Tissue Uptake of Circulating Thrombopoietin Is Increased in Immune-Mediated Compared With Irradiated Thrombocytopenic Mice

Blood ◽  
1999 ◽  
Vol 93 (8) ◽  
pp. 2515-2524 ◽  
Author(s):  
Mei Chang ◽  
John X. Qian ◽  
Sun min Lee ◽  
John Joubran ◽  
George Fernandez ◽  
...  
Keyword(s):  
Degradation Products ◽  
Inverse Correlation ◽  
Electron Microscopic ◽  
Significant Inverse Correlation ◽  
Thrombocytopenic Purpura ◽  
Tissue Samples ◽  
Electron Microscopic Autoradiography ◽  
Splenic Macrophages ◽  
Immune Mediated ◽  
Total Capacity

Abstract We have previously demonstrated a significant inverse correlation between circulating thrombopoietin (TPO) levels and peripheral platelet (PLT) counts in patients with thrombocytopenia secondary to megakaryocytic hypoplasia but not in patients with immune thrombocytopenic purpura (ITP; Chang et al, Blood 88:3354, 1996). To test the hypothesis that the differences in the circulating TPO levels in these two types of thrombocytopenia are caused by differences in the total capacity of Mpl receptor-mediated TPO clearance, thrombocytopenia was induced in female CD-1 mice either by sublethal irradiation (irradiated) or rabbit antimouse PLT serum (RAMPS) for 1 day (1 d RAMPS) and 5 days (5 d RAMPS). A well-characterized murine model of autoimmune thrombocytopenic purpura, male (NZW × BXSB) F1 mice (W/B F1), was also included in this study. All thrombocytopenic mice and their controls received trace amounts of 125I-recombinant murine TPO (125I-rmTPO) intravenously and were killed 3 hours postinjection. Blood cell-associated radioactivity was significantly decreased in all 4 groups of thrombocytopenic mice. Significantly increased plasma and decreased whole spleen-associated radioactivity was observed in the irradiated group compared with controls (P < .05). While a lesser but still significant increase in plasma and decrease in whole spleen-associated radioactivity was observed in the 1 d RAMPS mice (P < .05), there were no significant differences between the 5 d RAMPS nor the W/B F1 male mice compared with controls, although whole spleen-associated radioactivity was higher in the W/B F1male. A significant inverse correlation of plasma and whole spleen-associated radioactivity was demonstrated in W/B F1male mice (r = −.91, n = 6, P < .05). There was also a decrease in bone (femur)/blood-associated radioactivity in the irradiated group compared with controls (P < .05), but a significant increase in 1 d and 5 d RAMPS mice (P < .01). Furthermore, the 125I-rmTPO uptake capacity within the spleen and marrow of immune thrombocytopenic mice appeared to be associated with a higher megakaryocytic mass when tissue samples were examined by light microscopy. Internalization of 125I-rmTPO by megakaryocytes and PLTs in the spleens and marrows of ITP mice was also demonstrated directly using electron microscopic autoradiography. Labeled PLTs were also found within splenic macrophages. Additionally, the mean PLT volumes of RAMPS mice were significantly higher than those of the control and irradiated mice (P < .05), as was the bound 125I-rmTPO (cpm) per million PLT (P < .05). Finally, significantly decreased 125I-rmTPO degradation products were only found in the plasma of the irradiated mice compared with control animals (P < .05). These data suggest that the lack of Mpl+ cells in the mice with thrombocytopenia secondary to megakaryocytic hypoplasia (irradiated) results in decreased uptake and degradation of TPO and higher circulating TPO levels. Furthermore, these data also suggest that, after a brief TPO surge in response to immune thrombocytopenia (1 d RAMPS), the lack of an inverse correlation of circulating TPO with PLT counts during steady-state immune thrombocytopenic mice (5 d RAMPS + W/B F1 male) is due, at least in part, to its uptake and degradation by the high PLT turnover and increased mass of megakaryocytes.

Tissue Uptake of Circulating Thrombopoietin Is Increased in Immune-Mediated Compared With Irradiated Thrombocytopenic Mice

Blood ◽  
1999 ◽  
Vol 93 (8) ◽  
pp. 2515-2524 ◽  
Author(s):  
Mei Chang ◽  
John X. Qian ◽  
Sun min Lee ◽  
John Joubran ◽  
George Fernandez ◽  
...  
Keyword(s):  
Degradation Products ◽  
Inverse Correlation ◽  
Electron Microscopic ◽  
Significant Inverse Correlation ◽  
Thrombocytopenic Purpura ◽  
Tissue Samples ◽  
Electron Microscopic Autoradiography ◽  
Splenic Macrophages ◽  
Immune Mediated ◽  
Total Capacity

We have previously demonstrated a significant inverse correlation between circulating thrombopoietin (TPO) levels and peripheral platelet (PLT) counts in patients with thrombocytopenia secondary to megakaryocytic hypoplasia but not in patients with immune thrombocytopenic purpura (ITP; Chang et al, Blood 88:3354, 1996). To test the hypothesis that the differences in the circulating TPO levels in these two types of thrombocytopenia are caused by differences in the total capacity of Mpl receptor-mediated TPO clearance, thrombocytopenia was induced in female CD-1 mice either by sublethal irradiation (irradiated) or rabbit antimouse PLT serum (RAMPS) for 1 day (1 d RAMPS) and 5 days (5 d RAMPS). A well-characterized murine model of autoimmune thrombocytopenic purpura, male (NZW × BXSB) F1 mice (W/B F1), was also included in this study. All thrombocytopenic mice and their controls received trace amounts of 125I-recombinant murine TPO (125I-rmTPO) intravenously and were killed 3 hours postinjection. Blood cell-associated radioactivity was significantly decreased in all 4 groups of thrombocytopenic mice. Significantly increased plasma and decreased whole spleen-associated radioactivity was observed in the irradiated group compared with controls (P < .05). While a lesser but still significant increase in plasma and decrease in whole spleen-associated radioactivity was observed in the 1 d RAMPS mice (P < .05), there were no significant differences between the 5 d RAMPS nor the W/B F1 male mice compared with controls, although whole spleen-associated radioactivity was higher in the W/B F1male. A significant inverse correlation of plasma and whole spleen-associated radioactivity was demonstrated in W/B F1male mice (r = −.91, n = 6, P < .05). There was also a decrease in bone (femur)/blood-associated radioactivity in the irradiated group compared with controls (P < .05), but a significant increase in 1 d and 5 d RAMPS mice (P < .01). Furthermore, the 125I-rmTPO uptake capacity within the spleen and marrow of immune thrombocytopenic mice appeared to be associated with a higher megakaryocytic mass when tissue samples were examined by light microscopy. Internalization of 125I-rmTPO by megakaryocytes and PLTs in the spleens and marrows of ITP mice was also demonstrated directly using electron microscopic autoradiography. Labeled PLTs were also found within splenic macrophages. Additionally, the mean PLT volumes of RAMPS mice were significantly higher than those of the control and irradiated mice (P < .05), as was the bound 125I-rmTPO (cpm) per million PLT (P < .05). Finally, significantly decreased 125I-rmTPO degradation products were only found in the plasma of the irradiated mice compared with control animals (P < .05). These data suggest that the lack of Mpl+ cells in the mice with thrombocytopenia secondary to megakaryocytic hypoplasia (irradiated) results in decreased uptake and degradation of TPO and higher circulating TPO levels. Furthermore, these data also suggest that, after a brief TPO surge in response to immune thrombocytopenia (1 d RAMPS), the lack of an inverse correlation of circulating TPO with PLT counts during steady-state immune thrombocytopenic mice (5 d RAMPS + W/B F1 male) is due, at least in part, to its uptake and degradation by the high PLT turnover and increased mass of megakaryocytes.

scholarly journals Splenic Macrophages in Thrombocytopenia

Blood ◽  
1969 ◽  
Vol 33 (2) ◽  
pp. 240-245 ◽  
Author(s):  
B. G. FIRKIN ◽  
R. WRIGHT ◽  
S. MILLER ◽  
E. STOKES
Keyword(s):  
Microscopic Examination ◽  
Electron Microscopic Examination ◽  
Splenic Tissue ◽  
Electron Microscopic ◽  
Thrombocytopenic Purpura ◽  
Hematologic Disorders ◽  
Ultrastructural Evidence ◽  
Splenic Macrophages ◽  
Intracellular Digestion ◽  
Morphologic Characteristics

Abstract Electron microscopic examination of splenic tissue obtained from patients with a variety of hematologic disorders has shown ultrastructural evidence for platelet breakdown within splenic histiocytes in seven out of eight patients with idiopathic thrombocytopenic purpura (I. T. P.). The morphologic characteristics of this intracellular digestion have been described.

Electron-microscopic autoradiography of tritiated testosterone in rat testis

1977 ◽  
Vol 26 (1) ◽  
pp. 339-346
Author(s):  
P.M. Frederick ◽  
H.J. van der Molen ◽  
D. Klepper ◽  
H. Galjaard
Keyword(s):  
Electron Microscope ◽  
Seminiferous Tubules ◽  
Cell Cytoplasm ◽  
Electron Microscopic ◽  
Electron Microscope Level ◽  
Tissue Samples ◽  
Electron Microscopic Autoradiography ◽  
Thin Sections ◽  
Freeze Dried ◽  
Lipid Inclusions

The feasibility of a technique for autoradiography of diffusible substances has been further tested by analysing the localization of steroids in rat testes with the light-and electron-microscope. Testes of rats were perfused with tritiated testosterone (3 min) followed by 15-min perfusion with buffer containing a 100-fold of unlabelled testosterone. Tissue samples were frozen, freeze dried, fixed in osmium vapour and embedded in Epon. To exclude extraction of steroids, contact with water and other solvents was prevented during cutting of thin sections on an ultracryotome and further treatments for autoradiography. Light- and electron-microscopic observations indicate that the highest concentration of labelled testosterone was present within the basal parts of the Sertoli cell cytoplasm and in lipid inclusions of Sertoli cells within the seminiferous tubules. This is the first account of autoradiography of steroids at the electron-microscope level.

Localization of Gallium-67 in Peritoneal Cells by Electron Microscopic Autoradiography

1973 ◽  
Vol 31 ◽  
pp. 404-405
Author(s):  
D. C. Swartzendruber ◽  
Norma L. Idoyaga-Vargas
Keyword(s):  
Clinical Trials ◽  
Soft Tissue ◽  
Tumor Tissue ◽  
Soft Tissue Tumors ◽  
Clinical Usefulness ◽  
Electron Microscopic ◽  
Normal Cells ◽  
Electron Microscopic Autoradiography ◽  
Peritoneal Cells ◽  
Gallium 67

The radionuclide gallium-67 (67Ga) localizes preferentially but not specifically in many human and experimental soft-tissue tumors. Because of this localization, 67Ga is used in clinical trials to detect humar. cancers by external scintiscanning methods. However, the fact that 67Ga does not localize specifically in tumors requires for its eventual clinical usefulness a fuller understanding of the mechanisms that control its deposition in both malignant and normal cells. We have previously reported that 67Ga localizes in lysosomal-like bodies, notably, although not exclusively, in macrophages of the spocytaneous AKR thymoma. Further studies on the uptake of 67Ga by macrophages are needed to determine whether there are factors related to malignancy that might alter the localization of 67Ga in these cells and thus provide clues to discovering the mechanism of 67Ga localization in tumor tissue.

An Electron Microscopic Study of the Acute Effects of Hypothalamic Releasing Factors on the Anterior Pituitary Gland

1968 ◽  
Vol 26 ◽  
pp. 232-233
Author(s):  
P.W. Coates ◽  
E.A. Ashby ◽  
L. Krulich ◽  
A. Dhariwal ◽  
S. McCann
Keyword(s):  
Anterior Pituitary ◽  
Microscopic Investigation ◽  
Uranyl Acetate ◽  
Electron Microscopic Investigation ◽  
Electron Microscopic ◽  
Tissue Samples ◽  
Thin Sections ◽  
Dense Membrane ◽  
Membrane Bound ◽  
Releasing Factors

The morphologic effects on somatotrophs of crude sheep hypothalamic extract prepared from stalk-median eminence were studied by electron microscopy in conjunction with concurrently run bioassays performed on the same tissue samples taken from young adult male Sherman rats.Groups were divided into uninjected controls and injected experimentals sacrificed at 5', 15', and 30' after injection. Half of each anterior pituitary was prepared for electron microscopic investigation, the other half for bioassay. Fixation using collidine buffered osmium tetroxide was followed by dehydration and embedment in Maraglas. Uranyl acetate and lead citrate were used as stains. Thin sections were examined in a Philips EM 200.Somatotrophs from uninjected controls appeared as described in the literature (Fig. 1). In addition to other components, these cells contained moderate numbers of spherical, electron-dense, membrane-bound granules approximately 350 millicrons in diameter.

Techniques For The Preparation of Tissue Samples Containing Injectable Polymer Microcapsules

1985 ◽  
Vol 43 ◽  
pp. 710-711
Author(s):  
G.E. Visscher ◽  
R. L. Robison ◽  
G. J. Argentieri
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Gastrocnemius Muscle ◽  
Degradation Process ◽  
Delivery Systems ◽  
Tissue Reaction ◽  
Electron Microscopic ◽  
Tissue Samples ◽  
Injectable Polymer ◽  
Microscopic Techniques

The use of various bioerodable polymers as drug delivery systems has gained considerable interest in recent years. Among some of the shapes used as delivery systems are films, rods and microcapsules. The work presented here will deal with the techniques we have utilized for the analysis of the tissue reaction to and actual biodegradation of injectable microcapsules. This work has utilized light microscopic (LM), transmission (TEM) and scanning (SEM) electron microscopic techniques. The design of our studies has utilized methodology that would; 1. best characterize the actual degradation process without artifacts introduced by fixation procedures and 2. allow for reproducible results.In our studies, the gastrocnemius muscle of the rat was chosen as the injection site. Prior to the injection of microcapsules the skin above the sites was shaved and tattooed for later recognition and recovery. 1.0 cc syringes were loaded with the desired quantity of microcapsules and the vehicle (0.5% hydroxypropylmethycellulose) drawn up. The syringes were agitated to suspend the microcapsules in the injection vehicle.

High-voltage electron microscopic studies of inflammatory cell attachment during blood-brain barrier inflammation

1990 ◽  
Vol 48 (3) ◽  
pp. 276-277
Author(s):  
A.S. Lossinsky ◽  
M.J. Song
Keyword(s):  
High Voltage ◽  
Inflammatory Cell ◽  
Cell Attachment ◽  
Electron Microscopic ◽  
Vascular Perfusion ◽  
Tissue Samples ◽  
High Voltage Electron Microscopy ◽  
Thin Sections ◽  
Voltage Electron ◽  
High Voltage Electron

Previous studies have suggested the usefulness of high-voltage electron microscopy (HVEM) for investigating blood-bram barrier (BBB) injury and the mechanism of inflammatory-cell (IC) attachment. These studies indicated that, in evaluating standard conventional thin sections, one might miss cellular attachment sites of ICs in their process of attaching to the luminal endothelial cell (EC) surface of cerebral blood vessels. Our current studies in animals subjected to autoimmune disease suggest that HVEM may be useful in localizing precise receptor sites involved in early IC attachment.Experimental autoimmune encephalomyelitis (EAE) was induced in mice and rats according to standard procedures. Tissue samples from cerebellum, thalamus or spinal cords were embedded in plastic following vascular perfusion with buffered aldehyde. Thick (0.5-0.7 μm) sections were cut on glass knives and collected on Formvar-coated slot grids stained with uranylacetate and lead citrate and examined with the AEI EM7 1.2 MV HVEM in Albany, NY at 1000 kV.

Permeability Enhancing and Chemotactic Activities of Lower Molecular Weight Degradation Products of Human Fibrinogen

1981 ◽  
Vol 45 (01) ◽  
pp. 090-094 ◽  
Author(s):  
Katsuo Sueishi ◽  
Shigeru Nanno ◽  
Kenzo Tanaka
Keyword(s):  
Molecular Weight ◽  
Degradation Products ◽  
Electron Microscopic Observation ◽  
Chemotactic Activity ◽  
Lower Molecular Weight ◽  
Electron Microscopic ◽  
Human Fibrinogen ◽  
Rabbit Skin ◽  
Molecular Weights ◽  
Active Fragments

SummaryFibrinogen degradation products were investigated for leukocyte chemotactic activity and for enhancement of vascular permeability. Both activities increased progressively with plasmin digestion of fibrinogen. Active fragments were partially purified from 24 hr-plasmin digests. Molecular weights of the permeability increasing and chemotactic activity fractions were 25,000-15,000 and 25,000 respectively. Both fractions had much higher activities than the fragment X, Y, D or E. Electron microscopic observation of the small blood vessels in rabbit skin correlated increased permeability with the formation of characteristic gaps between adjoining endothelial cells and their contraction.These findings suggest that lower molecular weight degradation products of fibrinogen may be influential in contributing to granulocytic infiltration and enhanced permeability in lesions characterized by deposits of fibrin and/or fibrinogen.

The Pathogenesis of Thrombotic Thrombocytopenic Purpura

1979 ◽  
Author(s):  
H. C. Kwaan
Keyword(s):  
Plasminogen Activator ◽  
Thrombotic Thrombocytopenic Purpura ◽  
Degradation Products ◽  
Vascular Lesions ◽  
Local Defect ◽  
Laboratory Findings ◽  
Thrombocytopenic Purpura ◽  
Fibrin Degradation Products ◽  
Severity Of The Disease ◽  
Circulating Levels

The vascular lesions with microthrombi were studied in 12 patients with thrombotic thrombocytopenic purpura (TTP), diagnosed by the characteristic clinical and laboratory findings and confirmed histologically in each case. While defibrination was not observed, and with only minimal changes in the circulating levels of fibrinogen, fibrin degradation products and plasminogen activator, the microthrombotic lesion was invariably present. Immunofluorescent and histochemical studies indicated that both platelet and fibrin were present in the microthrombi with the platelet components dominant in many cases. Using the fibrin slide method, plasminogen activator was demonstrated in the uninvolved blood vessels but totally absent in the vessels occluded by microthrombi. in contrast, fibrinolysis is always present in the vessels afflicted with other types of thrombosis, such as the microthrombi in disseminated intravascular coagulation. Since circulating fibrinolytic activity was normal in TTP, the absence of vascular fibrinolysis is a local defect due to either inhibition by the platelet deposits or by local vascular damage. The inability of thrombolysis may explain the absence of systemic defibrination and the severity of the disease.

High Levels of Plasma Protein C in Nephrotic Syndrome

1985 ◽  
Vol 53 (01) ◽  
pp. 005-007 ◽  
Author(s):  
I Pabinger-Fasching ◽  
K Lechner ◽  
H Niessner ◽  
P Schmidt ◽  
E Balzar ◽  
...  
Keyword(s):  
Nephrotic Syndrome ◽  
Plasma Protein ◽  
Protein C ◽  
Inverse Correlation ◽  
Elevated Plasma ◽  
Significant Inverse Correlation ◽  
At Iii ◽  
Thrombotic Tendency ◽  
Protein C Activity

SummaryIn patients with severe nephrotic syndrome determinations of plasma protein C : Ag levels (8 patients: 5 adults, 3 children) and protein C activity (3 out of 8 patients) revealed significantly elevated plasma protein C concentrations. Furthermore we observed a significant inverse correlation of protein C : Ag to AT III : Ag levels. No protein C : Ag could be detected in the urine of two patients studied. We conclude from our data, that changes of plasma protein C do not contribute to the high thrombotic tendency in nephrotic syndrome.

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