Search PubMed⌕ Search

Biomedical subjects

R Jansson

Publications and source records attributed to R Jansson.

At least 55 records · Page 3Linked to original sources

Free thyroxin index and direct measurements of free thyroxin compared for evaluating postpartum autoimmune thyroid dysfunction.

Measurement of free thyroxin (FT4) by a recently introduced commercial assay (Amerlex Free T4 RIA) was compared with the calculated free thyroxin index (FT4I) for serum from 104 postpartum women. Of these, 63 had transient thyroid dysfunction due to autoimmune thyroiditis, six had transient Graves' thyrotoxicosis, and 35 were euthyroid with no signs of autoimmune thyroid disease. The correlation between results for FT4 and the calculated FTI for 95 serum samples from women with no signs of autoimmune thyroiditis (r = 0.941; p = 0.0001) was almost identical to that for 270 serum samples from women with thyroid microsomal autoantibodies characteristic of autoimmune thyroiditis (r = 0.937; p = 0.0001). Furthermore, we observed no difference when the autoimmune group was subdivided according to low or high titers of thyroid microsomal antibodies. In no case did autoantibodies to thyroxin interfere with the FT4 assay. However, one woman had a spuriously low value for FT4I owing to interference by autoantibodies to triiodothyronine with the triiodothyronine resin uptake test. We conclude that the FT4 RIA assay provided diagnostic information in this group of postpartum women equivalent to that of the more elaborate procedure of determining FT4I.

Autoantibodies↗

Chromosomal breakage in multiple endocrine adenomatosis (types I and II).

Chromosomal analyses of cultured lymphocytes from nine patients with familial multiple endocrine adenomatosis (MEA) syndrome type I from six families and two patients - father and daughter - with familial MEA syndrome type II showed an increased frequency of chromosomal breakage. The frequency of sister chromatid exchanges was not increased.

Cells, Cultured↗

Thyroid-infiltrating T lymphocyte subsets in Hashimoto's thyroiditis.

In Hashimoto's thyroiditis, the thyroid gland is infiltrated with immunocompetent lymphocytes. In this study we have used the fine needle aspiration technique to obtain thyroid-infiltrating lymphocytes from 11 HT patients for surface marker studies. The cells were characterized using conventional T and B cell markers as well as monoclonal antibodies (OKT) to different T cell subsets in a microscale immunofluorescence assay. We observed a relative decrease in intrathyroidal suppressor phenotype T (OKT 8+) cell numbers compared with peripheral blood (13% vs. 26%; P less than 0.01 by Wilcoxon signed rank test). This resulted in an increased helper to suppressor T (OKT 4+/OKT 8+) cell ratio (4.7 vs. 2.1; P less than 0.01). Within the gland, a significant local accumulation of B cells was also registered (27% vs. 12%; P less than 0.01). As to circulating lymphocyte subsets, no differences were found between 18 Hashimoto's thyroiditis patients and 26 normal subjects. Our results are compatible with a local synthesis of thyroid-directed antibodies and emphasize the importance of studying the local immunity in organ-specific autoimmune disease.

Adult↗

Intrathyroidal concentrations of methimazole in patients with Graves' disease.

A sensitive gas chromatographic-mass spectrometric method enabled us to study intrathyroidal concentrations of methimazole in 20 euthyroid patients with Graves' disease on treatment with carbimazole and T4. There was no difference between patients receiving a final dose of carbimazole (10 mg), known to be totally bioactivated to methimazole (6.1 mg), 3-6 h before thyroid excision (518 ng/g thyroid tissue +/- 90 SEM) and patients who received the same dose 17-20 h before excision (727 ng/g thyroid tissue +/- 157 SEM), indicating a slow intrathyroidal turnover of the drug. On the other hand, the serum concentrations were much higher in the first group (102 ng/ml +/- 5 SEM vs. 16 ng/ml +/- 3 SEM), reflecting a short plasma half-life of the drug. The intrathyroidal concentrations of methimazole ranged from 230-1895 ng/g among individual glands but were similar in pieces from different parts of a single gland. These methimazole concentrations are lower than the concentrations reported by others to have an immunosuppressive action on lymphocytes in vitro.

Adult↗

Different aetiologies in post-partum thyroiditis?

During a 4 year period 19 women with post-partum onset of thyroid dysfunction have been seen in our clinic. Five women had high radioiodine uptake thyrotoxicosis (Graves' disease). Twelve women had hypothyroid symptoms starting within 3-6 months of delivery. All of these women had thyroid microsomal and/or cytoplasmic autoantibodies and thyroid lymphocytic infiltration suggesting aggravation of pre-existing subclinical autoimmune thyroiditis (Hashimoto's disease). At follow-up thyroid function gradually improved in all but signs of persistent thyroid hypofunction remained in seven. Thus women developing symptomatic postpartum hypothyroidism should be followed regularly and when thyroxine treatment is commenced in the post-partum period, it has to be continued indefinitely in many cases. Two women presented with transient low radioiodine uptake thyrotoxicosis and a small painless goitre. Thyroid cytology revealed thyroiditis but they had no thyroid autoantibodies. When followed after a succeeding delivery none of these women developed post-partum thyroid dysfunction in contrast to women in the autoimmune group. Probably the aetiology of thyroid dysfunction in these 2 women was different.

Autoimmune Diseases↗

Influence of electrical vagal stimulation and acetylcholine on the function of the feline gallbladder.

The effects of electrical stimulation of the vagus nerves on the function of the feline gallbladder and hepatic bile outflow were studied with a perfusion technique in vivo. After elimination of the muscarinic receptors with atropine, efferent stimulation of the cut vagus nerve in the neck relaxed the gallbladder, reduced the net water absorption rate across its wall, and increased the bile outflow from the liver. The results imply that the concentrating function of the gallbladder and the bile formation in the liver are under regulatory control by noncholinergic, nonadrenergic nerve fibres in the vagus nerves.

Acetylcholine↗

Comparative bioavailability of carbimazole and methimazole.

In this study we investigated the oral bioavailability of therapeutic doses of two antithyroid drugs, methimazole and carbimazole, in seven euthyroid subjects. To increase the statistical power deuterium-labeled methimazole was given orally as an internal standard together with the tested drugs. Using a recently described highly sensitive gas chromatographic-mass spectrometric assay for methimazole we found that intake of 15 mg carbimazole resulted in plasma concentrations of methimazole and pharmacokinetic data comparable to intake of an equimolar amount of methimazole, i. e., 9.2 mg. Maximum concentrations of 163 and 149 ng/ml, respectively, were reached in both instances at 0.9 h after intake of 15 mg carbimazole and 10 mg methimazole. The plasma half-life was 5.7 and 5.4 h, respectively. In contrast to previous suggestions the interindividual differences in pharmacokinetics were small. In conclusion, carbimazole was rapidly and totally bioactivated to methimazole, and the drugs should be regarded as equipotent when compared on a molar basis.

Administration, Oral↗

Adrenergic influence on concentrating function in the feline gall bladder.

The influence of adrenergic drugs and electrical stimulation of the splanchnic nerves on concentrating function and motility in the feline gall bladder and on heptic bile secretion have been studied in vivo. It was found that electrical stimulation of the splanchnic nerves and adrenergic alpha-receptor stimulation increase the rate of net water absorption from the gall bladder lumen. Adrenergic beta-receptor stimulation relaxed the gall bladder but did not influence the concentrating function. A direct effect on the mucosal cells and/or a ganglionic inhibition of intramural VIP-releasing neurons is suggested as a possible mechanism for the alpha-adrenergic increase of the net water absorption rate. The results are discussed in relation to the adrenergic influence on water absorption in the small intestine. As a functional consequence of an increase in the concentrating activity of the gall bladder in situations of high adrenergic activity a more rapid accumulation of organic contents in its lumen is suggested.

Absorption↗

Indomethacin intravenously--a new way for effective relief of biliary pain: a double-blind study in man.

Prostaglandins have been demonstrated to contract the gallbladder and induce fluid secretion into its lumen in experimental animals. Indomethacin is an effective inhibitor of prostaglandin synthetase and has recently been demonstrated to inhibit inflammatory fluid secretion into the gallbladder in experimental cholecystitis. A mechanism by which an increased prostaglandin synthesis will result in a raised intraluminal pressure in the gallbladder in patients with gallstone disease has been suggested. By inhibiting the synthesis of prostaglandins with indomethacin the intraluminal pressure is reduced and the biliary pain relieved. In a double-blind study with a placebo in 40 separate attacks of biliary pain in 37 patients with verified gallstone disease intravenous indomethacin was found to effectively relieve pain within 5 to 30 minutes. No serious side effects were seen, but nausea and vertigo of short duration were noticed in 10 of 21 cases of indomethacin treatment. The drug did not affect blood pressure, but a reduction of the pulse rate was usually seen.

Adult↗

Duplication cyst of the jejunum. Report of a case.

A 4-year-old boy presented with recurrent abdominal pain and melena. X-ray studies of the gastrointestinal tract and technetium scanning of the abdomen were normal. Laparotomy revealed a large duplication cyst in the proximal part of the jejunum. The cyst was intramesenteric and contained gastric mucosa with three peptic ulcers. The cyst was removed without bowel resection.

Child, Preschool↗

Inhibition of prostaglandin synthesis as a treatment for biliary pain.

Twenty patients with confirmed gallbladder disease were treated with intravenous indomethacin during 24 separate attacks of biliary pain. In all cases the pain was promptly relieved and there were no important side-effects. Indomethacin, and inhibitor of prostaglandin synthesis, may reduce intraluminal pressure in the gallbladder, and relieve pain.

Cholelithiasis↗