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Biomedical subjects

A Nilsson

Publications and source records attributed to A Nilsson.

At least 415 records · Page 23Linked to original sources
PubMed1988

Metabolism of chylomicron arachidonic and linoleic acid in the rat.

Chyle and chylomicrons, obtained after feeding thoracic duct cannulated rats [3H]arachidonic (20:4) and [14C]linoleic acid (18:2) in cream, were injected i.v. into recipient animals. 7.5-15 min after injection, the 14C/3H ratio of the triacylglycerols remaining in plasma was about half of that in the injected chylomicrons, indicating that the chylomicron remnants formed retained relatively more [3H]20:4 than [14C]18:2. The 14C/3H ratio of plasma diacylglycerols was about 6-fold lower than that of plasma free fatty acids. The proportion of [3H]20:4 found in plasma cholesteryl esters was several-fold higher than that of [14C]18:2. Inhibition of hepatic lipase by a specific antiserum did not significantly influence the clearance of triacylglycerols, but increased the amount of 3H in plasma diacylglycerols. It also prevented the rapid clearance of phosphatidylethanolamine from plasma. The liver uptake of [3H]20:4 exceeded that of [14C]18:2. Antiserum against hepatic lipase diminished the difference. In contrast, the 14C/3H ratio of adipose tissue was higher than that of the injected chyle lipoproteins.

Adipose Tissue↗
PubMed1988

Immunohistochemical localization of insulin-like growth factor I in the adult rat.

Rabbit antisera against native human insulin-like growth factor I (IGF-I; somatomedin C) or a synthetic tetradecapeptide, representing the carboxyterminal amino acids 57-70 of human IGF-I, were used to map immunohistochemically the distribution of IGF-I immunoreactive material in adult rats. Both antisera were specific for IGF-I, as characterized by immunoabsorption, immunoblotting and radioimmunoassay. There was no cross-reactivity to IGF-II, relaxin or pro-insulin; substances having a high degree of structural homology with IGF-I. High IGF-I immunoreactivity was observed in spermatocytes of the testis; in oocytes, granulosa and theca interna cells of the ovary during early stages of follicle development; in some lymphocytes and in reticular cells of lymphoid and hematopoietic organs; in salivary gland duct cells; in the adrenal medulla, the parathyroid gland and the Langerhans' islets. Chondrocytes in the epiphyseal and rib growth plates and at articular surfaces showed strong IGF-I immunoreactivity. Brown but not white fat cells were stained. Nerve cells in the peripheral and autonomic nervous system showed faint to intense IGF-I immunoreactivity. In contrast, neurons and neuroglial cells in the central nervous system were generally negative; motor neurons being an exception. Erythropoietic, thrombocytopoietic and myeloic cells in the bone marrow showed IGF-I immunoreactivity, but only at defined developmental stages. Hepatocytes showed faint IGF-I immunoreactivity, but became more intensely stained after pretreatment with colchicine. The present results suggest that IGF-I is synthetized by cells in several tissues and organs in the adult rat. There was an apparent association between the localization of IGF-I and cell differentiation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Mercury in fish in Swedish lakes.

The aim of this work has been to try to obtain a picture of the past, present and future mercury situation in fish in Swedish lakes, to make an estimate of the number of lakes threatened by 'blacklisting', and to see if the data can be used to reveal anything about the impact of liming on the Hg content in pike. The register contains a broad set of data from 1456 lakes. The main results are as follows. Trend analyses indicate that the Hg content in 1-kg pike seems to increase with time. This is interesting since there has been a significant decrease in mercury emissions from Swedish industries during the last two decades. High Hg contents in 1-kg pike appear in a very characteristic pattern, linked to specific sources of Hg emission. The data indicate that old Swedish 'sins' are still causing a lot of problems. The factors governing the leakage of Hg from soils to water ought to be a very important topic for further studies. The Hg content in pike shows the highest correlation with the following parameters: Hg in surficial sediments, pH, distance from point source and water hardness, lake water alkalinity and conductivity, water retention time, size of drainage area and lake surface. A formula which provides the best possible degree of explanation (r2 = 0.78) has been derived. At present there are about 250 lakes 'blacklisted' in Sweden due to high Hg content in fish. Our data show that there are at least 9400 lakes that ought to be 'blacklisted' today. A successful liming operation will alter the chemical conditions in lakes and also decrease the Hg content in fish.

Journal Article↗
PubMed1988

Relation of sedation and amnesia to plasma concentrations of midazolam in surgical patients.

The kinetics and dynamics of midazolam were investigated in 20 female patients undergoing lower abdominal surgery. The relation between the plasma concentrations of midazolam and pharmacokinetic end points was evaluated after an intravenous infusion regimen in 10 patients given an epidural anesthetic. The remaining 10 patients were anesthetized with a totally intravenous anesthetic technique with midazolam and alfentanil. The effect was assessed by means of a rating scale divided into degree of sedation and amnesia. A good correlation was found between plasma level of midazolam and pharmacodynamic response. The relation between the quantal response data and the plasma concentration was represented by an s-shaped concentration-effect curve. Despite similar kinetics of midazolam in the two groups, the postoperative drowsiness was more pronounced in the group receiving total intravenous anesthesia. The concomitant administration of alfentanil shifted the concentration-effect curve regarding sedation to the left.

Adult↗
PubMed1988

Evaluation of zinc status in subjects with Crohn's disease.

Zinc status was evaluated in 30 subjects with Crohn's disease. Intestinal resection had previously been performed in 23 of the subjects. The concentrations of zinc were determined in plasma, erythrocytes, percutaneous muscle biopsies, and in urine collected during 24 hours. The results were compared with those in 19 healthy controls. Most of the patients had a normal zinc status. The levels of zinc were, however, reduced (i.e., less than mean -2 SD for controls) in plasma for five, in erythrocytes for two, and in muscle biopsies for six subjects with Crohn's disease. The mean concentrations of zinc in plasma and erythrocytes were reduced (P less than 0.05), whereas the mean content of zinc in muscle biopsies and the mean urinary excretion of zinc were not significantly different, in subjects with Crohn's disease. The various zinc parameters did not correlate to each other. The results indicate that some subjects with Crohn's disease had an intracellular zinc depletion, which, however, was not reflected by a reduction in levels of zinc in plasma.

Crohn Disease↗
PubMed1988

Vitamin E deficiency in phrynoderma cases from Sri Lanka.

Phrynoderma cases were identified in a village close to Colombo in Sri Lanka. The alpha-tocopherol level in plasma was 3.3 +/- 0.6 mumol/L among the phrynoderma patients (n = 11) and 13.0 +/- 2.3 mumol/L among the control subjects (p less than 0.002). A test on glutathione reductase activity in erythrocytes revealed a stronger riboflavin deficiency among patients than among control subjects (p less than 0.005). No significant differences were found between the groups with regard to plasma levels of retinol, retinol-binding protein, vitamin B-12, folic acid, thiamin, selenium, zinc, or essential fatty acid pattern. Primary malnutrition may partly explain the deficiency of alpha-tocopherol and riboflavin observed in phrynoderma cases.

Adult↗
PubMed1988

Pharmacokinetics of alfentanil in total i.v. anaesthesia.

Alfentanil was administered, together with midazolam, as part of a total i.v. anaesthetic technique. The pharmacokinetics of alfentanil were determined in 10 female patients undergoing lower abdominal surgery. The dose regimen of alfentanil, based on simulation studies, consisted of a two-stage infusion following an initial bolus dose. The kinetics of alfentanil were described by a linear two-compartment open model. The total plasma clearance ranged between 93 and 431 ml min-1 (mean 249 ml min-1). The apparent volume of distribution at steady-state ranged between 0.27 and 0.64 litre kg-1 (mean 0.44 litre kg-1). The apparent volume of distribution (Vd beta) was 0.58 litre kg-1, resulting in a terminal half-life of 112 min. Alfentanil concentrations at the time of extubation and postoperative analgesic requirements were also monitored. Good correlation between respiratory depression and plasma alfentanil concentration was found. Neither lower abdominal surgery nor the simultaneous administration of midazolam seemed to affect the kinetics of alfentanil as compared with results from studies in healthy volunteers. The short half-life of alfentanil, resulting from a small volume of distribution, makes it suitable as part of a total i.v. technique. Consideration must be paid, however, to interindividual differences in the pharmacodynamic response and in plasma clearance.

Adult↗
PubMed1988

Galanin inhibits amylase secretion from isolated rat pancreatic acini.

The neuropeptide galanin is present in intrapancreatic nerve fibers and is known to affect the secretion of the islet hormones. Its most potent effect is thereby the inhibition of insulin secretion. In the present study, we investigated whether galanin influences amylase secretion from isolated rat pancreatic acini. Acini were isolated by the collagenase digestion technique and incubated for 45 min in a Krebs-Henseleit medium with or without addition of the cholinergic agonist carbachol or the C-terminal octapeptide of cholecystokinin (CCK-8) in the presence or absence of galanin. Carbachol, at its optimal concentration (10(-5) M), stimulated amylase secretion to 11.8 +/- 0.5% of total amylase content compared to 4.3 +/- 0.3% in controls (p less than 0.001). Galanin, (10(-8)-10(-9) M), reduced the carbachol-induced amylase secretion to 10.4 +/- 0.3% (p less than 0.01). Galanin at concentration levels below 10(-10) M had no significant effect. At 10(-8) M, CCK-8 stimulated amylase secretion to 9.7 +/- 0.6% compared with 5.2 +/- 0.3% in controls (p less than 0.01). Galanin (10(-7) M) reduced this stimulation to 8.0 +/- 0.4% (p less than 0.05). Galanin did not affect basal amylase secretion. It is concluded that the intrapancreatic neuropeptide galanin weakly inhibits carbachol- and CCK-8-induced amylase secretion from isolated rat pancreatic acini. Thus, galanin has the capability to directly affect not only endocrine but also exocrine pancreatic secretion although its effect of inhibiting amylase secretion seems weak.

Amylases↗
PubMed1988

Incidence of severe hypoglycemia and its causes in insulin-treated diabetics.

In a one-year prospective study in insulin-treated diabetics, 61 episodes of severe hypoglycemia demanding medical assistance were registered in 46 patients. The incidence of severe hypoglycemia was estimated at 0.07 per patient and year. Mean age (50 +/- 16.9 yr), diabetes duration (19 +/- 11.6 yr), HbAlc (7.8 +/- 1.8%) and daily insulin dose (0.63 +/- 0.23 IU/kg) in these patients (SH group) did not differ from a control group matched for sex and age. However, the patients in the SH group were treated with relatively less short-acting insulin than the patients in the control group (25 +/- 13.8% vs. 39 +/- 24.5%; p less than 0.01). This finding may indicate that multiple injection therapy with a higher relative amount of short-acting insulin could reduce the risk of severe hypoglycemia, provided the metabolic control is unaltered.

Adolescent↗
PubMed1988

Magnesium, potassium and zinc deficiency in subjects with type II diabetes mellitus.

The concentrations of magnesium, potassium and zinc were determined in plasma, erythrocytes, muscle biopsies, and in urine collected during 24 hours, in 18 subjects with type II diabetes mellitus (DM). Magnesium was also determined in mononuclear cells. The results were compared with those in 35 (magnesium and potassium analyses) or 26 (zinc analyses) healthy controls. Subjects with type II DM had lower concentrations of magnesium (3.79 +/- 0.32 vs. 4.29 +/- 0.22 mmol/100 g FFDS), potassium (40.5 +/- 5.17 vs. 46.1 +/- 3.81 mmol/100 g FFDS) and zinc (231 +/- 29 vs. 247 +/- 23 ng/mg FFDS) in skeletal muscle. Furthermore, the urinary excretions of magnesium and zinc were higher, as compared with those in healthy controls (5.00 +/- 2.68 vs. 3.62 +/- 1.47 mmol/24 hours, and 683 +/- 285 vs. 326 +/- 205 micrograms/24 hours, respectively). The contents of magnesium, potassium and zinc plasma did not correlate with the corresponding concentrations in skeletal muscle or circulating blood cells, as investigated in healthy controls, diabetics and in all subjects together, implying that the plasma concentrations are not useful in the assessment of electrolyte status. Hence, deficiency of electrolytes frequently occurs, and should be looked for, in subjects with type II DM.

Adult↗
PubMed1988

Insulin stimulates the uptake of chylomicron remnants in cultured rat hepatocytes.

The effects of insulin (10-1000 microU ml-1) on chylomicron remnant uptake and degradation were studied in hepatocyte monolayer cultures. Both uptake and degradation were stimulated by insulin. The degree of stimulation was influenced by cell density, being most pronounced in sparse cultures. The uptake was stimulated in a dose-dependent fashion and was noticed already at a physiological insulin level (100 microU ml-1). At this insulin concentration uptake was stimulated by approximately 50% (range 26-84%). As suggested by the increase in Vmax for the remnant uptake, the number of lipoprotein receptors on the hepatocytes was increased by 100 microU ml-1 of insulin. Apolipoprotein-E-free low density lipoproteins (LDL) competed much less efficiently for the uptake of radioactive remnants than did unlabelled remnant particles. About half of the stimulatory effect of insulin on the remnant uptake could, however, be abolished by adding an excess of LDL, indicating that at least part of the stimulation by insulin was due to increased activity of the LDL receptor. This study thus shows that physiological insulin levels increase chylomicron remnant uptake in hepatocyte monolayer cultures. It is assumed that the effect of insulin is to increase the number of lipoprotein receptors at the cell surface, and at least part of the stimulation is due to an increase in LDL receptor activity.

Animals↗
PubMed1988

Effect of total intravenous anaesthesia with midazolam/alfentanil on the adrenocortical and hyperglycaemic response to abdominal surgery.

The effect of anaesthesia on the hyperglycaemic and adrenocortical response induced by surgery was studied in patients undergoing abdominal hysterectomy. The study group was anaesthetized with midazolam and alfentanil using a totally intravenous anaesthetic technique. A reference group received anaesthesia with thiopentone, alfentanil and nitrous oxide. Midazolam 0.42 mg.kg-1 was given as a loading infusion followed by a maintenance infusion of 0.125 mg.kg-1.h-1. Alfentanil was given as a bolus dose of 0.075 mg.kg-1 in both groups, followed by a loading infusion of 0.3 mg.kg-1.h-1 for 15 min and a maintenance infusion of 0.065 mg.kg-1.h-1. Increments of alfentanil were given whenever heart rate or systolic blood pressure exceeded pre-induction values by more than 10%. During anaesthesia mean arterial pressure and heart rate were similar in both groups and there was no difference in alfentanil requirement. An immediate increase in blood glucose concentrations was seen following incision, but maximum concentrations were measured in the early postoperative period. Serum cortisol concentrations decreased after induction of anaesthesia. During surgery they returned to pre-induction values, and in the postoperative period they increased to about twice the pre-induction values. It is concluded that midazolam/alfentanil anaesthesia is as effective as anaesthesia induced by thiopentone, alfentanil and nitrous oxide in suppressing the stress-response to surgery until the postoperative period. No signs of prolonged adrenocortical depression were observed.

Alfentanil↗
PubMed1988

Effects of the benzodiazepine antagonist flumazenil on postoperative performance following total intravenous anaesthesia with midazolam and alfentanil.

Postoperative performance following total intravenous anaesthesia (TIVA) using midazolam and alfentanil was studied with and without the administration of a single dose of a benzodiazepine antagonist, flumazenil (Ro 15-1788). Performance was compared with a reference group anaesthetized with thiopentone, alfentanil and nitrous oxide. All patients were assessed by use of a rating scale which took into account the degree of sedation, amnesia, comprehension and cooperation as well as temporal and spatial orientation. There was a slow recovery following TIVA with somnolence and amnesia lasting several hours. Administration of flumazenil 1.0 mg i.v. at extubation caused a significant reduction of sedation (P less than 0.001) during the first postoperative hour, with patients fully awake or only lightly sedated, but was later followed by resedation. The patients of the reference group were moderately sedated during the observation period. Five and six hours postoperatively there was no difference between the groups. Amnesia was more profound in the groups that received midazolam; the effect of the antagonist could only be seen for 15 min after its administration. Comprehension and cooperation, as well as orientation, were equally good in the antagonist and in the reference group during the immediate postoperative period, whereas in the TIVA group a gradual improvement over the first hours was seen. In the antagonist group there was no increase in the number of analgesic requirements, no anxiety attacks or other adverse effects. It is concluded that flumazenil offers an improvement in postoperative performance following TIVA induced by midazolam and alfentanil, but the effects are of short duration.

Alfentanil↗
PubMed1988

Absorption and metabolism of orally fed arachidonic and linoleic acid in the rat.

[3H]arachidonic [( 3H]20:4) and [14C]linoleic acid [14C]18:2) were fed to rats in Intralipid or cream. Later (30-240 min) the stomach, small intestine, plasma, and liver were analyzed for radioactivity in different lipid classes. [3H]20:4 and [14C]18:2 were emptied from the stomach and absorbed by the intestine at similar rates. The [3H]20:4:[14C]18:2 ratio of the lipids in the small intestinal wall increased, however, with time. This was due to a higher retention of [3H]20:4 than [14C]18:2 in intestinal phospholipids. In contrast, more of the [14C]18:2 was in triacylglycerol of the small intestine and plasma. The highest 3H:14C ratios were found in phosphatidylethanolamine and phosphatidylinositol. The 3H:14C ratio of intestinal phosphatidylcholine varied with the type of fat vehicle used, being highest in the Intralipid experiments. After feeding Intralipid (30-60 min), significantly more of the plasma [3H]20:4 than plasma [14C]18:2 was in diacylglycerol, the 3H:14C ratio of which was much higher than that of plasma free fatty acids. [3H]20:4 and [14C]18:2 of chyle triacylglycerol are thus metabolized differently.

Administration, Oral↗
PubMed1988

Comparison of histology and clinical variables to DNA ploidy in canine mammary tumors.

Flow cytometric DNA analysis was done on 132 canine mammary tumors from 99 dogs to evaluate the relation to histology and to clinical staging. Seventy-one tumors (54%) were histologically malignant; 38 (54%) of these were aneuploid and 33 (46%) were diploid. Fifty-two (39%) tumors were histologically benign, of which 45 (87%) were diploid and seven (13%) aneuploid. There were nine dysplastic mammae (7%); two were aneuploid and the rest diploid. DNA indices varied from 0.72 to 2.35. Of 58 mammary carcinomas, 25 (43%) were diploid and 33 (57%) were aneuploid (of the latter, 16 showed hypodiploidy and 17 hyperdiploidy with a predominance between DNA index 1.10 and 1.50). Three tumors (two carcinomas and one malignant mixed tumor) were multiploid with two aneuploid cell populations. The histological type varied within eight tumors, and in four of these the DNA index also varied. DNA indices varied within three tumors with uniform morphology. No correlation was found between DNA index and age of the dogs, nor between DNA index and tumor size. No significant differences were found between DNA index and histology, tumor growth pattern, or tumor location. Benign tumors were smaller than carcinomas, which were smaller than malignant mesenchymal tumors. Tumors growing adherent to the skin were larger than those not adherent to the skin. The regional lymph nodes were examined in 33 cases. No significant difference between the mean DNA index and presence of lymph node metastasis was found. These results show the possibility of using flow cytometry for DNA analysis in canine mammary tumors.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Regulation of insulin-like growth factor messenger ribonucleic acid in rat growth plate by growth hormone.

The mechanism of action for the stimulatory effect of GH on longitudinal bone growth is not yet clarified. Several recent reports indicate that GH has a direct effect at the site of the epiphyseal growth plate, as opposed to the somatomedin hypothesis which holds that the effect of GH is mediated by circulating insulin-like growth factors (IGFs). Using a RNA probe in a solution hybridization assay we investigated the presence of IGF-I mRNA in rat rib growth plate. Hypophysectomy resulted in a decrease in the number of IGF-I mRNA copies compared to that in normal rats. Replacement treatment with GH restored the number of transcripts in a specific and dose-dependent manner. The results show that GH regulates the level of IGF-I mRNA in rat rib growth plate and give further support to the hypothesis that locally produced IGF-I might contribute to the stimulatory effect of GH on longitudinal bone growth.

Actins↗