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Biomedical subjects

J H Pedersen

Publications and source records attributed to J H Pedersen.

At least 37 records · Page 2Linked to original sources
PubMed1986

Effect of ganglionic blockade on endogenous circulating pancreatic polypeptide, vasoactive intestinal polypeptide, substance P, neurotensin and noradrenaline in healthy controls and long-term insulin-dependent diabetic patients.

Plasma pancreatic polypeptide (PP), vasoactive intestinal polypeptide (VIP), substance P (SP), neurotensin (NT) and noradrenaline (NA) were measured in eight healthy subjects and 12 long-term insulin-dependent diabetic patients with and without autonomic neuropathy, before and after intravenous infusion of the ganglionic blocking agent trimethaphan camsylate, in order to determine the influence of the autonomic nervous system on the baseline values of the substances. The basal levels of the measured substances were not significantly different in healthy subjects and patients with or without diabetic autonomic neuropathy. In healthy subjects, the ganglionic blockade induced a significant decrease in PP (80%) (P less than 0.02), NA (58%) (P less than 0.05), NT (27%) (P less than 0.05) and a significant increase in SP (30%) (P less than 0.05), while the VIP concentration remained unchanged. The diabetic patients had nearly the same significant decrease in PP (68%) (P less than 0.01), NA (50%) (P less than 0.01), NT (22%) (P less than 0.02), VIP (21%) (P less than 0.05) and increase in SP (73%) (P less than 0.01). No relationship was found between the autonomic neuropathy and changes of the substances during ganglionic blockade. The results indicate that the postganglionic part of the autonomic nervous system participates in the maintenance of a normal baseline level of PP, NT and NA, but not of VIP. The regulation of VIP may be disturbed in long-term diabetic subjects.

Adult↗
PubMed1986

Effect of neurotensin in the dumping syndrome.

The possibility that the gut peptide, neurotensin, may contribute to the dumping syndrome was investigated in 17 patients with a long history of dumping after a Billroth II gastrectomy for duodenal ulcer. After a test meal plasma levels of neurotensin were higher than in normal subjects, but no correlation to the severity of symptoms was found. In eight of the patients with meal-provoked dumping symptoms, intravenous infusion of neurotensin in relevant doses produced neither symptoms nor changes in blood glucose, blood pressure, or pulse rate. The apparent plasma half-life of neurotensin (t1/2 = 2.3 min) did not differ from that previously found in normal subjects. The results indicate that it is unlikely that neurotensin alone has a pathogenetic role in the dumping syndrome in gastrectomized patients.

Aged↗
PubMed1985

Comparison of ultrasonography and transhepatic cholangiography in the evaluation of obstructive jaundice.

The diagnostic value of ultrasonography and percutaneous cholangiography was compared in 114 consecutive patients with obstructive jaundice. The final diagnosis was obtained by surgery or autopsy. Transhepatic cholangiography diagnosed obstruction and its level in all patients, whereas ultrasonography failed to find obstruction in 3 patients and was unable to determine the level in 11 patients. The cause of obstruction was correctly assessed in 106 patients by transhepatic cholangiography and in 74 by ultrasonography. In 15 patients with obstruction caused by common duct calculi ultrasonography only diagnosed the five, and in 9 patients malignant obstruction was diagnosed as calculi. Ultrasonography is a reliable tool for diagnosis of obstructive jaundice and in most cases for localisation of the level of the obstruction. However, diagnosis of the cause of obstruction and of its precise topography requires direct cholangiography.

Adult↗
PubMed1984

Development and validation of a specific radioimmunoassay for PHI in plasma.

A sensitive and specific radioimmunoassay for the recently isolated neuropeptide with N-terminal histidine and C-terminal isoleucine amide (PHI) has been developed which can detect 3.0 pmol/l of the peptide in plasma. The routine antiserum produced in rabbit had a titre of 1:800 000 and recognized the sequence 3-8 of the 27 amino acid peptide. Labelling of PHI with 125I was performed by the chloramine T method, and labelled PHI was separated from unlabelled on an octadecylsilyl (ODC)-silica column. Non-specific interference in the assay was excluded by extraction of plasma with ethanol to a mean recovery of 82.4%. Plasma samples diluted parallel to the standard curve and behaved as PHI on ODC-silica column. The intra-assay and inter-assay coefficient of variation (CV) values at a level of 24.0 pmol/l were 6.3% and 13.1%, respectively. In 75 normal adults, the fasting PHI concentration ranged from 3.5-30.0 pmol/l with a mean of 14.2 pmol/l. In 235 children, the PHI concentration varied with age. Ingestion of a meal caused a rapid and short-lived increase in the PHI concentration.

Adolescent↗
PubMed1984

Plasma levels of neurotensin in gastroplasty for morbid obesity.

Fasting and postprandial plasma levels of the tridecapeptide neurotensin were determined in ten women before and three months after gastroplasty for morbid obesity. Measurements were by radioimmunoassay in unextracted plasma with two antisera recognizing intact neurotensin (NT1-13) or intact neurotensin together with small C-terminal fragments, which may circulate as metabolites of neurotensin. Levels of both intact neurotensin and C-terminal immunoreactivity in obese women were in the same order of magnitude as those found previously in lean persons. Fasting levels measured with both antisera were significantly reduced following gastroplasty (P less than 0.01). Meal-stimulated levels and increments were unchanged. The cause of this prolonged reduction is at present unknown, but may be a reduced luminal stimulation of the small intestine or an altered vagal tonus following gastroplasty.

Adult↗
PubMed1984

Neurotensin induced inhibition of gastric acid secretion in duodenal ulcer patients before and after parietal cell vagotomy.

The influence of the vagal nerve on the inhibitory effect of neurotensin on pentagastrin stimulated gastric acid secretion was investigated in seven duodenal ulcer patients before and after parietal cell vagotomy without drainage. Preoperatively, neurotensin inhibited gastric acid secretion, whereas no effect was found postoperatively. Plasma concentration of neurotensin was identical pre-and postoperatively. This study shows that the inhibitory effect of neurotensin on gastric acid secretion is dependent on an intact vagal innervation of the parietal cell area.

Adult↗
PubMed1983

Circulating glucagon after total pancreatectomy in man.

In five totally pancreatectomized human subjects the secretion of gut-derived glucagons was stimulated by ingestion of a meal rich in fat and carbohydrates. Glucagon-like immunoreactivity in plasma, measured with an antiserum against the 6-15 sequence, increased fivefold in response to the meal. Glucagon like immunoreactivity measured with a antiserum against the C-terminal sequence was initially normal (12-13 pmol/l), increased slightly (to 20 pmol/l), and then decreased (to approximately 6 pmol/l). The chromatographic profile of glucagon-like immunoreactivity in plasma at maximum stimulation was studied after concentration by affinity chromatography. Both assay systems identified two peaks (at Kd-values of 0.30 and 0.60-0.65, and 0.30 and 0.70, respectively). The position at Kd 0.70 corresponds to that of glucagon 1-29. The same components may be identified in plasma from normal subjects. It is concluded that the human intestine is capable of generating all of the molecular forms of glucagon which normally are present in plasma.

Adult↗
PubMed1983

Preparation of 125I-(Tyr 3)- and 125I-(Tyr 11)- neurotensin for radioimmunoassay.

The chloramine-T method for radioiodination of neurotensin for radioimmunoassay was studied. As conventional procedures produced heterogeneous preparations, labelling was performed with a low amount of chloramine-T (1.8 nmol) in the presence of excess of peptide (6 nmol). Purification and complete separation of labelled from unlabelled peptide was obtained by ion-exchange chromatography on SP Sephadex C-25. Four labelled components were identified by isoelectric focusing, enzymatic cleavage and studies of immunoreactivity. The two components representing monoiodinated preparations labelled at Tyr 3 or Tyr 11 could be isolated. Depending on the binding site of the particular antiserum the appropriate tracer could be selected for use in the radioimmunoassay. The specific radioactivities were high (2303 (2137-2407) microCi/nmol and 1927 (1608-2307) microCi/nmol (median and range] and the stability of the label and the reproducibility of the procedure was good.

Iodine Radioisotopes↗
PubMed1982

Two oral contraceptives, efficacy, serum proteins, and lipid metabolism. A comparative multicentre study on a triphasic and a fixed dose combination.

A triphasic, combined oral contraceptive containing 30 - 40 - 30 micrograms ethinyloestradiol (EE), and 50 - 75 - 125 micrograms levonorgestrel was compared with a fixed dose combination containing 30 micrograms EE and 150 micrograms desogestrel in a randomized multicentre trial in 193/199 women and 1 063/1 073 cycles, respectively. The duration of the trial was six months. Eleven centres in Denmark, Sweden, and Norway participated. Contraceptive reliability, bleeding control and side effects were evaluated. Influence on serum sex hormone binding globulin (SHBG) and transcortin was assayed as well as lipid metabolism. Three pregnancies occurred in the group using the triphasic regimen but none in the fixed dose regimen. Two of the three pregnancies were considered drug failures and the third a possible interaction. Possible reasons for the triphasic contraceptive failure are discussed with special reference to a British report on eight pregnancies. Bleeding control appeared to be equally good for the two preparations. However, the number of cycles with spotting, breakthrough bleeding and missed withdrawal bleeding were above the levels reported earlier on the triphasic regimen. About 80 per cent of the women completed the planned six months on either combination. Side effects were generally mild and in accordance with earlier reports on low dose oral contraceptives. Metabolically the triphasic levonorgestrel combination increased SHBG 100 per cent versus 200 per cent for the fixed desogestrel combination. Transcortin rose about 98 and 110 per cent, respectively. Both preparations induced similar changes in the levels of lipids and lipoproteins with the exception of a significant increase in the arachidonic content of cholesterol during treatment with the desogestrel-containing preparation.

Adolescent↗
PubMed1982

Ultrasonic localization of the porta hepatis prior to percutaneous transhepatic cholangiography.

Sixtyfour jaundiced patients were randomly allocated to have fine needle PTC performed with or without prior ultrasonographical localization of the porta hepatis. The general success rate was 97% and complications occurred in two patients (3%). Ultrasonography prior to PTC did not significantly reduce the number of needle passes in the liver parenchyma, the failure rate or the number of complications. Ultrasonic scanning, however, should precede PTC to disclose patients with obstructive jaundice and reveal hepatic and perihepatic abnormalities.

Adult↗
PubMed1982

Ultrasonography, 99mTc-DIDA cholescintigraphy, and infusion tomography in the diagnosis of acute cholecystitis.

Ultrasonography, 99mTc-DIDA cholescintigraphy, and infusion tomography of the gallbladder were compared in a prospective study comprising 45 consecutive patients clinically suspected of having acute cholecystitis. The diagnosis of acute cholecystitis was established or excluded by operation in 35 patients, by oral cholecystography in 5, and by intravenous cholangiography in 5. The predictive values of a positive and a negative test were 100% and 83%, respectively, by ultrasonography and 98% and 88% by cholescintigraphy. Corresponding values for infusion tomography were 87% and 33%. The results suggest that in patients suspected of having acute cholecystitis, 99mTc-DIDA cholescintigraphy and ultrasonography provide a rapid and reliable diagnosis.

Acute Disease↗
PubMed1981

Internal endoprosthesis as treatment of obstructive jaundice in pancreatitis.

In five patients with pancreatitis, obstructive jaundice was relieved by internal drainage of the biliary tract with an endoprosthesis inserted by percutaneous transhepatic technique. The average duration of treatment was 3.5 months. The endoprosthesis were removed by means of a duodenoscope, and jaundice did not recur.

Adult↗
PubMed1981

Dynamic sonography in the evaluation of jaundice.

The value of dynamic sonography as a screening procedure in 84 jaundiced patients was examined and compared with the clinical evaluation of a blind prospective study. The predictive value of the sonographic diagnosis of obstruction was 97% and 84% in nonobstruction. The corresponding values of the clinical distinction were 87% and 92% respectively. The level of obstruction was demonstrated in 95% and the cause of obstruction was diagnosed in 68%. When the cause of jaundice is uncertain or obstruction is suspected clinically, dynamic sonography can offer high diagnostic accuracy and guidance for invasive investigations.

Adult↗