Hemostasis Activating Factor and von Willebrand’s Syndrome

1979 ◽  
Author(s):  
C.M. Kirchmaier ◽  
A. Sayegh ◽  
N. Bender ◽  
St. Lenhard ◽  
M. Wintrich ◽  
...  
Keyword(s):  
Glass Bead ◽  
Subcutaneous Tissue ◽  
Primary Hemostasis ◽  
Tissue Extracts ◽  
Different Types ◽  
Group A ◽  
Rapid Stimulation ◽  
Normal Controls ◽  
Citrate Blood ◽  
Stimulation Of

Small amounts of subcutaneous tissue extracts containing a “hemostasis activating factor”(HaF) induce pseudopode formation and sphering in freshly drawn citrate blood and they markedly enhance platelet retention in glass bead columns. If HaF (50 μl/ml) was added to freshly drawn citrate blood together with a fresh cryoprecipitate (50μ1/ml) from normal PPP, retention was further increased. Cryoprecipitate alone (50μ1/ml) did not induce morphologic platelet changes or enhance platelet retention,I H 15 patients with v.Willebrand syndrome (VWS) spontaneous morphologic platelet changes after blood sampling did not differ from normal controls. But two different types of VWS patients could be distinguished in the retention test: In the first group low retention was increased to norma 1 after the addition of HaF. In a second group a very small or missing increase of platelet retention was found with HaF alone; but retention was “normalised” by adding small amounts of cryoprecipitate together with HaF.VWF may be essential for the rapid stimulation of platelets by HaF in primary hemostasis.

On the Effects of a Hemostasis Activating Factor (HaF) from Subcutaneous Tissue on Platelet Retention

1979 ◽  
Author(s):  
A. Sayegh ◽  
C.M. Kirchmaier ◽  
St. Lenhard ◽  
M. Wintrich ◽  
N. Bender ◽  
...  
Keyword(s):  
Glass Bead ◽  
Subcutaneous Tissue ◽  
Blood Sampling ◽  
Retention Rates ◽  
Healthy Individuals ◽  
Trigger Mechanism ◽  
Enhancing Effect ◽  
Primary Hemostasis ◽  
Thromboplastic Activity ◽  
Citrate Blood

Extracts of human subcutaneous tissue with a very low thromboplastic activity strongly stimulate platelets (sphering and pseudopode formation) within seconds if added to blood directly at blood sampling (30 μ/ml citrate blood). To study the effect of this hemostasis activating factor (HaF) on platelet retention a special glass bead column with basically low retention (0-15 % in healthy individuals) was prepared. If HaF 50μl/ml) was added to freshly drawn citrate blood retention was increased from a mean of 12 % to a mean of 57 %. Even higher retention rates were obtained by adding a cryoprecipitate from normal PPP (50μl/ml) together with HaF. 100μl/ml of cryoprecipitate markedly enhanced platelet retention. FeibaR (Immuno) alone did not increase platelet retention. Together with HaF FeibaR (50μl/ml citrate blood) induced a 85% retention. The enhancing effect of HaF on platelet retention is probably caused by rapid platelet stimulation and may be an essential trigger mechanism for primary hemostasis.

Tissue Extract Induced Platelet Stimulation, Primary Hemostasis And Thrombosis

1981 ◽  
Author(s):  
K Breddin ◽  
N Bender ◽  
M C Kirchmaier
Keyword(s):  
Thrombus Formation ◽  
Subcutaneous Tissue ◽  
Induce Platelet Aggregation ◽  
Primary Hemostasis ◽  
Tissue Extracts ◽  
Atheromatous Plaques ◽  
Interference Contrast Microscopy ◽  
Von Willebrand

Subcutaneous tissue, blood vessels, muscle and different organs of different species (Human, pig, dog and rat), contain an activity which within seconds transformes disk shaped platelets into sphered forms with pseudopodes (stimulated platelets) in freshly drawn citrated blood or whole blood.Morphologic platelet changes were investigated using interference contrast microscopy. Retention was measured with a modified glass bead filter.Platelet stimulation was accompanied in vitro by enhanced adhesion and enhanced aggregability. The tissue extracts did not induce platelet aggregation. The active fractions were free of thromboplastic activity. In vivo reversible platelet stimulation could be demonstrated in rat mesenteric vessels. Even in the presence of the platelet stimulating tissue extracts plgtelets retained their disklike shape if incubated at 37°C.It is likely that local release of this Hemostasis Activating Factor (HAF) from damaged cells intensely and rapidly enhances primary hemostasis in the presence of von Willebrand factor. Atheromatous material is rich in platelet stimulating activity. The role of local platelet stimulation at defective endothelial cells, vessel wall ruptures and atheromatous plaques as a trigger for thrombus formation has to be established.

scholarly journals Defective utilization of haem in selenium-deficient rat liver

1983 ◽  
Vol 214 (1) ◽  
pp. 53-58 ◽  
Author(s):  
M A Correia ◽  
R F Burk
Keyword(s):  
Rat Liver ◽  
Selenium Deficiency ◽  
Oxygenase Activity ◽  
Haem Oxygenase ◽  
Rapid Stimulation ◽  
Normal Controls ◽  
Stimulation Of

We have previously suggested that an inherent defect in hepatic haem utilization was responsible for the rapid stimulation of hepatic microsomal haem oxygenase activity observed in selenium-deficient rats given phenobarbital, a well known inducer of haem formation. To test this hypothesis, hepatic haem content was deliberately raised in selenium-deficient rats by administration of either tryptophan or allylisopropylacetamide, or by injecting haem itself. We now report that selenium-deficient rats are apparently relatively less efficient in utilizing hepatic haem than normal controls. The findings detailed in the present paper thus indicate that stimulation of hepatic microsomal haem oxygenase activity is indeed a manifestation of abnormal haem utilization in selenium deficiency. This suggests a novel role for selenium in hepatic haem metabolism.

Express Saccades and Smooth Pursuit Eye Movement Function in Schizophrenic, Affective Disorder, and Normal Subjects

1993 ◽  
Vol 5 (3) ◽  
pp. 303-316 ◽  
Author(s):  
Anne B. Sereno ◽  
Philip S. Holzman
Keyword(s):  
Response Time ◽  
Eye Movement ◽  
Smooth Pursuit ◽  
Normal Subjects ◽  
Control Group ◽  
Saccadic Response ◽  
Group A ◽  
Schizophrenic Group ◽  
Movement Function ◽  
Normal Controls

Saccadic and smooth pursuit eye movements were recorded in three groups of subjects: a schizophrenic group, a non-schizophrenic psychotic patient comparison group, and a normal control group. Schizophrenic subjects demonstrated a greater decrease in saccadic response time than did normal controls in a gap task (when the fixation point was turned off 150 msec before the target appeared). The psychiatric comparison subjects did not differ from normal controls. Further, only schizophrenic subjects demonstrated a relation between smooth pursuit and saccadic eye movement performance, such that subjects with impaired smooth pursuit showed a larger decrease in saccadic response time in the gap task. The relation between performance on the gap task and quality of smooth pursuit and its relevance for a prefrontal deficit hypothesis of schizophrenia are discussed.

scholarly journals D8/17 and CD19 Expression on Lymphocytes of Patients with Acute Rheumatic Fever and Tourette's Disorder

2004 ◽  
Vol 11 (2) ◽  
pp. 330-336 ◽  
Author(s):  
Julie L. Weisz ◽  
William M. McMahon ◽  
Jill C. Moore ◽  
Nancy H. Augustine ◽  
John F. Bohnsack ◽  
...  
Keyword(s):  
B Cells ◽  
Rheumatic Fever ◽  
Acute Rheumatic Fever ◽  
Neuropsychiatric Disorders ◽  
Streptococcal Pharyngitis ◽  
Tourette’S Disorder ◽  
Compulsive Disorder ◽  
Tourette's Disorder ◽  
Group A ◽  
Normal Controls

ABSTRACT D8/17, an alloantigen found on B lymphocytes, has been reported to be elevated in patients susceptible to rheumatic fever and may be associated with autoimmune types of neuropsychiatric disorders. The pediatric-autoimmune-neuropsychiatric-disorders-associated-with-streptococci model is a putative model of pathogenesis for a group of children whose symptoms of obsessive-compulsive disorder and Tourette's disorder (TD) are abrupt and may be triggered by an infection with group A streptococci. As a test of this model, we have examined D8/17 levels on the B cells of patients with TD and acute rheumatic fever (ARF) along with those on the B cells of normal controls by flow cytometry. We have utilized several different preparations of D8/17 antibody along with a variety of secondary antibodies but have been unable to show an association with an elevated percentage of D8/17-positive, CD19-positive B cells in either ARF or TD. We did find, however, that the percentages of CD19-positive B cells in ARF and TD patients were significantly elevated compared to those in normal controls. Group A streptococcal pharyngitis patients also had an elevated percentage of CD19 B cells, however. These studies failed to confirm the utility of determining the percentage of B cells expressing the D8/17 alloantigen in ARF patients or our sample of TD patients. In contrast, the percentage of CD19-positive B cells was significantly elevated in ARF and TD patients, as well as group A streptococcal pharyngitis patients, suggesting a role for inflammation and/or autoimmunity in the pathogenesis of these disorders.

Properties of Unitary IPSCs in Hippocampal Pyramidal Cells Originating From Different Types of Interneurons in Young Rats

1997 ◽  
Vol 77 (4) ◽  
pp. 1939-1949 ◽  
Author(s):  
Mohamed Ouardouz ◽  
Jean-Claude Lacaille
Keyword(s):  
Reversal Potential ◽  
Pyramidal Cells ◽  
Mean Amplitude ◽  
Paired Pulse ◽  
Young Rats ◽  
Different Types ◽  
The Mean ◽  
Paired Pulse Depression ◽  
Types Of Interneurons ◽  
Stimulation Of

Ouardouz, Mohamed and Jean-Claude Lacaille. Properties of unitary IPSCs in hippocampal pyramidal cells originating from different types of interneurons in young rats. J. Neurophysiol. 77: 1939–1949, 1997. Whole cell recordings were used in hippocampal slices of young rats to examine unitary inhibitory postsynaptic currents (uIPSCs) evoked in CA1 pyramidal cells at room temperature. Loose cell-attached stimulation was applied to activate single interneurons of different subtypes located in stratum oriens (OR), near stratum pyramidale (PYR), and at the border of stratum radiatum and lacunosum-moleculare (LM). uIPSCs evoked by stimulation of PYR and OR interneurons had similar onset latency, rise time, peak amplitude, and decay. In contrast, uIPSCs elicited by activation of LM interneurons were significantly smaller in amplitude and had a slower time course. The mean reversal potential of uIPSCs was −53.1 ± 2.1 (SE) mV during recordings with intracellular solution containing potassium gluconate. With the use of recording solution containing the potassium channel blocker cesium, the reversal potential of uIPSCs was not significantly different (−58.5 ± 2.6 mV), suggesting that these synaptic currents were not mediated by potassium conductances. Bath application of the γ-aminobutyric acid-A (GABAA) receptor antagonist bicuculline (25 μM) reversibly blocked uIPSCs evoked by stimulation of all interneuron subtypes. In bicuculline, the mean peak amplitude of uIPSCs recorded with potassium gluconate was reduced to 3.5 ± 4.4% of control ( n = 7). Similarly, with cesium methanesulfonate, the mean amplitude in bicuculline was 2.9 ± 3.1% of control ( n = 13). Application of the GABAB receptor antagonist CGP 55845A (5 μM) resulted in a significant and reversible increase in the mean amplitude of uIPSCs recorded with cesium-containing intracellular solution. Thus uIPSCs from all cell types appeared under tonic presynaptic inhibition by GABAB receptors. Paired stimulation of individual interneurons at 100- to 200-ms intervals did not result in paired pulse depression of uIPSCs. For individual responses, a significant negative correlation was observed between the amplitude of the first and second uIPSCs. A significant paired pulse facilitation (154.0 ± 8.0%) was observed when the first uIPSC was smaller than the mean of all first uIPSCs. A small, but not significant, paired pulse depression (90.8 ± 4.0%) was found when the first uIPSC was larger than the mean of all first uIPSCs. Our results indicate that these different subtypes of hippocampal interneurons generate Cl−-mediated GABAA uIPSCs. uIPSCs originating from different types of interneurons may have heterogeneous properties and may be subject to tonic presynaptic inhibition via heterosynaptic GABAB receptors. These results suggest a specialization of function for inhibitory interneurons and point to complex presynaptic modulation of interneuron function.

Stimulation of blood platelets by extracts of subcutaneous tissue

1979 ◽  
Vol 14 (2-3) ◽  
pp. 341-351 ◽  
Author(s):  
Norbert Bender ◽  
Carl Kirchmaier ◽  
Brigitte Bartsch ◽  
Doris Lindenborn ◽  
Klaus Breddin
Keyword(s):  
Subcutaneous Tissue ◽  
Blood Platelets ◽  
Stimulation Of

Convergence of management practices in India’s IT sector with ana priorivalidation

2018 ◽  
Vol 12 (4) ◽  
pp. 402-421
Author(s):  
Jayashree Mahesh ◽  
Anil K. Bhat
Keyword(s):  
Cluster Analysis ◽  
Operations Management ◽  
Management Practices ◽  
Qualitative Interviews ◽  
A Priori ◽  
Statistical Testing ◽  
Content Type ◽  
Empirical Survey ◽  
Different Types ◽  
Group A

PurposeThe purpose of this paper is to document similarities and differences between management practices of different types of organizations in India’s IT sector through an empirical survey. The authors expected these differences to be significant enough for us to be able to groupa priorithis set of companies meaningfully through cluster analysis on the basis of the similarity of their management practices alone.Design/methodology/approachUsing a mixed-methods approach, 73 senior-level executives of companies working in India’s IT sector were approached with a pretested questionnaire to find out differences on eighteen management practices in the areas of operations management, monitoring management, targets management and talent management. The different types of organizations surveyed were small and amp; medium global multinationals, large global multinationals, small and medium Indian multinationals, large Indian multinationals and small and medium local Indian companies. The differences and similarities found through statistical testing were further validateda priorithrough cluster analysis and qualitative interviews with senior-level executives.FindingsThe management practices of multinationals in India are moving toward Western management practices, indicating that management practices converge as the organizations grow in size. Though the practices of large Indian multinationals were not significantly different from those of global multinationals, the surprising finding was that large Indian multinationals scored better than global multinationals on a few practices. The practices of small and medium Indian companies differed significantly from those of other types of organizations and hence they formed a cluster.Practical implicationsThe finding that large Indian IT multinationals have an edge over global multinationals in certain people management practices is a confirmation of the role of human resource practices in their current success and their continuing competitive advantage.Originality/valueThis is perhaps the first study of its kind to document state of specific management practices across different types of organizations in India’s IT sector and then use measures on these practices to group a priori these organizations for validation.

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