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Biomedical subjects

N Holst

Publications and source records attributed to N Holst.

At least 37 records · Page 2Linked to original sources
PubMed1990

A characterization of immunoreactive somatostatin in human milk.

In the present work, somatostatin-like immunoreactivity (SLI) in human milk was characterized. In the early postpartum period, SLI levels were highest on the first day after delivery, and then gradually declined. From the fifth day postpartum, SLI levels in milk seemed unchanged. On the fifth day after delivery, milk SLI was significantly (p less than 0.01) higher than plasma SLI (126.3 +/- 11.7 vs. 17.6 +/- 1.1 pmol/L). The results indicate an active transport from blood or synthesis of somatostatin within the mammary gland. Gel filtration studies of skimmed milk, as well as milk exposed to urea and HCl, and aspirated milk from the human premature newborn, revealed that the main portion of milk SLI either represents somatostatin covalently bound to a larger protein, or more likely, a high molecular weight variant of somatostatin.

Adult↗
PubMed1990

The effects of secretin on prolactin, estradiol, vasoactive intestinal polypeptide, and somatostatin levels in women.

The effect of graded doses of intravenous secretin (0.5, 1.0, and 2.0 CU.kg-1.h-1) on serum prolactin and estradiol levels, as well as plasma vasoactive intestinal polypeptide and somatostatin levels was studied in 6 normally cycling and healthy women, and compared with the hormone levels obtained by a control infusion with physiologic saline (0.15 mol/l). A significant decrease in serum prolactin concentrations was found with increasing doses of secretin at steady-state levels of plasma secretin (+30 to +60 min). A significant negative correlation (p less than 0.007, r = -0.2764) existed between serum prolactin and plasma secretin concentrations at steady-state conditions. No effect of graded doses of secretin was observed on serum estradiol levels and plasma concentrations of vasoactive intestinal polypeptide and somatostatin. The results suggest a dose-related inhibitory effect of secretin on prolactin release in women.

Adult↗
PubMed1989

A new cell culture assay for quality control in IVF.

A new, simple and sensitive bioassay for quality testing in IVF is described. This bioassay (Medi-Cult Hybritest, GEA Ltd, Biotech Division, Hvidovre, Denmark) is based on the culture of the rapidly growing mouse hybridoma cell line 1E6 in a defined serum-free culture medium. The use of serum-free conditions greatly increases the sensitivity to toxic substances, due to the absence of binding proteins. The testing of known toxic agents showed that this assay disclosed cytotoxicity with a high sensitivity. The Hybritest thus provides a simple yet sensitive and reproducible bioassay for quality control of culture media, water, chemical compounds and equipment in an IVF programme. Tests of different batches of culture media showed that media for IVF should be processed from powder and high-quality sterile water. It is important not only to test the single components of the culture media, but also the final product in a sensitive test system.

Animals↗
PubMed1989

Plasma secretin concentrations during normal human pregnancy, delivery, and postpartum.

Plasma concentrations of secretin were measured at 4-week intervals throughout eight normal pregnancies and again twice postpartum, and in another six women during parturition and the early postpartum period. Comparisons were made with levels in 16 normal non-pregnant women. Plasma secretin concentrations increased during pregnancy with maximum levels at 36 weeks. The increase was statistically significant from week 28 to 36, compared with non-pregnant levels. By 5 days after delivery plasma secretin levels were similar to the non-pregnant levels. No significant changes in plasma secretin were observed during delivery and early postpartum. The altered secretin levels may be of importance for heartburn in pregnancy, calcium metabolism, and the changes in renal haemodynamics.

Adult↗
PubMed1989

Plasma gastrointestinal hormones during spontaneous and induced menstrual cycles.

Plasma levels of secretin, vasoactive intestinal polypeptide (VIP), somatostatin (SRIH), motilin, and/or pancreatic polypeptide, as well as serum estradiol, progesterone, PRL, LH, FSH, and/or GH were measured during the follicular phase, midcycle, and luteal phase of a spontaneous menstrual cycle in eight women and during ovarian stimulation with clomiphene citrate/human menopausal gonadotropin and hCG for in vitro fertilization in nine women. Plasma SRIH concentrations were significantly (P less than 0.02) higher in the luteal phase of spontaneous menstrual cycles than in follicular phase and midcycle. Serum GH levels, however, did not change. Plasma motilin concentrations also were higher in the luteal phase than at mid-cycle (P less than 0.04). Plasma secretin, VIP, and pancreatic polypeptide concentrations did not change during the cycle. Throughout the spontaneous menstrual cycle we found significant positive correlations between plasma SRIH and serum progesterone (P less than 0.007; r = 0.5869), plasma motilin and serum progesterone (P less than 0.02; r = 0.5331), plasma secretin and serum estradiol (P less than 0.04; r = 0.4711), and plasma secretin and serum PRL (P less than 0.02; r = 0.5507). During ovarian stimulation both plasma secretin and VIP gradually increased to a peak on cycle days 0 and 1, respectively (day 0 = the day of hCG injection), whereas plasma SRIH did not change. Serum estradiol and PRL increased significantly, and both peaked on cycle day 1. During ovarian stimulation plasma secretin correlated significantly with serum estradiol (P less than 0.00001; r = 0.9333), serum PRL (P less than 0.03; r = 0.6521), and plasma VIP (P less than 0.03; r = 0.6534). In addition, plasma VIP and serum PRL both correlated significantly with serum estradiol (P less than 0.05; r = 0.6024 and P less than 0.04; r = 0.6384, respectively). These results indicate 1) a possible effect of progesterone on the release of SRIH and motilin during the spontaneous menstrual cycle; 2) the unaltered serum GH concentrations in the luteal phase of the spontaneous menstrual cycle despite elevated plasma SRIH levels are probably due to a stimulatory effect of both progesterone and motilin on GH release; and 3) the increase in plasma secretin and VIP concentrations during ovarian stimulation is probably secondary to the concomitant increase in serum estradiol and/or PRL. We suggest that estradiol and/or PRL beyond a certain threshold level stimulate the release of secretin, and possibly also VIP, into plasma.

Adult↗
PubMed1988

Gastrointestinal regulatory peptides during oxytocin infusion in post-term pregnancies.

The plasma concentrations of the gastrointestinal regulatory peptides vasoactive intestinal polypeptide (VIP), insulin, secretin, somatostatin, motilin, pancreatic polypeptide (PP) and gastric inhibitory polypeptide (GIP), as well as blood glucose, were measured in eight healthy women before, during and after oxytocin infusion in post-term pregnancies. Plasma VIP increased significantly (P less than 0.01) during oxytocin infusion. Plasma secretin showed a significant (P less than 0.05) decrease during oxytocin infusion. Plasma somatostatin remained unchanged during oxytocin infusion, but thereafter a significant (P less than 0.05) increase occurred. Both plasma motilin and plasma PP showed a non-significant increase during oxytocin infusion with sustained levels thereafter. No changes were found for plasma insulin, GIP and blood glucose.

Adult↗
PubMed1988

Characterization of secretin-like immunoreactivity in pregnancy.

The plasma secretin-like immunoreactivity (SLI) in 23 healthy females was elevated in late pregnancy (34 +/- 3 pmol/l) as compared with 23 non-pregnant female controls (12 +/- 2 pmol/l; p less than 0.01). The plasma SLI in pregnancy eluted close to albumin on a Sephadex G-200 column, whereas 50-75% of the recovered SLI was displaced to the elution volume of free secretin when plasma was exposed to 6 mol/l urea. When 125I-labelled secretin was incubated with plasma in the absence of secretin antibodies, 40% of the intact label eluted in the void volume of a Sephadex G-50 Fine column in pregnancy, compared with only 18% in the nonpregnant state. The present study supports the notion that secretin circulates bound to plasma proteins and suggests that the protein binding of secretin is enhanced in late pregnancy, a feature common to several classical hormones.

Adult↗
PubMed1986

Plasma vasoactive intestinal polypeptide, insulin, gastric inhibitory polypeptide, and blood glucose in late pregnancy and during and after delivery.

The plasma levels of the gastrointestinal regulatory peptides vasoactive intestinal polypeptide, insulin, and gastric inhibitory polypeptide, as well as blood glucose, were measured in six healthy women before, during, and after normal parturition at term. Plasma levels of vasoactive intestinal polypeptide increased significantly (p less than 0.05) during delivery and remained significantly elevated for 15 minutes post partum. Plasma insulin levels rose significantly (p less than 0.05) within 5 minutes after delivery and stayed three-fold and significantly elevated for 120 minutes post partum. Plasma levels of gastric inhibitory polypeptide decreased significantly (p less than 0.05) between 5 and 30 minutes after delivery. Blood glucose levels were significantly (p less than 0.05) increased during labor, delivery, and the early postpartum period compared to late pregnancy. These findings suggest a mediating role for vasoactive intestinal polypeptide, insulin, and gastric inhibitory polypeptide in the physiologic adaptations to normal pregnancy, delivery, and the postpartum period.

Adolescent↗
PubMed1986

Gut peptides in lactation.

The circulating levels of prolactin (PRL), vasoactive intestinal polypeptide (VIP), somatostatin (SRIH), cholecystokinin (CCK), pancreatic polypeptide (PP), insulin, motilin and blood glucose were measured in nine nursing women 27-40 days after delivery to establish the possible role of some gastrointestinal regulatory peptides in human breast feeding. During the last 20 min of suckling a significant (P less than 0.05) increase in serum PRL was observed concomitantly with a significant decrease in plasma SRIH levels (P less than 0.05 at 20 min and P less than 0.01 at 30 min). There was a highly significant inverse correlation between mean PRL and SRIH levels during the first 30 min of breast feeding (r = -0.996, P less than 0.001). Pancreatic polypeptide (pp) also increased significantly (P less than 0.01) during nursing, while there were no changes in the plasma levels of the other gastrointestinal regulatory peptides studied.

Adult↗
PubMed1986

Plasma concentrations of motilin, somatostatin and pancreatic polypeptide before, during and after parturition.

The plasma concentrations of the gastrointestinal regulatory peptides motilin, somatostatin and pancreatic polypeptide were measured in 6 pregnant women, 17-35 years old. Plasma samples were drawn 2-3 weeks before, during, and immediately after labor, and 24 h as well as 1 year after delivery. Plasma motilin levels did not change during labor, but peaked non-significantly upon delivery, and were thereafter significantly elevated 24 h post partum (p less than 0.05). Plasma motilin concentrations measured one year after delivery were almost identical with the pre-term values. Plasma somatostatin rose non-significantly during labor and peaked transiently upon delivery (p less than 0.05), whereas plasma pancreatic polypeptide increased significantly during the second stage of labor (p less than 0.05). The plasma motilin increase may be part of a compensatory mechanism leading to augmented gastrointestinal motility after delivery.

Adolescent↗
PubMed1983

Precancerous lesions of the cervix uteri in infertile women.

A study of 318 patients with tubal infertility and a control group of 200 unselected infertile women yielded 14 (4.4%) and 1 (0.5%), respectively, with precancerous lesions of the cervix uteri. The one patient in the control group with severe dysplasia was later shown to have tubal infertility. The overall incidence of premalignant lesions of the cervix uteri as reported to the National Cancer Registry of Norway was 0.1% for the age group and period studied. Women with tubal infertility represent a small but comparatively high risk group for the development of precancerous lesions of the cervix uteri.

Adult↗
PubMed1983

Hysterosalpingography in the evaluation of infertility.

Hysterosalpinography (HSG) was performed in 220 women for evaluation of infertility. Laparoscopy or laparotomy for final assessment of tubal patency were carried out in 110. HSG revealed a normal tubal patency in 66.8 per cent, whereas abnormal patency was found in 24.1 per cent. At operation, 85.7 per cent of the HSG diagnoses were confirmed. A clear correlation existed between previous lesions in the genital tract and pathologic findings at HSG and operation. The pregnancy rate following HSG was 15.4 per cent. It is concluded that HSG is of great value in the initial evaluation of infertility. The findings facilitate the decision regarding the final operative procedure: laparoscopy or laparotomy.

Adult↗