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Biomedical subjects

P Henriksson

Publications and source records attributed to P Henriksson.

At least 91 records · Page 5Linked to original sources

Orchidectomy versus oestrogen for prostatic cancer: cardiovascular effects.

One hundred consecutive patients aged up to 75 with newly diagnosed cancer of the prostate suitable for hormonal treatment were included in a controlled study of the cardiovascular effects of oestrogen versus orchidectomy. In all cases pre-existing cardiovascular morbidity was excluded. Of the 100 patients, 91 were strictly randomised to receive either oestrogen (n = 47) or orchidectomy (n = 44) and 9 (6 given oestrogen, 3 orchidectomy) either chose their own treatment (five cases) or had it selected for them by the urologist (four). Oestrogen was given in the lowest recommended dosage in Sweden--namely, as 160 mg polyestradiol phosphate intramuscularly every month for the first three months, then 80 mg monthly, plus ethinyloestradiol 1 mg by mouth daily for the first two weeks, then 150 micrograms daily. At entry to the study the two treatment groups showed no difference in demographic characteristics or conventional risk factors for cardiovascular disease. During the first year, however, 13 (25%) of the patients given oestrogen suffered major cardiovascular events as compared with none of the patients after orchidectomy. Patients in the oestrogen treatment group who did not have minor signs of atherosclerosis at entry to the study suffered a similar incidence of cardiovascular complications to those who did have these signs at entry. The substantially increased risk of cardiovascular complications in patients given oestrogen for prostatic cancer warrants careful consideration when choosing treatment for this disorder.

Aged↗

In vivo production of prostacyclin and thromboxane in patients with acute myocardial infarction.

The in vivo production of prostacyclin and thromboxane was monitored by measuring their major urinary metabolites 2,3-dinor-thromboxane B2 and 2,3-dinor-6-keto-prostaglandin F1 alpha in ten patients with acute myocardial infarction, five on standard treatment and five receiving prostacyclin infusion. During acute myocardial infarction excretion of 2,3-dinor-thromboxane B2 and 2,3-dinor-6-keto-prostaglandin F1 alpha, measured by a gas chromatography-mass spectrometry method with deuterated internal standards, was significantly increased. This indicates that thromboxane and prostacyclin synthesis are increased during the development of acute myocardial infarction. The excretion data for 2,3-dinor-thromboxane B2 showed that after administration of aspirin there was less pronounced and more variable inhibition than expected. Prostacyclin infusion did not markedly affect the excretion of the thromboxane metabolite.

6-Ketoprostaglandin F1 alpha↗

Biosynthesis of factor XIII B subunit by human hepatoma cell lines.

The plasma transglutaminase, factor XIIIa (FXIIIa), circulates as a zymogen containing two proteins, A and B, arranged in a noncovalent tetrameric complex, A2B2. Biosynthesis of plasma FXIII has not previously been demonstrated. In the present study, direct evidence has been obtained that two human hepatoma cell lines, Hep G2 and PLC/PRF/5, synthesize and secrete FXIII B protein. Secretion of the B subunit of FXIII by Hep G2 was demonstrated by immunoblotting. De novo synthesis by Hep G2 was confirmed in 35S-methionine-labeled cultures. Radiolabeled conditioned medium was concentrated, mixed (1:1) with purified B protein, and examined by crossed immunoelectrophoresis with antiserum to the B subunit. The single protein precipitin arc of purified B protein comigrated with the radiolabeled FXIII from Hep G2 visualized by autoradiography, indicating both electrophoretic and antigenic identity. The data presented here represent the first demonstrations of biosynthesis of FXIII B protein by any cell type and suggest that the liver is the site of synthesis of FXIII B protein. Further analysis of concentrated Hep G2 serum-free conditioned medium (SFCM) and cell lysate by immunoblotting following nondenaturing agarose gel electrophoresis demonstrated the FXIII A protein as well as the B protein and also revealed synthesis and secretion of the A and B proteins by PLC/PRF/5. Crossed immunoelectrophoresis studies of Hep G2 SFCM and cell lysate suggest that Hep G2 cells also synthesize and secrete the plasma FXIII zymogen. With a specific radioimmunoassay for B protein, FXIII was found in Hep G2 SFCM at approximately 4 ng/mL; with an amplified rocket immunoelectrophoresis technique the level was approximately 5 ng/mL.

Carcinoma, Hepatocellular↗

Formation of 15-HETE as a major hydroxyeicosatetraenoic acid in the atherosclerotic vessel wall.

Atherosclerosis was induced in New Zealand White rabbits through cholesterol feeding. Aortae were taken out from treated animals and incubated with arachidonic acid. Aortae from cholesterol-fed animals converted arachidonic acid into 15-hydroxy-5,8,11,13-eicosatetraenoic acid (15-HETE). This conversion was not seen in aortae from control animals. The immediate precursor of 15-HETE, 15-HPETE, is an inhibitor of prostacyclin synthetase and might hamper prostacyclin production.

Animals↗

In vivo production of thromboxane in acute human myocardial infarction: a preliminary study.

Using a specific quantitative method based on gas chromatography-mass spectrometry the urinary excretion of 2,3-dinor-TxB2 was measured in five patients with acute myocardial infarction shortly after the onset of symptoms. The urinary excretion of 2,3-dinor-TxB2 was markedly higher than seen in normals in three of the five patients. This increased excretion of 2,3-dinor-TxB2 during and after the development of myocardial necrosis indicates an involvement of thromboxane A2 in the pathogenesis of at least some cases of acute myocardial infarction.

Aged↗

Influence of orchidectomy or oestrogen treatment on serum levels of pregnancy associated alpha 2-glycoprotein and sex hormone binding globulin in patients with prostatic cancer.

Peripheral serum levels of testosterone, immunoreactive oestrogens (E2), FSH, LH, prolactin and growth hormone (hGH) and two steroid-sensitive proteins, 'pregnancy-associated alpha 2-glycoprotein' (alpha 2-PAG) and sex hormone binding globulin (SHBG), were measured in patients with prostatic cancer before treatment and after orchidectomy or during combined oral and intramuscular oestrogen treatment. Following orchidectomy, the serum levels of testosterone and E2 decreased whilst the levels of FSH and LH increased significantly. No changes were noted in the serum levels of alpha 2-PAG, SHBG or prolactin. Oestrogen treatment significantly decreased the serum levels of testosterone, FSH and LH whilst levels of alpha 2-PAG, SHBG and prolactin were increased significantly. Serum levels of hGH during oestrogen treatment were significantly higher than in patients subjected to orchidectomy. These data are at variance with the established dogma of the oestrogen/androgen balance as a physiological regulator or liver protein synthesis, and indicate that factors other than the endogenous steroids may be operative. hGH may play an important role in this respect.

Aged↗

Prostacyclin infusion in patients with acute myocardial infarction.

To investigate whether prostacyclin protects ischaemic myocardium in humans the effect of prostacyclin or placebo was studied in two groups of patients with acute myocardial infarction who presented within six and 16 hours of the onset of symptoms. Intravenous infusion of prostacyclin or placebo was started immediately after admission at a rate corresponding to 4-5 ng/kg/minute. The infusion was maintained for 72 hours. Clinical status, electrocardiograms, plasma enzyme activity, infarct extension during the infusion, and reinfarction after the infusion were studied. Prostacyclin was well tolerated by most patients: neither systemic blood pressure nor heart rate differed between the two groups. In the 11 patients who received treatment within six hours of the onset of symptoms prostacyclin significantly lowered the maximum plasma activities of creatine kinase MB and lactate dehydrogenase. In the 19 patients who received treatment 6-16 hours after the onset of symptoms prostacyclin had no such effect. None of the patients receiving prostacyclin had an extension of the infarction during the infusion, whereas four patients receiving placebo did; this difference was significant. These data are the first to provide evidence that prostacyclin might limit myocardial injury in patients with acute myocardial infarction.

Adolescent↗

Identification of intracellular factor XIII in human monocytes and macrophages.

Factor XIII is a blood protransglutaminase that is distributed in plasma and platelets. The extracellular and intracellular zymogenic forms differ in that the plasma zymogen contains A and B subunits, while the platelet zymogen has A subunits only. Both zymogens form the same enzyme. Erythrocytes, in contrast, contain a tissue transglutaminase that is distinct from Factor XIII. In this study other bone marrow-derived cells were examined for transglutaminase activity. Criteria that were used to differentiate Factor XIII proteins from erythrocyte transglutaminase included: (a) immunochemical and immunohistochemical identification with monospecific polyclonal and monoclonal antibodies to Factor XIII proteins, (b) requirement for thrombin cleavage to express activity, (c) pattern of fibrin cross-linking catalyzed by the enzyme, and (d) different electrophoretic mobilities in nondenaturing gel systems. By these criteria human peripheral blood monocytes, peritoneal macrophages, and monocytes maintained in culture contain an intracellular protransglutaminase that is the same as platelet Factor XIII. The monocyte-macrophage protein is thrombin-sensitive, and under appropriate conditions there is no enzyme expression without activation of the zymogen. Both the monocyte-macrophage zymogen and enzyme have the same electrophoretic mobilities as platelet Factor XIII zymogen and enzyme. Antibody to A protein reacts with the monocyte-macrophage protein. B protein is not associated with this intracellular zymogen. By immunoperoxidase staining monocyte-macrophage protein seems to be localized in the cytoplasm, similar to the known cytoplasmic distribution of platelet and megakaryocyte Factor XIII. These procedures were also used to study populations of human granulocytes and lymphocytes, and protransglutaminase activity was not observed in these cells.

Acyltransferases↗

A specific, fluorescent activity staining procedure applied to plasma and red blood cells in congenital factor XIII deficiency.

The activity staining procedure introduced by Stenberg & Stenflo (1979) has been applied to studies on human blood transamidases (transglutaminases; endo-gamma-glutamine:epsilon-lysine transferases; e.g. factor XIII). The technique combines agarose gel electrophoresis with activity staining based on the transamidase catalysed incorporation of monodansylthiacadaverine (N-(5-amino-3-thiapentyl)-5-dimethylamino-1-naphtalenesulfonamide) into casein. The method permits detection of plasma factor XIII activity down to 1% of the normal adult standard. The technique was used on plasma from two patients with tentative congenital plasma factor XIII deficiency (based on clot solubility). No activity was found in platelet poor as well as in platelet rich plasma which confirmed the diagnosis. In the erythrocytes studied in genetic determinations of the plasma and red blood cell transamidases. Using immunoelectrophoresis, the plasma factor XIII b subunit was found to be 43% and 44% of the concentration in normal standard plasma.

Adolescent↗

Characteristics of the factor VIII protein and Factor XIII in various factor VIII concentrates.

The in vitro properties of 5 factor VIII preparations (AHF-Kabi, Hemofil Hyland, AHF-Profilate Abbott, Kryobulin Immuno and Factorate High Purity Armour) and an ordinary cryoprecipitate were studied with reference to factor VIII clotting activity (VIII:C), factor VIII clotting antigen (VIII:CAg), factor VIII related antigen (VIIIR:Ag) (EI, IRMA, CIE), ristocetin cofactor activity (VIIIR:RCF), fibrinogen and factor XIII. All the preparations with the exception of Factorate had higher levels of VIII:CAg than VIII:C indicating inactivation of the biological activity of VIII:C during the procedure. AHF-Kabi (fraction I-0) and the cryoprecipitate, the only preparations capable of normalising the defect in patients with von Willebrand's disease, showed the same level of VIIIR:Ag determined by EI and by IRMA, while all the other preparations (i.e. cryoprecipitates purified further in different ways) had considerably lower levels of VIIIR:Ag determined by IRMA than by EI. Based on these in vitro techniques it seems to be possible to predict which preparations can be used successfully in patients with von Willebrand's disease, while no such conclusions can be made from VIIIR:RCF determinations. EI yielded similar concentrations of factor XIII a subunit in all the preparations tested. 3 functional assays showed high factor XIII activities in AHF-Kabi but low or no activities in the others. Thus, considerable differences were found on the in vitro properties of the proteins in 5 factor VIII concentrates and a cryoprecipitate. The action of proteases and the techniques used in the purification procedure are probably of crucial importance for the properties of the various factors.

Antigens↗