Epinephrine and dopamine beta-hydroxylase secretion from bovine adrenal.

1978 ◽  
Vol 234 (6) ◽  
pp. E600
Author(s):  
T P Jacobs ◽  
D P Henry ◽  
D G Johnson ◽  
R H Williams
Keyword(s):  
Activity Analysis ◽  
Single Stimulus ◽  
Repetitive Stimulation ◽  
Initial Value ◽  
Gradual Decline ◽  
Dopamine Beta Hydroxylase

The perfusate of the isolated, acetylcholine-stimulated bovine adrenal was studied for epinephrine (E) concentration and dopamine beta-hydroxylase (DBH) activity. Analysis of single stimuli showed that DBH disappeared from the perfusate with a t1/2 of 19.1-29.0 min. whereas E disappeared with a t1/2 of 0.78-1.0 min. Stimulation every 5 min over 105 min caused a gradual decline in E concentration to 36% of its initial value, whereas DBH activity reached a plateau after the second stimulus and thereafter remained unchanged. The decline in E was not influenced by addition of catecholamine precursors and biosynthetic cofactors to the medium and was not accompanied by a shift in the ratios of E and norepinephrine (NE) in the perfusate. Inhibitors of DBH activity were not detected in the perfusate and nonexocytotic leakage of DBH into the perfusate did not occur. These results document the temporal dissociation of the appearance and disappearance of DBH and E after a single stimulus and the progressive dissociation of DBH and E secretion under conditions of prolonged perfusion with rapid and repetitive stimulation. Possible explanations of these observations are offered.

Bestimmung des zerebralen Blutflusses mittels des 81 Rb/81 mKr-Generatorsystems

1990 ◽  
Vol 29 (01) ◽  
pp. 7-12 ◽  
Author(s):  
J. Bialy ◽  
F.-J. Hans ◽  
E. Oberhausen ◽  
W.J. Peters ◽  
M. Schmitt ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Blood Circulation ◽  
Semiconductor Device ◽  
Animal Experiments ◽  
Initial Value ◽  
Brain Arteries ◽  
Sufficient Concentration ◽  
Static Quantity

A method is being developed which not only measures cerebral blood flow as a static quantity but also its changes with time. For that purpose a semiconductor device ascertains the proportion of intracerebral81 Rb and 81mKr activities. By opening the haemato-encephalic barrier in animal experiments a sufficient concentration of intracerebral81 Rb could be attained and the modified blood circulation after step-wise ligature of all brain arteries brought into relation to the corresponding Rb/Kr quotient. Over the range from undisturbed to completely interrupted cerebral blood flow this quotient varied up to 25% of its initial value.

In-vitro- und In-vivo-Wirkung von Schilddrüsenhormon auf das Wachstum von Neuroblastomzellen

1990 ◽  
Vol 29 (03) ◽  
pp. 120-124
Author(s):  
R. P. Baum ◽  
E. Rohrbach ◽  
G. Hör ◽  
B. Kornhuber ◽  
E. Busse
Keyword(s):  
Cell Differentiation ◽  
Neuroblastoma Cells ◽  
Control Group ◽  
Initial Value ◽  
Initial Rise ◽  
Biphasic Effect ◽  
Contrast Microscopy ◽  
Morphological Sign

The effect of triiodothyronine (T3) on the differentiation of cultured neuroblastoma (NB) cells was studied after 9 days of treatment with a dose of 10-4 M/106 cells per day. Using phase contrast microscopy, 30-50% of NB cells showed formation of neurites as a morphological sign of cellular differentiation. The initial rise of the mitosis rate was followed by a plateau. Changes in cyclic nucleotide content, in the triphosphates and in the activity of the enzyme ornithine decarboxylase (ODC) were assessed in 2 human and 2 murine cell lines to serve as biochemical parameters of the cell differentiation induced by T3. Whereas the cAMP level increased significantly (3 to 7 fold compared with its initial value), the cGMP value dropped to 30 to 50% of that of the control group. ATP and GTP increased about 200%, the ODC showed a decrease of about 50%. The present studies show a biphasic effect of T3 on neuroblastoma cells: the initial rise of mitotic activity is followed by increased cell differentiation starting from day 4 of the treatment.

Loss of Thrombin-Induced Ca2+ Mobilization in a Subpopulation of Platelets during Storage

1991 ◽  
Vol 66 (03) ◽  
pp. 350-354 ◽  
Author(s):  
Rob Fijnheer ◽  
Christa H E Homburg ◽  
Berend Hooibrink ◽  
Martine N Boomgaard ◽  
Dirk de Korte ◽  
...  
Keyword(s):  
Human Platelets ◽  
Flow Cytometer ◽  
Maximal Concentration ◽  
Gradual Decline ◽  
Platelet Storage ◽  
Functional Defect ◽  
Total Fluorescence ◽  
Induced Changes

SummaryThrombin-induced changes in cytosolic free Ca2+ ([Ca2+]i) were studied in human platelets that had been stored for up to 6 days. Changes in [Ca2+]i were measured with Indo-1-loaded platelets and quantitated with two different methods: (i) measurement of the changes in total fluorescence; (ii) measurement of the [Ca2+]i changes in individual platelets in a flow cytometer, allowing the detection of non-responding platelets. The maximal concentration of [Ca2+]i after stimulation with 0.5 U of thrombin/ml decreased from 544 ± 58 nM (mean ± SEM, n = 6) on day 0, to 276 ± 9 nM on day 3 and to 203 ± 23 nM on day 6. The percentage of platelets responding to 0.5 U of thrombin/ml declined from 90 ± 2% on day 0 to 72 ± 4% on day 3, and to 47 ± 8% on day 6. Nevertheless, also the responding platelets showed a decreased rise in [Ca2+]i.The study shows that during platelet storage a decrease in the rise in [Ca2+]i upon thrombin stimulation occurs. This decrease is partly due to the formation of a subpopulation of platelets that is completely unresponsive and partly due to a decreased responsiveness in the remainder of the platelets; it is not due to a gradual decline in [Ca2+]i rise in all platelets. This phenomenon provides new insight in the functional defect of stored platelets.

A Higher than Expected Incidence of Factor VIII Inhibitors in Multitransfused Haemophilia A Patients Treated with an Intermediate Purity Pasteurized Factor VIII Concentrate

1993 ◽  
Vol 69 (02) ◽  
pp. 115-118 ◽  
Author(s):  
Kathelijne Peerlinck ◽  
Jef Arnout ◽  
Jean Guy Gilles ◽  
Jean-Marie Saint-Remy ◽  
Jos Vermylen
Keyword(s):  
Factor Viii ◽  
Randomized Trials ◽  
Specific Factor ◽  
Factor Viii Inhibitor ◽  
Haemophilia A ◽  
Viral Inactivation ◽  
Gradual Decline ◽  
Inhibitor Level ◽  
Factor Viii Concentrates ◽  
Viii Inhibitor

SummaryIn May 1990, 218 patients with haemophilia A regularly attending the Leuven Haemophilia Center were randomly assigned to a group receiving either of two newly introduced factor VIII concentrates: factor VIII-P, an intermediate purity pasteurized concentrate, or factor VIII-SD, a high purity concentrate treated with solvent-detergent for viral inactivation.Patients were followed from May 1990 until October 1991. Between August 1991 and October 1991 a clinically important factor VIII inhibitor was detected in five out of the 109 patients receiving factor VIII-P while none of the 109 patients receiving factor VIII-SD developed such antibodies. All patients acquiring an inhibitor had previously been clinically tolerant to transfused factor VIII with 200 to more than 1,000 days of exposure to factor VIII prior to May 1990. Patients with inhibitors were transfused daily with 30 U factor VIII-SD per kg body weight, which was associated with a gradual decline of the inhibitor level. In all patients the antibodies were relatively slow-acting and predominantly directed towards the light chain of factor VIII.This study demonstrates a higher than expected incidence of factor VIII inhibitors associated with the use of a specific factor VIII concentrate in multitransfused haemophilia A patients. It indicates the usefulness of evaluating newly introduced concentrates in prospective, randomized trials.

UKRAINIAN ENTERPRISES INNOVATIVE ACTIVITY ANALYSIS

2018 ◽  
Vol 44 (2) ◽  
pp. 122-128
Author(s):  
A. V. Skubilina ◽  
◽  
О. O. Makeeva ◽  
Keyword(s):  
Activity Analysis ◽  
Innovative Activity
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