug with minimal cerebral actions, increased the gastrin concentration after sham feeding in about half the experiments. This heterogeneous effect supports a non-cholinergic vagal release of gastrin and a cholinergic inhibition of gastrin release but also indicates a complex interaction at the level of the gastrin cells during vagal activation. Evidence for an inhibitory vagogastrone mechanism in DU patients has been found but its effect is weak and transient. Proximal gastric vagotomy abolished the acid responses to both insulin hypoglycemia and sham feeding, in accordance with the view that the direct nervous excitation of the acid-secreting glands is the predominating stimulus in the vagal activation of gastric acid secretion in man. Atropine in low doses or benzilonium inhibited the acid response to sham feeding by only 65%. This finding suggests that the direct vagal excitation of the acid-secreting glands is mediated only partially by cholinergic neurotransmission. Gastric acidification inhibited the gastric acid secretory response to insulin hypoglycemia both in healthy subjects and in DU patients. The inhibitory effect was significantly less in DU patients, however, supporting the concept of a defective inhibition by antral acidification in DU patients.

Adult↗
PubMed1979

Synchronous oscillations in the basal secretion of pancreatic-polypeptide and gastric acid. Depression by cholinergic blockade of pancreatic-polypeptide concentrations in plasma.

The effect of cholinergic blockade on the concentrations of pancreatic-polypeptide (PP) in plasma was studied in 19 patients with duodenal ulcer (DU) and 16 control subjects. PP concentrations increased with age both in control subjects and in DU patients. In the DU patients atropine or benzilonium, an antimuscarinic agent with minimal cerebral actions, reduced PP concentrations from 47 (8-220) to 28 (7-53) pmol/liter, n = 18, median and total range. In the control subjects atropine suppressed the PP concentrations from 17 (0-257) to 11 (0-41) pmol/liter, n = 15. Cholinergic blockade had only a minor effect in 1 patient and 1 control, both with high PP concentrations. Both in the DU patients and in the control group the suppression by the cholinergic blockade was most marked in subjects with elevated PP concentrations. Spontaneous acid and PP secretion were measured simultaneously in 25 DU patients. No correlation was found between median acid secretion and median concentrations of PP. However, in the individual patient a positive covariation was found between fluctuations in spontaneous acid secretion and fluctuations in PP concentration. P less than 0.005. We conclude that plasma concentrations of PP in the basal state are suppressible by cholinergic blockade and that PP concentrations fluctuate synchronously with the spontaneous secretion of gastric acid. These results suggest that PP concentrations in plasma before and after cholinergic blockade may possibly serve as indicator of abdominal vagal tone.

Adult↗
PubMed1978

Gastric acid responses to adequate and modified sham feeding and to insulin hypoglycemia in duodenal ulcer patients.

In duodenal ulcer patients the effect of vagal activation of gastric acid secretion by the intricate procedure of adequate sham feeding for 15 min has been compared with the effects of vagal stimulation induced by more easily accomplishable methods. The comparison involved modified sham feeding for 15 min by a 'chew-and-spit' technique and insulin hypoglycemia produced by i.v. injected insulin in the doses 0.1, 0.15, or 0.2 U/kg b.w. In 6 patients the peak and 2-hour acid responses to adequate sham feeding (10.7 mmol/30 min and 29.7 mmol) did not significantly differ from corresponding responses to modified sham feeding (9.1 mmol/30 min and 25.2 mmol). The peak and 2-hour acid responses to insulin in a dose of 0.1 U/kg (8 patients) were not significantly different from the sham-feeding responses. The 2-hour acid responses to insulin in the doses of 0.15 (6 patients) and 0.2 U/kg (17 patients) were significantly higher than the sham-feeding response. Furthermore, the peak acid response to insulin in a dose of 0.15 U/kg was significantly higher than the peak sham-feeding response. The gastric acid responses to modified sham feeding and insulin in a dose of 0.1 U/kg b.w. in duodenal ulcer patients seem to satisfactorily reflect physiological vagal activation of acid secretion.

Duodenal Ulcer↗
PubMed1978

The vagogastrone mechanism in man.

From experiments on the dog evidence has accumulated of vagal release of a candidate hormone inhibiting gastric acid secretion--vagogastrone. The nature and origin of vagogastrone are uncertain. The inhibitory effect of vagogastrone is characteristically exerted against gastrin-stimulated acid secretion from the vagally denervated parietal cell area. In the present study vagal activation by sham feeding significantly inhibited the submaximal acid response to continuous i.v. infusion of pentagastrin in seven duodenal ulcer patients previously subjected to proximal gastric vagotomy. The inhibitory effect was slight--16% reduction--and of short duration. Sham feeding had no effect on the pentagastrin-stimulated acid secretion in six subjects with an intact stomach. The results favour the existence of a vagogastrone mechanism in man, but the inhibitory effect seems to be of quantitatively minor importance, at least in the duodenal ulcer patient.

Adult↗
PubMed1977

The effect of intragastric pH-variations on the gastric acid response to insulin hypoglycaemia in healthy subjects and duodenal ulcer patients.

The gastric acid response to i.v. injection of 0.15 U of soluble insulin/kg b.w. was determined in healthy subjects and duodenal ulcer patients during intragastric perfusion with water, 0.1 M HC1, and alkaline buffer (pH 8.3). Perfusion with hydrochloric acid significantly reduced the peak gastric acid output following insulin in 6 healthy subjects (reduction 45%, p less than 0.05) but had no significant effect on the peak gastric acid response to insulin in 7 DU patients (reduction 16%, p greater than 0.05). The 2.5-hour gastric acid response to insulin was, however, significantly reduced in both groups (56% and 35%, respectively) by exogenous acidification of the stomach. The gastric acid response to insulin hypoglycaemia in 3 DU patients was the same with intragastric water and alkaline buffer perfusion. The reduction of the gastric acid response to insulin hypoglycaemia by intragastric acidification corresponded to a reduced volume secretion and could not be ascribed to increased back diffusion of hydrogen ions or duodenal inhibition. These findings suggest that the gastric acid response to insulin hypoglycaemia is inhibited by a low intragastric pH in man, and that DU patients are less sensitive to the inhibitory mechanism than healthy subjects.

Adult↗
PubMed1977

Surgical management of gastroduodenal haemorrhage.

We have presented a retrospective study of the surgical management of 299 patients bleeding from duodenal ulcer, gastric ulcer or gastritis. The overall mortality rate was 15%-5% for elective and 25% for emergency operations. The mortality increased with age and reached 50% for emergency operations in patients over the age of 70. Patients with low admission haemoglobin values, who had episodes of hypovolemic shock or who required immediate transfusions were also at risk. A Billroth I gastric resection proved to be the safest operative procedure. Based on our results, we are supporting a program calculated to reduce the mortality attending gastroduodenal bleeding, especially in those patients requiring an emergency operation. The basic principles of this program are constant observation, prompt diagnosis and early surgical intervention.

Blood Transfusion↗