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Biomedical subjects

H Emanuelsson

Publications and source records attributed to H Emanuelsson.

At least 145 records · Page 8Linked to original sources

Iohexol in coronary angiography. A comparison of ionic and non-ionic contrast media.

Iohexol (350 mg I/ml) has been compared with meglumine-Na-Ca metrizoate (370 mg I/ml) in selective coronary angiography in 37 adult patients. Iohexol was very well tolerated and resulted in only minor changes in blood pressure and ECG parameters. Changes in blood pressure and R-R interval were significantly more marked following injections of metrizoate than after injections of iohexol. Arrhythmias were not observed following injections of iohexol, while two patients had AV block II after injection of metrizoate. Both contrast media gave similar and adequate demonstration of the coronary vessels. The findings suggest that iohexol has distinct advantages over metrizoate in selective coronary angiography.

Adult↗

Effects of iohexol and metrizoate on myocardial blood flow and metabolism.

In 10 patients coronary sinus blood flow (CSBF) was measured during and after injection of iohexol and meglumine-Na-Ca metrizoate in the left coronary artery. Oxygen saturation, lactate concentration and hematocrit were determined in the aorta and coronary sinus before and after a second injection of the two contrast media. The increase in CSBF was significantly more marked and sustained after injection of metrizoate than after iohexol and myocardial arterio-venous oxygen difference was significantly lower. Myocardial oxygen consumption and lactate metabolism were not adversely affected by any of the contrast media. The fall in hematocrit in coronary sinus blood was significantly greater after metrizoate.

Contrast Media↗

A case of arrhythmogenic right ventricular dysplasia with ventricular fibrillation.

A case of repeated attacks of ventricular fibrillation is described. The patient suffered from an arrhythmogenic right ventricular dysplasia (ARVD) documented by right and left ventriculograms and myocardial biopsies obtained during surgical treatment of the arrhythmia. The histological changes were interpreted as being signs of fresh myocardial damage of unknown origin in addition to a replacement of the normal myocardium by adipose and fibrotic tissue. The repeated attacks of ventricular fibrillation in this patient contrast to the arrhythmia spectrum noted in the available literature on ARVD, mostly stable chronic ventricular tachycardias.

Adult↗

Role of the polyamines in germ cell differentiation and in early embryonic development.

The physiological function of the polyamines in germ cell differentiation and in early embryonic development was studied with the aid of the highly specific polyamine synthesis inhibitors DL-alpha-methylornithine (MO) and DL-alpha-difluoromethylornithine (DFMO). In the invertebrate Ophryotrocha labronica DFMO-induced polyamine deficiency severely affected nucleolar formation and activity in germ cell differentiation as revealed by RNA-labelling experiments and by ultrastructural analysis. Both in an invertebrate (Ophryotrocha labronica) and in a vertebrate (chick), inhibitor-induced polyamine deficiency caused a block of embryonic development at gastrulation. The major ultrastructural effect observed in the arrested embryos was an interference with nucleolar formation. Our data suggest that polyamine synthesis is essential for the ribosomal gene expression that is associated with oogenesis and embryogenesis.

Animals↗

Essential role of the polyamines in early chick embryo development.

The polyamines putrescine, spermidine and spermine were analyzed in chick embryos during the first 2 days of development. A rapid increase in the activity of ornithine decarboxylase (ODC), the initial and rate-limiting enzyme in polyamine synthesis, was observed immediately after onset of incubation. Peak activities were found at 15 and 23 h of incubation. The first peak coincides with gastrulation and the second peak with early neurulation in the embryo. All three polyamines varied in a similar manner as did ODC, with putrescine and spermidine at about the same level and spermine at a lower level. The ODC activity was blocked by alpha-difluoromethylornithine, an enzyme-activated irreversible inhibitor. The inhibitor was administered to embryos in ovo at 5 h of incubation, i.e. prior to the first major increase in ODC activity. This block prevented the accumulation of the polyamines and inhibited development as gastrulation, suggesting a decisive role for polyamines in this developmental event.

Animals↗

Polar granules and pole cells in the embryo of Calliphora erythrocephala: ultrastructure and [3H]leucine labelling.

The polar granules in Calliphora undergo a gradual fragmentation during early cleavage, but reaggregate after pole-cell formation. Autoradiographic analysis showed that the pole cells in Calliphora acquire a higher [3H]leucine label than the rest of the embryo during the blastoderm stage. Such an increased label was not seen in the pole plasm before pole-cell formation or in the pole cells during gastrulation. Electron microscopic autoradiography revealed that the polar granules are substantially labelled during the blastoderm stage. At the same time, characteristic nuclear blebs appear in the pole cells. The observations are consistent with the hypothesis that polar granules contain maternal messenger RNA, which is released and translated into proteins.

Animals↗

Possible involvement of putrescine in nucleolar formation in early embryos.

Continuous treatment of developing eggs of the polychete Ophryotrocha labronica with alpha-methylornithine, which inhibits synthesis of putrescine, led to arrest of development at gastrulation. The present ultrastructural analysis suggests that the arrest of development is due to failure to form nuclei, and thus reveals a possible role for putrescine in nucleolar formation. Further support for this contention was provided by means of electron-microscopical autoradiography. It was found that newly synthesized putrescine, derived from administered 3H-ornithine, labeled the nucleoli intensely at the time of their normal appearance during gastrulation, the time at which the rate of endogenous putrescine synthesis is maximal. These observations have led to the conclusion that putrescine synthesis may be directly involved in formation of nucleoli.

Animals↗

Inhibition of putrescine synthesis blocks development of the polychete Ophryotrocha labronica at gastrulation.

Development eggs of the polychete Ophryotrocha labronica were analyzed for polyamines during the first 6 days after fertilization. The spermine content dominated initially, but gradually decreased. It was surpassed by putrescine, which rapidly increased to a maximum on the 3rd day, i.e., at the inception of grastrulation. The spermidine content was low during the entire period. Treatment of eggs with the putrescine synthesis inhibitor alpha-methylornithine from the onset of development led to developmental arrest at gastrulation and to an abnormally low content of putrescine in the treated embryos. Methylglyoxal bis(guanylhydrazone), an inhibitor of spermine and spermidine synthesis, had no visible effect of development. Our observations strongly suggest that putrescine synthesis is indispensable in early embryonic development of Ophryotrocha.

Animals↗

Pronounced deficiency in T-cells and lymphocyte chromosomal aberrations in a patient with sarcoidosis, myelofibrosis and acute leukaemia following thorotrast angiography.

A patient exposed to thorotrast angiography developed sarcoidosis 21 years after the injection and myelofibrosis 13 years later. On the latter occasion an extreme deficiency in circulating lymphocytes forming rosettes with sheep erythrocytes (T-cells) was observed and a large fraction of the cells had chromosomal aberrations. Acute leukaemia developed 1 year later. The multiple clinical symptoms may be related to radiation-induced destruction of bone marrow tissue, mutations in haemopoietic cells and depression of cell-mediated immunity.

Autoradiography↗

Effect of cortisol on human fetal lung in organ culture: a biochemical, electron-microscopic and autoradiographic study.

Human fetal lung tissue obtained during the second trimester was cultured as organ culture with or without cortisol. The effect of cortisol on the phospholipid metabolism, as related to the appearance of osmiophilic lamellar bodies and the localisation of newly incorporated choline, was studied. In cortisol-treated explants, the concentration of saturated lecithins and the incorporation of (Me-3H)-choline into saturated lecithins increases significantly concomitantly with an increased number of osmiophilic lamellar bodies. The labelled choline is predominantly associated with these bodies. The obtained results indicate that cortisol accelerates the synthesis of pulmonary surfactant in the human fetal lung as early as in the second trimester.

Body Height↗