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Biomedical subjects

A Nilsson

Publications and source records attributed to A Nilsson.

At least 505 records · Page 28Linked to original sources
PubMed1982

Binding of bile salts to fibre-enriched wheat bran.

A new commercial product of fibre-enriched wheat bran was tested for its binding of bile salts in vitro. The wheat bran preparation was standardized and through enzymatic digestion of protein and starch contained 78 per cent fibre (w/w). Fibre-enriched wheat bran bound with high capacity both conjugated and unconjugated bile salts. Binding was saturable, reversible and showed no specificity towards tauro- or glycine-conjugated bile salts. Binding was rapid, dependent on pH, was enhanced by the presence of high salt concentrations and partially inhibited by 6 M urea. This indicated that binding was a combination of hydrophobic and hydrophilic interactions.

Bile Acids and Salts↗
PubMed1981

Uptake and degradation of rat chylomicron remnants, produced in vivo and in vitro, in rat hepatocyte monolayers.

1. The uptake of small and large chylomicrons in rat hepatocyte monolayer cultures was compared to the uptake of chylomicron remnants prepared either in vitro with pure milk lipoprotein lipase or in hepatectomized rats. 2. Small chylomicrons (Sf less than 400) markedly inhibited remnant uptake and were taken up more efficiently than large ones (Sf greater than 400), indicating that size may be an important factor for the rate of uptake. The Lineweaver-Burk analysis of the data indicated that the V values for the uptake of both small chylomicrons (Sf less than 400) and of remnants prepared either in hepatectomized rats or in vitro was significantly higher than for chylomicrons with Sf greater than 400, whereas the Km values for the different particles did not differ significantly. 3. Preincubation of chylomicrons with serum caused marked changes in their apolipoprotein composition. A loss of apolipoprotein A-I and an increase in apolipoprotein E content was observed by scanning of SDS-polyacrylamide gels. Th preincubation decreased, however, the subsequent uptake of the chylomicrons. In contrast, the uptake of remnants prepared in vivo, or in vitro with serum present, exceeded that of remnants prepared in vitro with albumin or fetal calf serum as the fatty acid acceptor. 4. The data thus indicate that both the decrease in size and the changes in the particle surface during lipolysis with serum present are likely to contribute to the differences seen in the rate of uptake between native chylomicrons and remnants in hepatocyte monolayers.

Animals↗
PubMed1981

Antibody responses to live and killed poliovirus vaccines in the milk of Pakistani and Swedish women.

The effect of poliovirus vaccination on mucosal immunity was studied in lactating women because secretory IgA antibodies to poliovirus in milk may reflect intestinal immunity. Swedish mothers lacked significant titers of secretory IgA antibodies in their milk before vaccination. Subcutaneous vaccination with killed poliovirus vaccine resulted in low but transient increases in titers of secretory IgA antibodies in the milk of most of these women. Pakistani mothers had significant titers of secretory IgA antibodies in their milk before immunization; these titers increased after subcutaneous poliovirus vaccination in 45% of the women. Peroral vaccination of Pakistani women with liver poliovirus vaccine diminished already existing titers of secretory IgA antibodies in their milk. The decrease in titer was especially pronounced when the liver poliovirus vaccine was given together with a subcutaneous vaccine consisting of killed Vibrio cholerae organisms; the mean titer of secretory IgA antibodies in milk 14 days after vaccination was about 40-fold lower than it was before vaccination.

Adult↗
PubMed1981

Effects of hypothyroidism and cholesterol feeding on the clearance of chylomicron remnants in vivo and by rat hepatocyte monolayers.

The hepatic catabolism of chylomicron remnants in normal rats and in hypothyroid rats which were either normocholesterolaemic or made hypercholesterolaemic by feeding cholesterol and cholic acid was studied in vivo and in hepatocyte monolayers. In vivo, the clearance of injected chylomicron remnants labelled with either cholesteryl- or retinyl ester was delayed in the hypercholesterolaemic hypothyroid rats, but not in normocholesterolaemic hypothyroid rats. Cholesteryl-ester-rich hepatocytes from hypercholesterolaemic hypothyroid rats took up remnants less efficiently than did normal hepatocytes. Hepatocytes from normocholesterolaemic hypothyroid rats had a lower cholesteryl ester content and took up remnant particles to a greater degree than did normal hepatocytes. When normal hepatocytes were incubated with hypercholesterolaemic serum or with mevalonolactone, which increased cell cholesteryl ester content, there was a slight suppression of remnant uptake. Also, addition of triiodothyronine to hepatocyte monolayers suppressed rather than increased uptake of chylomicron remnants in hepatocytes. Thus, the study suggests that chylomicron remnant uptake by the liver is not inhibited by hypothyroidism per se but by the cholesterol accumulation in hepatocytes that is the consequence of cholesterol and bile acid feeding of the rats. Although the cholesteryl ester content in hepatocytes seems to determine remnant uptake, the regulation of uptake does not seem to be as effective as that of the LDL receptor in extrahepatic cells.

Animals↗
PubMed1981

Screening for congenital hypothyroidism. I. Laboratory results of a pilot study based on dried blood samples collected for PKU screening.

A pilot study was performed to establish optimal conditions for nation-wide screening for congenital hypothyroidism in Sweden. The levels of T4 and TSH were determined by automated radioimmunoassay in the dried blood spots, routinely collected for PKU screening on the fifth postnatal day, from all 19 792 infants born in the Stockholm area during a 14-month period. To identify safe minimum recall criteria for routine use, infants were recalled if the TSH level was more than 30 mU/l of plasma or--if they were not preterm--the T4 concentration was less than -2 S.D. of the mean. Altogether 160 infants were recalled. Seven newborns with congenital hypothyroidism were identified, 6 with primary and one with secondary hypothyroidism. Five infants had decreased levels of thyroxine-binding globulin. The results of the follow-up analyses from recalled infants showed that determination of the reverse-T3 level may be of diagnostic value around the 23rd day of life. The results of the clinical investigation of recalled infants are reported in a subsequent paper and a programme for nation-wide screening for congenital hypothyroidism is proposed.

Congenital Hypothyroidism↗
PubMed1981

Screening for congenital hypothyroidism. II. Clinical findings in infants with positive screening tests.

In a pilot screening programme for congenital hypothyroidism, PKU filter paper blood samples from 20 000 infants born in Stockholm were analysed for TSH and T4 to identify optimal conditions for routine nationwide screening. Among 160 infants with positive screening tests, 7 infants (group I) had true-positive results, 6 had primary and one secondary hypothyroidism. The 153 infants with false-positive tests were divided into group II:74 infants with an isolated increased TSH level; group III: 71 infants with an isolated decreased T4 concentration; and group IV: 8 infants with increased TSH and decreased T4 levels. In group I the clinical signs and symptoms of hypothyroidism varied when the diagnosis was made at 3 weeks of age. The median hypothyroid index score was 8 (range 0--18). In groups II-IV most infants showed very few signs of hypothyroidism. The median hypothyroid index scores were 1, 1, and 0, respectively. Clinical findings were of little value in the individual case for distinguishing true from false positive screening tests. We suggest that nation-wide screening should be based on TSH analyses of PKU blood samples, with a cut-off level corresponding to 50 mU/l of plasma. Recall frequency will be less than 0.1%.

Congenital Hypothyroidism↗
PubMed1980

Isolation and characterization of chicken secretin.

Chicken secretin has been isolated and its structure determined. It is composed of 27 amino acid residues, and has an amidated C terminus. The amino acid sequence is His-Ser-Asp-Gly-Leu-Phe-Thr-Ser-Glu-Tyr-Ser-Lys-Met-Arg-Gly-Asn-Ala-Gln-Val-Gln -Lys-Phe-Ile-Gln-Asn-Leu-Met-NH2. The structure shows distinct similarities to that of porcine secretin, amino acid identities occur at 14 positions (residues 1-4, 6-9, 11, 14, 17, 20, 24 and 26) but considerable differences are also present among the remaining 13 positions. Chicken secretin further shows a clear structural similarity to the vasoactive intestinal peptide (37% identical positions), the gastric inhibitory peptide (30% identical positions) and to glucagon (52% identical positions), suggesting wide evolutionary and functional relationships.

Amino Acid Sequence↗
PubMed1980

Inhibition of hepatic chylomicron remnant uptake in the cholestatic rat.

[3H]retinal- or [3h]cholesterol- and [14C]fatty acid-labeled chylomicrons and chylomicron remnants were injected intravenously into normal rats and rats subjected to partial or total obstruction of the bile duct 8 or 48 h earlier. The clearance from plasma of the [3H]retinyl and the [3H]cholesteryl esters in 30-120 min was markedly decreased in rats with total obstruction, and the uptake of 3H by the liver was significantly less than in control rats. The elimination of the [14C]triacylglycerol of the native chyle lipoprotein was not significantly affected, and the delayed plasma clearance was seen also when the [3H]lipid ester radioactivity was injected as chylomicron remnants prepared in vitro. If only one of the two main bile duct branches was ligated, the uptake of radioactivity did not differ markedly in the obstructed and unobstructed part of the liver and only small effects on the plasma disappearance were seen. The defective clearance of the chylomicron remnants was thus not related to the obstructed bile flow per se but rather to the consequences of the total obstruction, such as the high plasma bile acid level or the accumulation of abnormal lipoproteins in plasma.

Animals↗
PubMed1980

Chromosome counts of 90Sr-induced osteosarcomas in mice. I. Transplanted tumour series.

From 90Sr-induced primary tumours, three transfer series were established by serial in vivo transplantation. Chromosome counts were obtained from 2 of the primary tumours and 284 transplanted tumours. The recording of abnormalities was limited to numerical chromosome deviations and the occurrence of metacentric configurations. By means of the serial tumour transplantation the numerical chromosome progression was also analysed. Though appearing at different stages of the tumour evolution, similarities in chromosome pattern were observed.

Animals↗
PubMed1980

Effect of syngeneic bone marrow and thymus cell transplantation to 90Sr irradiated mice.

Mice irradiated with 90Sr in doses of 14.8 and 25.9 kB/q/g body weight were given bone marrow or thymic cells intravenously at monthly intervals, or in single doses at 120 or 170 days after injection of 90Sr. At the low dose level a high incidence of lymphoreticular tumours in all cell treated groups occurred as compared with animals irradiated with 90Sr only. At the high dose level only the bone marrow transplanted group contracted a high incidence of lymphoreticular neoplasia. Furthermore, a somewhat decreased osteosarcoma incidence in the cell transplanted animals appeared to be indicated. However, the results obtained are inconsistent and difficult to evaluate. Therefore, it seems necessary to repeat the experiments, if more precise conclusions should be possible to draw.

Animals↗
PubMed1980

Age and dose related carcinogenicity of 90Sr.

90Sr was given at three different dose levels (29.6, 14.8 and 7.4 kBq/g b.w.) to groups of mice aged 300, 150, 75 and 25 days. It was found that the incidence of osteosarcomas was highest in the 75-day-old-group and lowest in the two oldest age groups. The frequency of lymphoreticular tumours was inversely dose-related (highest incidence in the lower dose series) and not dependent on age at the time of 90Sr injection. The frequencies of soft tissue tumours indicate that these tumours are more related to age than to the dose employed.

Age Factors↗
PubMed1980

Induction of neoplasia by 140Ba in mice.

C57Bl mice of both sexes were given intraperitoneal injections of 140Ba-nitrate at 3 different dose levels (55.5, 37.0 and 18.5 kBq/g b.w.). Osteosarcomas were found in all groups and the osteoblastic type was the most common. In the middle and the highest dose groups, female mice developed tumours more frequently than the males. The irradiation doses were calculated to the femur, lumbar vertebrae and sternum and turned out to vary between 6 and 0.7 Gy.

Animals↗
PubMed1980

Induction of pituitary tumours by combination of oestrogenic hormones and 90Sr.

The present investigation was initiated to analyse the carcinogenic effect of combined treatment with 90Sr and oestrogenic hormones or corticosteroids in inbred CBA mice. Pituitary tumours appeared in a remarkably high incidence in mice treated with oestrogens + 90Sr in low doses--0.925 kBq/g body weight (44%) and 1.850 kBq/g body weight (37%)--as compared with mice treated with 90Sr only--1 and 3 per cent, respectively. The syncancerogenic effect is ascribed the oestrogen induced proliferation of pituitary cells and their increased sensitivity to radiation. The reverse relation found between number of pituitary tumours and dose of 90Sr in oestrogen treated mice is explained by the reduction of the survival time with increasing dose. Preneoplastic histologic changes of the pituitary are described and pituitary tumours which mainly appeared in pars distalis, are classified according to the growth and tinctorial characteristics.

Adenoma, Acidophil↗
PubMed1979

Some properties of the chylomicron remnant uptake by rat hepatocyte monolayers.

The effect of mild proteolytic treatment on chylomicron remnant uptake by rat hepatocyte monolayers was studied both at 4 degrees C and at 37 degrees C. At 4 degrees C binding of remnants to the cells was considerably lower than at 37 degrees C, and preincubation of the cells with pronase (2 micrograms/ml) further descreased binding of remnants at 4 degrees C by 63%. At 37 degrees C the effect of preincubation of pronase was less marked, suggesting that reconstruction of remnant binding structures(s) may occur. Only marginal effects on remnant catabolism by cytochalasin B in hepatocyte monolayers were evident. There was thus no positive evidence for a role of microfilaments during interiorization of remnant particles by the cells. Remnant uptake in hepatocytes was not inhibited by EDTA, the presence of asialofetuin, or treatment of the cells with neuraminidase. This indicates that remnant binding sites are different from the hepatic receptor for desialylated glycoproteins. The lack of effect of EDTA is also at variance with the observation that the receptor-mediated uptake of low-density lipoproteins in human fibroblasts depends on the presence of divalent cations.

Animals↗
PubMed1979

Method for measurement of maximal isometric muscle strength with special reference to the fingers.

A method for measurement of the maximal isometric muscle strength in the fingers is presented. Details of the apparatus designed for avoidance of hysteresis in mechanical components on measurement of low strengths are given. The measurement of low strengths is described. The measurement procedure is simple both for examiner and for the subject. Values for finger muscle strength in normal persons are presented.

Equipment and Supplies↗