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Biomedical subjects

A Sjögren

Publications and source records attributed to A Sjögren.

At least 55 records · Page 3Linked to original sources
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

Enhanced vasoconstrictor responses to potassium, 5-hydroxytryptamine, and prostaglandin F2 alpha of isolated coronary arteries from magnesium-deficient rats. Comparison with vasomotor activity of aorta.

Wistar rats were fed a low magnesium diet for 8 or 12 weeks, resulting in reduced levels of magnesium in plasma, heart, and skeletal muscle, as compared with pair-fed control rats. The magnesium-deficient rats also had reduced tissue levels of potassium. Coronary arteries and thoracic aorta from magnesium-deficient rats and control rats were incubated in tissue baths and the contractile responses to potassium, 5-hydroxy-tryptamine, and prostaglandin F2 alpha were investigated using a sensitive in vitro system. The concentration-contraction curve, for all agents was shifted to the left in coronary arteries from magnesium-deficient rats. In aorta from magnesium-deficient rats, the pattern of change in reactivity to these agonists was not uniform: the concentration-contraction curve for 5-hydroxytryptamine was shifted to the left, the contractile response to prostaglandin F2 alpha was reduced, while there was no change in the response to potassium. The contractile response to the administration of calcium to calcium-depleted, potassium-depolarized vessels from magnesium-deficient rats was enhanced; the effect was more pronounced in coronary arteries as compared to the aorta. Hence, the vasomotor reactivity of coronary arteries appears to be more sensitive than is the aorta during magnesium-deficient conditions.

Animals↗
PubMed1988

Prognosis after withdrawal of chronic postinfarction metoprolol treatment: a 2-7 year follow-up.

In a randomized double-blind postinfarction study 301 patients were treated with either metoprolol 100 mg b.i.d. (n = 154) or placebo (n = 147) for three years. After the three-year treatment period the study preparation was gradually withdrawn over one week, followed by another 2-7 year follow-up. Mortality and morbidity data were studied both during the intervention period (reported elsewhere) and over the period following withdrawal of study therapy. During the period following the withdrawal of the trial preparation, there were 16 (14%) and 31 (24%) deaths in the previously placebo and metoprolol groups, respectively (P = 0.10). Corresponding figures for reinfarctions and cerebrovascular events were 15 (13%) vs. 12 (9%) and 14 (12%) vs. 9 (7%) (NS). From a Cox regression analysis taking 13 different variables into account, a model describing the risk for subsequent death was constructed. The model identified the following important variables: sex (relative risk (rr) = 2.4), beta-blocker withdrawal (rr = 2.1), performance on exercise test and digitalis treatment (rr = 2.3, P less than 0.05). The present results, as well as those from other studies, seem to favour continuous postinfarction beta blocker therapy provided that there are no severe side-effects from therapy. Digitalis therapy in postinfarction patients in sinus rhythm may have adverse effects on survival during long-term follow-up.

Adolescent↗
PubMed1988

Efficacy and tolerability of transdermal nitroglycerin in heart failure. A noninvasive placebo controlled double-blind cross over study.

The efficacy of transdermal nitroglycerin was investigated in 18 patients with moderate to severe congestive heart failure in a placebo-controlled, double-blind, crossover study. Treatment periods were of four weeks, following a one week dose titration period during which the maximum tolerated dose within the range of 5-15 mg was estimated. Therapeutic effects were evaluated by clinical examination (NYHA class), treadmill exercise, echocardiography and patient subjective scaling of general well being, cardiac symptoms and dyspnoea. Both patient and investigator analogue scaling of general well being showed improved scores indicating an improvement throughout the study. This tendency was even more marked when comparing inclusion values with those after each treatment period (P less than 0.05). However, when comparing values before with those after each treatment period, only the investigator scaling of heart failure level proved significantly higher after the placebo period (P less than 0.05). No other findings of significance were observed. We conclude that transdermal nitroglycerin given in the present doses over four weeks fails to improve the clinical situation in patients with moderate to severe congestive heart failure.

Administration, Cutaneous↗
PubMed1988

Prolactin and gonadotrophin interactions on progesterone formation in cultured human granulosa cells.

Human granulosa cells were isolated from preovulatory follicles during cycles stimulated with HMG-HCG or clomiphene-HMG-HCG or from unstimulated cycles. The cells were cultured for 6-8 days in medium M199 containing fetal calf serum under 5% CO2 in air. Highly purified human prolactin and human chorionic gonadotrophin were added alone or in combination to the cultures, and the content of steroids in the medium was measured every second day, utilizing conventional RIA techniques. In the presence of HCG the formation of progesterone (P) increased 3-5-fold over the control level with maximal effect after 4 days. In cells derived from clomiphene-HMG-HCG stimulated cycles, prolactin per se did not influence basal P formation but reduced the stimulatory effect of HCG. This was only seen in granulosa cells from follicles greater than 20 mm in diameter. In experiments with Forskolin, an adenylate cyclase activator, P formation was stimulated and the stimulation was counteracted by the concomitant presence of prolactin, indicating that prolactin did not interfere with the LH-HCG receptor. In cells from smaller follicles, or in cells from follicles aspirated from the natural cycle prior to the endogenous LH peak, P formation was stimulated by HCG but the addition of prolactin did not reduce this stimulatory effect. The results are discussed in relation to earlier reports on prolactin effects in vitro both on laboratory animals and human material.

Cells, Cultured↗
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

The three-dimensional structures of S-layers of two novel Eubacterium species isolated from inflammatory human processes.

The three-dimensional structures of the crystalline surface layers of two species of Eubacteria have been determined by electron microscopy and computerized image processing. The S-layer of Eubacterium sp. ES4C has tetragonal symmetry, with a unit cell spacing of 10.6 nm and a thickness of 9.5 nm, while that of Eubacterium sp. AHN 990 has hexagonal symmetry a = b = 15.7 nm and a thickness of 13 nm. The resolutions in the reconstructions were 2.5 nm and 1.8 nm, respectively. The reconstruction of the S-layer of strain ES4C reveals a distinct domain structure: a major tetramer, arms connecting adjacent unit cells, and a minor tetramer. The S-layer of strain AHN 990, on the other hand, has a rather complex arrangement, centred around the six-fold axis.

Eubacterium↗
PubMed1988

The influence of magnesium on the release of calcium from intracellular depots in vascular smooth muscle cells.

Vasoconstrictor responses to prostaglandin F2 alpha and noradrenaline were investigated in ring segments of feline femoral, coronary and cerebral arteries incubated in calcium-free solutions containing different concentrations of magnesium (1.2, 4.4 and 13.2 mM). Contractions produced by prostaglandin F2 alpha and noradrenaline were depressed when calcium was omitted from the incubation solution. The presence of raised concentrations of magnesium (4.4 or 13.2 mM) in the tissue bath further depressed the prostaglandin F2 alpha and noradrenaline contractions in calcium-free medium. In a separate set of experiments the vessel wall contents of cAMP and cGMP were measured before and after the additions of 4.4 or 13.2 mM magnesium; stable relaxations by magnesium were noted but there was no parallel change in the vessel content of cAMP or cGMP. The results indicate that magnesium may interfere with the release of calcium from intracellular depots, and that neither adenylate cyclase, nor guanylate cyclase are involved in the dilator activity of magnesium in isolated arteries.

Animals↗
PubMed1988

Vasomotor changes in isolated coronary arteries from diabetic rats.

Contractile responses to prostaglandin F2 alpha, serotonin, noradrenaline, and potassium were examined in isolated intramyocardial arteries of Wistar rats 8 weeks after the induction of diabetes mellitus by administration of streptozotocin (STZ). The concentration-response curves obtained were compared with those noted in vessels both from age- and from weight-matched control rats. Light and electron microscopy did not reveal any major change in coronary artery wall thickness or morphology. There was no difference in the pattern of vasomotor responses between the two control groups. Contractile responses to prostaglandin F2 alpha, and potassium were significantly reduced, while contractile responses to serotonin and noradrenaline were unaltered in coronary arteries from diabetic rats. The vasomotor responses to noradrenaline and potassium showed a biphasic pattern in control vessels, i.e. contraction noted at high agonist concentrations was preceded by slight, but reproducible relaxation at lower concentrations. In diabetic vessels these relaxant responses were absent. The contraction produced by noradrenaline was markedly enhanced by the presence of propranolol in both diabetic and control vessels. Dilator responses to verapamil, diltiazem, nifedipine, papaverine and magnesium were studied in serotonin-precontracted coronary arteries; the concentration-response curves obtained by verapamil and diltiazem were shifted to the right in diabetic vessels. It appears justified to use vessels from age-matched rats as controls when vasomotor reactivity in coronary arteries from STZ-diabetic rats is investigated. The reduction in contractile responses to prostaglandin F2 alpha and potassium, and the reduction or lack of relaxant responses to noradrenaline, potassium, verapamil and diltiazem, in diabetic coronary arteries, indicate a selective modification of the coronary circulation by the diabetic disease.

Animals↗
PubMed1988

Evaluation of magnesium status in Crohn's disease as assessed by intracellular analysis and intravenous magnesium infusion.

The magnesium status was evaluated in 30 subjects with Crohn's disease and in 30 controls. Subjects with Crohn's disease had lower concentrations of magnesium in muscle biopsy specimens (p less than 0.001), mononuclear cells (p less than 0.05), and in urine collected during 24 h (p less than 0.001) as compared with controls. After intravenous infusion of 60 mmol magnesium and 80 mmol potassium to 17 subjects with Crohn's disease a significant increase in concentrations of magnesium in muscle specimens (p less than 0.05), mononuclear cells (p less than 0.01), and plasma (p less than 0.01) was noted. The retention of intravenously infused magnesium was significantly higher in subjects with Crohn's disease than in 11 healthy controls (p less than 0.001) and was inversely correlated with the content of magnesium in muscle specimens (r = -0.52; p less than 0.05). The implication of these findings is that analysis of magnesium in muscle specimens and estimation of magnesium retention during an intravenous magnesium infusion are useful to confirm a suspected magnesium deficiency.

Adolescent↗
PubMed1988

Oral administration of magnesium hydroxide to subjects with insulin-dependent diabetes mellitus: effects on magnesium and potassium levels and on insulin requirements.

Intra- and extracellular levels of magnesium and potassium were determined in 16 subjects with insulin-dependent type I diabetes mellitus (IDDM) and 30 healthy controls. Subjects with IDDM had lower levels of magnesium in muscle biopsies (p less than 0.001), plasma (p less than 0.001), and mononuclear cells (p less than 0.05), and higher urinary excretions of magnesium (p less than 0.01), and lower levels of potassium in muscle biopsies (p less than 0.001), and erythrocytes (p less than 0.05), as compared with those in controls. Magnesium hydroxide (500 mg/day) was administered orally to the diabetics. The levels of magnesium and potassium in muscle biopsies increased (p less than 0.001; p less than 0.001), while the plasma levels of magnesium and the urinary excretions of magnesium increased only temporarily, during 21 weeks of treatment. The requirements of insulin were reduced (p less than 0.001) during the course of the study, whereas the levels of glycosylated hemoglobin (HbA1c) and glucose were not changed. The findings indicate that administration of magnesium hydroxide is useful to treat muscular magnesium and potassium deficiency in diabetics.

Adult↗
PubMed1987

Clinical experience in an in vitro fertilization and embryo replacement program of a new method for analysis of urinary estrogens.

The clinical experience in an IVF/ER program of a newly developed commercial kit (Estradiol enzymatique; BioMerieux) to determine urinary estrogens enzymatically, is reported. The study included 157 cycles, and the main indication for treatment was infertility due to tubal factor. Follicular development was stimulated in most cases by a combination of clomiphene citrate, human menopausal gonadotropin and chorionic gonadotropin. In addition to the previously used method to monitor follicular growth, ultrasound, daily urinary estrogens (estradiol + estrone) levels were assayed. A correlation between the pattern of urinary estrogen and the clinical results was found. In cycles with continuously rising estrogen up to the time of hCG administration a higher rate of in vitro fertilization and clinical pregnancies were obtained as compared to cycles where urinary estrogen declined or levelled off. It is concluded that this enzymatic assay of urinary estrogens is a good alternative to increase the precision of follicle monitoring when radioimmunological assay of serum estradiol levels cannot be obtained on a daily routine basis.

Chorionic Gonadotropin↗
PubMed1987

The regulatory role of FSH in steroid formation by luteinized human granulosa cells in culture.

Granulosa cells were aspirated from human pre-ovulatory follicles following a combined clomiphene-gonadotrophin stimulation in an in-vitro fertilization (IVF) programme. The cells were cultured for 8 days in medium M199 containing 10% bovine fetal calf serum under 5% CO2 in air. Pure human FSH and human LH were added alone or in combination to the culture in various concentrations and the progesterone (P) and oestradiol-17 beta (E2) levels in the medium were measured every second day by a conventional RIA technique. In the presence of FSH or LH the formation of P increased 2- to 3-fold with the pronounced effect after 4 to 6 days in culture. Addition of testosterone (T) (3 X 10(-7) M) to the culture medium affected neither basal nor gonadotrophin stimulated P formation. In this system, only minute amounts of E2 were formed and neither FSH nor LH stimulated its formation. When the medium was fortified with T, basal E2 formation increased 50- to 100-fold. FSH further stimulated this conversion significantly after 6 and 8 days of culture, while LH had no significant influence.

Cells, Cultured↗
PubMed1987

Availability of reaction with antibodies of the pneumococcal C-polysaccharide on the surface of capsulated pneumococci.

Antigen detection for diagnosis of pneumococcal infections has earlier been based on the use of antibodies against capsular antigens. Methods based on the demonstration of C-polysaccharide (PnC) have the advantage of using antibodies against one single species-specific antigen instead of applying a polyvalent mixture of antisera against 83 different capsular antigens. Very little has been done earlier to evaluate the accessibility of the PnC on the surface of pneumococcal cells, particularly cells carrying capsules, and the release of PnC to the environment. We have used a monoclonal anti-PnC antibody in an ELISA inhibition test to demonstrate PnC during growth from four different Streptococcus pneumoniae strains (capsular types 1, 3 and 19F) and a C-mutant strain, reported to carry PnC as a small capsule. Heavily-capsulated types 3 and 19F exposed more PnC on their surface than the type 1 strain, and considerable amounts of PnC were released to the culture medium during growth. The C-mutant strain differed from the other strains in that it exposed less PnC on its surface. The type 1 strain and the C-mutant released approximately the same amount of PnC to the culture medium. Treatment with antibiotics during growth caused a decrease in surface-located PnC but did not significantly affect the amount released. The total accessible PnC in these cultures was quite significant and well above the limit of detection in an ELISA earlier described for the detection of PnC in clinical samples. The results presented here give support to the notion that the demonstration of PnC in clinical samples should provide a good basis for diagnosis of pneumococcal pneumonia.

Antibodies, Bacterial↗
PubMed1987

A microcalorimetric study of the sodium-potassium-pump and thermogenesis in human skeletal muscle.

Thermogenesis in human skeletal muscle was monitored by measurement of heat production using perfusion microcalorimetry. Heat production significantly correlated with relative body weight. The energy expenditure of the Na-K-pump (delta P), assessed after inhibition by ouabain in Krebs-Ringer phosphate buffer containing glucose and insulin, amounted to 6% of the total heat production in vastus lateralis muscle. Muscle potassium positively correlated with delta P (r = 0.84, P less than 0.005). For rectus abdominis muscle delta P was 8-15%; 95% confidence interval for the difference was 3-5% when comparison was made with vastus lateralis. The finding of a positive relationship between delta P and muscle magnesium (r = 0.68, P less than 0.04) is possibly explained by the dependence of ATP hydrolysis on internal magnesium. Our data on resting thermogenesis in small muscle samples agree to previous estimates of O2 consumption in human skeletal muscle in vivo.

Adolescent↗
PubMed1987

Direct vasomotor effects of theophylline and enprofylline on human coronary artery in-vitro: comparison with feline coronary and cerebral arteries.

The vasomotor effects of theophylline and enprofylline were investigated on circular segments of human coronary artery taken 6 h after death. Isolated arterial segments were examined using a sensitive myograph and isometric contractions were recorded with Grass transducers. The results were compared with those obtained in feline coronary and cerebral arteries. Theophylline and enprofylline induced pronounced relaxation of all types of precontracted arteries. In feline cerebral arteries the potency for eliciting relaxation was slightly higher for theophylline compared with enprofylline, while there was no difference in potency for the methylxanthines in coronary arteries. Prostaglandin F2 alpha frequently induced rhythmic contractions in human, but not in feline coronary arteries. Theophylline increased the amplitude of the rhythmic contractions while this was not seen following administration of enprofylline. Whether this mode of activity by theophylline contributes to its arrhythmogenic properties in-situ requires clarification.

Animals↗
PubMed1987

Interaction between extracellular magnesium and the passage of calcium through the sarcolemma during depolarization of isolated feline coronary and femoral arteries.

The mode of action of Mg2+ on vascular smooth muscle has been examined in isolated feline coronary and femoral arterial segments using a sensitive in vitro method. Potassium (124 mM) was added to feline coronary and femoral arteries incubated in a calcium-free buffer solution containing 10 microM EGTA, and magnesium in various concentrations (1.2, 4.4 or 13.2 mM). Potassium induced during these conditions a small contraction whose magnitude was attenuated by raised concentrations of Mg2+ (4.4 and 13.2 mM). Subsequent cumulative addition of calcium (10(-6)-3 x 10(-3) M) resulted in concentration-dependent contractions. The magnitude of these contractions was magnesium-dependent; the contraction elicited was depressed and a dextral shift of the extracellular calcium concentration-response relation was noted in the presence of increased concentrations of Mg2+ (4.4 and 13.2 mM). In separate experiments performed on potassium-depolarized (124 mM) feline coronary arteries it was noted that magnesium-induced relaxation was not changed by the presence of propranolol (10(-6) M), cimetidine (10(-6) M) or atropine (10(-5) M). In addition, the mechanical removal of the endothelium did not affect the dilator effect of Mg2+, as examined in potassium-depolarized (124 mM) feline femoral arteries. Hence, it may be concluded that Mg2+ may interfere with the passage of extracellular calcium through the sarcolemma, and that the dilator effect of magnesium is not the result of a direct action on beta-adrenoceptors, histamine H2 or cholinergic receptors, or requires the presence of an intact endothelium.

Adrenergic beta-Antagonists↗