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Biomedical subjects

M Ekman

Publications and source records attributed to M Ekman.

At least 55 records · Page 3Linked to original sources
PubMed1993

Comparative absorption of ferrous and heme-iron with meals in normal and iron deficient subjects.

The relative intestinal absorption of heme- and non heme-iron in connection with a standardized test meal was studied in a group of fertile women given 16 mg Fe in the form of FeSO4 and 2 mg Fe in the form of hemoglobin. Both in normal subjects and in women with iron deficiency, the heme-iron was significantly better absorbed (16.13% +/- S.D. 8.0 vs 4.59 +/- 3.4, p < 0.01 and 22.03 +/- 8.9 vs 9.45 +/- 7.8, p < 0.05). For targeted prophylaxis of iron deficiency with small, side-effect-free doses, heme-iron is thus a valuable component which increases the absorption by about 40%. Heme-iron does not cause high concentrations in the intestinal lumen of free radical inducing, possibly harmful ferric iron.

Administration, Oral↗
PubMed1992

Malignant lymphoma associated with human AIDS and with SIV-induced immunodeficiency in macaques.

Malignant lymphomas associated with human (HIV) and simian (SIV) immunodeficiency virus infections are reviewed and compared. Recent observation of a high frequency of lymphomas in a series of cynomolgus macaques, highly immunodeficient after infection with SIVsm(smm3) are described. In addition to the increased frequency in human and monkey AIDS, SIV and HIV lymphomas share several important features. Clinically and by histology they present as aggressive high-grade malignant tumors with a predilection for extranodal growth in viscera, skin, central nervous system, testis, and retroorbitally. Most malignant lymphomas are of B-cell origin. AIDS lymphomas in humans are heterogeneous with regard to Epstein-Barr virus (EBV) association. Similarly, most lymphomas in monkeys experimentally infected with SIV tested to date were shown to be associated with an EBV-like simian herpes virus. These observations point to the possibility of using SIV-immunodeficient macaques for study of EBV and other oncogenic and immunosuppressive factors in AIDS-associated lymphomagenesis.

AIDS-Related Complex↗
PubMed1992

Macrophage association of polyomavirus in progressive multifocal leukoencephalopathy: an immunohistochemical and ultrastructural study. Case report.

Progressive multifocal leukoencephalopathy (PML) in a patient following autologous bone marrow transplantation for a non-Hodgkin's centroblastic lymphoma was studied by immunohistochemistry and transmission electron microscopy. Our observations indicate that a large amount of polyomavirus, most probably JC virus, is taken up and segregated within vacuoles of macrophages by phagocytosis. A relevant role of macrophages in the pathogenesis of PML is emphasized.

Brain↗
PubMed1991

Comparative absorption of calcium from carbonate tablets, lactogluconate/carbonate effervescent tablet, and chloride solution.

Intestinal absorption of calcium from three different labelled calcium preparations (all containing 500 mg elemental calcium) was determined using the whole body retention and urinary excretion of 47Ca in 14 normal subjects. Chewable calcium carbonate tablets showed a significantly (p less than 0.05) better mean minimum absorption of calcium (25.6% in exp. I, 22.8% in exp. II) than calcium given in the form of a lactogluconate/carbonate effervescent tablet, (17%), but similar to calcium in a chloride solution (24.7%). The minimum calcium absorption varied from 85 to 128 mg. All the preparations were taken with standardized low calcium test meals.

Adult↗
PubMed1989

Cigarette smoke impairment of human lymphocyte function by inhibition of transglutaminase.

The in-vitro and in-vivo effects of cigarette smoke were studied in human peripheral blood lymphocytes by applying a method for the capping of beta 2-microglobulin- or phytohaemagglutinin (PHA)-stimulated lymphocyte transformation (measured as (3H)thymidine incorporation) involving the transglutaminase pseudosubstrate monodansylthiacadaverine (MDTC), whose presence resulted in significantly reduced capping and (3H)thymidine incorporation in a concentration-dependent manner. The addition of dimethyl sulphoxide-soluble particles from cigarette smoke to lymphocytes in vitro significantly reduced the capping ability and the PHA-induced (3H)thymidine incorporation. Whereas no significant change in MDTC-dependent capping inhibition was seen in lymphocytes from smokers after 10 d abstinence from smoking. there was a marked decrease in (3H)thymidine incorporation in lymphocytes from smokers after smoking three cigarettes following 10 h abstinence. The tentative conclusion is that exposure to cigarette smoke, or smoke extract, impairs MDTC-dependent capping inhibition and PHA-stimulated lymphocyte transformation by transglutaminase inhibition.

Adult↗
PubMed1988

Human herpesvirus-6 (HHV-6, HBLV) in sarcoidosis and lymphoproliferative disorders.

Serologic studies were done to estimate the antibody prevalence against human herpesvirus 6 (HHV-6) in patients with malignant lymphomas, Sjögren's syndrome and sarcoidosis. Serologic studies showed IgG antibody titers against HHV-6 in up to 41% of patients with sarcoidosis, 50-70% with malignant lymphomas and in 36% with Sjögren's syndrome. In situ hybridization on lymph node biopsies was positive for HHV-6 genome in 1 out of 5 sarcoidosis lymph nodes.

Antibodies, Viral↗
PubMed1987

Validation of a colorimetric method for determination of atmospheric formaldehyde.

Aqueous formaldehyde was stabilized in pH 7 phosphate buffer with excess sodium bisulfite of fixed and known concentration. The 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) procedure described previously was used to determine excess bisulfite colorimetrically. The slope of the calibration line (absorbance at 412 nm vs. formaldehyde concentration) is -0.350 A.U./ug CH2O/mL (correlation coefficient: 0.9995). The precision of the method at the 95% confidence level is indicated by the mean percentage relative error (1.81 +/- 1.67) and mean percentage standard error (0.42 +/- 0.39). Gaseous formaldehyde of known concentrations (ppm) in air was absorbed from air samples in pH 7 buffer and determined by the DTNB method. For the determination of formaldehyde in air, the precision and accuracy were demonstrated at the 95% confidence level by the mean percentage relative error (5.04 +/- 3.2), the mean percentage standard error (1.72 +/- 1.0), the mean percentage recovery (99.9 +/- 2.7), and the mean percentage absolute error (1.86 +/- 1.6). The graphic comparison of air concentration found vs. air concentration calculated shows a slope of 0.993 ppmfound/ppmcalcd (correlation coefficient: 0.9993).

Air Pollutants↗
PubMed1987

Radioactive iodine and cesium in travellers to different parts of Europe after the Chernobyl accident.

Thyroid uptake of 131I was measured in 130 volunteers following the nuclear power plant accident at Chernobyl in April 1986. Ninety of these volunteers had been travelling in different parts of eastern Europe at the time of or immediately after the accident while 40 persons were permanently in Sweden. Also, 28 additional healthy volunteers, living in Sweden, were chosen for a long-term follow-up of the time-course of 134Cs and 137Cs whole body uptake. The highest levels of 131I were found in persons having visited Poland (mean value 3.27 kBq +/- 3.68 SD, extrapolated to April 27) while persons that had stayed in other parts of eastern or northern Europe showed significantly lower levels (p less than 0.01). The whole body burdens of cesium radionuclides were barely detectable immediately after the accident but increased gradually throughout the observed period. After five months nine farmers from a high fallout area in central Sweden had reached mean values of 4.20 kBq (+/- 3.34 SD) of 134Cs and 137Cs while six nonfarmers from the Stockholm area showed significantly lower levels, 0.64 kBq (+/- 0.24 SD, p less than 0.05). The radiation doses from the observed amounts of iodine and cesium isotopes reported in this study reflect only a marginal addition to the already existing dose from the natural environmental background radiation.

Accidents↗
PubMed1986

Effects of insulin on the total number of [3H]ouabain binding sites in normal human lymphocytes and after stimulation in vitro with concanavalin A.

The effects of insulin in vitro on the total number of [3H]ouabain binding sites were studied in normal and concanavalin A-stimulated human T-lymphocytes after incubation for 18 and 42 h with 0, 10(2) and 10(5) mIU/l of insulin. While no effect on [3H]ouabain binding could be demonstrated in non-stimulated cells, a significant decrease could be produced in concanavalin A-stimulated cells. Mean +/- SD for the total number of [3H]ouabain binding sites per cell after 18 h incubation time with concanavalin A in the absence of insulin was 46,099 +/- 6,620 as compared with 44,783 +/- 8,347 in the presence of 10(2) mIU/l of insulin (non-significant) and 42,406 +/- 7,066 in the presence of 10(5) mIU/l (p = 0.031). The corresponding 42-h values were 47,075 +/- 9,412, 43,761 +/- 9,273 (p = 0.033) and 43,824 +/- 9,312 (p = 0.005).

Binding Sites↗
PubMed1981

An EBV-associated, Swedish case of Burkitt-type malignant lymphoma.

Morphological, serological, DNA-homology and immunofluorescence studies of a rapidly fatal malignant lymphoma in a 25-year-old Sweden male revealed most of the characteristics of an EBV-associated Burkitt lymphoma. The various findings are discussed in relation to previously reported observations on endemic (African) and non-endemic Burkitt lymphomas.

Adult↗
PubMed1979

Vascular anti-permeability effects of beta-receptor agonists and theophylline in the lung.

In conscious guinea-pigs the effect of theophylline, terbutaline and isoprenaline on histamine-induced increase in lung weight was examined. Animals exposed to a saline aerosol had a lung weight to body weight ratio of about 0.8%. Exposure to a histamine aerosol raised this value to about 1.1 (P less than 0.001). Theophylline 55 mg/kg and 110 mg/kg was given orally, terbutaline 0.1 mg/kg and isoprenaline 0.01 mg/kg and 0.03 mg/kg subcutaneously before exposure to histamine. The three drugs prevented the lung weight effect produced by histamine aerosol (P less than 0.01, P less than 0.001, P less than 0.001, P less than 0.1, P less than 0.001 respectively). Changes in lung blood content did not contribute to the weight-reducing effects. The potency ratio found between terbutaline and isoprenaline suggests that beta-2-receptors might be involved in the anti-permeability effect. Propranolol-treated animals did not survive in the histamine-aerosol unless they received theophylline; neither bronchodilator nor antipermeability effects of theophylline were antagonized by propranolol. It is concluded that in guinea-pigs theophylline and beta-agonists, in bronchodilating doses have the additional effect of preventing permeability oedema in the lung.

Administration, Oral↗
PubMed1978

Terbutaline preventing permeability effects of histamine in the lung.

In unanaesthetized guinea-pigs the effect of terbutaline on histamine-induced increase in lung weight was studied. Terbutaline 0.1 mg/kg and 0.3 mg/kg was given subcutaneously 5 min. before exposure during 60 min. to a histamine aerosol. Terbutaline markedly prevented the histamine-induced increase in lung weight. This effect is discussed in relation to the mechanism of action of mediator-induced increase in vascular permeability.

Animals↗
PubMed1976

Contractile effects of histamine in large and small respiratory airways.

The described technique allows recording of circular smooth muscle activity in isolated airways approx. 1 mm in diameter (bronchioles). It also allows recording of graded contractile and relaxant responses to drugs. Bronchiolar preparations and spirally cut airways (diameters 3-6 mm) were obtained from cat, dog, guinea-pig and man. Histamine is shown to contract cat bronchioles, large airways in cat being unaffected. The contraction is blocked by brompheniramine, but not by atropine. Other contractile agents, cholinoceptor-stimulants, prostaglandin F2alpha'5-hydroxy-tryptamine, and potassium contract the isolated cat airways irrespective of their size. In preparations from dog, guinea-pig and man,histamine was shown to contract both small and large respiratory airways. The effect was blocked by brompheniramine, which did not change the effect of acetylcholine or pilocarpine. Both large and small airways contracted to cholinoceptor stimulation Within species, small and large airways were similarly sensitive to the contractile agents, except for histamine in cat airways. The present findings show a size-and species dependent effect of histamine in respiratory airways. The effect of histamine in isolated cat airways might partly explain the pulmonary effect of histamine in vivo. The importance of including both small and large airways in studies of contractile and relaxant effects is emphasized.

Animals↗